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Abstracts key sessions
K01
Biomaterials: competition between host tissue cell integration and bacterial colonization
Henk Busscher, Anna Yue, Brian Zhao, Ren Ren, Roel Kuijer, Henny Van Der Mei, Ed Rochford
UMCG, The Netherlands
30
Aim: The fate of an implant has been described by Anthony
Gristina1 as “the race for the surface” between microorganisms trying to colonize an implant surface and tissue cells
attempting to integrate the biomaterial. Won by tissue cells,
this provides protection to an implant. Here, observations on
simultaneous bacterial colonization and tissue cell integration of biomaterial surfaces are presented with the aim of
identifying the value of the race for the surface concept in
predicting the faith of a biomaterial implant.
Methods: Using an established model to study the race for
the surface2, tissue cell integration in the absence and presence of different bacterial strains relevant to oral and orthopedic implant-associated infections is compared.
Results: Generally, tissue cells are at a disadvantage in the
race for the surface in the presence of adhering bacteria,
contaminating an implant surface as in per-operative infection. Similar observations were made when challenging an
existing layer of tissue cells with bacteria, as occurring in late
haematogenous infections. However, depending on the cell
type, bacterial strain and biomaterial involved, cells are sometimes stimulated to integrate with a biomaterial through enhanced expression of focal adhesins in presence of bacteria.
A dental implant setting provided different results than an
orthopedic one.
Conclusions: (1) the race for the surface proceeds according to different mechanisms in an oral implant setting than
in an orthopedic one. (2) contaminating bacteria on a biomaterial surface do not necessarily negatively impact tissue
integration. References: 1. Gristina AG. Biomaterial-centered
infection: Microbial adhesion versus tissue integration. Science 1987;237:1588-95. 2. Subbiahdoss G, Grijpma DW, Van
der Mei HC, Busscher HJ, Kuijer R. Microbial biofilm growth
versus tissue integration on biomaterials with different wettabilities and a polymer brush coating. J Biomed Mater Res
Part A 2010;94A:533-8.
Acknowledgements
This paper has been funded by UMCG, SASA BV, Institut Straumann. HJB is director-owner of SASA BV. Authors declare no
potential conflicts of interest with respect to authorship and/
or publication of this article. Opinions and assertions contained herein are those of the authors and are not construed
as necessarily representing views of the funding organizations or their employer(s).
K02
Issues in translational infection research
David Grainger
214
University of Utah, USA
Significance: Increasing numbers of medical devices now
available for clinical implant use, often in aging populations
and increasingly in developing countries, have become a significant health care issue due to enhanced infection incidence
intrinsically related to implanted medical devices. These devices are also implanted against a background of increasing
antibiotic-resistant bacterial populations. Progressively more
antibiotic-resistant infections, requiring ever more refined
treatment options, are therefore predicted to emerge with
greater frequency. Improvements in the prevention, diagnosis and treatment of these device-associated infections
will remain priority targets both for clinicians and the trans-
lational research community charged with addressing these
challenges. Increasing clinical scrutiny, insurance reimbursement and cost containment issues have prompted increased
research into improved methods to assess infections and to
implement new technologies that reduce implant-associated
infections. Nonetheless, critical challenges face both preclinical research and clinical laboratories for improving implant
antimicrobial efficacy, diagnosis and treatment of medical
device-associated infections. A classic problem is lack of in
vitro-in vivo correlation, validation or efficacy for any given
method or approach. A second issue is the lack of commercial enthusiasm to take any approach forward in a regulatory
33rd Annual Meeting of the European Bone & Joint Infection Society
pathway toward clinical use. Uncertainty in the regulatory
environment and substantial costs associated with both preclinical models and clinical trials preclude strong economic
grounds for technology development.
Aim: This presentation will review antimicrobial experimental designs, approaches to endowing medical devices with
antimicrobial properties, and current barriers to their clinical
translation.
Methods: Literature review of antimicrobial methods, strategies and recent commercialization of combination devices
embellished with some personal R&D experiences and medical device commercialization anecdotes.
Results: Few academic approaches to innovating antimicrobial medical device designs or reports of improved anti-infection efficacy ever translate to clinical use. Few new clinical approaches or products are evident. Validation of in vitro results
against in vivo and clinical results is rare.
Conclusions: Preclinical strategies predictive of ultimate
clinical efficacy should serve as a control point for effective
translation of new technologies to clinical applications. The
development of new anti-infective medical devices requires
a validated preclinical testing protocol; however, reliable validation of experimental and preclinical antimicrobial methodologies currently suffers from a variety of technical limitations. These include the lack of agreement or standardisation
of experimental protocols, a general lack of correlation between in vitro and in vivo preclinical results and lack of validation between in vivo preclinical implant infection models and
clinical (human) results. Device-associated infections pose
additional challenges to practicing clinicians concerning diagnosis and treatment, both of which are complicated by the
biofilms formed on the medical device.
References
Busscher, et al., Sci. Transl. Med. 4, 153rv10 (2012); Grainger et
al., Biomaterials, 2013 34:9237-43; Brooks et al., Chapter 13 in
K03
New insights in anti-biofilm agents
Lorenzo Drago
217
IRCCS Galeazzi Hospital, Italy
31
The bacterial colonization of implanted materials is promoted
by the ability of the bacteria to produce protein-specific adhesions and extracellular polymeric substances (EPS) on their
surfaces. Bacteria in biofilms evade host defenses and are
more resistant to antibiotics. Both gram positive, i.e. Staphylococci and Gram-negative bacilli are the pathogens most
commonly involved in these cases. Orthopaedics is currently
the largest market of biomaterials worldwide and implantrelated infections, although relatively rare, remain among the
first reasons for joint arthroplasty and osteosynthesis failure.
Bacteria start implant infection by adhering to biomaterials and producing biofilms, which represent a major reason
for bacterial persistence, in spite of antibiotic treatment and
host’s defence. In the last two decades, a number of different
antibiofilm agents have been studied and both in vitro and
in vivo results appear now promising, even if their effective
role in orthopaedics remains to be assessed. In this review,
we introduce an original classification of antibiofilm agents,
based on their mechanism of action and examine the available data concerning their possible application to orthopae-
dic implant-related infections. Molecules that interfere with
biofilm production (biofilm prevention agents) include antiadhesion compounds, quorum sensing inhibitors, non-steroideal anti-inflammatory drugs, and antimicrobial peptides;
N-acetylcysteine and specific enzymes promise the greatest
therapeutic possibilities by disrupting established biofilms
(biofilm disrupting agents). The identification of antimicrobials able to bypass the biofilm barrier (biofilm bypassing
agents), and antibiofilm vaccines are further strategies aimed
to reduce the impact of biofilm-related infections, opening new pathways in controlling implant-related infections.
However, this review shows that still insufficient knowledge
is currently available as to regard the efficacy and safety of
the investigated antibiofilm strategies to treat infection that
involve bone tissue and biomaterials commonly implanted
in orthopaedics, pointing out the need for further research
in this promising field. Confocal laser scanning microscopy, if
properly used, can be a useful method to study and develop
new antibiofilm compounds.
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts key sessions
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Abstracts key sessions
K04
K10
Laboratory assessment of infection
Bone transport treatment in infected defects
Alex Soriano
Hospital Clínic de Barcelona, Spain
Johan Lammens
UZ Leuven, Belgium
ABSTRACT NOT AVAILABLE
ABSTRACT NOT AVAILABLE
K05
K11
Nuclear imaging of prosthetic joint infections
To flap or not to flap. Indications and methods
Alberto Signore
EANM, Italy
Jan Maerten Smit
Vumc, Amsterdam
ABSTRACT NOT AVAILABLE
ABSTRACT NOT AVAILABLE
K06
K12
Microbiological assessment of infection
Masquelet technique in postraumatic infections
Maria Eugenia Portillo
Laboratori de Referència de Catalunya, Spain
Michel Tanner
Universitätsklinik Heidelberg, Germany
ABSTRACT NOT AVAILABLE
ABSTRACT NOT AVAILABLE
K07
K13
New insights in antibiotic therapy of pji
Spondylitis
Andrej Trampuz
Charite, Germany
Cumhur Oner
UMC Utrecht, The Netherlands
ABSTRACT NOT AVAILABLE
ABSTRACT NOT AVAILABLE
K08
K14
Insights in surgical therapy of pji: 1-stage therapy in pji, advantages and disadvantages
Heinz Winkler
Privatklinik Döbling, Austria
33
Spondylodiscitis
Andreas Korge, Bernhard Zillner
Schön klinik München, Germany
ABSTRACT NOT AVAILABLE
K09
2-Stage therapy in pji, advantages and disadvantages
Carlo Romano
CRIO, Italy
ABSTRACT NOT AVAILABLE
33rd Annual Meeting of the European Bone & Joint Infection Society
Within the spectrum of already rare infections on the entire
musculoskeletal system, infections on the spine represent
an only small collective with 2-4 %. The incidence of a spondylodiscitis amounts to 2/100000/year in the western world.
The lumbar spine is affected in 2/3 of all cases. Source of
infections are mostly hematogenous spreading or iatrogenic following invasive interventions. Despite numerous improvements in radiological and microbiological diagnostics
and despite extended treatment strategies, the therapy of a
spondylodiscitis remains nowadays still a challenge for both
physicians and patients. To a considerable extent, a problematic delay of 2-6 months before making a definite diag-
nosis of an inflammatory pathology, contributes to this challenge. Initial symptoms such as exhaustion, night sweats
and subfebril temperature are unspecific. Progressive back
pain and an increasing kyphotic posture of the spine might
lead to the diagnosis of a spinal infection. A septic course
can occur in 10-15%. With a predominantly elderly patient
population, a conglomerate of possible risc factors intensifies the challenge to find an appropriate treatment concept.
Currently available imaging tools enable both an optimization of diagnostics and interventional measures. Magnetic
resonance imaging represents the dominating radiological
technique to detect location and extent of a spondylodis-
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts key sessions
citis. CT guided percutaneous biopsy might help to identify the underlying pathogen which is mostly unspecific
and bacterial. Knowledge concerning the microbiological
spectrum of pathogens for the selection of an antibiogramadapted antibiosis represent a fundamental treatment pillar
especially when realizing non-surgical treatment concepts.
The supply with a stabilizing brace completes a non-surgical therapeutic approach. In case of choosing surgical
concepts for the treatment of a spondylodiscitis, an instrumented immobilization of the affected region has gained
general validity in the meantime. Internal screw-rod fixation
systems on the posterior thoracic and lumbar spine and
plate constructs on the anterior cervical spine deliver the re-
Abstracts key sessions
quired limitation of the mobility. Removal of the destroyed
disc and bone defects from posterior or anterior with local
debridement as well as a bridging and stabilization of the
defect area with an interponate complete the surgical concept. During the last decade, the paradigm of a defect support with an autogeneic solid bone graft has given way in
favor of the use and application of cages. For an additional
defect restoration around these cages, both the traditional
corticocancellous bone chip grafting and allogeneic bone
substitutes are available. Updated literature documents
better outcome results in surgically treated patients when
compared to patients with non-surgical treatment concepts
K15
The infected spondylodesis
Jose Consciência
Universidade Nova de Lisboa, Portugal
ABSTRACT NOT AVAILABLE
K16
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Diagnostics in diabetic foot osteomyelitis
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Ben Lipsky
University of Oxford, United Kingdom
ABSTRACT NOT AVAILABLE
K17
Antibiotic therapy in infected diabetic foot osteomyelitis
Eric Senneville
Hospital Dhron, France
ABSTRACT NOT AVAILABLE
K18
Surgical therapy in diabetic foot osteomyelitis
Larry Lavery
University of Texas, USA
ABSTRACT NOT AVAILABLE
33rd Annual Meeting of the European Bone & Joint Infection Society
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
Abstracts free paper sessions
Abstracts free paper sessions
F002
F001
Sascha Colen1, Julien De Haan2, Michiel Mulier2, Jose Stuyck2, Jorg Roosen2
1
University Hospitals Leuven, Leuven, Belgium
2
University Hospitals Leuven, Department Of Orthopaedic Surgery, Leuven, Belgium, Leuven, Belgium
Assessment of bact/alert fan blood culture bottles inoculated with sonication fluid for the
diagnosis of implant-associated-infection
Ana Siverio1, Margarita Salvadó1, Daniel Pérez2, Albert Alier2, Santos Martínez2, Luisa Sorlí2, Juan Pablo Horcajada2, Luis Puig2,
María Eugenia Portillo1
1
Laboratori De Referència De Catalunya, El Prat De Llobregat, Barcelona, Spain
2
Hospital Del Mar, Barcelona, Spain
36
Aim: Despite sonication is a method that improves the diagnosis of implant-associated-infection (IAI), its estimated
sensitivity is 70-80%. Blood culture bottles with antimicrobial removal systems are recommended for patients who
develop fever while on antibiotics. We evaluated the BacT/
Alert FAN blood culture bottles inoculated with sonication
fluid for the diagnosis of IAI and compared it with periprosthetic tissue culture and sonication fluid culture.
Methods: Patients in whom any material was explanted for
any cause in our institution were included from 6/2013 to
12/2013. A standardized diagnostic algorithm was applied
including sampling of 5 tissues, sonication of removed implants and inoculation of sonication fluid into BacT/Alert FAN
aerobic and anaerobic blood culture bottles. IAI was defined
when: (i) visible purulence, (ii) sinus tract, or (iii) clinical signs
of infection. Additionally, in prosthetic joint infection cases 2
more criteria were considered (iv) leukocyte count and neutrophil% in synovial fluid and (v) histopathology. Aseptic fail-
ure (AF) was defined when none of the criteria was fulfilled.
Results: 75 implants were included (52% IAI, 48% AF): 45
(60%) joint prostheses and 30 (40%) osteosynthesis materials. 22 (56%) patients with IAI received antibiotics previously to surgery. The sensitivity of periprosthetic tissue
culture, sonication fluid culture and BacT/Alert culture was
59%, 87% and 100% respectively (p<0.05); whereas the
specificity was 100% for the 3 techniques. The sensitivity for
these techniques in patients receiving antibiotics was 55%,
73%, and 100% (p <0.05). On day 1, tissue and sonication
fluid cultures were positive in 18% and 28% whereas 72%
of the pathogens were detected by Bact/Alert FAN bottles
(p<0.01).
Conclusions: Inoculation of sonication fluid into BacT/Alert
FAN blood culture bottles detected all IAI cases (including
those with antibiotics) with a specificity of 100%. Moreover,
it significantly reduced the time to positivity compared with
periprosthetic tissue culture and sonication fluid culture.
Figure: Comparison of detection rate and day of detection in patients with IAI
33rd Annual Meeting of the European Bone & Joint Infection Society
Value of pre-operative aspiration diagnosing a prosthetic joint infection of the hip based on
microorganisms
Aim: The purpose of this study was to compare the results
of cultures of pre-operative aspiration with per-operatively
taken cultures and make recommendations regarding antibiotic treatment until cultures and sensitivity of intra-articular
taken samples are known.
Methods: The records of 238 patients with 238 total hip
arthroplasties, suspected for infection, were reviewed. The
results of the cultured pre-operative taken aspiration fluid
and the intra-operative taken cultures (biopsies, fluids and
swaps) were compared based on the kind of microorganisms.
Results: Specificity, sensitivity and accuracy showed results
of 95%, 74% and 84%, respectively. But comparing the microorganisms cultured pre- and per-operatively, 72 of the 152
cultured species were identical, only 48% correct match
is found. This translated to the number of patients we see
48.4% correct matching, with 17.2% (23/134) of non-treated
and 16.4% (22/134) of partial-treated patients with broadspectrum antibiotics direct post-operative based on the
findings of aspiration.
Conclusions: The results presented in this study showed
similar results presented in literature regarding sensitivity
and specificity. However, comparing the cultured micro-organisms pre- and per-operatively, pre-operative aspiration
has a poor diagnostic value for detecting the right microorganism. With a micro-organism detected with aspiration
only in half of these cases the same kind of micro-organism
is found per-operatively resulting in a possible wrong antibiotic treatment when this treatment is based on the results
of culturing the pre-operative taken aspiration fluid.
F003
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Prolonged bacterial culture to detect periprosthetic joint infection: how long is long enough?
Karola Waar, Yvonne Roelofs, Marian van der Veen-Legters, Rudolf Muiser
Izore, Centre For Infectious Diseases Friesland, Leeuwarden, Netherlands
Aim: Periprosthetic infection is probably the most feared
complication of joint arthroplasty. The detection rate of the
current microbiological methods in the diagnosis of periprosthetic infection is limited because standard methods
may fail to detect biofilm-forming or fastidious bacteria.
There is no clear agreement on the appropriate cultivation
period. In this study we evaluate the duration of culture
in relation to the clinical relevance of the isolated bacteria
from periprosthetic samples.
Methods: From July 2009 to December 2012 periprosthetic
samples were extensively cultured on 3 different liquid and
5 different solid media for 21 days. Isolates were defined as
clinical relevant if reporting the growth of the micro-organism to the clinician led to antibiotic therapy that was active
against this micro-organism. Time to first growth of organisms was monitored. If a series of periprosthetic samples
yielded multiple identical isolates, only the time to growth
of the first was included.
Results: A total of 373 periprosthetic samples from 292
patients yielded positive cultures. From these positive cultures, 489 unique isolates were identified and 309 of these
isolates from 193 patients were considered clinical relevant.
After 7 and 14 days, the detection rate via culture of all clini-
cal relevant isolates was respectively 86 and 92%. The median time to isolation for the clinical relevant isolates was 3
days, median time to isolation of the non-relevant isolates
was 19 days. The most frequently (30%) detected micro-organism was coagulase-negative staphylococci (CNS), about
half of these isolates were considered clinical relevant and
the median time to isolation was 4 days. Besides CNS, the
spectrum of detected species consisted of 18% Staphyloccus aureus (100% relevant, 2 days), 13% Propionibacterium
species (16% relevant, 18 days), 11% Enterobacteriaceae
(82% relevant, 3 days), other species were detected in frequencies below 7%. Of the isolates that were detected in
the first week 20% was considered to be non-relevant, this
was 37 and 81% in the second and third week.
Conclusions: Prolonged bacterial culture is a necessary tool
in the detection of periprostetic joint infections, as in the
third week of culture still 8% of the clinical relevant isolates
was isolated.
With prolonged culture the chance of contamination and
therefore overtreatment grows. Considering the results of
this study, three weeks of culture might be long enough, although evaluation of even longer culture can be necessary
before this conclusion can be confirmed solidly.
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
Abstracts free paper sessions
F004
F005
Analysis of the yield of a 14 days incubation protocol for tissue biopsies in orthopaedic
device-associated infections
New diagnostic algorithm in evaluation of patients with prosthesis related problems in the
hip or knee
Peter Wahl1, Nora Schwotzer2, Dominique Fracheboud3, Emanuel Gautier3, Christian Chuard3
Vesal Khalid1, Lone Heimann Larsen2, Henrik Carl Schønheyder3, Trine Rolighed Thomsen4, Jan Lorenzen5, Ramune Aleksyniene6,
Majbritt Frost6, Sten Rasmussen1, Study group PRIS7
1
Orthopaedic Surgery Research Unit, Aalborg University Hospital, Aalborg, Denmark, Aalborg, Denmark
2
Department Of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark And Center For Microbial Communities,
Department Of Biotechnology, Chemistry And Environmental Engineering, Aalborg University, Denmark, Aalborg, Denmark
3
Department Of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark, Aalborg, Denmark
4
Center For Microbial Communities, Department Of Biotechnology, Chemistry And Environmental Engineering, Aalborg
University, Denmark And Danish Technological Institute, Medical Biotechnology, Aarhus C, Denmark, Aalborg, Denmark
5
Danish Technological Institute, Medical Biotechnology, Aarhus C, Denmark, Aarhus, Denmark
6
Department Of Nuclear Medicine, Aalborg University Hospital, Denmark, Aalborg, Denmark
7
PRIS-Study Group, Aalborg, Denmark
Cantonal Hospital Winterthur, Winterthur, Switzerland
University Hospital Center Lausanne, Lausanne, Switzerland
3
Hfr Fribourg - Cantonal Hospital, Fribourg, Switzerland
1
2
Aim: Microbiological cultures of tissue samples remain the
mainstay for the diagnosis of infection. Prolonging incubation and increasing the number of samples has been proposed to optimize sensitivity of cultures, in order to detect
slow-growing bacteria present in orthopaedic implant-associated infections. This study assesses the yield of a 14 days incubation protocol for tissue biopsies from joint replacement
and internal fixation device revisions in a general orthopaedic and trauma surgery setting.
Methods: Retrospective analysis of a prospectively collected
cohort of cases of orthopaedic and trauma revision surgery
from a single institution, where tissue biopsies had been
sampled between August 2009 and March 2012. Only the
first revision was considered.
Results: A total of 499 tissue biopsies had been sampled
in 117 cases. At least one sample showed microbiological
growth in 70 cases (60%). Among these 70 cases, 58 (83%)
were classified as infections, whereas 12 (17%) were considered as contaminants. The median time to positivity was 1
day (range 1-10) in case of infection, and 6 days (range 1-11)
in case of contamination. Cultures were positive within 7 days
of incubation in 56 (96.6%) of the cases of infection.
Conclusion: This study shows a benefit for prolonging microbiological culture incubation up to 7 days, but not beyond.
While longer incubation might be of interest in particular
situations, where the prevalence of slow-growing and anaerobic bacteria is higher, it does not appear to be productive in
this setting of general orthopaedic and trauma surgery.
38
Aim: Revision surgery after total hip (THA) or knee arthroplasty (TKA) is globally occurring more frequently due to an
increasing number of primary surgeries. The cause is aseptic loosening, infection or chronic pain. Although some are
operated on the clinical suspicion of chronic infection, postoperative microbiological testing does not always correlate
with the preoperative diagnosis and the operation may not
have been required. Hence there is a need for a new scientific approach for diagnostics. The PRIS project (www.jointprosthesis-infection-pain.dk) has addressed this issue in a
collaborative effort of hospitals, research institutions, and
industry. The aim is to improve diagnostics of patients experiencing problems after TKA or THA.
Methods: Patients who experienced a prosthetic related
problem were included in this prospective study (except for
recurrent dislocations).They were evaluated according to
the algorithm including biomarkers in blood, nuclear imaging and microbiology (culturing, sequencing).
Upon radiographic signs of loosening, without a suspicion of
infection, a revision is performed on the suspicion of an aseptic loosening. If signs of radiographic loosening are lacking, >
2 months since primary arthroplasty, patients are investigated with advanced nuclear hybrid imaging with 99Tc – HDP
SPECT/CT, 111In-labeled WBC combined with 99Tc-nannocol
bone marrow SPECT/CT and 18F-FDG PET/CT. Focal findings
were evaluated against the clinical suspicion of infection by a
multidisciplinary panel, and if findings were consistent with
the clinical suspicion of infection either a diagnostic procedure or revision surgery was recommended. Joint fluid, soft
tissue biopsies, bone biopsies, prosthetic swab (in situ) and
the prosthetic component are sampled from all revisions for
microbiological and biomolecular analysis. Furthermore tissue specific analysis of blood is performed.
Results: As of January 2014, 166 patients were included. A
total of 126 patients underwent revision, 88 on suspicion of
aseptic loosening and 38 patients on suspicion of an infection. 40 patients were classified as having a chronic pain
problem and did not undergo surgery.
Conclusion: The ultimate classification of patients awaits results from Next Generation Sequencing of the prospectively
collected diagnostic specimens and one –year follow up of
all patients. It is expected that the algorithm will be a useful
tool in evaluating patients presenting with a TKA- or THA
related problem.
PRIS is supported by The Danish Council for Technology and
Innovation.
F006
Microbiologic diagnosis based on implant sonication in 219 cases of total hip and knee
arthroplasty revision surgery
Christen Ravn1, Michael Kemp1, Per Kjaersgaard-Andersen2, Soeren Overgaard1
Odense University Hospital, Odense, Denmark
2
Vejle Hospital, Vejle, Denmark
1
Aim: To compare cultivation of joint aspirate and periprosthetic tissue with culture of sonication fluid from removed
hip and knee prostheses.
Methods: We conducted a prospective study on consecutive prosthetic joint revisions during one year (2012.11.01-
33rd Annual Meeting of the European Bone & Joint Infection Society
2013.10.31) at our institutions. Inclusion criteria were joint
revision of THA or TKA on any indication, whereas re-operations without removal of prosthetic parts were excluded.
The prostheses were individually sonicated due to a wellestablished protocol (Trampuz et al. N Engl. J Med., 2007).
September 11-13, 2014 - Utrecht - The Netherlands
39
Abstracts free paper sessions
Aliquots of sonication fluid (SF) were cultured under aerobic
and anaerobic conditions, and considered positive with >10
colonies/ml. Sonication, culture and interpretation was performed by a dedicated microbiologist blinded to the clinical
situation.
Conventional sampling of synovial fluid and five tissue biopsies was performed systematically in each revision and
cultured due to best practice. PJI was defined as growth of
the same microorganism in at least two cultures of synovial
fluid or periprosthetic tissue. Positive culture of one tissue
sample or joint fluid alone was defined as contamination.
Results: We included 219 consecutive revisions of total hip
(135) and knee (84) arthroplasties. Deep infection was expected in 54 revisions due to clinical and serological findings. Aseptic loosening (AsL) indicated 72 revisions, and the
remaining 93 revisions were indicated mainly by mechanical complications (MeC).
Conventional culture methods diagnosed 56 cases of PJI
(26%) of which 8 resp. 4 were revised due to AsL and MeC.
Positive culture of sonication fluid was found in 63 cases (29
Abstracts free paper sessions
%) of which 9 resp. 7 were revised due to AsL and MeC.
Among the 54 revisions indicated by deep infection, a bacterial specie was found by conventional methods in 44 (81
%) and by sonication in 47 (87 %). By merging the culture
results from sonication and conventional methods a bacterial diagnosis was found in 51 (94 %) of revisions indicated
by PJI, and in 71 of all revisions.
Most common bacteria found in conventional samples
/ sonication fluids were S. aureus (15/16), S. epidermidis
(18/20) and other coagulase negative staphylococci (9/9). P.
acnes in large numbers were found only in SF (0/4). Discordance of bacterial species between the diagnostic modalities was found in 2 cases.
Conclusions: We found high concordance in bacterial diagnosis between conventional methods and sonication.
Culture of sonication fluid revealed 7 more positive cultures than by conventional methods, and furthermore the
merged results gave valuable information of the causative
bacterial specie in 94 % of the revisions indicated by deep
infection.
F007
Revision knee arthroplasty for septic failure: three years experience
40
Fabrizio Cortese1, Gianluca Piovan1, Giuseppe Niccoli1, Stefania Marocco2, Andrea Angheben2, Chiara Savio3, Davide Brunelli4,
Claudio Zorzi1
1
Orthopedic And Traumatology Department Sacro Cuore- Don Calabria Hospital Negrar, Verona, Italy
2
Centre For Tropical Disease Sacro Cuore-Don Calabria Hospital Negrar, Verona, Italy
3
Service Of Microbiology Sacro Cuore-Don Calabria Hospital Negrar, Verona, Italy
4
Health Care Department Sacro Cuore-Don Calabria Hospital Negrar, Verona, Italy
Aim: The purpose of this study was to evaluate our experience in management and treatment of infected knee arthroplasty, focusing on the reliability of diagnostic procedures.
Methods: We retrospectively reviewed data on 158 cases
of knee arthroplasty revision performed in our orthopedic
division between January 2011 and December 2013. The
study included all patients with diagnosis of septic or aseptic failure of knee arthroplasty. Patients were divided in two
groups: Group A included 122 patients with aseptic failure
of the joint prosthesis and Group B was formed by 36 patients with septic failure of the joint prosthesis. All patients
underwent appropriate preoperative work-up including
physical evaluation, routine radiographs, blood tests (full
blood count, ESR and CRP) and labeled leukocyte scintigraphy. Synovial fluid aspiration was performed in all patients
of Group B, but in only 28 cases the pathogen was identified.
Patients were followed for a minimum of six months (mean
14,6 months). All patients were treated by the orthopedic
surgeon in association with the infectivologist according to
an institutional protocol for revision TKA. In Group B, 28 patients underwent two-steps revision knee arthroplasty, six
patients underwent one-step revision arthroplasty and one
patient underwent knee arthrodesis after a two-times revision of antibiotic-impregnated spacer block. Tissue samples
(5 to 10 samples) were collected during surgery in all 158
cases for microbiological culture; the test was considered
positive when at least two samples showed growth of the
same pathogen.
Results: Group A: in 36 over 122 patients microbiological
cultures were positive. These patients were treated with
specific antibiotic therapy for almost eight weeks: in 32 patients no signs of infection appeared, while in the remaining
four patients two step revision was then performed.
Group B: All patients undergone two-steps revision had
positive microbiological culture on tissue samples taken
during the first surgery. At the time of second surgery, microbiological cultures turned negative in 26 over 28 cases;
specific antibiotic therapy was administered. Three patients
over six undergone one-step revision knee arthroplasty
showed microbiological positivity. These three patients and
one patient undergone two step revision presented signs
of infection after a mean time of five months after surgery.
Conclusions: We believe that despite a thorough preoperative evaluation, is still difficult to diagnose TKA infections.
Microbiological cultures are an easy and useful tool which
permit to perform an early and specific therapy when necessary. Two steps procedure showed better results in terms
of eradication of the infection.
33rd Annual Meeting of the European Bone & Joint Infection Society
F008
Comparison of pcr and bactec culture in the diagnosis of prosthetic joint infection
G. El Khoury2, M. van Cauter3, J.L Gala2, H. Rodriguez3, J.C. Yombi1, Olivier Cornu1
1
Université Catholique De Louvain, Brussels, Belgium
2
Orthopaedic And Trauma Department, Brussels, Belgium
3
Cliniques Universitaires St-Luc, Brussels, Belgium
Aim: To assess the usefulness of Polymerase Chain Reaction
(PCR) in the diagnosis of prosthetic joint infection (PJI)
Methods: fluid aspiration was obtained from patients with
underlying prosthetic arthroplasty. Bactec culture and PCR
were performed and results assessed according to the criteria of prosthetic joint infection (PJI) of the Workgroup of the
Musculoskeletal Infection Society.
We further compared the microbiology and PCR results of
the preoperative joint fluid aspiration and connected them
to the eventual intraoperative biopsy culture. Concordance
between two tests is obtained when both are positive (double positive, DP) and identify the same microorganism, or
when both are negative (double negative, DN).
Results: Our sample consisted of 31 PJI and 31 non PJI. Microbiology and PCR for the PJI group were positive in 23
(74.19%) and 20 patients (64.52%), respectively. These results fall down to 2 (6.45%) and 9 patients (29.03%) for non
PJIs. Concordance between PCR and microbiology was obtained in 15 PJI (48.39%) (11 DP and 4 DN) and 21 non PJI
(67.24%) (21 DN). Surgery was carried in 35 patients (27 PJI
and 8 non PJI). Concordance of the microbiology and the intraoperative surgical biopsy was 59.26% for PJI patients (14
DP and 2 DN) and 87.5% for non PJI patients (7 DN). As for
PCR, concordance was of 37.03% in the PJI group (9 DP and
1 DN) and 50% in the non PJI group (4 DN).
When the microbiology was negative and the PCR positive,
surgical treatment was carried in 8 of the 13 cases, yielding
either a negative result (4 cases) or a Staphylococcus (4 cases), all of which were not concordant with the PCR.
Sensitivity, specificity, positive predictive value, positive
likelihood ratio (LR) and negative LR were of 0.64, 0.71, 0.69,
0.67, 0.22 and 0.5 for PCR and 0.74, 0.94, 0.92, 0.78, 11.5 and
0.27 for microbiology, respectively.
Discussion: Our results are less promising than those found
in the current literature. However, our analysis was conducted on the preoperative joint fluid aspiration, while other authors carried their analysis on intraoperative fluid aspiration
, after disruption of the biofilm or on surgical biopsies. We
demonstrate that PCR is not as useful as previously thought
in guiding the surgeon towards a surgical treatment for PJI.
Conclusions: PCR is not a very reliable test for diagnosing a
PJI in the preoperative setting.
References
Vandercam B. J. Mol. Diagn. 2008; 10:537–543.
Cazanave C. Journal of Clinical Microbiology. 2013;51(7):
2280–2287.
Metso L. Acta Orthop. 2014 Apr;85(2):165-70.
F009
Evaluation of antimicrobial activity of eight different antibiotic-containing cement elutions
against 18 different organisms; an in-vitro comparison
Robert Townsend, Steve Davies, Alison McKinven, David Partridge
Sheffield Teaching Hospitals, Sheffield, United Kingdom
Aim: Incorporating antimicrobial agents into bone cements
to prevent infection in total joint arthroplasty is a commonly used method of delivering local antimicrobial prophylaxis. To be effective, the antimicrobial must be both active
against commonly isolated organisms from prosthetic joint
infections (PJI) and also eluted from the cement whilst retaining its antimicrobial efficacy. Eight different samples of
various antimicrobial containing cement types of identical
size were prepared in triplicate. These were then compared
for their elution properties using agar diffusion methodology against 18 known organisms.
Method: The eight cements tested were from three different companies containing varying antimicrobial agents
and concentrations. The cement tablets were incubated 24
hours at 37ºC in 10ml phosphate buffered saline (PBS) and
then diluted 1 in 10 and 1 in 100 in PBS. 150μL of each solution was then transferred into 9mm diameter bore holes
cut into pre-seeded organism lawned-plates for each of the
organism types. These plates were then incubated 24 hours
at 37ºC, following which the zone sizes of any inhibition by
the solutions were measured.
Results: Cement A showed the greatest overall antimicrobial activity for all organisms tested. When organisms are susceptible to the antibiotics being included in the various cements, Cement B gave the largest zones, due to the greater
diffusion capabilities of Gentamicin and Clindamycin, when
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41
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compared to Vancomycin.
Conclusion: Based upon this in-vitro testing Cement A
shows the broadest antimicrobial effect against all organisms tested. It also showed activity against seven organisms when the initial elution was diluted 100 fold. When the
Zone Size
Cement A Cement B
organism susceptibility patterns are known, Cement B is a
useful alternative as it showed activity against nine organisms when diluted 100 fold.
All Cements were provided by Biomet Ltd.
In vitro characterization of a vancomycin eluting injectable bone graft
Eva Lidén, Veronica Sandell, Argyrios Kasioptas, Fredrik Lindberg
Bonesupport Ab, Lund, Sweden
Cement C Cement D Cement E
Cement F Cement G Cement H
>40mm
1
2
0
0
1
1
1
1
30-39mm
4
9
2
2
1
0
0
0
20-29mm
24
17
17
13
14
21
11
13
10-19mm
12
8
13
16
16
11
10
10
9mm
13
18
22
23
22
21
32
30
Comparing Zone Diameter as a Marker of Antimicrobial Activity for the eight different Cements
F010
A two stage re-implantation protocol for the treatment of deep periprosthetic hip infection.
Mid to long-term results in a tertiary referral center
George Macheras, Panagiotis Lepetsos, Antonis Stylianakis, Spyridon Michail, Dimitrios Argyris, Panagiotis Anastasopoulos,
Nikitas Schizas, Moyssis Lelekis
Kat Hospital, Kifissia, Greece
42
Aim: In spite of its incidence decreasing to 1% nowadays,
deep periprosthetic hip infections remain a research, diagnostic, therapeutic and cost-related problem. The purpose
of our study is to present the long-term results of the twostage re-implantation protocol in the treatment of periprosthetic hip infections.
Methods: We retrospectively investigated all cases of periprosthetic hip infections treated at our institution between
1999 and 2007. All patients were treated with two-stage reimplantation protocol. In brief, after the diagnosis of periprosthetic hip infection, the patients underwent surgical
removal of all implants, cement and suspicious tissues, and
postoperatively received intravenous antibiotics for 6 weeks.
In the condition of clinical improvement and normal laboratory examinations, and 2-4 weeks after completing the antibiotic regimen, a new prosthesis was re-implanted. Patient
demographics, surgical interventions, postoperative complications, culture results and clinical outcome were recorded.
Results: The study included 42 patients with periprosthetic
hip infections (mean age 67.2 years; range 59 – 73 years;
64.3% female). Infection presented 6 months to 15 years
after the last operation (mean 7.2 years). Inflammation was
detected in biopsy in 69% of patients, periprosthetic tissue cultures were positive in 76% and radiological signs of
F011
loosening were evident in 86% of patients. Mean follow-up
time was 8.4 years (range 6 to 13 years). In 25 cases (78.1%),
a single infecting microorganism was detected, while in 7
cases (21.9%) more than one bacteria were isolated. Isolated bacteria were coagulase negative staphylococci (39.6%),
Gram negative bacteria (22.7%), Staphylococcus aureus
(18.2%) and other bacteria (15.9%). One patient underwent
surgical debridement because of persistent raised CRP. The
protocol was successfully repeated 4 months after the initial
re-implantation in one obese, diabetic patient because of
recurrence of the infection. Two patients under vancomycin
presented a temporary raise in serum creatinine and one
patient developed a superficial vein thrombosis, one week
after re-implantation, treated conservatively. The mean Harris Hip Score (HHS) improved from a mean of 38.2 preoperatively to a mean of 88.6 at final follow-up (P < 0.001). At the
latest follow-up, all patients were free of infection, had well
functioning hip arthroplasties and had no radiological signs
of loosening.
Conclusions: Two-stage re-implantation produces excellent
outcome in the treatment of periprosthetic hip infections.
Treatment of such infections is quite demanding, requires
long hospitalization and should be better performed in specialized referral centers.
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: To characterize antibiotic elution pattern and bone remodeling of a bone substitute consisting of hydroxyapatite
(HA) and calcium sulfate (CS), impregnated with vancomycin
and iohexol.
Method: A mixture of 18.5 g powder (40 wt% HA, 60 wt%
CS) and 8 mL iohexol solution containing 1000 mg vancomycin* was characterized by high strain oscillation/moldability tests, injectability tests (16 G needle) and setting time
measurements (ASTM C266-08). Radiopacity was characterized according to ASTM F640-07.
Cured samples with identical volume (10 mL) but different
surface areas (24 and 100 cm2), were placed in Ringer solution (37°C), and 20 % of the solution was exchanged and
analyzed daily for vancomycin during 4 weeks.
Bactericidal effect of vancomycin-loaded beads (0.14 mL)
was investigated through the obtained zone of inhibition
on Staphylococcus aureus (EP 2.7.2) agar plates, with single
beads (N=3) daily moved to a new agar plate during 2 weeks.
Possible impact of vancomycin on bone remodeling was investigated by bilateral injection of 0.6 mL of paste, with (40
mg) or without vancomycin into the femoral condyle (N=10)
of rabbits, being sacrificed and histologically examined after
12 weeks. Serum-vancomycin was followed for 7 days.
Results: Vancomycin-loaded paste was injectable up to 6
min and moldable until 8 minutes. Initial and final setting
times were reached at 8 and 14 min, respectively. The radi-
opacity of a 2 mm thick sample was higher than that of a 2
mm aluminium reference.
High and low surface area samples exhibited identical vancomycin elution patterns, with an incubate conc. exceeding
1000 µg vancomycin/mL during the first week, remaining
above 4 µg vancomycin/mL for at least 4 weeks. The preserved activity was confirmed by serially exposing new agar
plates to the same vancomycin beads during 2 weeks.
Vancomycin did not negatively affect bone remodeling.
s-vancomycin peaked at 1.8 ± 0.3 µg/mL (mean ± SD) 4
hours after surgery, being undetectable after 48 hours.
Conclusion: This vancomycin-eluting bone substitute presents with characteristics compatible with mini-invasive
techniques, through its good injectability and radiovisibility. Concomitant bone remodeling and a reproducible
elution pattern, with a high initial vancomycin peak and
an extended therapeutic tail over 4 weeks, makes it a suitable bone graft substitute in challenging environments, or
in high risk patients. The release is surface-independent, indicating an extended-release mechanism based on microporosity. Concomitant bone formation was not negatively
affected by the high local vancomycin concentration.
References
* CERAMENT™│V, BONESUPPORT AB, Sweden. CE-mark
pending
F012
Inflammatory cytokines and bone degradation in implant-associated infection
Ulrike Dapunt1, Susanne Maurer2, Thomas Giese2, Matthias Gaida3, Gertrud Maria Hänsch2
1
Department Of Orthopaedics And Trauma Surgery, Heidelberg University, Heidelberg, Germany
2
Department Of Immunology, Heidelberg University, Heidelberg, Germany
3
Department Of Pathology, Heidelberg University, Heidelberg, Germany
Aim: Implant-associated infections remain a severe problem in the field of endoprosthetic surgery. These infections
are difficult to treat, because many bacterial species form
biofilms on implants, which are relatively resistant towards
antibiotics. Immune cells are able to recognize and attack
biofilms, though the immune response might be inefficient
and lead to a persistent inflammatory response, which ensues in tissue degradation, osteoclastogenesis and hence
implant loosening. The exact pathomechanisms concerning
osteoclast generation in implant infections are still unclear.
Therefore, we evaluated whether the pro-inflammatory cytokines MIP1α and MIP2α might be associated with osteo-
clastogenesis and whether local tissue cells (osteoblasts)
might also be capable of expressing aforementioned cytokines.
Methods: To address the question how the local inflammatory response is linked to bone degradation, tissue samples
were taken during surgery and gene expression of the macrophage inflammatory proteins MIP1α (CCL3) and MIP2α
(CXCL2) was assessed by quantitative RT-PCR. In a series of
in vitro experiments, the MIP production by primary osteoblasts after stimulation with bacteria was evaluated. Moreover, CCL3 as an inducer of osteoclastogenesis was examined in vitro.
September 11-13, 2014 - Utrecht - The Netherlands
43
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Results: MIPs were expressed predominantly at osteolytic sites, in close correlation with CD14 which was used
as marker for monocytes/macrophages. Co-localisation of
MIPs with monocytic cells could be confirmed by histology.
In vitro experiments revealed that aside from monocytic
cells, also osteoblasts were capable of MIP production when
stimulated with bacteria; moreover, CCL3 induced the differentiation of monocytes to osteoclasts.
Abstracts free paper sessions
Conclusion: In conclusion, the multifunctional chemokines
CCL3 and CXCL2 are produced locally in response to bacterial infection of bones. In addition to their well described chemokine activity, these cytokines can induce generation of
bone resorbing osteoclasts, thus providing a link between
bacterial infection and osteolysis.
F013
Patterns of bone evolution near implants experimentally colonised by Staphylococci and
Propionibacteria
Thomas Fintan Moriarty, Vincent Stadelmann, R Geoff Richards
Ao Research Institute Davos, Davos, Switzerland
44
Aim: A dynamic process of bone formation and resorption
takes place around all orthopedic implants directly after
insertion. Despite its importance, the effect of bacterial
colonisation on the temporal pattern of peri-implant remodeling is still largely unknown and not detectable with
conventional radiography until significant bone changes
have occurred. The aim of this study was to evaluate the
morphological changes of bone adjacent to an implant in
the presence of infections caused by Staphylococcus aepidermidis and Propionibacterium acnes, as measured by in
vivo microCT.
Methods: A previously described rat model was used in this
study (Stadelmann 20??). Rats were allocated to groups (n=6)
which received either a sterile screw, or screws colonised
by Staphylococcus epidermidis or Propionibacterium acnes
(multiply phylotypes) placed in the proximal part of the right
tibia. The self-tapping cancellous bone screws were custom
made of PEEK containing 20% BaSO4 for improved microCT
contrast. Bone changes around the screws were assessed
using in vivo microCT at regular intervals over 27 days.Bone
implant contact (BIC), bone volume/total volume (BV/TV)
and bone changes (structure formation and resorption) were
computed from the differences between two consecutive
scans. Upon euthanasia, samples were processed to generate
quantitative bacteriological counts from the screw itself, the
surrounding bone and overlying soft tissue.
Results: All sterile screws remained sterile upon completion
of the study and the S. epidermidis group were infected
at completion. The P. acnes groups displayed inconsistent
colonisation, in a phylotype dependent manner, indicating
differrences in pathogenicity between the phylotypes. In
the sterile group, we observed a steadyincrease in BIC, BV/
TV and strength until day 14, which then steadied. In the
S. epidermidis group, we observed a decrease in BIC, BV/
TV and strength until day 9, at which time BIC plateaued,
but BV/TV and strength increased again to the level of the
sterile groups by day 27. In the P. acnes groups, BIC and BV/
TV were slightly lower until day 9, but then caught up with
sterile specimens.
Conclusion: The analysis of bone formation and resorption
over time revealed that the differences between sterile and
infected groups are only a result of differences in resorption
rates, while bone formation is left unaffected. The fluctuations observed probably reflect an early osteomyelitis followed by an immune response and bone healing. Importantly, these pathogens cause detectable bone changes
early post-implantation, which may be difficult to detect
even one month later, despite the presence of infection.
F014
Staphylococcus epidermidis infection increases in the presence of unstable fixation: evidence
in a murine fracture model
Thomas Fintan Moriarty, Marina Sabate Bresco, Liam O’ Mahony, Katharina Kluge, R Geoff Richards, Stephan Zeiter
Ao Research Institute Davos, Davos, Switzerland
Aim: Instability of fracture fixation constructs is considered
a risk factor for delayed healing and infection; however, little
experimental data is available confirming this belief, or describing the underlying mechanisms. In this study, a murine
model using custom-made osteosynthesis plates was used
to investigate bacteriological and immunological outcomes
when fractures are fixed with rigid or non-rigid (i.e. flexible)
constructs. Implant associated osteomyelitis was developed
in some groups using a clinical isolate of Staphylococcus
epidermidis, one of the leading etiologic agents of orthopedic infections.
Methods: Rigid and flexible titanium plates, with or without
Staphylococcus epidermidis contamination (104 CFU), were
used to fix a femoral osteotomy in C57bl/6 mice (female, 2026 week old). Mice were sacrificed at 7, 14, 30 and 40 days after surgery (n=4-9 per group). Live bacteria from the implant,
bone and soft-tissue were quantified. Isolated bacteria were
confirmed to be the inoculated S. epidermidis strain with
RAPD (Random Amplified Polymorphic DNA) PCR. Lymph
node and bone cells were characterized by flow cytometry.
Results: In the non-inoculated groups the rigid plate resulted in a stable fixation, leading to healing by intramembranous ossification and the flexible plate resulted in an un-
F015
Correlation of histopathology and microbiology in patients with rheumatoid arthritis and
joint infections
Ulrich Illgner1, Ludwig Bause1, Veith Krenn2
Clinic For Rheumaorthopaedic Surgery St Josef Stift Sendenhorst, Sendenhorst, Germany
2
Medical Center For Histology, Cytology And Molecular Diagnostics Trier, Trier, Germany
1
Introduction: It can be difficult to distinguish between synovitis due to rheumatism and synovitis due to a bacterial
infection. Microbiological detection of bacteria is not always successful and the clinical significance of low virulent
bacteria often remains uncertain.Therefore, the histopathological finding of inflammation reactions is very important.
Aim: Goal of the study was to detect correlation of histopathological and microbiological results in joint infections.
Methods: Deep samples were taken during surgery from
patients with clinically clear signs of infections and rheumatoid arthritis who underwent surgery between April and
August 2011. Histopathological diagnosis was carried out
by conventional enzyme and immunohistochemical techniques based on defined criteria of bacterial infection in tissues, synovial tissue and bone.
33rd Annual Meeting of the European Bone & Joint Infection Society
stable fixation, leading to a more endochondral ossification
and stabilizing callus formation. In the inoculated groups,
the unstable group had a higher infection rate compared
to stable fractures, at all time-points over 40 days. Bacterial counts reduced from bone and soft tissue over time,
however, the number of bacteria forming the biofilm on
the implant remained similar over time in all groups. When
analyzing cells from bone it was observed that the percentage of macrophage lineage cells generally increased over
time in all groups (infected and not-infected) but more so
in animals with flexible implants, regardless of the presence
or absence of infection. From lymph nodes, cell populations
were characterized according to cytokine production. IL-17
cells were increased at early time-points in infected animals,
especially in the ones that could clear the bacteria. This suggests a role of Th17 response in infection clearance. IL-10+
and IFN-gamma+ cells were similar between all groups at
early time-points, increasing in not-infected animals later.
Conclusion: Infection rates are influenced by the implant
stability, with unstable constructs increasing infection rate.
This observation seems to be connected to altered immune
cell responses between both models.
This work was funded by AOTrauma
10 females with a mean age of 61.7 years. Staphylococcus
aureus was the most commonly detected bacteria and in 4
cases bacteria could not be demonstrated. In 3 out of this 4
patients histopathology showed clear signs of infection corresponding to the clinical course of a low-grade infection
with surgical revisions even though bacteria could not be
found in microbiological samples. The correlation between
the histopathological signs of an infection and microbiological detection of bacteria was 93.3%.
Conclusions: In patients with rheumatoid arthritis the combination of histopathology and microbiology significantly
increased the safety of detecting an infection or contamination. There has been no funding.
September
Results: A total of 20 patients were included,
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F016
Decreasing proportion of neuroischemic foot ulcers in diabetic patients, 1995-2010
Eivind Witsø1, Stian Lydersen2
St.Olavs University Hospital, Trondheim, Norway
2
Norwegian University Of Science And Technology; St. Olavs University Hospital, Trondheim, Norway
may promote bacterial resistance if inoculation occurs.
There therefore exist a Faustian pact with ALAC between
prevention of infection and bacterial resistance. Neverthe-
less, Joint registry figures still report better outcome for infection prevention with the use of ALAC compared to joint
replacement using plain cement or uncemented fixation.
1
Aim: We have previously reported on a decrease in diabetic
and non-diabetic amputations in the city of Trondheim,
Norway from 1996 to 2006 (Witsø et al. 2012). In the same
period we did not observe any increase in the rate of invasive and non-invasive vascular procedures, indicating that
there has been a decrease in vascular obstructive disease in
the population. Consequently, we would expect to observe
a decrease in the number of patients with neuroischemic
diabetic foot ulcers in the same population. We analysed
data from the out-patient diabetic foot clinic in Trondheim
in the period 1996-2010, and compared the proportion of
neuropathic and neuroischemic diabetic foot ulcers in the
three periods 1996-2000, 2001-2005 and 2006-2010.
Methods: In the period 1996-2010 we performed screening
for neuropathy and angiopathy in 1004 patients with diabetes mellitus. The patients were 64 (14-93) years old, 54%
were males, they had been diagnosed as diabetic patients
for 15 (0-71) years, 58% used insulin and 22% had diabetes
mellitus type 1. Screening for neuropathy was performed
with a Semmes-Weinstein monofilament (10 gram) and a
128 Hz tuning fork. Patients with a foot ulcer and no palpable pulses at the ankle joint were referred to the Department
of Vascular Surgery for further evaluation. The patients were
classified as having either a) no foot ulcer, b) a neuropathic
ulcer, c) a neuroischemic ulcer, or c) other pathological condition (as a Charcot joint).
Results: In the three periods (1996-2000, 2001-2005, 20062010) 420, 350 and 235 patients were examined, respectively.
The proportion of neuropatic/neuroichemic foot ulcers was
51/102 in 1996-2000, 41/73 in 2001-2005 and 38/35 in 20062010. Through the three periods the proportion of patients
with neuroischemic foot ulcers decreased compared to patients with no foot ulcer, patients with neuropathic foot ulcers
and patients with other pathological conditions (p=0.010).
Conclusions: Analyses of data from the out-patient diabetic foot clinic in Trondheim support the results of previous
studies on diabetic amputations in the midst-part of Norway. It appears that the rate of vascular obstructive disease
has decreased in the diabetic population, resulting in less
diabetic amputations and neuroischemic foot ulcers.
46
F018
Intra-articular injections of hyaluronic acid less than 6 months before total hip arthroplasty. Is
it safe?
Sascha Colen1, Liselore Maeckelbergh2, Marcus Van Diemen2, Alain Dalemans2, Michel Van den Bekerom3, Michiel Mulier2
University Hospitals Leuven, Leuven, Belgium
2
University Hospitals Leuven, Department Of Orthopaedic Surgery, Pellenberg, Belgium, Leuven, Belgium
3
Onze Lieve Vrouwe Gasthuis, Department Of Orthopaedic Surgery And Traumatology, Amsterdam, The Netherlands,
Amsterdam, Netherlands
1
Aim: Hyaluronic acid (HA) can be injected into an arthritic
hip joint to reduce pain and to improve functionality. Several studies report intra-articularly administrated HA to be
safe. Minor adverse effects normally disappear spontaneously within a week. To assess the influence of intra-articular
injections with HA on the outcome of total hip arthroplasty
(THA), we compared the outcome of THA in patients who received an intra-articular HA injection 6 months or less prior
to surgery (injection group) with that of patients undergoing THA without any previous injection in the ipsilateral hip
(control group).
Results: One-hundred thirteen patients (118 hips) could be
included in the injection group, and 452 patients (495 hips) in
the control group. No differences in baseline characteristics
and risk factors for infection between the two groups were
seen. The clinical outcome and the majority of complication
ratios were equal in both groups. However, there was a higher rate of periprosthetic joint infections (P<0.001) and postoperative wound infections (p=0.014) in the injection group.
Conclusions: These data suggest that intra-articular injections of the hip performed 6 months or less prior to THA
may propose a risk for increased rates of PJI. We recommend
refraining from performing an arthroplasty within 6 months
after intra-articular administration of HA in the hip.
F017
Antimicrobial activities, antibiotic release and antibiotic resistance of acrylic cement
retrieved up to 27 years following primary implantation
Herbert Gbejuade, Jason Webb, Andrew Lovering
Southmead Hospital, Bristol, United Kingdom
F019
One stage and two stage infected tha and tka revisions: a serie of 168 patients. Is there
criterias to help us to decide which procedure to realise?
Gérard Giordano, Guillaume Krin, Julien Remi, Eric Bonnet
Joseph Ducuing Hospital, Toulouse, France
Introduction: The use of antibiotic loaded bone cement
(ALAC) is a proven means of preventing and managing
prosthetic joint infections. However, it is known that less
that 30% of the overall amount of antibiotics contained in
the cement is ever released.
Aim: To evaluate the evaluation of the antimicrobial activities, antibiotic release and antibiotic resistance
Methods: 49 patients undergoing revision hip arthroplasty
for mechanical failure and for which antibiotic loaded cement were used during their primary hip replacement were
recruited for this study. The mean interval between the
primary hip arthroplasty and the revision surgery was 140
months (11.7 years). From each patient, atleast one of three
modes of sampling was performed: bone cement retrieval
(for assessment of antimicrobial properties) and joint fluid
aspirate or urine sample collection (both for antibiotic concentration assays). A bacillus subtilis was used to assess for
antimicrobial activity, while urinary and joint aspirate gen-
tamicin concentrations were determined by immunoassay.
In addition, gentamicin was tested for resistance using a Coagulase negative staphylococci (CoNS) strain.
Results: 97% of the retrieved cement samples demonstrated significant antimicrobial activity in the Bacillus subtilis
bioassay. And although none of the patients had detectable
urinary gentamicin at the sensitivity limit of the assay, 96%
of the joint aspirates collected had detectable gentamicin
at a mean concentration of 0.5mg/L.
At the start of the experiment the CoNS strain was sensitive
to gentamicin, however, resistance developed after just four
culture cycles and that resistance also occurred against the
other aminoglycosides tested alongside gentamicin.
Conclusion: Our study demonstrates that even ALAC as old
as 27 years still elutes antibiotics at levels effective enough
against certain bacteria. Undesirably, in these aseptic joint
failures, the low concentrations of gentamicin measured
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: To Try to define the criterias for one stage or two stage in
the treatment of peri prosthetic infections (PPI).
Study: We report a retropropective and monocentric study of
168 patients (98 male - 70 female) treated between 2008 and
2013 in the Joseph Ducuing Hospital by the same surgeon.
Each patient was followed by a multidisciplinary team with
a mean follow up of 23 month (1 - 5 years). The Mac Pherson
score was used to evaluate the preoperative statut. 85 THA
(one resurfacing), 81 TKA (two unicompartimental prostheses) and 2 total shoulder arthroplasties were treated. In three
cases, the infection was simultaneous and bilateral. 98 one
stage revisions and 70 two stages were performed.
Results: For the 85 THA, we performed 47 one stage revisions
and 38 two stages (one case of total femur reconstruction).
The rate of failure is 4,7% without significant differences between the two procedures (3 one stage, 1 two stage). For 81
TKA PI, 49 one stages and 32 two stages were realised with
21 cases of one stage navigated revisions. The rate with 9,5%
of failure is higher than for the THA PI (2 one stages, 5 two
stages) without significant differences.
In this study, the decision of one or two stage doesn’t depend
of the germ (except for 3 fungic infections). Only an unpredictible bone defect after removing the prothesis can change
the one stage decision (2 cases). The preoperative defect
can be managed by surgical techniques (massive allograft,
custom made, megaprostheses…). We describe our bone
limits to performe one stage by describing extreme cases.
The global rate of success is 92,9% (95,3% for THA PI, 90,5%
forTKA PI, 2/2 for the two shoulder protheses).
According the Mac Pherson score analysis, the systemic comorbidities seem to be major factors of failure for THA PI, and
the local preoperative complications could compromise the
result of periprosthetic infection of TKA.
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Conclusion: no definitive criterias was valide only some tendances : we decide a priori one stage revision for hip and
knee PI and with caution if there’s cumulated systemic issues for the hip and local issues for the knee. The two most
Abstracts free paper sessions
difficult issues are probably the peroperative bone defect
which change our prosthetic strategies and the soft-tissus
statut of the TKA PI. One stage and two stage revisions provide the same results for the infection control in this study.
F020
Review of prosthetic joint infections receiving outpatient parenteral antimicrobial therapy
(opat) in south london teaching hospital
Shara Palanivel, Sarah Moger, Matt Laundy, Peter Riley
St George’s Hospital, London, United Kingdom
48
Aim: OPAT has been established at St George’s Hospital,
South London since 2009. Since this time a database recording details of patients receiving OPAT has been set up.
We reviewed the data recorded on patients treated for Prosthetic Joint Infections with OPAT.
Methods: Since 2009 75 patients have received OPAT for PJI
and were either hip or knee replacements. Bed days saved
ranged from 1 to 81 days.
There was a variety of causative organisms, some polymicrobial. Outcome of the OPAT episodes were separated into 4
categories according to BSAC criteria:
Success - Completed therapy in OPAT with no change in antimicrobial agent, no adverse events, cure or improvement
and no readmission
Partial Success - Completed therapy in OPAT with either
change in antimicrobial agent or adverse event not requiring admission.
Failure of OPAT - Readmitted due to infection worsening or
due to adverse event. Death due to any cause during OPAT.
Indeterminate outcome - Readmission due to unrelated
event eg chest pain.
In view of the BSAC definitions, we classified success and
partial success categories as a favourable outcome from
OPAT.
Results: 75 patients have received OPAT for PJI and were either hip or knee replacements. Bed days saved ranged from
1 to 81 days. Median 28 and mean of 27.9 days.
43 of 75 (57.3%) were success and 11 of 75 were partial success, meaning 54 of 75 (72%) were treated favourably with
OPAT.
9 of 75 (12%) failed on OPAT and the remaining 12 (16%)
had an indeterminate outcome.
Conclusions: All patients receiving OPAT for PJI had saved
bed days ranging 1-81 days saved. This amounts to a considerable financial saving as well as a favourable outcome
for the patients themselves.
The majority of these patients did not require further readmission for their Prosthetic Joint Infection.
Our findings support that OPAT improves patient outcomes
in the treatment of Prosthetic Joint Infection.
Funding: This was a retrospective study and no additional
funding was required.
F021
A two stage re-implantation protocol for the treatment of periprosthetic knee infection.
Long-term results in a tertiary referral center
Macheras George, Panagiotis Lepetsos, Antonis Stylianakis, Spyridon Michail, Dimitrios Argyris, Panagiotis Anastasopoulos,
Nikolaos Kyriakopoulos, Moyssis Lelekis
Kat Hospital, Kifissia, Greece
Aim: The reported incidence of periprosthetic knee infection in modern practice is between 0.5% and 3% and remains a diagnostic and therapeutic problem. The purpose
of our study is to present the long-term results of the twostage re-implantation protocol in the treatment of periprosthetic knee infections.
Methods: We retrospectively investigated all cases of periprosthetic knee infections treated at our institution be-
tween 2000 and 2008. All patients were treated with twostage re-implantation protocol. In brief, after the diagnosis
of periprosthetic knee infection, the patients underwent
surgical removal of all implants, cement, necrotic bone and
non-viable infected tissue and a spacer was placed. Multiple
tissue samples were taken for cultures and histological examination. Postoperatively, patients received intravenous
antibiotics for 6 weeks. In the condition of clinical improve-
33rd Annual Meeting of the European Bone & Joint Infection Society
ment and normal laboratory examinations, and 2-4 weeks
after completing the antibiotic regimen, a new prosthesis
was re-implanted. Patient demographics, surgical interventions, postoperative complications, culture results and clinical outcome were recorded.
Results: The study included 38 patients with periprosthetic
knee infections (mean age 64.7 years; range 45 - 73 years;
84% female). The initial indication for total knee replacement was primary osteoarthritis in 34 patients and rheumatoid arthritis in four. Mean follow-up time was 12.4 years
(range 6 to 14 years). Isolated bacteria were Staphylococcus
aureus (n = 15), Gram negative bacteria (n = 8), coagulase
negative staphylococci (n = 7), and other bacteria (n = 4),
while in 2 patients no microorganism was isolated. Four
patients developed a recurrent infection and were treated
using the same protocol, two successfully and two unsuccessfully. One of them was treated with knee arthrodesis
because of extensive bone loss and degeneration of the
patellar tendon while the other was amputated because of
infection with vancomycin-resistant Enterococcus and multiple comorbidities. Six patients underwent new surgical
debridement because of persistent raised CRP, followed by
further six weeks of antibiotics. There was one case of aseptic loosening after 13 years. The infection was eradicated
successfully in 35 patients (92.1%).
Conclusions: Two-stage re-implantation produces excellent
outcome in the treatment of periprosthetic knee infections.
Treatment of such infections is quite demanding requires
long hospitalization and should be better performed in specialized referral centers.
F022
Periprosthetic joint infection with Propionibacterium with or without rifampicin treatment:
one and two year results
Anouk M.E. Jacobs1, Fidel Vos2, Jacques F. Meis3, Miranda L. van Hooff4, Jon H.M. Goosen1
Department Of Orthopaedic Surgery, Prosthetic Joint Infection Unit, Sint Maartenskliniek, Nijmegen, Netherlands
2
Department Of Internal Medicine, Radboud University Medical Center, Nijmegen, Netherlands
3
Department Of Medical Microbiology And Infectious Diseases, Canisius-Wilhelmina Ziekenhuis, Nijmegen, Netherlands
4
Department For Scientific Research, Sint Maartenskliniek, Nijmegen, Netherlands
1
49
Aim: Currently, Propionibacterium is frequently recognized
as the causative micro-organism of Periprosthetic Joint Infection (PJI) (1-2). However, optimal treatment has yet to
be determined. The aim of this study was to ascertain the
outcome of treatment for Propionibacterium-associated PJI
of the shoulder, hip and knee at one and two year followup. Furthermore, we attempted to determine differences in
outcome of postoperative antibiotic treatment with or without rifampicin.
Methods: We retrospectively included patients with joint arthroplasty of the shoulder, hip, and knee, diagnosed with a
Propionibacterium-associated PJI between November 2008
and February 2013, and a minimal follow-up of one year.
The PJI criteria were based on the Musculoskeletal Infection
Society criteria (3). Patients’ medical records were reviewed
to assess treatment strategy, retention of the joint arthroplasty and signs of persistent infection at one and two years
after final infection treatment.
Preliminary results: Fifty-four patients with a mean followup of 26 months after final treatment for Propionibacterium-associated PJI of the knee (24), hip (15), and shoulder
(15) were analyzed. Late infections were treated with onestage (63%) or two-stage exchange surgery (24%). In case
of an early or hematogenous infection open debridement
(13%) was performed. All cases were treated with a three
month postoperative antibiotic regimen, 61% received a
combination of oral antibiotics with rifampicin (of which
85% clindamycin-rifampicin). Based on retention of the
prosthesis and the absence of persistent infection, 94% and
87% of the patients were rated as successful at one and two
year follow-up, respectively. When comparing the antibiotic
treatment groups with and without supplementary rifampicin no significant differences were seen at one (p = 0,631) or
two (p = 0,626) year follow-up.
Conclusion: Our preliminary results suggest that Propionibacterium-associated PJI treated with surgery in combination
with long-term antibiotics has a successful outcome at one
and two year follow-up of 94% and 87%, respectively. These
rates are similar to outcomes reported in previous studies (4,
5). However, our preliminary results indicate no difference
when treated with or without supplementary rifampicin. We
need a prospective randomized study to underline our results.
References
1. Titecat M. Orthop Traumatol Surg Res. 2013 Oct;99(6):653-8.
2. Singh JA. J Shoulder Elbow Surg. 2012 Nov;21(11):1534–41.
3. Musculoskeletal Infection Society. 2013 Aug 1. http://www.msis-na.
org/international-consensus/. Accessed 2014 Apr 17.
4. Tsaras G. Infect Control Hosp Epidemiol. 2012 Dec;33(12):1207-12.
5. Zeller V. J Infect. 2007 Aug;55(2):119-24.
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
Abstracts free paper sessions
F023
Prolonged postoperative antibiotic regimen reduced the rate of prosthetic joint infection
after revision knee arthroplasty
Guillem Claret1, Eduard Tornero1, Sebastián Garcia1, Juan Carlos Martínez-Pastor1, Mercè Piazuelo2, Jésica Martínez-Castillejo2,
Jordi Bosch1, Josep Maria Segur1, Josep Mensa1, Alejandro Soriano1
1
Hospital Clinic Barcelona Bone And Joint Infection Disease Unit, Barcelona, Spain
2
Hospital Clinic Barcelona, Barcelona, Spain
50
Aim: The aim of the present study was to describe the rate
of prosthetic joint infection after total or partial knee revision arthroplasty due to aseptic loosening in our institution
before and after the modification from short (1 day) to long
(5 days after surgery) antibiotic prophylaxis.
Methods: Antibiotic prophylaxis from January 2007 to September 2010 consisted of one dose of intravenous 800 mg
of teicoplanin and 2g of ceftazidime during induction of anaesthesia and 1 g of ceftazidime after 2h of the first dose.
From October 2010, it was decided to prolong the administration of antibiotics using vancomycin 1 g/12h and ceftazidime 2 g/8h intravenously until the 5th post-operative day.
There were no other major changes in patient management
or surgical technique. Cox regression analysis was performed to identify independent predictors of PJI.
Results: During the study period 341 revision surgeries met
the inclusion criteria. 203 (59.5%) patients received short
antibiotic prophylaxis whereas 138 (40.5%) received long
antibiotic regimen. Although the long group had more comorbidity, the prevalence of PJI was significantly lower than
in the short group (2.2% vs 6.9%, P=0.049). A prolonged
postoperative antibiotic treatment was the only variable
independently associated with a lower rate of PJI (HR: 0.20,
CI95%: 0.04-0.92).
Conclusion: five days of antibiotic prophylaxis have been
associated with a significantly lower infection rate in revision knee arthroplasty due to aseptic loosening.
Graph 1: Succes rate vs Protocol adherence
References:
• Liu C, Kakis A, Nichols A, Ries MD, Vail TP, Bozic KJ. Targeted Use of
Vancomycin as Perioperative Prophylaxis Reduces Periprosthetic Joint
Infection in Revision TKA. Clin Orthop Relat Res 2014;472:227–31.
• Mortazavi SMJ, Molligan J, Austin MS, Purtill JJ, Hozack WJ, Parvizi
J. Failure following revision total knee arthroplasty: infection is the
major cause. Int Orthop 2010;35:1157–64.
• Mortazavi SMJ, Schwartzenberger J, Austin MS, Purtill JJ, Parvizi J.
Revision Total Knee Arthroplasty Infection: Incidence and Predictors.
Clin Orthop Relat Res 2010;468:2052–9.
• Bratzler DW, Dellinger EP, Olsen KM, Perl TM, Auwaerter PG, Bolon MK,
et al. Clinical practice guidelines for antimicrobial prophylaxis in surgery. American Journal of Health-System Pharmacy 2013;70:195–283.
F024
The effect of adherence to an infection management protocol on the outcome of prosthetic
joint infections of hip and knee
David Provoost, Hans Hendriks, Laura van Dommelen, Robin van Kempen
Maxima Medical Centre, Veldhoven, Netherlands
Aim: Prosthetic joint infections cause significant problems
and morbidity for the patient. The purpose of this study
was to describe the treatment outcome for prosthetic joint
infections in routine practice in the course of the introduction of an infection management protocol and to evaluate
whether outcome improved with stricter adherence to the
protocol.
Methods: We retrospectively analyzed all hemihip, total
hip, total knee and revision arthroplasies that were treated
for a prosthesic joint infection from January 2008 until December 2012. We included only those patients who had at
least one positive pre-operative or intra-operative culture.
We defined success as retaining of the previously infected
prosthesis and a survival of minimal one year.
We analyzed the protocol adherence by valuing different
Conclusions: This is the first study to show that the
success rate of the treatment of prosthetic joint infection improves on stricter adherence to the treatment
protocol. More rigorous adherence to infection management protocols in prosthetic joint infections could
therefore improve patient care and by limiting costly
treatment failures reduce health care costs.
traceable parts of the protocol and adding up absence or
presence of the different items. This was based on the following parameters: acquisition of infection parameters pre-operative, the amount of cultures taken during the operation, the
postoperative follow up by infection parameters, the correct
amount of operations before a prosthesis was removed and
the correct duration of post-operative antibiotics.
Results: We included 119 patients (61 total hip arthroplasties, 24 hemi hip arthroplasties, 21 total knee prosthesis and
13 revision arthroplasties) The overall treatment success
percentage was 73,1 %, this percentage was stable over the
investigated period. According to graph 1 There appears to
be a higher success tendency on stricter adherence to our
treatment protocol (83%) as opposed to less strict adherence (71,4%).
33rd Annual Meeting of the European Bone & Joint Infection Society
F025
Activity of bioactive glass s53p4 on different planktonic microorganisms performed by
microcalorimetry
Elena Maiolo1, Laura Sessa2, Inês Ferreira3, Andrej Trampuz1, Olivier Borens4
1
Charité - University Medicine Berlin, Berlin, Germany
2
Infectious Diseases Service, University Hospital Lausanne (Chuv), Lausanne, Switzerland
3
Research Institute For Medicines/Faculty Of Pharmacy, University Of Lisbon, Lisbon, Portugal
4
Septic Surgical Unit, Department Of Surgery And Anesthesiology, University Hospital, Lausanne, Switzerland
Aim: The activity of bioactive glass (BAG) S53P4 in different
sizes and volumes was tested on planktonic microorganisms using a highly sensitive assay measuring growth-related heat production (microcalorimetry).
Methods: S. aureus (ATCC 29213), S. epidermidis (ATCC
35984), E. faecalis (ATCC 19433), C. albicans (ATCC 90028)
and E. coli (ATCC 25922) were tested. Test strains (~10^6
CFU/ml) were added in sealed glass ampoules containing
Müller Hinton broth with or without BAG and placed into
the microcalorimetry at 37°C. BAG was tested on planktonic
microorganisms in different granule sizes (0.5-0.8 mm and
<45 µm) and volumes (1 and 2 g). The heat flow produced
and the total heat were recorded and analysed.
Results: At granule sizes 0.5-0.8 mm and <45 µm, the total heat peak decreased compared to the growth control.
When 0.5-0.8 mm BAG was used, the total heat decreased
proportionally with the increasing of BAG volumes of 1
and 2 g, except for E. coli where no significant differences
were detected. When comparing the activity of the different
granules sizes, <45 µm showed a better activity against all
the microorganisms used than 0.5-0.8 mm BAG. BAG S53P4
0.5-0.8 mm showed to have an activity against all the microorganisms, except E. faecalis, whereas BAG S53P4 <45
µm inhibited the growth of all microorganisms. Conclusion:
Microcalorimetry allowed real-time evaluation of antibacterial activity of bioactive glass on staphylococci and other
microorganisms. BAG S53P4 should also be tested with
anaerobe microorganisms and against the biofilm form of
microorganisms in order to have a better overview of his
antimicrobial activity.

Activity of bioactive glass on microorganisms growth.
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Abstracts free paper sessions
Abstracts free paper sessions
F026
Microbiological profiles of prosthetic knee infection as predictors of exchange arthroplasty
outcome
Ammar Abbas, Sanjeev Agarwal, Rhidian Morgan-Jones
Cardiff And Vale University Health Board, Cardiff, United Kingdom
Background: The types and numbers of the infecting organisms are amongst the factors that influence the outcomes of
surgical treatment of prosthetic knee infections. The aim of
this study is to detect the correlation between the microbiological profiles and the outcomes of prosthetic knee infections treated with exchange arthroplasty in our institution.
Method: We reviewed the results of a consecutive series
of 40 chronically infected total knee replacements treated
with two-stage revision arthroplasty over a 4-year period.
Patients’ demographics, medical co-morbidities, number of
previous surgical interventions, culture results and clinical
outcome were recorded.
Results: There were 26 males and 14 females. The average
age was 86.7 years (22 to 91 years). The average follow-up
duration was 26 months (12 to 56 months). The overall success rate was 75%. The commonest organism was Coagulase negative Staphylococcus. Gram-negative organisms
were grown in 50% of the cultures in the treatment-failure
group. Additionally, 80% of the cultures in this group were
poly-microbial, and in 80% of cultures one or more multidrug resistant organisms were demonstrated. In contrast,
there were no Gram-negative infections in the success
group. In this group poly-microbial and multi-drug resistant
infections were shown in 22% and 22% of the cultures, respectively.
Conclusion: This study provides evidence that poly-microbial, multi-drug resistant and gram-negative infections are
predictors of treatment failure.
2011 and June 2013. We analyzed all patients with indication for implant removal due to any reason. OAI was defined
if at least one of the following criteria was present: open
wound exposing fractured bone and/or OS devices with
gross evidence of infection; intraoperative tissue with visible purulence as determined by the surgeon; presence of
a draining fistula communicating with the internal implant;
acute inflammation in intraoperative OS tissue detected by
histopathology; or microbial growth in intraoperative periimplant tissue cultures. Minimal of two tissue samples were
taken and sent under sterile conditions to the laboratory for
culture. The removal implants were packed into sterile containers and covered with Ringer’s solution, vortexed for 30
seconds and sonicated for 5 minutes. The sonicated fluid is
them cultured and the microorganisms isolated were identi-
fied according to standard method. Statistical analysis was
performed McNemar’s test for related proportions.
Results: Infection was the main reason for OS removal
(60%). Sensitivity, specificity, PPV and NPV of peri-prosthetic
tissue culture was 56,6 % (IC: 47,6-65,3), 96,4 (IC: 87,7-99,6),
97,7% (IC: 90,7- 99,2), 50,9% (IC: 41,7 a 60,1), respectively.
Sensitivity, specificity, PPV and NPV of sonication culture
was 89,9 (IC: 83,4 a 94,5) (p< 0,05), 91,1 (IC: 80,4 a 97), 95,8
(90,6 a 98,2), 79,6 (IC: 68,2 a 87,7) (p< 0,05) respectively. The
organisms isolated from culture of fluid sonication were: coaguase-negative Staphylococcus (22,7%), Staphylococcus
aureus (28%), bacillus gram negative (34%) e polimicrobial
flora (15,7%).
Conclusion: Sonication fluid cultures improved the microbiological diagnosis of OAIs.
F028
Surgical pathogen eradication in bone infections – a sisyphean task?
Mario Morgenstern, Christoph Erichsen, Fintan Moriarty, Sven Hungerer, Matthias Militz, Volker Bühren
Bg Unfallklinik Murnau, Murnau, Germany
52
Figure 1. Comparison of the microbiological
profiles in the two treatment outcome groups
F027
Ostheosyntesis-associated infections: role of sonication fluid cultures of removed implants to
improve microbiological diagnosis
Mauro Salles, Maysa Yano, Cely Barreto
Santa Casa De Sao Paulo School Of Medicine, Sao Paulo, Brazil
Surgical implantations of orthopedic devices have been
increased for fracture fixations (osteosynthesis) including
intra-medullary nails, plates, screws and external-fixation
pins. Secondary soft tissue and implant-associated bone
infection, however, is still the most important threat and
diagnosis is challenging. Sonication has been applied to
dislodge microorganisms from the surface of removed prosthetic joints devices showing an improvement in the etiological diagnosis of prosthetic joint infections when com-
Aim: The treatment of bone and implant-related infections
poses a challenge to both surgeons and microbiologists.
Multiple surgical procedures as well as systemic and local antibiotics are needed to cure persistent infection and
to restore the function of the limb. Treatment may require
months for successful outcome, however, in this time a
change in the infecting organism may be observed, although only minimal literature is available on this topic. The
purpose of this study is to map the bacterial flora causing
bone infections at our hospital and to monitor the persistence of the infecting organisms against possible superinfection with new species during treatment.
Methods: We retrospectively reviewed the data of patients
treated with a bone or implant infection of the lower extremity in our department over a period of 8 years. In total, 449
patients with bacterial growth around the affected bone or
implant were included. In addition to the identity and antibiotic resistance profile of the initial infecting pathogen,
every subsequent pathogen, isolated during surgical treatment of the affected site was similarly documented.
Results: In total, 87 different bacterial species were recorded from bone and implant-related infections. On average,
2.5 different pathogens were isolated across multiple surgeries from the site of interest of each patient. The most
common bacteria that could be proven in the first surgery
were Staphylococcus aureus (42.5%), Staphylococcus epidermidis (24.3%), coagulase negative staphylococci as a
group (CoNS) (37.4%), Enterococcus faecalis (8.7%) and
Pseudomonas aeruginosa (6.0%). In the subsequent surgeries, a pathogen change was observed in 247/449 patients,
with S. epidermidis the predominant pathogen in 54.3%
and CoNS in 72.9% of all patients experiencing a superinfection. Surprisingly, S. aureus (13.4%), and even more
so MRSA (1.6%), were less likely to occur as super-infecting
pathogens. Statistical analysis revealed that S. epidermidis
and CoNS were significantly more frequently detected in a
pathogen change than S. aureus and all other gram positive
and gram negative bacteria (p<0.05).
Conclusion: This study involving a large patient cohort,
reveals that multiple pathogens are involved in a bone or
implant infection of a single patient. S. aureus could be
detected as the predominant species in the first operative
revision, but in successional surgeries coagulase negative
staphylococci could be isolated as a super-infecting pathogen in the majority of the patients experiencing a pathogen
change. Further studies and analysis are required to clarify
the causation of the pathogen change.
pared with periprosthetic tissue cultures.
Objectives: To compare the sensitivity, specificity, positive
predictive value (PPV) and negative predictive value (NPV)
of conventional peri-implant tissue culture samples with
culture of samples obtained by sonication of explanted
ostheosynthesis (OS) in the microbiological diagnosis of
ostheosynthesis-associasted infections (OAI).
Methods: Prospective cohort study performed at the Santa
Casa de São Paulo School of Medicine, between August
33rd Annual Meeting of the European Bone & Joint Infection Society
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Abstracts free paper sessions
Abstracts free paper sessions
F029
Subsidence of bioactive glass granules, morselized cancellous allograft, and tricalcium
phosphate granules in an in situ defect model
Dennis Hulsen1, 2,Jan Geurts2,Chris Arts2, 3,Bert van Rietbergen3
Eindhoven University Of Technology, Eindhoven, Netherlands
Maastricht University Medical Center, Maastricht, Netherlands
3
Eindhoven University Of Technology, Maastricht, Netherlands
1
2
54
Aim: Bioactive glass (BAG) is an osteoconductive graft material that possesses antibacterial properties, but thus far has
rarely been used in treatment of load-bearing bone volume
defects. In a previous experiment, confined compression
tests showed that mixing BAG granules with allograft improved the mechanical behavior of the graft layer. In order
to better assess the capability of such materials to restore
mechanical properties when filling bone defects, the aim
of this study was to characterize the influence of graft layer
composition on subsidence – a measure for implant instability – in an in situ defect model.
Methods: Four materials were tested in cadaveric porcine
tibias: BAG granules, human morselized allograft, a 1:1
volume mixture of those two (MIX), and tricalcium phosphate (TCP) granules. A cylindrical defect was created in the
tibial plateau (n=5 per group) using a 20.4 mm pillar drill.
Three mL graft material was impacted in the defect using
a custom-made impaction device. Tibias were placed in a
mechanical test machine and subjected to 2000 cycles of
uniaxial compression on the graft layer. Loading mimicked
stress levels while walking (up to 850 N). During loading,
displacement of the load applicator was used to measure
subsidence of the graft layer over time.
Results: Already after 10 loading cycles a subsidence equal
to half of the final subsidence was reached. This initial subsidence was higher for allograft (1.73 mm) compared to
BAG (0.82 mm) and MIX (1.13 mm). In addition, TCP also
showed higher subsidence (1.35 mm) then BAG. Long-term
subsidence after 2000 cycles was lower for MIX (1.70 mm)
than for both allograft (2.71 mm) and TCP (3.04 mm). Longterm subsidence for the MIX and BAG (1.77 mm) groups was
equal. An interesting observation was the small variability in
long-term subsidence for the MIX group; a standard deviation of 0.11 mm versus 0.64, 0.28, and 0.51 mm for the BAG,
allograft, and TCP groups respectively.
Conclusions: Different graft layer compositions lead to difference in subsidence. In particular for pure allograft and TCP
layers, relatively high initial and long term subsidence was
found. The pure BAG layer had lower initial and long term
subsidence. The subsidence for the MIX group was almost as
good as that of pure BAG, but with very low variation, and is
therefore proposed here as the material of choice.
Acknowledgements: This study was sponsored in kind (materials) by BonAlive Biomaterials Ltd. No additional disclosures
from all authors.
F030
Does the type of anaesthesia affect the outcome in patients undergoing surgery for
osteomyelitis with microvascular muscle flaps?
Martin McNally1, John Kendall2, Chris Taylor3, Svetlana Galitzine4
1
Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
2
Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford, United Kingdom
3
Oxford University Hospitals Nhs Trust, Oxford, United Kingdom
4
Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
Aim: Radical excision of osteomyelitis with free muscle flap
reconstruction involves very long operations which have
traditionally been performed under general anaesthetic
(GA). Since 2007, we have introduced regional anaesthesia
with sedation (RA+Sed) as an alternative to GA with or without RA. This has been popular with patients1. We wished to
objectively assess the possible impact of RA+Sed on surgical and patient outcomes and compare this to GA+/-RA.
Methods: Medical records of 79 consecutive patients who
underwent osteomyelitis surgery with free tissue transfer
were reviewed. The choice of anaesthetic was governed by
anaesthetists’ and patients’ preferences. Regional anaesthesia, without GA, required epidural or combined spinalepidural in the lumbar spine, with infusion continued for
postoperative pain relief. Type of anaesthesia, patient comorbidities, severity of osteomyelitis, postoperative complications, length of surgery and length of hospital stay were
analysed.
33rd Annual Meeting of the European Bone & Joint Infection Society
Results: 31 patients had RA+Sed and 48 had GA+/-RA. The
groups were comparable in age (mean 51 vs 49 years; range
18-84), ASA grade, Cierny & Mader stage and duration of
surgery (mean 471 vs 495 minutes; range 320 to 849).
All operations were completed as planned. After surgery,
in the GA+/-RA group, one patient required unplanned ITU
transfer for postoperative ventilation and one had a pulmonary embolus. In the RA+Sed group, one patient had postoperative pneumonia. There were four early postoperative
flap anastomotic failures requiring return to theatre, all in
the GA+/-RA group (4/48 vs 0/31; p=0.09). Mean hospital
stay was 17 days in RA+Sed group and 20 days in the GA+/RA group (p=0.043).
Conclusions: In this study, RA+Sed demonstrated a trend
towards fewer postoperative complications, including flap
failures and a significantly reduced length of stay in hospital. After RA+Sed, patients recovered faster and were able
to engage in rehabilitation at an earlier stage. These objective outcome measures correlate well with patient reported
experience with RA+Sed1. Although regional anaesthesia
with sedation may be more labour-intensive in theatre,
these results suggest that it is an acceptable technique and
can be better than general anaesthesia due to a positive effect on outcomes.
1) Patient reported experience and outcomes of epidural anaesthesia
and sedation for major orthoplastic lower limb surgery. S Galitzine, S
Perera, M Edington, J Kendall, MA McNally EFORT London 2014.
F031
Sonication for diagnosis of non-prosthetic-joint orthopaedic infections
Andrew Jonathan Brent1, Maria Dudareva2, Rachael Colledge2, Mel Figtree3, Robert Newnham2, Philip Bejon4, Andrew
Woodhouse2, Adrian Taylor2, Martin McNally2, Bridget Atkins2
1
University Of Oxford & Oxford University Hospitals NHS Trust, Headington, Oxford, United Kingdom
2
Oxford University Hospitals Nhs Trust, Oxford, United Kingdom
3
Royal North Shore Hospital, Sydney, Australia
4
University Of Oxford & Oxford University Hospitals NHS Trust, Oxford, United Kingdom
Background & Aims: The optimal management of bone
and joint infection relies on sensitive and specific microbiological diagnostics. Recent studies of prosthetic joint infections suggest that sonication of explanted prostheses may
increase culture yield and perhaps replace conventional
tissue sampling. Data are limited on the role of sonication
for diagnosis of other orthopaedic infections. We aimed to
compare sonication with standard tissue sampling for diagnosis of orthopaedic infections other than PJI.
Methods: We introduced sonication of explanted joint prostheses and other hardware, in addition to standard tissue culture, for diagnosis of bone and joint infections at our centre.
Standard protocols were used for tissue processing and sonication; positive tissue culture defined as isolation of an indistinguishable organism from ≥2 samples; and positive sonication culture as isolation of an organism at ≥50 cfu/ml. We
used McNemar’s exact χ2 test to compare the performance
of each method using both published clinical, and composite
clinical and microbiological, definitions of infection.
Results: We received 74 non-prosthetic-joint specimens for
sonication, including orthopaedic hardware (44), cement
(20), and bone (10). A median of 5 peri-prosthetic tissue
samples were received from each procedure (interquartile
range 4-5). Tissue culture was more sensitive than sonication using both the clinical and composite definitions of infection (table 1). Tissue culture sensitivity remained higher
than sonication when analysis was confined to orthopaedic
hardware; cement; and patients who had received antibiotics within 14 days prior to surgery. Limiting the number
of tissue specimens included in the analysis reduced tissue
culture sensitivity but not below that of sonication, and the
addition of sonication to tissue culture did not appreciably
increase sensitivity.
Conclusion: Standard tissue culture appears more sensitive
than sonication for the diagnosis of orthopaedic infections
other than PJI.
Table. Performance of periprosthetic tissue sampling and sonication for PJI diagnosis
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Abstracts free paper sessions
Abstracts free paper sessions
F032
Protocols and treatments of periprothetic joint infections in the netherlands and belgium
Sascha Colen1, Jesse Kuiper2
1
University Hospitals Leuven, Leuven, Belgium
2
Department Of Orthopedic Surgery, Center Of Orthopaedic Research Alkmaar (CORAL), Alkmaar Medical Center, Alkmaar,
Netherlands
56
Aim: This study presents the results of a questionnaire sended to all hospitals in The Nederlands and Belgium about
their existing protocols and the actual treamtent of periprosthetic joint infections of the hip and knee.
Results: 51 hospitals in the Netherlands (54%) and 30 in
Belgium (52%) responded to our questionnaire. 44% in the
Netherlands and 86% in Belgium were teaching hospitals.
Most of the hospitals had an average of 100-400 THAs and
TKAs (NL: 69 and 71%, respectively and B: 66 and 85%, respectively) each year. 50% of the hospitals had 1-3 PJIs per
year. 50% of the hospitals had a multidisciplinary approach,
and in most cases decisions were made in consultation with
a medical microbiologist. In the Netherlands, more hospitals have a working protocol for antibiotic treatment (86%)
and operative treatment (76%) than in Belgium: 75% and
58%, respectively.
If antibiotic therapy is given without knowledge of the causative micro-organism, in the Netherlands penicillin-like antibiotic agents (flucloxacillin and amoxicillin/clavulate) are
used in 20%, cephalosporins in 30% and a combination of
agents in 30%. In Belgium, this is distributed clearly differently: 25% penicillin-like agents, 7% cephalosporins, 11%
vancomycin, and 40% a combination of agents. Rifampicin
was often added to the antibiotic treatment regiment: 80%
of the Dutch orthopedic surgeons always or usually add this
agent, and 50% of the Belgian orthopedic surgeons add this
agent always or usually, and 40% sometimes.
There was less discussion about the operative treatment
of early infections: almost always DAIR (Debridement, Antibiotics, Irrigation and Retention). In the treatment of late
infection, 2-stage revision is the first choice, and is always
or often performed for late infection in 74% in the Netherlands, and in 93% in Belgium.
The exchange of mobile components during DAIR procedure is much higher in Belgium (75% always) than in the
Netherlands (40% always). 88% of the Dutch, and 74% of
the Belgian orthopedic surgeons use local antibiotic delivery systems after DAIR. Sponges are used in 22% and 30%
respectively, and beads in 18% and 15%.
The use of spacers during a 2-stage procedure is also different between the two countries: in the Netherlands 44%
of the surgeons use a spacer (50% pre-fab, 50% handmade)
versus 79% in Belgium (80% pre-fab, 20% handmade). In
the Netherlands, sponges and beads are more often used
after resection: 40% versus 10% (both countries 2/3 beads,
1/3 sponges)
The minimum period until reimplantation also differs. 98%
of the Dutch orthopedic surgeons report a minimum period until reimplantation, of which 36% uses a minimum of
6 weeks and 48% a minimum of 3 months. In Belgium, 72%
report a minimum period, which means that 28% makes the
decision for reimplantation based solely on the absence of
infection in clinical and laboratory findings (including aspiration results). When a minimum period is reported, this period is shorter than in the Netherlands: 49% reports a minimum of 6 weeks and 17% a minimum of 3 months.
Conclusions: As these results show, a lot of different treatment regimes are used in each country, and there are also
great differences between countries, in this case the Netherlands and Belgium. Most hospitals claim to act based on protocols, but these seem to differ significantly, or are not always
followed thoroughly, seeing the results from our survey.
Follow-up ranged from 2 years to more than 15 years. Hip
function was evaluated, using the modified Harris Hip Score
(mHHS) and the Hip disability and Osteoarthritis Outcome
Score (HOOS). Visual Analogue Scale (VAS) measured pain.
Yearly follow-up included radiographs of the affected hip
and blood sampling for inflammatory parameters.
Results: After revision surgery, average mHHS was 63%
and average HOOS was 54%. VAS pain averaged 26.8 on a
100-point scale and 40% of patients had no pain. Non-infectious prosthesis-related complications occurred in 32%.
Most common were periprosthetic fractures, leg length
discrepancy and dislocation. Reinfection occurred in 13%
of these patients and Coagulase Negative Staphylococcus
(CNS) was isolated in 67%.
Conclusions: Two-stage revision surgery is an accepted
treatment for infected THAs. However, complications are
common and hip function afterwards is modest. As previous studies have shown, CNS is an important microorganism in reinfection.
F034
Risk factors associated with orthopedic-implant infections: osteosynthesis and arthroplasty
Mauro Salles, Maysa Yano, Osmar Avanzi
Santa Casa De Sao Paulo School Of Medicine, Sao Paulo, Brazil
Objectives: To target preventive measures, we aim to establish risk factors (RF) associated with prosthetic-joint and
osteosynthesis infections.
Methods: Longitudinal prospective cohort study performed at the Santa Casa de São Paulo School of Medicine,
between August 2011 and June 2013. We analyzed all patients with indication for implant removal and orthopedicimplant associated infections was defined when at least one
of the following criteria was present: purulent synovial fluid
or pus around the implant; acute inflammation on histopathological, sinus tract communication with the implant,
wound with drainage, necrosis or cellulite; microbial growth
periprosthetic tissue or sonication fluid. Continuous data
were analyzed by Student t test, and categorical data by use
Fisher exact test. RF for PJI was analyzed by both univariate
and multivariate logistic regression analyses. P-values were
two-tailed, with P< 0.05 considered statistically significant.
Results: We evaluated 86 patients submitted to arthroplasty
and 168 to osteosynthesis (OS). For PJI 64% of patients met
the criteria for infection associated with prostheses and 36%
had aseptic loosening. OS patients, 68.5% had a diagnosis
of implant-associated infection. In the univariate analysis for
risk factors for infections due to arthroplasty was diabetes
mellitus, rheumatoid arthritis (RA), smoking, alcoholism, use
of steroids, and more than one surgical revision. For Osteosynthesis (OS) patients, 68.5% had a diagnosis of infection
associated with implants. Diabetes mellitus, smoking, alcohol consumption and older age (median 40.9 years and 20.9
years p <0,05) were identified as risk factors for infection associated to OS. Patients submitted to revision surgery with
exchange of the implant also had higher rates of infection.
Discussion: Risk factor for PJI and OS infection surgical revision was an important factor for infection. Factors associated with immunossupresion were also associated with
orthopedic implant-associated infections.
F035
F033
Two-stage revision of an infected total hip arthroplasty
Sascha Colen1, Marcus Van Diemen2, Alain Dalemans2, Jose Stuyck2, Michiel Mulier
University Hospitals Leuven, Leuven, Belgium
2
University Hospitals Leuven, Department Of Orthopaedic Surgery, Leuven, Belgium, Leuven, Belgium
1
Aim: Periprosthetic infection of a total hip arthroplasty
(THA) is commonly treated with a two-stage revision procedure. After resection of the infected THA and placement
of a cement spacer loaded with antibiotics, in a second procedure a revision THA is performed to restore hip function
and mobility. Revision surgery implies a significant risk for
complications. In the literature, only small studies exist addressing this matter. This study focuses on hip function, rate
of complication and reinfection after two-stage revision surgery for an infected THA.
Methods: From January 1996 to April 2010, 136 patients underwent revision surgery after removal of an infected THA.
33rd Annual Meeting of the European Bone & Joint Infection Society
Are all calcium sulphate carriers the same? A comparison of two antibiotic carriers in the
management of chronic osteomyelitis
Jamie Ferguson, Neal Jacobs, Ulrik Kähler Olesen, David Stubbs, Matthew Scarborough, Martin McNally
Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
Aims: The use of absorbable antibiotic carriers in the treatment of chronic osteomyelitis allows dead space management, can deliver high local levels of antibiotics and negates
the need for further surgery for removal. We compared the
outcomes of two commercially available local antibiotic carriers containing calcium sulphate and an aminoglycoside in
the treatment of a group of patients with surgically treated
chronic osteomyelitis.
Methods: A consecutive series of 263 patients with chronic
osteomyelitis were treated surgically with excision, implantation of calcium sulphate pellets containing aminoglycoside and soft-tissue closure. The first 195 cases were treated
with carrier A, a calcium sulphate pellet containing steric
acid and aminoglycoside[1]. The next 68 cases were treated
September 11-13, 2014 - Utrecht - The Netherlands
57
Abstracts free paper sessions
with carrier B, a calcium sulphate pellet containing calcium
carbonate, hydrogenated triglyceride and aminoglycoside.
The change in product choice was necessitated by temporary unavailability of carrier A only. There was no other
change in treatment. The incidence of wound leakage and
recurrence of infection, were compared.
Results: There were no statistical differences between the
two groups for age and sex. The percentage of cases with
Cierny-Mader anatomic types for carrier A and B were; Type
I, 6.2% vs. 14.7%, II 0.5% vs. 2.9%, III 73.8% vs. 48.5% IV 19.5%
vs. 33.8%. There was a trend towards higher physiologic
classification in group B. Mean follow-up was 3.6 yrs (range
1-7.1) for carrier A and 2.3 yrs (1.3-3.4) for carrier B. There
was no statistically significant difference in the mean carrier
volume used (A; 22.4mls vs. B; 20.5mls: p=0.658)
Wound leakage was seen in 36/195 cases (18.5%) for carrier A compared to 5/68 cases with carrier B (7.4%) (p=0.03).
Abstracts free paper sessions
Seroma was seen in 9 cases with carrier A and none with
carrier B (p=0.07). Recurrence was seen in 18 (9.2%) with
carrier A versus 4 (5.9%) with carrier B (p=0.39). Early postoperative wound ooze was not predictive of recurrence in
either group.
Conclusions: Carrier B was associated with significantly
lower wound leak rates and less seroma formation. This was
despite poorer physiologic hosts in group B. It would seem
that not all calcium sulphate carriers are the same, particularly with regard to persistent wound leakage. The formulation of the material, with addition of other compounds, may
be important in determining the rate of wound complications.
[1] Ferguson JY et al. Bone Joint J 2014;96-B:6
No benefits in any form have been received or will be received from any
company directly or indirectly related to this study.
F036
Hematogenous septic arthritis of the native hip in adults
Efthymios Papasoulis, Paul Holtom, Michael Patzakis, Charalampos Zalavras
University Of Southern California, Los Angeles, United States
58
Aim: Hematogenous septic arthritis of the native hip is far
more common in children and very few series have described this disease in adults. This study aims to identify the
clinical, imaging, laboratory, and microbiologic features of
hematogenous septic hip arthritis in adults.
Methods: This is a retrospective review of 52 hematogenous
septic hips in 51 patients (36 male, 15 female) treated at our
institution. Mean age was 48 years (range, 20-70 years). Comorbidities were present in 88% of patients. Most common
comorbidities were intravenous drug abuse (43%), liver disease (35%) and diabetes mellitus (33%).
Results: Pain was present in 98% of patients, fever in 40%,
while 25% were unable to ambulate. Median duration from
onset of symptoms to treatment was 47 days (range, 1 day4 years).
Joint narrowing or destruction in radiographs were present
in 67% of patients. Three patients presented with chronic
hip dislocation and two patients with femoral neck fracture. MRI demonstrated adjacent osteomyelitis in 82% of
patients.
Median C-reactive protein (CRP) was 109 mg/L and median
erythrocyte sedimentation rate (ESR) was 105 mm/h. The
sensitivity of elevated ESR (>22 mm/h) and elevated CRP
(>7 mg/L) was 100% and 98%, respectively. Median synovial
white blood count (WBC) was 69,277/ml with 93% polymorphonuclear (PMN) cells. Synovial WBCs >25,000/ml had a
sensitivity of 86% and PMNs>85% had a sensitivity of 89%.
Elevation of either synovial WBCs >25,000/ml or PMNs>85%
had a sensitivity of 96%.
In 90% of hips an organism was isolated, with positive aspiration cultures in 60% of cases, and positive intra-operative
cultures in 67%. The most common pathogen was Staphylococcus aureus (SA), isolated in 67% of cases with positive
cultures. Sixty percent of SA were oxacillin resistant. Gramnegative and anaerobic organisms were isolated in 6% and
10% of hips, respectively.
Irrigation and debridement was performed in 37% of hips,
while resection arthroplasty was deemed necessary in 63%
of hips. Older age, intravenous drug abuse, and delayed
presentation or diagnosis were significantly associated with
the need for resection.
Conclusions: Inflammatory markers of CRP and ESR are very
sensitive for diagnosis of hematogenous septic arthritis of
the adult native hip. The most common pathogen is Staphylococcus aureus. Delay in presentation or diagnosis is associated with need for resection arthroplasty of the hip as a
salvage procedure.
33rd Annual Meeting of the European Bone & Joint Infection Society
F037
Clinical and cost effectiveness of the negative pressure wound therapy in prevention of septic
complications in traumatology
Vladimir Obolenskiy1, Dmitry Sychev2 , Alexey Semenisty3, Alexander Ermolov1, Andrey Konnov2
City Hospital 13, RNRMU, Moscow, Russia
2
City Hospital 13, Moscow, Russia
3
City Hospital 13, Moscow; AO Trauma, Moscow, Russia
1
Aim: To assess the effectiveness of negative pressure wound
therapy (NPWT) in prevention of septic complications (SC)
in traumatology.
Materials and Methods: Analysis of treatment outcomes of
151 patients with open fractures 3A-3B (Gustilo & Anderson)
of the limbs (OFL) was performed. All patients underwent
primary surgical wound treatment (necrectomy, cleansing
with antiseptics, covering the bone with soft tissue, fasciotomy) together with the empirical antibacterial therapy for
hemodynamic stabilization and stabilization of the fracture
with Synthes or Smith&Nephew standard fixation rods; repositioning and final fixation was performed under EOC control.
87 patients (experimental group: 50 males, 37 females, mean
age was 50.3±2.2 years) at the end of the surgical procedure
were treated with NPWT; dressing change every 2-3 days. The
control group: 64 patients (45/19, 40.7±1.7) with traditional
topical antiseptics were used. Following formation of granulation tissue in the wound, secondary sutures were applied
and at the same period, the final osteosynthesis.
Results: 6,9% cases of wound complications were observed
in the experimental group while in the control group 14.1%
of wounds have become complicated. Mean time to the
secondary sutures applicationin patients of the experimental group was 7.5±0.9 days and in the control - 9.1±1.3 days
(р<0,02). Mean duration of hospital stay was 26.5±1.4 and
34.6±2.4 days, respectively (р<0,05). Mean treatment cost
per patient was EUR 1888.28 and EUR 2226.55, respectively
(р<0,05).
Conclusions: NPWT is an effective method for prevention of
SC in patients with OFL.
59
F038
Gaenslen split-heel approach for chronic osteomyelitis of the calcaneum: an effective new
protocol for an old operation
Martin McNally1, Adrian Kendal2
1
Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
2
Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford, United Kingdom
Aim: Chronic osteomyelitis of the calcaneum is uncommon
but is an increasing problem with operative fixation of heel
fractures and the high prevalence of diabetes mellitus.
In 1931, Gaenslen reported treatment of haematogenous
calcaneal osteomyelitis by surgical excision through an incision on the sole of the heel. The wound was managed by
open secondary healing around a rubber insert. This was
before the discovery of antibiotics. We have modified this
approach to allow shorter healing times and early mobilisation in a modern series of cases with haematogenous, postsurgical and diabetic osteomyelitis.
Methods: Fourteen patients with mean age 54.8 years
(range; 20-88) and Cierny-Mader Stage IIIB chronic osteomyelitis were treated with split-heel incision, calcaneal osteotomy, radical excision of infected bone and direct skin
closure. Bone defects were filled with implantation of an
antibiotic carrier. All patients had parenteral antibiotics for
6-12 weeks.
4 patients had diabetic foot infection with neuropathy, 4
had infection after open fracture fixation, 4 had haematog-
enous osteomyelitis and 2 had Grade 4 pressure ulceration
with bone involvement. 12 had discharging sinuses and 11
had undergone previous surgery for infection.
Microbiological culture grew Staphylococci in 11 and Gram
negative organisms in 4, with polymicrobial infection in 6
patients were mobilised non-weight-bearing in a special
splint for a mean of 12 weeks (range; 9-19).
Primary outcomes were eradication of infection, time to sinus/ulcer healing, mobility and need for modified shoes.
Results: Mean hospital stay was 19.7 days (range; 7-44).
Minimum follow-up was 19 months (mean 54.7 months).
12 patients (86%), had no recurrence of infection at final follow-up. One patient had a recurrence at 12 months treated
by amputation.
Ulcers and sinuses healed in 12 patients between 4 and 15
weeks. One had persistent ooze which healed at 1 year. A
second patient had continued infection and a below-knee
amputation at 19 months.
8 patients mobilised unaided and 9 required modified shoes
for walking. Only four used normal footwear.
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
Conclusions: Split-heel approach allows good exposure of
the infected bone to give effective excision of chronic calcaneal osteomyelitis. Surgical wounds healed quickly and
most ulcers/sinuses healed within an acceptable time. The
recurrence rate was encouraging in this difficult condition.
Abstracts free paper sessions
Functional outcome was good for two thirds of patients but
most will need custom shoes to give comfortable weightbearing.
Gaenslen FJ JBJS[Am] 1931; 13: 759-765.
F039
Treatment of infected nonunions of the long bones with compression-distraction techniques
Redento Mora1, Anna Maccabruni2 ,Barbara Bertani1, Gabriella Tuvo1, Stefano Lucanto1, Federica DeRosa1, Luisella Pedrotti1
Dept. Of Orthopedics And Traumatology, University Of Pavia, Pavia, Italy
2
Dept. Of Infectious Diseases, University Of Pavia, Pavia, Italy
1
60
Aim: The aims of the management of infected nonunions
are infection healing, bone consolidation, preservation of
the limb length. Our indications are based on the Umiarov’s
classification and principles of treatment with circular external fixation.
Patients and methods: Treatment begins after accurate débridement and specific antibiotic therapy.
Hypertrophic nonunions are treated with gradual distraction (monofocal distraction osteosynthesis); normotrophic
nonunions with alternating phases of compression and
distraction (monofocal compression - distraction osteosynthesis); atrophic nonunions with metaphiseal corticotomy,
reshaping of the bone ends and bone transport (bifocal
compression – distraction osteosynthesis); nonunions with
bone and soft tissue loss are treated with epidermato-fascio-osteoplasty (a special kind of bifocal compression – distraction osteosynthesis with simultaneous bone and soft
tissue regeneration and elimination of wide tissue losses
without previous sterilization, closure of the soft tissue or
use of grafts, because the transported fragment takes fascia
and skin along).
476 cases were treated between 1986 and 2010 , with a follow up of 3 - 27 year (15 humeral: 9 type 1 and 6 type 2);
64 femoral: 31 type 1, 14 type 2, 19 type 3; 397 tibial: 149
type 1, 52 type 2, 76 type 3, 120 type 4) . Average age was
36 years (range: 20-64). 361 patients were male, 115 female.
Cultures were positive for Staphylococcus in all cases, for
Pseudomonas in 72 cases.
Results: Treatment lasted from 4 to 8 months for type 1, 5 to
9 months for type 2, and 6 to 11 months for type 3; in type
4 infected nonunions the bone resection was from 6 to 18
cm, with an average of 11cm, and the healing time was 7-18
months.
No intraoperative complications were observed. One patient,
treated by epidermato-fascial-osteoplasty, died 40 days after
operation due to pulmonary embolism. 43 patients developed a superficial infection at wire sites. In 49 cases breakage
of wires was observed. There were no cases of infection recurrence after healing. Docking site troubles were observed in
45 cases, bone regenerate troubles in 7 patients.
Overall results were evaluated according to the Paley classification: bone results were excellent/good in 84% of cases;
functional results were excellent/good in 95 % of cases. In
particular, in type 4 infected nonunions infection was eliminated, bone and soft tissue were reconstructed, rehabilitation period was shortened.
Conclusion: Débridement is the most important step in the
treatment. These techniques are particularly demanding,
but they can provide excellent results in the management
of infected nonunions.
F040
Infected defected non union-treatment by fixas
treatment of larger bone defects without autografted cancellous bone with regenerate which is appropriate with its
width and density. This has been, certainly, made easier with
tehnical improvements of fixators and dynamic possibilities
of structures with area, flexible and extrafocal stability.
Methods: When solving infected non-union with bone defects, beside regaining bone continuity and length there is
a problem of infection, which is the heaviest complication
in bone-joint surgery. Joint contractures, skin and soft tissues defects, with adherent and celoid scars, after reedited
operations in 80% of cases, make the condition of the patient worse, treatment results uncertain and secondary
amputation more certain.This work presents possibilities
of compression – distraction method by Fix-AS, for solving
large bone defects (up to of the bone corps) with distraction
calus, and without spomgious bone transplantation, with
consolidation in natural ways.
1ST GROUP: fixation with shortening of extremities and
achieving the length after cover the soft tissue defect.
• by lenghtening in the area of non union,
• by lenghtening after proximal or distal corticotomy.
2nd GROUP: fixation of the non union with the full length of
the extremity and levelling with the nearby joint areas and
treatment of the defect, either by
• internal transport,
• external transport.
Results: Followed by ways at solving contractures, deformations achieving full length of extremity with simultaneous
infection sanation and non-union consolidation in natural
ways. For the last 25 years we*ve successfully treated 445
non-union Follow up 20 years (15-25), of which 250 infected
ones, 195 with bone defect, 51 over 5 cm , which is especially emphasized in this work. This work analyses and presents
infection – defect non-union, after war injuries and failed
treatment by others methods.
Conclusion: This way, extremity is saved even in heaviest cases, unlike other methods (bone grafting, free flap), which were
more expensive and unformal, often ended by an amputation.
F041
Treatment of septic diaphysial long bone non-union with use of dynamic beams of r-konzal
external stabiliser in clinical material
Adrian Brychcy, Marek Dróżdż, Piotr Walczak, Jerzy Białecki, Wojciech Marczyński
Professor Gruca Teaching Hospital; The Centre Of Postgraduate Medical Education, Otwock, Poland
Aim: Treatment of septic diaphysial long bone non-union
remains a complex therapeutic problem. External stabilisation with use of R-Konzal stabiliser is used in Poland for over
30 years and provides rigit stabilisation of bone fragments
with their proper orientation. Solution veryfied in treatment of osteitis has however limited possibilites of dynamisation and providing interfragmental compression. The
modernised design of R-Konzal external stabiliser dynamic
beams is herein presented.
Methods: We assessed a history of 61 consecutive patients
with septic diaphysial non-union of tibia and femur treated
with use of R-Konzal external stabiliser. An effectiveness of
dynamisation of the stabiliser with use of the modernised
construction (group B) was compared with performed hitherto technique of eccentric shifting of static beams (group
A). The time of bone union, the average number of pin resta-
bilisations, and percentage of „partial union” was assessed
in two groups treated with different methods.
Results: In the group of patients treated with use of the dynamic beams mean time of obtained bone union was average 5,1 month shorter. Lower percentage of „partial union”,
below 50% of diaphysial circumference, as well as lower
number of required pin’s restabilisations per patient were
also noted in that group. No correlation between time of
bone union and time of inflammatory process prior the surgical treatment or presence of a fistula was observed.
Conclusions: Presented modern solution enhances load
bearing with the interfragmentary bone tissue, not with a
static stabiliser’s beams. Biomechanical essence of the stabiliser provides optimal bone healing environment and shortens time of bone union obtainment.
Sabic nedzad
Poliklinika Dr Sabic, Zenica, Bosnia and Herzegovina
Introduction: Treatment of bone defect in orthopaedy
caused removing pathlogical processes (mostly tumors),
then in traumatology of defect caused by primary trauma,
war injuries and finally after radical debriding or complications-non union followed by infections, has always been of
interest to surgeons and a challenge for methods and sci-
ence in general. Getting the new-quality bone by distraction
of pineal body (epiphysis-growth plate, Ring 1958, Zivyalov and Plaskin 1968, Ilizarov 1969, Monticelli and Spineli
1981) as well as by distraction calus after corticotomy and
metaphysary lenghtening (Ilizarov 1971, 1988, 1989, Alberty 1990, Terjesen 1984, 1988, Adolphson 1990), has enabled
33rd Annual Meeting of the European Bone & Joint Infection Society
September 11-13, 2014 - Utrecht - The Netherlands
61
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Abstracts free paper sessions
F042
Perioperative risk factors and comorbidities related to acute operative infections following
proximal femoral fractures in elderly people
Daniel Haro Fernández, Ivan Fuentes López, Isidor Marchan Garcia, Lucia Gómez García, Alfredo Matamala Pérez, Francesc
Anglès Crespo
University Hospital Of Mutua Terrassa, Terrassa, Barcelona, Spain
62
Background: Post- operative infections following proximal
femoral fractures in elderly patients are a common complication (5 - 10%).
The main objective of our study was to determine perioperative risk factors and comorbidities of these patients affected of acute infections aftershave femoral fractures.
Patients and methods: We retrospectively reviewed 448
consecutive proximal femoral fractures from January 2012
to December 2013 treated surgically. We identified 21 cases
of acute infections. Data collected included age, sex, body
mass index (BMI), fracture classification (AO) and surgical
treatment, surgical time, antibiotic prophylaxis, use of temporary drainage, sphincter incontinence, concomitant infections during hospitalization, preoperative haemoglobin
and blood transfusions, wound evaluation, infection and
death rates and Barthel Index ( preoperative, during admission and at discharge).
Results: Our infection rate was 21/448 (4.7%). The average
age of these patients was 81 years (range 65- 97 years). Sixteen patients were female (76.2%). The mean BMI was 27.34
kg/m2. The mean follow- up was 285 days (range 30 - 636
days). The average score of Barthel Index preoperative, during admission and at discharge were 74, 20 and 38 points
respectively. The most common tupe of fracture was intertrochanteric fracture (42.9%).
Mean surgical time was 118 minutes. Correct antibiotic prophylaxis was performed in 85.7% of cases.
Mean preoperative haemoglobin was 11.6 g/dl, only in 3
patients (14.3%) a temporary drainage was used and 15 patients (71.4%) required blood transfusions.
Eleven patients (52.4%) had sphincter incontinence and 6
patients (28.5%) desvelo pedían urinary tract infection during admission.
All patients were initially treated with surgical debridement
and antibiotic treatment, and in 10 patients (47.6%) no implants were removed. In 3 patients revision of THE osteosynthesis was performed in one stage and in 8 patients in a
two-stage procedure.
According with microbyological findings, 14 patients (66.6%)
had polimicrobian infections, and in 12 patients (57.1%)
Gram-negative microorganisms were isolated.
Death rate was 19% (4 patients).
Conclusion: Deterioration and comorbidities in elderly
people, the presence of concomitant infections during admission, sphincter incontinence and excessive surgical time
were frequent findings in our serie of patients with post- operative infections.
The high infection rate specially caused by Gram-negative
microorganisms may make su rethink an alternative antibiotic prophylaxis in these group of patients.
F043
Reconstruction of defects of long bones with a new innovative procedure – in vitro and
cadaver experiments, results and analysis
Matthias Militz1, Markus Oehlbauer1, Christoph Miethke2, Catherine Ebner3, Jan Wieding3, Rainer Bader3
1
Trauma Center Murnau, Murnau, Germany
2
Ch. Miethke Und Co Kg, Potsdam, Germany
3
Department Of Orthopaedics, University Medicine Rostock, Rostock, Germany
Aim: The gold standard in reconstruction of defects of long
bones is the callus distraction. The advantage is the reconstruction of a real hollow autogeneous bone. However,
several disadvantages such as very long term treatments,
complications with the fixation device and technical failures
have not been resolved yet. An alternative is the vascularized fibula transfer. The filling of the defect with vascularized autologous bone counts as main advantage of this procedure. The major disadvantage is the small diameter of the
fibula in comparison to the pre-existing bone which should
be reconstructed though. As a result, a long time of consolidation and bone growth to achieve mechanical stability is
necessary. To reduce the disadvantages of both methods,
the time of treatment and the risk of complications, the advantages of the callus distraction and the transplantation
of vascularized fibula should be combined. With the expansion of the longitudinal callusformation in the fibula a hollow bone with a minimal diameter of appr. 13 mm in the
bone marrow is being produced. After maturing the callus,
the transplantation of the vascularized fibula is being per-
33rd Annual Meeting of the European Bone & Joint Infection Society
formed to fill the defect. With this method the duration of
the therapy and the side effects are dramatically reduced
Methods: Anatomical studies with sawbone ( SAWBONE®)
and pta-catheter (Fa. BBraun, Germany) to show the principle functions, helped realizing the idea of the combination
of callusdistraction and fibulatransfer. .Therefore a model of
the fibula bone was splitted longitudinal over a length of 8
cm with a saw. Passing a primary performed canal on the tip
of the fibula the pta-catheter was inserted in the bone marrow canal of the fibula. With the increasing filling of the ptacatheter the diameter also elongates and the prior splitted
halves of the cortical part of the fibula show an expansion.
With a comparable setting, anatomical investigations on
human cadaver were performed to further develop a suitable surgical approach and effective techniques. For the
assessment of the biomechanical parameters a model was
generated. With optical measurement and non-contact and
material independent systems (ARAMIS, GOM mbH, Braunschweig, Germany) the movements of the cortical halves of
the fibula were registered. Static and dynamic tests were
used to simulate the procedure.
Results: The principle of the callus distraction as a method
to reconstruct bone is also feasible in reverse: from distraction to expansion. For this surgical approach the anatomi-
cal requirements exist at the fibula bone. The dimension of
the expanding device has to be at least 3mm for insertion.
To prepare the fibula for the callus expansion the bone has
to be canulated with a wire and than longitudinal splitted
into two halves in the diaphyseal part with a saw. The protocol for expansion can be compared with the exertion of
the callus distraction. The distance for distraction has to be
appr. 13 mm. With a healing-index of 50 days/cm it implies
a treatment duration until transplantation of 6 weeks independent from the length of the defect. A nail stabilizes the
bone, wich has to be reconstructed, and the transplanted
expanded fibula with a “bone marrow canal” of appr. 13 mm.
Conclusion: Instead of transplanting an inadequate small
fibula to fill a defect of a long bone the creation of a hollow
bone graft with stand-alone vascularity seems to inaugurate
a new dimension in reconstructing defects of long bones.
The anatomical tests illustrated above suggest a technical,
anatomical as well as surgical way to carry out this procedure for the human use. An interdisciplinary collaboration
between plastic and reconstructive orthopedic surgeons is
a major precondition. Further investigations to develop a
technical device for expansion and clinical use are currently
under development.
F044
Missed low-grade infection in suspected aseptic loosening has no mid to long-term
consequences on the survival of total hip arthroplasty
Willemijn Boot1, Dirk Jan Moojen2, Els Visser1, Mechteld Lehr1, Tommy de Windt1, Gijs van Hellemondt3, Jan Geurts4, Niek Tulp5,
Wim Schreurs6, Bart Burger7, Wouter Dhert1, Debby Gawlitta1, Charles Vogely1
1
University Medical Center Utrecht, Department Of Orthopaedics, Utrecht, Netherlands
2
Onze Lieve Vrouwe Gasthuis, Department Of Orthopaedics, Amsterdam, Netherlands
3
Sint Maartensclinic, Department Of Orthopaedics, Nijmegen, Netherlands
4
Maastricht University Medical Center, Department Of Orthopaedics, Research Institute Caphri, Maastricht, Netherlands
5
Isala Clinics, Department Of Orthopaedics, Zwolle, Netherlands
6
University Medical Center St. Radboud, Department Of Orthopaedics, Nijmegen, Netherlands
7
Medical Center Alkmaar, Department Of Orthopaedics, Alkmaar, Netherlands
Background and Aim: Aseptic loosening and infection
are two of the most common causes for revision of hip implants. As an underdiagnosis of infections is observed in
patients with aseptic loosening, current diagnostic tools are
considered suboptimal. In previous research in 176 patients
we showed that by using optimized diagnostics, 4-13% of
patients diagnosed with aseptic loosening had a low-grade
infection. In the current multicenter prospective follow-up
study on the same cohort the influence these low-grade
infections have on mid to long-term implant survival was
investigated.
Methods: Between September 2012 and February 2013,
the patients included in the initial study received a two-part
questionnaire. Part A requested information about additional revisions of their total hip arthroplasty (THA). In part
B, data on quality of life, pain and implant function were
collected by means of the EQ-5D, Oxford Hip Score (OHS)
and Visual Analogue Pain scale (VAS pain). Additional information was retrieved from medical records. Data were compared between patients with aseptic loosening (AL) and
patients with confirmed low-grade infection (INF).
Results: After receiving informed consent, information
about the clinical status was available for 173 of 176 patients (98%). The study population consisted of 123 women and 50 men. Between the period of the first study and
the current follow-up (mean 7 years 7 months), 31 people
passed away. No significant difference in the number of additional revisions was found between the AL and the INF patients. Furthermore, survival analysis showed no significant
difference in time to revision in the INF patients compared
to the AL patients. No significant difference was observed
between the AL patients and the INF patients for the quality
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63
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of life as measured by the EQ-5D. The outcomes for function
and pain as measured by the OHS and VAS pain showed no
significant difference between both groups.
Conclusion: The results of this follow-up study suggest that
underdiagnosis of infection in aseptic loosening of THA has
no significant mid to long-term influence on both implant
survival and quality of life. These observations are in line with
Abstracts free paper sessions
the findings of our initial study after one year follow-up.
Funding source
This study was supported by an institutional research grant
from Stryker Orthopaedics (Mahwah, NJ). Stryker had no
role in planning the study, data collection, analysis, interpretation of data, or in writing of the manuscript.
F045
in bone cells, and their activation affects osteoclasts differentiation and activity. PJI is mainly due to Staphylococcus
Aureus, a Gram positive bacterium recognized by TLR2, and
more rarely by Gram negative bacteria such as Pseudomonas, recognized by TLR4.
Methods: In this study, in order to evaluate the potential diagnostic role of TLR2 and TLR4 in the early detection of PJI,
TLR2 and TLR4 serum levels, as well as canonical inflammatory markers (CRP, IL-6, TNF alpha and IL-1) were evaluated
in 30 post-operative PJI patients and in not septic patients
undergoing prosthetic revision.
Results: In septic patients TLR2 level is higher and corre-
lates with inflammatory markers (IL-6 and CRP), while TLR4
display no significative differences. Accordingly, IL-1beta,
the main TLR2 co-player of the inflammatory response to
S.Aureus, is higher in septic patients than in not septic patients.
Conclusions: These results strongly suggest that TLR2 is essential in the inflammatory response to pathogen induced
PIJ. Thus, the measure of serum TLR2 could be very informative in the early detection of PJI and, therefore, it could be
considered potential diagnostic tool that could be associated with canonical clinical markers of inflammation in order
to improve the diagnosis of prosthetic joint infection
The role of intraoperative frozen section histology for diagnosis of infection in hip and knee
arthroplasty revision surgery
Paolo Di Benedetto, Vanni Cainero, Renato Gisonni, Alessandro Beltrame, Araldo Causero
Clinic Of Orthopedic Azienda Ospedaliero-Universitaria Di Udine, Udine, Italy
64
Aim: The diagnosis of a suspected infected prosthesis is often difficult, but is important for the choice of treatment.
Even at surgery, it is not easy to assess whether the prosthesis is infected or not even though this may be important
for the choice of surgical procedure. Aim of this study is to
asses the value of intraoperative frozen section analysis that
is used in evaluating possible infection in cases of hip and
knee revision arthroplasty, serving as an adjunct to preoperative and intraoperative studies.
Patients and Methods: Between November 2008 and January 2012 we examined sections and cultured periprosthetic
tissues in prosthetic revision in 82 cases, including 45 hips
and 37 knees. For preoperative diagnosis, we use the history (pain, drainage), laboratory analysis [erythrocyte sedimentation rate (ESR), protein C, blood count], radiology,
nuclear medicine and synovial fluid analysis. Nevertheless
these tests show low confidence levels. We assessed sensitivity (SE), specificity (SP), positive predictive value (PPV),
negative predictive value (NPV). Samples of tissues were
taken to be analyzed immediately from frozen sections, to
be processed on a routine basis later, and to be referred for
bacteriological cultures. A finding of 5 or more polymorphonuclear leukocytes per field at a magnification of 400x
was considered positive for infection.
Results: The analysis of frozen sections for infection was
compared with the results of routine culture. Concordance
index between frozen section and cultures was 86,9% and
the Chi-Square Test was not significative. Comparison with
the results of culture showed a sensitivity of 71,4%, a specificity of 93,7%, a PPV of 83,3%, an NPV of 88,2%.
Conclusions: In hip and knee prosthetic revision surgery
frozen section analysis has a good specificity and sensibility, but the absence of polymorphonuclear leukocytes does
not exclude periprosthetic infection. It is a quick and inexpensive test and we believe that frozen section is of value in
revision surgery when infection cannot be ruled out.
F046
Tlr-2: a new potential diagnostic marker of prosthetic joint infection
Emanuela Galliera1, Christian Vassena2, Monica Gioia Marazzi3, Massimiliano Marco Corsi Romanelli4, Lorenzo Drago5
1
Department Of Biomedical, Surgical And Oral Science , Università Degli Studi Di Milano, IRCCS Galeazzi Orthopaedic Institute,
Milan, Italy
2
Irccs Orthopaedic Institute Galeazzi, Milan, Italy
3
Department Of Biomedical Science For Health, Università Degli Studi Di Milano, Milan, Italy
4
Department Of Biomedical Science For Health, Università Degli Studi Di Milano, IRCCS Policlinico San Donato, Milan, Italy
5
IRCCS Galeazzi Orthopaedic Institute, Department Of Biomedical Science For Health, Università Degli Studi Di Milano, Milan, Italy
F047
Can sonication improve detection of orthopaedic implant infections?
Bostjan Kocjancic1, Andrej Laposa2, Samo Jeverica3, Ladislav Simnic1, Andrej Trampuz4, Drago Dolinar1
University Medical Center Ljubljana, Department Of Orthopaedic Surgery, Ljubljana, Slovenia
2
General Hospital Novo Mesto, Department Of Surgery, Novo Mesto, Slovenia
3
Institute Of Microbiology And Immunology, Faculty Of Medicine, University Of Ljubljana, Ljubljana, Slovenia
4
Charité - Universitätsmedizin Berlin, Centre For Musculoskeletal Surgery, Germany, Berlin, Germany
1
Introduction: In recent years the implementation of sonication in the diagnosis of orthopaedic implant infections
has improved the detection of subclinical infection. With
the use of sonication of removed orthopaedic material we
can prove the presence of biofilm. The method has already
shown encouraging results especially in cases of preoperative antibiotic therapy.
Aim: The aim of the study was to detect infections of orthopaedic material using sonication and standard diagnostic methods, and to compare the obtained results of both methods.
Methods: For the purpose of the study we sonicated all
explanted material at revision surgery and cultured the obtained samples. At the same time soft tissue biopsies were
collected and analyzed for infectious agents. The results
were compared, analyzed and additional therapy was applied, if an infection of the material was proven.
Results: During the period from September 2009 to the end
of September 2013 we studied 206 cases (161 patients) of
revision surgery (140 cases of revision hip arthroplasty, 43
cases of revision knee arthroplasty, 8 cases of revision foot
surgery, 15 cases of revision spine surgery). Of studied cases
infection was proven in 15 (7,3%) cases by soft tissue biopsies only, 76 cases (36,9%) were diagnosed both by soft
tissue biopsies and sonication, 42 cases (20,4%) were diagnosed only by sonication of explanted prosthetic material
and in 73 cases (35,4%) all results were negative. The statistical analysis has shown statistically significant (p<0,05)
improvement of infection detection using sonication.
Conclusions: According to our experience the implementation of sonication has shown an improvement in the diagnosis of orthopaedic implant infections. Despite certain
limitations, sonication should be considered in doubtful
cases of revision surgery. The use of sonication should be
emphasized in cases of preoperative antibiotic treatment.
F048
The value of 18-fdg pet-ct in the diagnosis and management of implant-related infections
of the tibia
Shai Shemesh, Steven Velkes
Rabin Medical Center, Petah Tikva, Israel
Aim: Prosthetic joint infection (PJI) is a severe complication
in patients undergoing athroplasty, often requiring implant
replacement and long term antibiotic treatment. Since the
clinical presentations of PJI are often unclear and the efficacy of diagnostic approaches are different, there is still a
continuous need to improve diagnostic methods for the
early detection of PJI. Among innate immunity mediators,
Toll-like receptors(TLRs) plays a crucial role in inflammation because they sense pathogen-derived molecules and
initiate the inflammatory response. TLRs are also expressed
33rd Annual Meeting of the European Bone & Joint Infection Society
Background: Positron emission tomography (PET) combined with Computerized Tomography is gaining ground in
clinical settings due to its added value of combined meta-
bolic and anatomical imaging. PET CT has shown promising results in diagnosing both acute and chronic infection
of the axial and appendicular skeleton. PET imaging has an
September 11-13, 2014 - Utrecht - The Netherlands
65
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advantage in patients with metallic implants because FDG
uptake, in contrast to magnetic resonance imaging (MRI)
and standard computed tomography (CT), is not hampered
by metallic artifacts. The role of PET-CT in the evaluation of
implant related infections involving the tibia in particular
has not been thoroughly studied.
Aim: To retrospectively evaluate the diagnostic value of
18-FDG PET/CT in trauma patients with suspected implantrelated infections.
Methods: We retrospectively reviewed 9 patients who underwent internal fixation to the tibia following trauma (4
open fractures, 5 closed fractures) and presented with signs
of an implant-related infection of the tibia. In evaluating
the patients we used standard work-up methods (X-rays,
lab tests) and used advanced imaging techniques (PET-CT)
Abstracts free paper sessions
in order to confirm the diagnosis and decide upon the preferred treatment (surgical vs. conservative).
Results: PET-CT validated our working diagnosis 8 out of 9
patients. In particular, it helped distinguish between: infected
nonunion (n=4), aseptic nonunion (n=1), soft tissue infection
(n=2) and chronic osteomyelitis (n=1) and no infection (n=1).
The overall sensitivity and specificity of PET/CT for identifying
an osseous infection were 85.7% and 100% respectively The
PET/CT helped demonstrate the extent of osseous involvement and was found to be a valuable tool in preoperative
planning, dictating the aggressiveness of surgical treatment.
Conclusion: In our experience, PET-CT is a promising imaging method in cases of implant-related infections of the
axial skeleton, to be used as a supportive measure in clinical
decision making.
F049
Evaluation of pre- and per-operative diagnosis of periprosthetic joint infection in hip revision
arthroplasty
Marc Nijhof, Menno Bénard
Sint Maartenskliniek, Nijmegen, Netherlands
66
Aim: The diagnosis of periprosthetic joint infection (PJI)
after hip arthroplasty is still challenging, with an ongoing
discussion on the proper tests for diagnosis1. A recent international consensus has been formed concerning guidelines
for PJI in general2. The aim of this study was to evaluate preand per-operative diagnosis of periprosthetic joint infection
in hip revision arthroplasty with respect to these guidelines.
Methods: Over one year, 155 patients (98 females), who
underwent prosthetic hip revision surgery, were enrolled.
Mean age of the group was 66±11y, mean BMI was 27±5.
There were 144 (including 2 for infection) one-stage and 9
two-stage procedures. For three diagnostic tests (1. pre-operative ESR and/or serum CRP; 2. pre-operative aspiration;
3. per-operative sonication) sensitivity, specificity, positive
and negative predictive values (PPV, NPV), and accuracy
were calculated. These measures were also calculated for
all combinations of the tests (i.e. 1+2/1+3/2+3/1+2+3). Two
or more positive per-operative periprosthetic cultures with
phenotypically identical organisms was used as the “golden
standard” to which the tests were compared.
Results: Of the total group, 48 cases received an aspiration
and in 130 cases per-operative sonication was performed.
Of all cases, 6 were found positive by per-operative cultures.
Overall, aspiration scored best with a PPV of 0.56 as the lowest performance measure (Table 1). Both ESR/CRP and sonication had a low PPV. The accuracy of all tests was acceptable. Any combination of the three tests did not improve
diagnostic accuracy.
Conclusion: Based on our results and with respect to the international consensus, aspiration is the recommended test
for pre-operative diagnosis of PJI in hip revision surgery.
Sonication has no added value in hip revision surgery.
F050
The prevention methods of the infections of the area of the surgical intervention at the
patients of an orthopaedic profile in the groups of risk
Vladimir Obolenskiy1, Stanislav Golev1, Iskander Zakirov2, Pulad Leval1
1
City Hospital 13, Moscow, Russia
2
Rufp, Moscow, Russia
Aim: to estimate efficiency of various wound coverings in
prevention of the infections of the area of the surgical intervention (IASI) at the patients of an orthopedic profile in the
groups of risk.
Methods: The analysis of the results of the treatment of 30
patients which transferred endoprosthesis replacement of
the hip joint, carried to the groups of risk was conducted:
revision arthroasty, associated obesity and diabetes. The
perioperative antibacterial prevention was conducted to all
the patients during 24 hours. All the patients were divided
in a random way into 3 groups of 10 people.
In the 1-st group (4 men, 6 women; middle age 57,7 + 3,9
years) after sewing up of the wound, the Aquacell Ag Surgical
bandage*) was applied. The changing of a similar bandage
was carried out on the 5-th and on the 12-th days when the
seams were removed. In the 2-nd group (4 men, 6 women;
middle age 56,0 + 3,8 years) after sewing up of the wound,
the vacuum assisted bandage of PICO*) was applied. The
changing of a similar bandage was carried out on the 5-th
and on the 12-th days when the seams were removed.
In the 3-rd group (3 men, 7 women; middle age 54,8 + 2,9
years) after sewing up of the wound, the aseptic gauze bandage was applied, with the subsequent daily processing
of the section zone by solution of the povidon-iodine and
changing of the bandage before removal of the seams.
Results: In the 1-st group the average period of staying
in the hospital was 13,5 + 0,2 days; the IASI cases within 3
months were not detected. In the 2-nd group the average
period of staying in the hospital was 14,8 + 0,8 days; the IASI
cases within 3 months were not detected. In the 3-rd group
the average period of staying in the hospital was 18,1 + 2,3
days; 3 cases of the IASI in the form of the suppuration of the
wounds and the ligature fistulas were detected within 2-3
weeks from the moment of the operation.
Conclusions: Using of the interactive and vacuum assisted
bandages in the early postoperative period can afford to
reduce the IASI frequency at the patients of an orthopedic
profile in the groups of risk.
References
*) Aquacell Ag Surgical, ConvaTec;
**) PICO, Smith&Nephew
F051
Correlation between bacterial phenotype and clinical outcome in orthopedic device related
bone infections with staphylococcus aureus
Christoph Erichsen1, Mario Morgenstern1, Virginia Post2, Fintan Moriarty2, Matthias Militz1,Volker Bühren1
1
Bg Unfallklinik Murnau, Murnau, Germany
2
Ao Research Institute Davos, Davos, Switzerland
References
1 Müller M;J Orthop Surg.2008;3:31
2 Parvizi J;Bone Joint J.2013 Nov; 95-B(11):1450-2
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: Staphylococcus aureus remains the predominant cause
of orthopedic device-related bone infection worldwide. Bacterial virulence factors such as biofilm formation, toxin secretion and antibiotic resistance make surgical and medical
treatment a challenge. In this study, we analyzed the clinical
outcome of a large number of S. aureus associated orthopedic device-related bone infections and cross-referenced the
results with laboratory measurements of bacterial virulence
in the infecting strains. The central aim is to determine if there
is a correlation between bacterial virulence factors such as
biofilm formation or hemolysis and the clinical outcome.
Methods: One hundred patients with intra-operative cultures of S. aureus from implant related bone infections were
enrolled into this prospective study over a period of 20
months. All bacterial isolates were analyzed in terms of an-
tibiotic resistance profile, biofilm forming ability, hemolysis
and staphyloxanthin production. The clinical data recorded
for each patient included: affected bone or joint, type of implant, acute or late-onset infection, open or closed fracture,
number of revision surgeries and relevant comorbidities. A
one year follow up was achieved with 94 patients. Statistical
comparisons were made using the χ² test.
Results: The majority of patients suffered from infection
related to a fracture fixation device (75%), with 23 patients
(25%) related to endoprostheses. The majority of cases involved the lower extremity (91%). Twenty five percent of
all cases were open fractures and 23% of all infections occurred during the first eight weeks after initial surgery. Most
patients (66%) had to undergo more than six revision surgeries. In 72% of patients, surgical treatment was complet-
September 11-13, 2014 - Utrecht - The Netherlands
67
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ed after twelve months, with 35% of all patients reaching a
Restitutio ad Integrum. Most isolates (94%) were Methicillin
sensitive S. aureus (MSSA) and six were Methicillin Resistant
(MRSA). Laboratory analysis of the virulence of the causative
microorganisms revealed that 52% of isolated bacteria were
biofilm formers: 44% were weak, 4% intermediate and 3%
strong biofilm formers. Thirty-eight percent displayed hemolytic activity and 63% were staphyloxanthin producers.
Statistical analysis did not reveal any statistically significant
Abstracts free paper sessions
correlation between bacterial phenotype and the documented clinical outcomes. However, patients with open
fractures, one or more comorbidity and late onset infections
showed a significantly worse outcome (p<0,05).
Conclusions: Patients with comorbidities, open fractures or
a late onset of implant related infection have a significantly
worse clinical outcome at one year follow-up. A correlation
between the bacterial properties such as biofilm formation
and the clinical outcome could not be shown.
F052
Propionibacterium acnes infection by osteoarticular
Aim: Although the bactericidal effect of strong electric
fields and the electrical enhancement of the efficacy of antimicrobials against biofilms bacteria “bioelectric effect” are
well known. There is little evidence in the literature on the
impact of an external electric field on the electrostatic interactions of bacteria with a charged substrate. The aim of
this study was to evaluate the capacity of a pulse bilateral
electric field to control the bacterial attachment on a stainless steel plates.
Methods: Previously sterilised circular metal plates of stainless steel (SS) were introduced in the center of a bottle,
flanked by two rectangular plates (fig 1). All of this montage was completely submerged in a liquid medium with
a known concentration of S. epidermidis (RP62A) and incubated during 1 hour at 36 Cº. During this period of time, a
200 Hz pulse electric field of 4A (square waves of 2.5 µseg)
was applied. After incubation, the circulate plate was removed, washed with PBS and sonicated during 5 minutes in
10 ml of saline. Different dilutions were performed and 100
µl of each one was cultured on agar plates. Three different
models were compared: one were the center plate was negative, other were it was positive and finally a control model
without electric current.
Results: A medium reduction of the 97.5% of bacterial attachment was observed when the electric field was applied.
This difference was statistically significant. The differences
between model with positive center plate and negative
center plate were not statistically significant.
Conclusion: A bilateral pulsed electric field is able to avoid
the 95% of bacterial attachment on SS plates. The polarity
of metal plate had not influence on bacterial attachment.
Isidor Marchan, Alfredo Matamala, Daniel Haro, Raul Figa, Lucia Gomez
University Hospital Mutua Terrassa, Barcelona, Spain
68
Introduction: Propionibacterium acnes is an anaerobic
Gram-positive bacillus which may be responsible for infections of prosthetic surgery and osteosynthesis, although a
skin saprophyte and traditionally been considered a nonpathogenic microorganism.
Target
-To describe the clinical features of osteoarticular infection arthroplasty / osteosynthesis for P.acnes.
- To evaluate retrospectively the effectiveness of treatment with moxifloxacin compared with amoxicillin or
clindamycin.
Material & mehtods: Retrospective descriptive study conducted between February 2005 - 21 November 2013 in patients with prosthetic (PTC or PTR ) or osteosynthesis material with positive cultures for P. acnes infection. Demographic
parameters, infection, medical and surgical treatment and
outcome were collected. Acute infection was defined when
diagnosed 6 weeks. The average treatment time was 15
months. Healing was considered when we obtained the
analytic normalization of CRP (< 0.5 mg/dl) and ESR (<20
mm/h), plus the proper management of pain (VAS <3).
Results: In 21 patients (14 men and 7 women) with a mean
age of 66 years; 16/21 were diagnosed with chronic infec-
tion arthroplasty (76.2%), 2/21 of acute infection arthroplasty (9.5 %), 2/21 of chronically infected osteosynthesis
(9.5%), and 1/21 (4.7%) of acute arthritis by inoculating
foreign body. The average from surgery to the diagnosis of
infection was 11 months, and in 16/21 (76%) the infection
was monomicrobial. Treatment with Amoxicillin was 6/21
(28.5%), Clindamycin in 5/21 (23.8%) and moxifloxacin in
10/21 (47.7%) according to the antibiogram and the clinical
context of the patient. The average duration of treatment
was 15 months (range 5-60). Toxicity were detected in 2/21
cases (9.5%), and another one for Clindamycin Moxifloxacin.
Were treated with surgical debridement 5/21 (23.8%) parts
on 2 times in 14/21 (66.6%), and withdrawal of most debridement osteosynthesis material in 2/21 (9.5%).
The mean patient follow-up was 20 months.
Moxifloxacin therapy showed a 50% cure versus 40% of patients treated with clindamycin and 33% in the amoxicillin
group.
Conclusions:
- The vast majority of infections are diagnosed late Pacnes.
- The Moxifloxacin appears to be an effective alternative
for the treatment of infections caused by P. acnes.
F053
The effect of perpendicular and bilateral pulsed electric field on bacterial attachment on inox
plates. An in vitro study
Lluís Font-Vizcarra1, Araceli González-Cuevas1, Josep Maria Sierra2, Laura García-Nuño1, Vicenç Diaz-Brito1, Juan Castellanos1,
Adrián Bermúdez3, Alex Soriano4
1
Parc Sanitari Sant Joan De Deu, Sant Boi De Llobregat, Spain
2
Hospital De Bellvitge, Barcelona, Spain
3
Innovative Minds S.L., Terrassa, Spain
4
Hospital Clinic, Barcelona, Spain
33rd Annual Meeting of the European Bone & Joint Infection Society
Six Bottles just after
manufacturing, ready to be
sterilised. Between the two
rectangular plates,
is possible to observe the
support where the circular
plate will be placed.
69
F054
Selection of an optimal antiseptic solution for intraoperative irrigation; an in vitro study
Stijn van Meurs1, Debby Gawlitta1, Diederik Kempen2, Karen Heemstra1, Rudolf Poolman2, Charles Vogely1, Moyo Kruyt1
University Medical Center Utrecht, Utrecht, Netherlands
2
Onze Lieve Vrouwe Gasthuis, Amsterdam, Netherlands
1
Background: With increasing bacterial antibiotic resistance
and an increased infection risk due to more complicated
surgical procedures and patient populations, prevention
of surgical infection is of paramount importance. Intraoperative irrigation with an antiseptic solution could provide
an effective way to reduce surgical infection rates. A major
advantage of antiseptics is that resistance is virtually nonexistent. The main disadvantage of these agents however,
is their inherent cytotoxicity, which can be detrimental to
wound-healing. Since most antiseptics possess a more potent bactericidal effect than required, reducing the concentration to decrease cytotoxicity is possible without losing its
bactericidal activity. Although many antiseptics are available, there is no data on which antiseptic irrigation protocolhas the least cytotoxicity at the minimal bactericidal
concentration.
Aim: The aim of the present in vitro study was to evaluate
candidate antiseptic agents applied for 2 minutes in terms
of minimal cytotoxicity while retaining a bacterial load reduction of at least 99.9%.
Methods: Bacteria (Staphylococcus aureus and S. epidermidis) and human cells were exposed to polyhexanide,
hydrogen peroxide, octenidine dihydrochloride, povidoneiodine, and chloorhexidine digluconate at various dilutions
for two minutes. Bactericidal properties were calculated by
means of the quantitative suspension method (n=6). The
minimal bactericidal concentration (MBC) was defined as
99.9% bacterial kill of the most resistant strain. In a second
experiment the cytotoxic effect of similar dilutions on human fibroblasts and human mesenchymal stromal cells was
determined by a WST-1 metabolic activity assay(n=6). After
assessment of the gross bactericidal and cytotoxic properties, a concentration range of interest around the generally
accepted bactericidal dosage yielding 99.9% reduction was
selected for a detailed analysis.
Results: All of the antiseptics except for polyhexanide were
bactericidal at the commercially available concentrations
with complete cytotoxicity. When diluted the cytotoxicity
decreased, but only povidone-iodine allowed cell survival
of both cell lines at the MBC of 1.3g/L. The other antisep-
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
tics only showed cell survival with concentrations below
the MBC. Second best was chloorhexidine digluconate, for
which some cell viability remained at a concentration seven
fold below the MBC of 0.78 g/L.
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Conclusions: Povidone-iodine diluted to a concentration of
1.3 g/L seems to be the most favorable antiseptic dilution
for 2 minutes intraoperative irrigation. This should be established by future clinical studies.
F056
Acetic acid lavage as part of debridement protocol during revision tkr
Ammar Abbas1, Amisha Mehta2, Rhidian Morgan-Jones2
Cardiff And Vale University Health Board, Cardiff, United Kingdom
2
University Hospital Of Llandough, Cardiff, United Kingdom
1
F055
A quantitative in-vivo analysis of staphylococcal biofilm formation on the surface of three
different calcium phosphate bone grafts
Ulrika Furustrand Tafin1, Bertrand Betrisey1, Thomas Ilchmann2, Marc Bohner3, Andrej Trampuz4, Martin Clauss5
1
Lausanne University Hospital, Lausanne, Switzerland
2
Kantonspital Baselland, Liestal, Switzerland
3
Rms Foundation, Bettlach, Switzerland
4
Charité - University Medicine, Berlin, Germany
5
Kantonspital Baselland, Liestal, Switzerland
70
Aim: Differences in physico-chemical characteristics of bone
graft substitutes designed for the management of bone defects may influence bacterial biofilm formation. The aim of
the study was to investigate in-vivo staphylococcal biofilm
formation of different calcium phosphate (CaP) bone grafts.
Methods: An established foreign-body infection model in
guinea pigs was used. Four sterile Teflon cages prefilled
with a cyclOS, CDHA or DCP scaffold were subcutaneously
implanted in the flanks of guinea pigs. Each material was
tested in two animals carrying four scaffolds. Cages were
inoculated with 10^4 cfu/ml of Staphylococcus aureus (2
strains) or S. epidermidis. 3h, 24h or 72h after infection,
animals were sacrificed and scaffolds explanted. Quantitative analysis of the biofilm was performed by sonication,
followed by conventional culture of the sonication fluid, as
well as by microcalorimetric quantification of the biofilm
remaining in the scaffold. Calorimetric time to detection
(TTD), defined as time to reach a heat flow signal exceeding
20 µW was measured. TTD indirectly quantifies the amount
of bacteria with a shorter TTD representing a higher amount
of bacteria.
Results: Independently of the material, both S. aureus strains
(A, B) formed an increasing amount of biofilm on the surface
of all scaffolds over time. For S. epidermidis (C) sonication
showed an increasing amount of biofilm on CDHA and DCP
but a decreasing amount on cyclOS between 3h and 24h
incubation. After 72h of incubation, sonication showed
no biofilm on the surface of DCP and cyclOS, but a stable
amount of biofilm on CDHA. Microcalorimetry showed an
increasing amount of biofilm on the CDHA scaffolds over
time. For DCP a stable amount of biofilm between 3h and
24 h incubation but a clearing of the infection was observed
after 72h. On cyclOs a decreasing amount of biofilm was
observed between 3h and 24h incubation and after 72h a
small amount of biofilm was detected by microcalorimetry.
Conclusions: Monitoring biofilm formation on the surface
of porous materials like CaP bone grafts is a challenging
problem with increasing clinical interest. Whereas S. aureus
in-vivo biofilm formation was not influenced by the differ-
ent structure of the CaP scaffolds in this study, the presence
of S.epidermidis biofilm could not be proven on DCP after
72h neither by microcalorimetry or conventional cultures.
We found no explanation from a single physico-chemical
characterization of the 3 CaP bone grafts thus have to postulate that biofilm formation is influenced by various parameters in parallel.

Introduction: Acetic Acid has been used in the management of infection since the time of Hipoccrates and has a
bactericidal spectrum covering Gram positive and negative
organisms. We wished to study the feasibility of using Acetic
Acid as part of the intra-articular debridement of infected
TKR at revision surgery.
Patients and Methods: Between October 2013 and March
2014, 3% Acetic acid was used as the final part of debridement of 10 infected TKR revision. Debridement involved cyclical synovectomy, curettage, intra-medullary reaming and
pulsed normal saline lavage. The final step was a 20 minute
Acetic acid soak followed by a repeat saline lavage.
Results: During the 20 minute soak, no tachycardia, increased respiratory rate or changes in blood pressure were
recorded. Post-operatively there were no wound complications or delayed wound healing. No early recurrent infection has been identified.
Conclusion: The use of 3% Acetic acid soak, as part of a radical debridement protocol, has shown no intra-operative or
post-operative complications. Acetic acid may have an additive effect on biofilm clearance and eradication of recurrent
prosthetic infection but this requires further research.
F057
Bactericidal activity of n-chlorotaurine against biofilm forming bacteria
Débora Cristina Coraça-Huber
Innsbruck Medical University, Innsbruck, Austria
Aim: Many orthopedic surgeons consider surgical irrigation
and debridement with prosthesis retention as a treatment
option for postoperative infections. Usually, saline solution
with no added antimicrobial agent is used for irrigation. We
investigated the activity of N-chlorotaurine (NCT) against
various biofilm forming bacteria in vitro and thereby gained
significant information on its usability as a soluble and well
tolerated active chlorine compound in orthopedic surgery.
Methods: Biofilms of Staphylococcus aureus were grown on
metal alloy discs and in polystyrene dishes for 48 hours. Subsequently, they were incubated for 15 min to 7h in buffered
solutions containing therapeutically applicable concentrations of NCT (1%, 0.5%, and 0.1%; 5.5 - 55 mM) at 37°C. NCT
inactivated the biofilm in a time and dose dependent manner.
71
Results: Scanning electron microscopy revealed disturbance of the biofilm architecture by rupture of the extracellular matrix. Reduction of carboxanilide (XTT) assays
showed inhibition of the metabolism of the bacteria in biofilms. Quantitative cultures confirmed killing of S. aureus,
Staphylococcus epidermidis and Pseudomonas aeruginosa
biofilms on metal alloy discs by NCT. Clinical isolates were
slightly more resistant than type strains, but counts of colony forming units were reduced at least 10-fold by 1% NCT
within 15 min in all cases.
Conclusion: NCT showed microbicidal activity against various bacterial strains in biofilms. If this can be transferred to
the clinical situation, should be the aim of future studies.
F058
Next generation antimicrobial hydroxyapatite coating − releasing property of silver ions and
antimicrobial property −
In-vivo biofilm formation on different CaP bone grafts evaluated by
sonication (left panel) and microcalorimetry (right panel)
33rd Annual Meeting of the European Bone & Joint Infection Society
Iwao Noda1, Hiroshi Miyamoto2, Masaya Ueno2, Shuichi Eto2, Masatsugu Tsukamoto2, Takayuki Akiyama2, Shunsuke Kawano2,
Motoki Sonohata2, Masaaki Mawatari2
1
Kyocera Medical Corporation, Osaka, Japan
2
Saga University, Saga, Japan
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
Aim: Bacterial infection related to orthopaedic implants is
a significant complication today. One of the ways to reduce
the incidence of implant-associated infections is assumed
to give antibacterial activity on the surface of implant itself.
We focused attention on silver (Ag), because it has strong
antibacterial activity, broad antibacterial spectrum and low
toxicity. We developed the novel thermal spraying technology of Ag containing hydroxyapatite (AgHA). However the
coating was not stable enough, because of its low crystallinity. Then in order to improve stability of the coating, crystallization process was added and some chemical and physical
properties were reported at EBJIS2012. In this study, releasing property of silver ions and antimicrobial property of
AgHA coating were evaluated.
Methods: AgHA was coated on titanium substrate using
the thermal spraying of HA powder containing silver oxide.
Conventional HA coating without Ag was used as a control.
The time-course releasing of Ag ions for one week and for
one month in fetal bovine serum (FBS) at 37°C was evaluated using the inductively coupled plasma-mass spectrometry (ICP-MASS). And the repeated releasing test of Ag ions
was performed for 24 hr at 37°C in FBS. Antimicrobial activity of the coatings was evaluated by the film adhesion meth-
Abstracts free paper sessions
od based on ISO 22196 using six bacteria; Staphylococcus
aureus, Methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus
epidermidis, Escherichia coli, Pseudomonas aeruginosa,
which are often responsible for surgical site infection (SSI)
related to orthopedic implant, and one fungus; Candida albicans. Microorganism was cultivated for 24 hr at 37°C.
Results: The time- course releasing test showed the releasing rate of Ag ions was high until 24 hr after immersion
and decreased gradually thereafter. In the repeated releasing test, released Ag amount was high at the 1st test, then
gradually decreased with repeated number. However, the
releasing of Ag ions was observed till one month in the long
term releasing test. On the other hand, comparing HA coating, AgHA coating showed strong antimicrobial activity for
all six bacteria and one fungus.
Conclusions: The AgHA coating released Ag ions at high
rate within 24 hr and showed strong antimicrobial activity
at 24 hr antimicrobial test. Therefore the AgHA coating is
expected to reduce the incidence of acute SSI. And the long
term slow release of Ag ions from the AgHA coating suggests possible prolonged antimicrobial effects of the AgHA
coating; that will be examined from now on.
F059
72
The effect of perpendicular unilateral continuous electric field on bacterial attachment on
inox plates. An in vitro study
Lluís Font-Vizcarra1, Araceli González-Cuevas1, Josep Maria Sierra2, Laura García-Nuño1, Vicenç Diaz-Brito1, Juan Castellanos1,
Adrián Bermúdez3, Alex Soriano4
1
Parc Sanitari Sant Joan De Deu, Sant Boi De Llobregat, Spain
2
Hospital De Bellvitge, Barcelona, Spain
3
Innovative Minds S.L., Terrassa, Spain
4
Hospital Clínic, Barcelona, Spain
Aim: Although the usefulness of direct electric field for the
detachment of bacteria from the conductive surfaces is well
known, there is little evidence in the literature on the impact of an external electric field on the progress of adherence. According with DLVO theory and due the negative
surface polarity of bacteria, a electrostatic repulsion from
negative charge surface should be expected, so in theory,
the bacterial adherence on negatively charged surfaces
should be lower. However recent studies have shown discrepancies between observations and theoretical expectations. The aim of this study was to evaluate the capacity of a
continuos electric field to control the bacterial attachment
on a stainless steel plates.
Methods: Two previously sterilised circular metal plates of
stainless steel (SS) were introduced in a culture flask. Every
plate was placed in front of the other (fig 1). All of this montage was completely submerged in a liquid medium with a
known concentration of S. epidermidis (RP62A) and incubated during 1 hour at 36 Cº. During this period of time, a direct
electric field of 600 µA was applied between the two plates
so one acts as anode and the other as cathode. After incubation, the circulate plate was removed, washed with PBS and
sonicated during 5 minutes in 10 ml of saline. Different dilutions were performed and 100 µl of each one was cultured on
agar plates. We compared the bacterial adhesion in negative
plates, positive plates and plates without electric field.
Results: A medium reduction of the 94% of bacterial attachment was observed when the electric field was applied. This
difference was statistically significant. The polarity of the
plate didn’t play a role in bacterial adhesion and the differences between the adherence on positive and negative
charged plates were not statistically significant.
Conclusion: A direct current is able to reduce the bacterial
adhesion of S. epidermidis. We didn’t find statistically significant differences between positive charged and negative
charged plates.
F060
Two-stage joint replacement performed early after septic arthritis: first experiences in seven
patients
Antoine Sébastien Acker1, Erlangga Yusuf2, Christophe Tissot1, Arthur Grzesiak1, Andrej Trampuz3, Olivier Borens1
Chuv, Lausanne, Switzerland
2
Uz Brussels, Brussels, Belgium
3
Charité, Berlin, Berlin, Germany
1
Introduction: Treatment options for severe septic arthritis
are limited. Joint lavage with appropriate systemic antibiotics and arthrodesis are among the options as well as joint
replacement after a disease free interval of six months to
one year to prevent reinfection. These options unfortunately often come with poor functional outcome for arthodesis
or are associated with a long period of pain and disability
before joint replacement and a low functional outcome. It is
reasonable to think that septic joint arthritis with important
joint destruction is almost analogous to prosthetic joint infection. Therefore two-stage arthroplasty with an antibiotic-impregnated cement spacer in the interval might be an
option.
Material: We report seven cases of native joint infection
(five knees, one hip and one shoulder) treated by removal of
the infected articular surfaces, placement of an antibiotic-
impregnated cement spacer followed by total joint replacement. The first stage was performed in all patients within
24 weeks after the diagnosis of septic arthritis The second
stage was performed in all patients within 6 weeks except
for one patient (3 months).
Results: Outcome was successful in all of the seven patients
as there was important pain reduction, no infection recurrence and all of the patients showed a satisfying functional
outcome at their last follow up !
Conclusions: Most of patients with joint destruction due to
infection will sooner or later need surgery and there is no
need to prolong the interval between diagnosis and definitive treatment. Two-stage joint replacement provides a safe
and early “definitive” treatment of severe septic arthritis and
reduces greatly the suffering and pain of patients.
F061
Two stage procedure in infected hip arthroplasty: optimal timing of reimplantation
Mathias Glehr1, Ines Vielgut1, Patrick Sadoghi1, Klaus-Dieter Kühn1, Gerold Schwantzer2, Matthias Wolf1, Florian Amerstorfer1,
Andreas Leithner1
1
Medical University Of Graz, Department Of Orthopedic Surgery, Graz, Austria
2
Medical University Of Graz, Department Of Medical Informatics, Statistics And Documentation, Graz, Austria
Superior view of a bottle with the two circular SS plates totally
submerged in liquid medium with S. epidermidis.
33rd Annual Meeting of the European Bone & Joint Infection Society
Introduction and Aim: Management of lower-extremity
periprosthetic joint infections remains a challenging task
and adequate treatment strategies seem to be mandatory.
The aim of this study was to figure out the influence of the
time period between implant removal and total hip arthroplasty (THA) re-implantation (“spacer-period”) in patients
who have undergone a two-stage joint reconstruction for
peri-prosthetic hip joint infection. In order to determine
the optimal timeframe for second-stage surgery (THA reimplantation, spacer exchange) the outcome of temporary
antibiotic loaded cement spacers was analysed.
Patients and Methods: A consecutive series of 76 patients
with native and peri-prosthetic hip joint infections who
have undergone two-stage revision surgery by the use of
antibiotic-loaded cement spacers were included in the
study between 2005 and 2010. The second stage operation
September 11-13, 2014 - Utrecht - The Netherlands
73
Abstracts free paper sessions
was performed when it was assumed that the bacterial joint
infection was eradicated (no clinical signs and symptoms of
infection, no species in the aspiration, improvement of laboratory infection values, and a negative 99mTc-leucocyte
scintigraphy). The further operative procedure was depending on the intra-operative findings (frozen section, local status). Ongoing or cured infection determined a negative or
positive negative outcome.
Results: The mean length of the implant-free period with
the antibiotic loaded spacer in situ was 12.6 weeks (range
0.6 to 91.3 weeks). Spacer re-implantation was necessary in
13 cases due to positive signs of acute infection in the frozen section and suspect intra-operative findings. 8 patients
have not been operated for a second time in the investigated
Abstracts free paper sessions
time period due to poor general conditions. In 40 patients we
observed a spacer retention period of 4-11 weeks, 5 patients
had a spacer retention period of less than 4 weeks and 23
patients of more than 11 weeks. We observed a significantly
higher proportion of patients free from reinfection in the 4-11
weeks group (90.0%) than in the patients with the shorter
spacer retention period (0.0%) and in the patients with the
longer spacer retention period (52.2%) (p<0.001).
Discussion: The optimal point of time for reimplantation,
according to this study, can be determined between four
and eleven weeks. Leaving a spacer longer than 11 weeks
based on the intention to heal out infection is useless. Reimplantaion earlier than four weeks seems to have a negative
effect on the outcome.
F062
Dual prophylaxis with cefuroxime plus teicoplanin reduces the rate of early prosthetic joint
infection
Eduard Tornero, Laura Morata, Guillem Bori, Juan Carlos Martinez-Pastor, Consuelo Climent, Wilson Londoño, Josep Mensa,
Sebastián García-Ramiro, Alex Soriano
Hospital Clinic Of Barcelona, Barcelona, Spain
74
Aim: The purpose of this study was to determine whether
dual antibiotic prophylaxis with a cephalosporin (cefuroxime) plus a glycopeptide (teicoplanin) reduces the rate of
prosthetic joint infection (PJI) after primary total knee (TKA)
and total hip arthroplasty (THA).
Methods: Patients who underwent TKA or THA between
February 2010 and February 2013 were prospectively registered in a database. Antibiotic prophylaxis from February
2010 to August 2011 consisted of 1.5 gr of cefuroxime during induction of anaesthesia and another 1.5 gr of cefuroxime 2 hours later. From September 2011, it was decided to
add one dose of 800 mg of teicoplanin during anaesthesia
induction. The PJI rate during both periods (cef-group and
combo-group) was compared and risk factors for infection
were analysed. A univariate and multivariate analysis using
a step-wise forward Cox regression model was performed.
Results: A total of 1786 patients were included in the study.
Forty-five (2’5%) patients had a PJI within the first 100 days
after surgery. There were 995 (55.7%) in cef-group and 791
(44.3%) patients in the combo-group. The PJI rate in combogroup was significantly lower than in the cef-group (1.26%
vs 3.51%, p=0.002). Staphylococcus aureus was not identified in any patient from the combo-group while this microorganism caused 45.7% of PJI in the cef-group (P= 0.008).
Male sex (HR: 3.81, 95%CI: 2.06-7.07), BMI>35 Kg/m2 (HR:
2.67, 95%CI: 1.32-5.39), presence of lung disease (HR: 2.48,
95%CI: 1.19-5.18) and red blood cell transfusion (HR: 3.67,
95%CI: 1.88-7.15) were independently associated with PJI.
Antibiotic prophylaxis with cefuroxime + teicoplanin were
associated with a lower risk of infection in comparison with
using cefuroxime alone (HR: 0.35, 95%CI: 0.17-0.73).
Conclusion: Dual antibiotic prophylaxis with a cephalosporin (cefuroxime) plus a glycopeptide (teicoplanin) reduces
the rate of PJI in primary TKA and THA.

Cumulative probability of being free of PJI within the
first 100 days of follow-up according to each group
33rd Annual Meeting of the European Bone & Joint Infection Society
F063
Functional and morbidity outcomes of single-stage revision for infected total hip
arthroplasty
Bruno Direito-Santos, Cecília Sá Barros, Eurico Bandeira Rodrigues, Ricardo Maia, Catarina Alves, Bartol Tinoco, Álvaro Gil,
Joaquim Martins Pereira, Manuel Vieira Silva
Hospital De Braga, Braga, Portugal
Introduction: Infection remains one of the most serious
complications of total hip arthroplasty. The best surgical
approach to infected prothesis is yet a theme of discussion.
Despite reinfection/relapse rates could be comparable to
two-stage approach, single-stage treatment is associated
with lower perioperative risk and superior functional outcomes. Knowledge and experience analysis is the key to establish standard decisions and to position each treatment
for each patient condition.
Aim: With this work, we aim to describe our department
experience with single stage revision for infected total hip
arthroplasty between 2009 and 2012.
methods: We performed a retrospective analysis of the
functional and morbidity outcomes of single stage revision
surgeries.
Results: In this period, 42 revisions for infected hip arthroplasty were performed. 22 of that were single-stage revision
for infected total hip arthoplasty with an average age of 71
years (range 44-91). 12 patients were women. The average
time of follow up was 23 months (range 8-55). The most
commonly isolated bacteria were Staphylococcus epidermidis (24%) and methicillin-resistant Staphylococcus aureus
(20 %) and the most used targeted antibiotics were vancomycin (21%), amoxycillin-clavulanate (14%) and rifampicin
(12%). The post-operative Merle d’Aubigné-Postel Score was
15/18 (range 9-17). In the follow-up period, 6 patients (27%)
required a re-intervention (2, component instability; 3, infection relapse; 1, mechanical pain with infection solved).
One patient died due to his basal alchoolic hepatic disease.
Conclusion: Single-stage revision is associated with an acceptable functional outcome and low re-intervention rate.
Our experience suggests that a less agressive surgical approach in addition to the best medical therapy could be a
suitable solution in selected patients.
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F064
Arthrodesis after failed septic total knee replacement: retrospective comparative study
between cemented nail “artificial-arthrodesis” and external-fixation knee fusion
José Vicente Andrés-Peiró1, Guillermo Rieiro-Mena1, Gustavo Yupanqui-Sandoval2, Xavier Flores-Sánchez1, Carles Amat-Mateu1,
Pablo Salvador Corona-Cardona1
1
Hospital Universitari Vall D’hebron, Barcelona, Spain
2
Hospital Virgen De La Cinta, Tortosa, Spain
Aim: Classically, the use of an external frame has been considered the technique of choice to achieve knee-fusion because its usefulness to achieve infection control after TKR infections. Recently a so-called “artificial” nail arthrodesis has
been promoted how a valid alternative in order to avoid the
hardly bony fusion and the excessive long length discrepancy. The aim of this retrospective study was to compare the
results and complications of knee arthrodesis using these
both techniques.
Methods: We perform a retrospective study of 27 patients
who underwent 35 arthrodesis procedures after failed septic TKR. We divide the patients in two groups, Group-A: cases
with a monolateral-EF knee fusion (n:27) and Group-B: cases
with a cemented IM “artificial” arthrodesis (n:8). Each patient
had undergone a mean of 4.9 (SD: 3,1; range: 1 to 16) previous procedures. The infection eradication rate, complications, reoperations as well as fusion rate and time to achieve
fusion (only on the EF group), were evaluated.
Results: In all cases, the indication was an infected TKR. The
most common isolated microorganism was Coagulasenegative Staphylococcus. Both groups were comparable in
terms of sex, age and McPherson host type. The mean inpatient stay for the nail-group was 22.7 days (SD: 14.8; range: 9
to 47) compared with 30.4 days (SD: 26.2; range: 6 to 120) for
the EF-group (p = 0,560). Thirteen patients in-group A (48%)
went on to confirmed primary arthrodesis at the end of FU.
Mean time to achieve fusion was 12.15 months (SD: 8.5;
range: 5 to 33). Post-operative complications causing readmission occurred in 16 cases (59,3%) in the Group-A, with 15
surgeries after the arthrodesis (55,5%), and in 4 cases (50%)
in Group-B, all of which required further surgeries (p = 0,473
for readmission; p = 0,548 for surgeries). All cases of EF required readmission and surgery for implant removal. Infection control was achieved in 17 cases in Group-A (63%) and
in 6 cases (75%) in Group-B (p= 0,481). Two cases of implant
breakage and pin removal was recorder in the Group B. In
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
1 case the nail had to be removed. No cases of amputation
after the procedure was founded in Group-A, but 1 patient
in-group B needed an above-knee-amputation to control
the infection.
Abstracts free paper sessions
Conclusion: We found no difference between the study
groups. The descriptive parameters show possible greater resource consumption in cases of external fixation due to the
increased inpatient stay, readmissions and extra surgeries.
F065
WITHDRWAN
F066
Propionibacterium acnes isolations in lower extremity prosthetic joint infections; a 10 years
experience revision
David Alejandro Muñetón, Dolores Rodriguez-Pardo, Xavier Flores Sánchez, Carlos Pigrau-Serrallach, Carles Amat, Pablo
Corona-Pérez
Hospital Universitario Vall D’hebron, Barcelona, Spain
76
Aim: Propionibacterim acnes(P. acnes) is normally found on
the human skin. It is a known responsible of shoulder prosthetic joint infections(PJIs), but its pathogenic role in lower
extremity PJIs is less known and its isolation on a single positive sample around a failed joint arthroplasty is of uncertain
significance. We aim to describe our clinical experience with
hip-knee PJIs due to P. acnes and to evaluate the clinical significance of a single positive sample to P. acnes.
Methods: Retrospective search of our institutional database
of all chronic hip-knee PJIs, diagnosed between July-2002
and July-2013, were P. acnes was isolated at least once. Patients were divided into two groups: group 1 (“confirmed”
P.acnes-PJI) comprised patients with isolation of P. acnes
from at least two different samples and group 2 (“possible”
P. acnes-PJI) comprised patients with isolation of P. acnes
from only one sample but with other PJI criteria. Values of
preoperative ESR and CRP, surgical and systemic antibiotic
treatment and outcomes were evaluated. Cure was defined
by the resolution of infection due to P. acnes after a minimum of 12 months of follow-up.
Results: Overall 28 episodes of PJIs in 28 patients (median
age 67,5 (60,7-73) years; 15 (54%) males) were included.
There were 18 (64%) Knees and 10 (36%) hips. In 19(68%)
cases the infected implant was a primary arthroplasty. According the McPherson classification 22(79%) patients were
considered type-A and 6 type-B and regarding the defined
group selection 17 (61%) patients belong to the group 1.
Twelve (43%) infections were polymicrobial. ESR-CRP levels
were available in 18 cases; ESR was > 30 mm/h in 5/11 (45%)
patients in group 1 but only in 1/7 (14%) in group 2. Regarding CPR it was > 3mg/dL in 4/12 (33%) patients in group 1
but only in 1/7 (14%) in group 2. Susceptibility profile was
available in 26 strains: all were resistant to metronidazole, 1
to clindamycin and 1 to vancomycin. Selected surgical treatment was an exchange-arthroplasty in 24 (85%) patients.
Only in 20 (71%) cases a selected antibiotic treatment,
mostly a clindamycin-based regimen, was administered for
a median of 12 months (range: 4-14). Global cure rate was
75% (18/24 (75%) patients treated with exchange-arthroplasty vs. 3/4 (75%) treated with prosthesis retention) after
a median follow-up of 29 months (range: 12-123).
Conclusions: In our experience, success rate in P. acnes
PJIs is 75%. Serological markers failed to identify cases of P.
acnes PJI.
F067
Prosthetic joint infections due to enterococcus spp. Which is the role of teicoplanin?
Cristina López Sánchez, Dolors Rodríguez-Pardo, Carles Pigrau, Pablo S. Corona, Carles Amat, Maily Lung, Xavier Flores, Benito
Almirante
Hospital Universitari Vall D’hebron, Barcelona, Spain
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: To evaluate the epidemiology and outcome of prosthetic joint infections (PJIs) due to Enterococcus spp. and to assess
the efficacy of teicoplanin on enterococcal PJIs treatment.
Methods: All PJIs due to Enterococcus spp. diagnosed in our
institution between January 2003 and December 2012 were
retrospectively reviewed. The diagnosis of enterococcal PJI
was established when >2 intraoperative cultures yielded
Enterocccus spp. Demographic, clinical and microbiological
data, surgical treatment and outcome were collected. We
considered as cases only patients that, strictly, were adjusted to a proper surgical treatment according the Zimmerli´s
algorithm. A teicoplanin-based treatment was considered
when teicoplanin was administered for ≥ 8 weeks. Failure
was defined as persistence or reappearance of clinical signs
of infection and positive cultures for Enterococccus spp. involving the need of an unplanned surgery, patient death or
suppressive antibiotic treatment. Only patients with a minimum follow-up of 12 months were included.
Results: Overall 26 episodes of PJIs in 22 patients were
identified. The median age was 72 (60 – 81.2) years, and 9
patients (41%) were men. There were 12 (55%) hip, 8 (35%)
knee, 1 (4.5%) shoulder, and 1 (4.5%) elbow prosthesis. According to Zimmerli’s criteria, we identified 15 (58%) early
postoperative and 11 (42%) delayed PJIs. Enterococcus fae-
calis was the causative microorganism in all PJIs except one,
in which Enterococcus faecium was isolated. Twelve (46%)
patients presented a polymicrobial infection. Debridement
with prosthesis retention was performed in 11 (42%) cases,
2-stage exchange in 9 (35.5%), resection arthroplasty in 4
(15%) and 1-stage exchange in 2 (7.5%). Intravenous antibiotic regimens were started with teicoplanin in 18 (69.2%)
patients, daptomicin in 5 (19%), ampicillin in 2 (8%) and linezolid in 1 (4%). In 6 cases oral antibiotics were prescribed
following intravenous therapy (4 linezolid, 1 levofloxacin
and 1 amoxicillin-clavulanic). Seventeen (65.2%) patients
completed a teicoplanin-based treatment. Only one patient
presented side effects that forced teicoplanin suspension.
Overall median duration time of antibiotic treatment was
90 (82.5 – 90) days. Global success rate was 62% (16/26
episodes) after a median follow-up of 34.5 (15.7 - 62.2)
months. Success rate increased to 82% when a teicoplaninbased regimen was used [median follow-up 35 (23.5 – 64.5)
months]. Teicoplanin was administered as outpatient parenteral antibiotic therapy (OPAT) in 13 patients (76%).
Conclusions: In our experience, success rate in enterococcal PJIs treated with adequate surgical therapy and a teicoplanin-based regimen was 82%. Teicoplanin was mainly
administered as OPAT and side effects were low.
F068
The cross-breaking strength and the antistaphylococcal activity of bone cement depending
on vancomycin and fosfomycin supplementation
Svetlana Bozhkova, Ekaterina Polyakova, Alexandr Afanasyev
R.R. Vreden Russian Research Institute Of Traumatology And Orthopedics, Saint-Petersburg, Russia
Antibiotic-laden bone cement has been shown to decrease
septic failure following total joint arthroplasty in high-risk
individuals. There are two main factors that influence the
elution of antibiotic from polymethylmethacrylate (PMMA)
spacers: the type of PMMA cement used, and the manner in
which the spacer is made.
Aim: To estimate of the cross-breaking strength and the antimicrobial activity of bone cement, comprising vancomycin or fosfomycin in different concentrations.
Methods: Bone cement samples comprising vancomycin (5
or 10% w/w) or fosfomycin (10 or 20% w/w) were prepared
based on 20 g commercial PMMA bone cement, including
4,22% w/w gentamycin (triplicate). The control samples
were PMMA cement without additional antibiotic. All samples had the same weight (0,54 ± 0,02 g). The cross-breaking
strength was determined by three-point bending test.
In order to estimate antimicrobial activity the each sample
was placed into the personal sterile container with 2 ml
0.9% solution NaCl and incubated at 35oC during 14 days.
Every day all solution from each sample was removed and
replaced by the fresh 2 ml solution. The samples were incubated again. Ten microliters of removed solution was
plotted (in duplicate) onto Mueller Hinton Agar with bacterial lawn: Staphylococcus aureus ATCC6538 (MSSA) and
ATCC33591 (MRSA) strains were used. Next day the results
of study were registrated. The bacterial lysis zone was indicative of antimicrobial activity of the samples.
Results: In comparision with control, the samples, comprising 5 or 10% w/w vancomycin showed decrease of the
cross-breaking strength by 17,1% and 26,3%, accordingly.
The samples, comprising 10 or 20% w/w fosfomycin - 14,6%
and 47,3%, accordingly.
The longest antimicrobial activity was observed for 20%
w/w fosfomycin supplementation: 21 days for MSSA and 5
days for MRSA strains. 10% w/w fosfomycin samples showed
antimicrobial activity during 21 (MSSA) and 3 (MRSA) days.
The antimicrobial activity of 10% w/w vancomycin samples
was observed during 4 (MSSA) and 3 (MRSA) days, 5% w/w
vancomycin – 3 (MSSA) and 2 (MRSA) days. As a comparison,
activity of control samples last 2 days for MSSA and 1 day for
MRSA strains.
Conclusions: The cross-breaking strength decrease of bone
cement was depended on amount and nature of antibiotic
supplementation. Probably adding of 20% w/w fosfomycin into bone cement led to longest antimicrobial activity,
because such antibiotic supplementation substantial decreased of structural behavior of cement and increased of
antibiotic diffusion into solution.
September 11-13, 2014 - Utrecht - The Netherlands
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F069
Intracellular proliferation of S. aureus in osteoblasts and effects of rifampicin and gentamicin
on S. aureus intracellular proliferation and survival
Walid Mohamed1, Ursula Sommer1, Eugen Domann2, Katrin Lips1, Reinhard Schnettler3, Volker Alt3
1
Laboratory Of Experimental Trauma Surgery, Justus-Liebig-University, Giessen, Germany
2
Institute Of Medical Microbiology, University Hospital Of Giessen-Marburg, Giessen, Germany
3
University Hospital Of Giessen-Marburg, Department Of Trauma Surgery, Giessen, Germany
78
Staphylococcus aureus is the most frequent causal agent for
bone infection. When S. aureus infection affects a total joint
arthroplasty, removal and replacement of joint is mostly required. Moreover, it was recently discovered that S. aureus
is able to invade osteoblasts thus escaping the extracellular
host antibacterial defense and even antibiotics. This plays a
significant role in persistence and recurrence of infection.
The aim of this study was to investigate whether (1) S. aureus is able to not only invade but also proliferate within
osteoblasts, (2) the mechanism of invasion and (3) to clarify
whether rifampicin or gentamicin can inhibit intracellular
proliferation and survival of S. aureus. SAOS-2 osteoblastlike cell line was infected with S. aureus EDCC5055 and S.
aureus Rosenbach 1884. In order to test the mode of bacterial internalization, SAOS-2 cells were treated 2h prior to
infection with cytochalasin D which is the major actin depolymerization agent. Immunofluorescence and transmission electromicroscopic (TEM) imaging were performed to
detect potential intracellular and proliferating bacteria. For
antibiotic experiments, SAOS-2 osteoblasts infected with S.
aureus were treated with 7.5 microgram/ml rifampicin or
30 microgram/ml, 100 microgram/ml, or 200 microgram/
ml gentamicin for 4h and 24h. Both S. aureus strains were
able to efficiently invade and proliferate within human osteoblasts shown by typical bacterial growth curves. Immunofluorescence microscopy showed intracellular invasion
of S. aureus while TEM demonstrated bacterial division and
disruption of lysosomal membranes as a sign of successful intracellular proliferation and survival. Cytochalasin D
was able to significantly reduce S. aureus invasion ability
suggesting that invasion was enabled by promoting actin
rearrangement at the cell surface. 7.5 microgram/ml of rifampicin was able to inhibit bacterial survival in human osteoblasts with almost complete elimination of bacteria after
4 h. Effects of gentamicin were dose-dependent but even
high doses with 200 microgram/ml of gentamicin were associated with a significant higher number of survived bacteria compared to rifampicin. In conclusion, S. aureus is not
only able to invade but also to proliferate in osteoblasts.
Invasion seems to be associated with actin rearrangement
at the cell surface. Rifampicin is effective in intracellular
eradication of S. aureus whereas gentamicin seems to have
a much weaker intracellular effect. Based on these data,
doses of rifampicin and gentamicin could be optimized for
local use to coat end prostheses and be able to reach the
intracellular compartments thus killing the probable intracellular persisting S. aureus without causing undesirable
systemic side effects.
Acknowledgements:
This work was supported by AO Clinical Priority Program
“Bone infection”.
F070
Clindamycin-rifampin combination therapy for staphylococcal periprosthetic joint infections
Joris Elbers, Borg Leijtens, Patrick Sturm, Bart-Jan Kullberg, Berend Schreurs
Radboud University Medical Centre, Nijmegen, Netherlands
Aim: Staphylococcal species account for more than 50%
of periprosthetic infections and antimicrobial therapy with
rifampin-based combination regimens has been shown effective. Guidelines recommend combining rifampin with
quinolones, and cure rates of 70-100% have been reported.
The combination of rifampin and clindamycin has not yet
been described. We evaluated the safety and efficacy of
clindamycin in combination with rifampin for the management of staphylococcal periprosthetic infections.
Methods: In a historical prospective study, we included
patients who received clindamycin-rifampin combination
therapy after one-stage revision or debridement and retention of a periprosthetic hip or knee infection by Staphylococcus aureus or coagulase-negative staphylococci. Patients were treated according to a standardized treatment
algorithm and followed for a median of 36 months.
Results: Of the 35 patients with periprosthetic staphylococcal infections, 30 had an infection of the hip, and five had
an infection of the knee. Seventeen patients underwent debridement and retention, 18 underwent one-stage revision.
Four patients (11%) discontinued clindamycin/rifampin due
to side effects. No case of Clostridium-associated diarrhea
33rd Annual Meeting of the European Bone & Joint Infection Society
was diagnosed. Efficacy failure occurred in two of 31 patients
(6%) completing the clindamycin-rifampin regimen. In the
debridement group, the cure rate was 93% (95% CI 61;99)
at four years; one clinical failure occurred, two weeks after
the end of clindamycin-rifampin treatment. In the one-stage
group, the cure rate was 94% (95% CI 63;99) at four years; one
microbiological failure occurred at seven months..
Conclusion: Combined therapy with clindamycin and rifampin is a safe and effective combination regimen for the
treatment of staphylococcal periprosthetic infection with
prosthesis retention or one-stage revision in patients tolerating these antibiotics.
F071
Evolution of chemotherapy in osteoarticular tuberculosis over last decade: a prospective
study comparing the clinico-radiological effectiveness of various regime I
Pranay Bhushan
St. Stephens Hospital, Delhi, India
Aim: The discussion over the duration, type of therapy and
regimen to be used in osteoarticular tuberculosis is losing
importance in all orthopaedic gathering. Still little consensus is there over the universality of a treatment regime for
osteoarticular tuberculosis.
Method: 340 new cases of osteoarticular tuberculosis were
included in the study that were medically treated in the department of orthopaedics in a tertiary care center between
2001 and 2011. Out of which 202 cases were of spinal tuberculosis and 138 cases of extraspinal tuberculosis. 88 cases
of spinal tuberculosis were treated by conventional method
and 114 cases by short course chemotherapy. 60 cases of
extraarticular tuberculosis were treated by conventional
chemotherapy and 78 cases by short course and intermittent therapy.
Result: All cases were diagnosed on clinical, radiological
and haematological basis. Cases who received conventional
therapy received 18-24 months of treatment irrespective to
the clinical, radiological and haematological parameters.
Whereas those who received short course (2HRZE+4 HR)
and intermittent therapy (DOTS) were evaluated for clinical
improvement, in the form of improvement in constitutional
symptoms, resolution of abscess, healing of sinus and fall
in ESR. All cases underwent regular radiological evaluation.
The duration of treatment was accordingly tailored with all
patients receiving a minimum of 6 months of continuous or
intermittent therapy.Maximum follow up was of 7.8 years
(conventional) minimum follow of 3 years (intermittent).
The trend of fall in ESR, clinical and radiological parameters
showed improvement beyond 2 years of initiation of treatment in cases that had stopped treatment at 6 months. But
the improvement was slow after six months even in cases
who received 24 months of chemotherapy. There were no
relapses in all the three groups.
Conclusion: The maximum incidence of cases and research
in the field of tuberculosis is in Asia and Africa. However
there is lack of consensus on the appropriate duration of
treatment. Hence there is a need to standardize treatment,
to prevent under-treatment, prevent acquired drug resistance, to avoid over-treatment, to minimize side effects and
to be able to monitor and compare treatment outcomes.
This study gives an insight over the evolution of different
regimes as well as gives an understanding of the clinical
treatment in osteoaticular tuberculosis.
September 11-13, 2014 - Utrecht - The Netherlands
Case: MRI picture
at Initiation of
treatment (Short
Course Chemotherapy2HRZE+4HR)
79
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F072
F073
Examining the in-vitro antimicrobial and in-vivo anti-biofilm efficacy of a peek-silver zeolite
composite in tackling surgical site spine infections
Recommendations for diagnosis and treatment of spondylodiscitis
Sriram Sankar , Joseph Crudden , Hans Jorg Meisel
Difusion Inc., Georgetown, United States
2
Berufsgenossenschaftliche Clinic In Bergmannstrost Halle/Saale, Halle, Germany
1
1
2
1
80
Background: Spine related surgical site infection (SSI) rates
vary from 3%-12% for instrumented fusion procedures and
account for $1.17 billion of the $3.5-$10 billion dollars spent
annually in the US on SSI’s. Also, difficulty in identifying spine
infections, with a mean time interval of 14 months after surgery, results in slow healing and removal of implants, estimated at 63% for infections detected after 30 days. Hence,
there is a critical need to develop bioactive spine implants
with a capacity to reduce infection risk and shorten fusion
timelines. A novel PEEK- silver zeolite composite (CleanFuze
TM) has been developed and is expected to have infection
resistive and osteoblast stimulative effects due to Ag ions
and ceramic zeolite particles respectively.
Aim:To evaluate the in-vitro antimicrobial and in-vivo antibiofilm efficacy of PEEK-silver zeolite(PK-Ag Ze) composite;
without compromising PEEK’s inherently attractive biomechanical properties.
Materials and Methods: In-vitro contamination model: PKAg Ze and PEEK surfaces(~1.23 sq.cm) were seeded with
GFP (green fluorescent protein) induced methicillin resistantStaphylococcus aureus for 4hrs to initiate bacterial
adhesion before the introduction of MG-63 osteoblast-like
cells (ATCC CRL-1427).Osteoblast proliferation characteristics on these inoculated surfaces were compared to their
un-inoculated controls(done in triplicates). Osteoblast proliferation was quantified using Alamar Blue assay while bacterial viability was determined via colony count technique.
Both assays were carried out on both- Day 3 and Day 7.
In vivo Antibiofilm Testing using a Rabbit Spine infection
Model: 12 NZW female rabbits- 2.5-3 kg.
• Rabbits 1, 5, 9- PEEK; Rabbits 2,6,10 - PK-Ag Ze; Rabbits
3,7,11,12- Surface Modified PK-Ag Ze; Rabbits 4, 8 surface
modified PEEK-silver zinc zeolite (PK Ag-Zn Ze).•Implant
screw placed across mammillary spinous process. L3 -control site with defect but no implant/inoculum. L6- site with
implant and infected with 500 cfu of MRSA in sterile saline.
•Equivalent implant sections explanted after a week were
analysed for biofilm formation qualitatively via crystal violet
assay and for microscopic features via histopathology.
Comparative Biomechanical Testing: Gamma sterilized (60-
80KGy) 22x8 PLIF PK-Ag Ze and PEEK cages were tested for
dynamic compression and torsion (ASTM F2267-03, F226704) in PBS at 37 ± 3°C. Non-sterilized PEEK and CF samples
were used for static impact (ASTM D256), flexural (ASTM
D790) , compressive (ASTM D695) and tensile analysis
(ASTM D638).
Results: The in vitro study revealed that PK-Ag Ze surfaces
protect osteoblasts from destruction by MRSA, thereby allowing for ~ 46 times greater osteoblast proliferation on its
surface compared to infected PEEK. PK-Ag Ze composites
even in the presence of MRSA show three times greater
proliferation of osteoblasts relative to uninfected plain PEEK
due to bioceramic zeolite particles.In the in vivo study, PEEK
implants displayed an intense purple colouration indicative of biofilm formation whereas surface modified PK-Ag
Ze showed little to no purple colouration, thus proving its
anti-biofilm properties. Importantly, inflammatory cell infiltrates and degenerative changes were less prevalent in
sites implanted with PK-Ag Ze, PK Ag-Zn Ze and surface
modified PK-Ag Ze compared to PEEK.Static biomechanical
studies revealed that PK-Ag Ze composites showed comparable biomechanical properties to PEEK and overcame the
minimum FDA mandated threshold of 3000N for 5 million
cycles under dynamic compressive loading and ±3Nm for 5
million cycles under cyclic torsional testing; from an implant
approval standpoint for vertebral body replacement and interbody fusion surgeries.
Conclusions: PEEK-Silver Zeolite composites demonstrate
increased in vitro osteoblast proliferation and improved
in-vitro antimicrobial potency, which was complimented
by enhanced in-vivo anti-biofilm efficacy and comparable
biomechanical properties relative to PEEK; thereby allowing
for an alternative biomaterial in spine and orthopedics with
improved biomaterial/implant characteristics.
Note:
PEEK Silver Zeolite(CleanFuze TM) cages have received European CE approval but are not FDA approved.
PEEK Silver Zinc zeolite is investigational and not CE/FDA
approved.
33rd Annual Meeting of the European Bone & Joint Infection Society
Bas Fransen1, Enrico de Visser1, Anke Lenting1, Bert Rodenburg2, Ton van Zwet3, Jet Gisolf2
1
Rijnstate Hospital, Department Of Orthopaedic Surgery, Arnhem, Netherlands
2
Rijnstate Hospital, Department Of Internal Medicine, Arnhem, Netherlands
3
Rijnstate Hospital, Department Of Medical Microbiology And Medical Immunology, Arnhem, Netherlands
Aim: Spondylodiscitis, also known as vertebral osteomyelitis, is a destructive disease with high morbidity and mortality¹,². Diagnosis is often delayed because of the rarity of the
disease and the fact that early symptoms are often non-specific³. There are currently no national guidelines on the diagnosis and treatment of spondylodiscitis in The Netherlands.
Methods: We performed a single-centre retrospective cohort study examining 49 patients over 18 years old treated
for spondylodiscitis in a 6 year time period.
Results: Mean age of patients was 69 years (range 40-89).
Most patients underwent a MRI-scan to confirm diagnosis
(n=30). In 39 patients a microorganism was found, most
commonly S. aureus (n=14), Streptococci (n=11) and gramnegative bacteria (n=11). All patients were treated with
antibiotics. Thirty-seven patients received antibiotic treatment for at least 6 weeks, 17 patients were treated for 90
days or longer. In 13 patients no adequate treatment was
started until culture results were available. Eleven patients
underwent surgery after their diagnosis. Two patients had
a recurrence.
Conclusions: Based on the findings in our study we recommend that, when considering spondylodiscitis as a possible
diagnosis, all patients should undergo thorough physical
examination, neurological screening, blood tests for infection and blood cultures. A MRI-scan should be performed,
followed by a PET-CT scan when results are inconclusive.
Ideally a CT-guided biopsy is performed before treatment is
started. Awaiting culture results all patients should receive
broad-spectrum antibiotics. Targeting only Gram-positive
microorganisms in empiric treatment will lead to delayed
adequate treatment in a substantial group of patients. A
multidisciplinary approach is advocated.
References:
¹ Gouliouris et al 2010, The Journal of antimicrobial chemotherapy;
2010;65 Suppl 3:iii11-24
² Zarghooni et al 2012, International Orthopaedics; 2012;36(2):405-11
³ Butler et al 2006, Spine; 2006;31(23):2695-700 Acknowledgements:
None of the authors reported any conflict of interests. No funding
was received for this study.
F074
Successful use of local gentamicin impregnated pmma-beads in treatment of deep surgical
site infections after instrumented spinal fusion
Daniël Maria Carolus Janssen, Maud Kramers, Geert Walenkamp, Paul Willems
Mumc, Maastricht, Netherlands
Aim: Surgical site infection (SSI) following instrumented spinal surgery is a potentially devastating complication. Defining an optimal treatment algorithm remains troublesome
because of variability in patient cohorts, definitions of infection, and instruments used to measure treatment efficacy in
studies published in literature.
In contrast to SSI of hip and knee arthroplasty, the routine
use of local gentamicin impregnated polymethylmethacrylate (PMMA)-beads to treat deep SSI after spinal surgery
has not been described earlier in literature. In patients who
require multiple surgical debridements, these beads can
be placed into the wound, permitting high local antibiotic
concentrations, despite poor tissue vascularity and without
systemic toxic side effects.1,2,3 The aim of this study is to
review experiences of the use of local gentamicin beads in
treatment for deep SSI after instrumented spinal surgery.
Methods: 488 adult patients underwent instrumented spi-
nal surgery between January 1999 and November 2011. 41
cases were complicated by deep SSI. Risk factors, diagnosis
and management of SSI were evaluated.
Patients were treated according to an algorithm for the
treatment of infection with debridement and systemic antibiotic treatment based on culture and sensitivity results.
Local gentamicin impregnated PMMA beads (60-240) were
used in patients treated with retention of the instrumentation. In patients with late onset SSI the instrumentation was
removed initially and gentamicin beads were only applied
in case with extensive local infection symptoms. Follow-up
was at least 2 years after treatment.
Infection-treatment was considered to be successful when
there was no recurrence of infection at follow-up, with normalized infection parameters and no clinical or radiological
signs of infection. Failure of treatment was defined as recurrence of infection or death related to infection.
September 11-13, 2014 - Utrecht - The Netherlands
81
Abstracts free paper sessions
Results: The incidence of deep SSI was 8.4% (41/488). The
most frequently cultured organism was Staphylococcus Aureus (47.2%).
Risk factors for SSI were: BMI > 30, rheumatoid arthritis,
ASA-III, use of NSAIDs or steroids, fracture as initial indication, blood transfusions and persistent cerebrospinal fluid
leakage. Three patients were lost to follow-up.
The overall success-rate of infection-treatment of deep SSI
was 86.8% (33/38).
Infections treated with retention of the instrumentation
had a success-rate of 84.0% (21/25)
Patients with late onset SSI treated with initial removal of the
instrumentation had a success-rate of 92.3% (12/13).
Conclusion: The additional use of gentamicin impregnated
PMMA-beads to surgical debridement and systemic antibiotics in the treatment of deep SSI after instrumented spinal surgery appeared to be successful with a success-rate comparable or even better to those found in literature (70-80%).4-5
Abstracts free paper sessions
References
1.Jan AP Geurts, Daniël MC Janssen, Alfons GH Kessels, and Geert
Walenkamp. Good results in postoperative and hematogenous deep
infections of 89 stable total hip and knee replacements with retention of prosthesis and local antibiotics. Acta Orthopaedica 2013; 84
(6): 509-516
2.Geert H.I.M. Walenkamp. Chronic osteomyelitis. Acta orthopedica
scandinavica. 1997; 68 (5): 497-506
3.Geert H.I.M. Walenkamp, Tom. B. Vree, Theo J.G. van Rens. Gentamicin-PMMA Beads, pharmacokinetic and nephrotoxicological study.
Clinical Orthopedic Related Research. 1986 April; (205): 171-83
4.S. Núňez-Pereira, E. Pellisé, D. Rodríguez-Pardo, C. Pigrau, J. Bagó, C.
Villanueva, E. Cáceres. Implant survival after deep infection of an instrumented spinal fusion. Bone Joint J 2013; 95-B: 1121-6
5.Michael T. Rohmiller, Behrooz A. Akbarnia, Kian Raiszadeh, Kamshad
Raiszadeh, and Sarah Canale. Closed Suction Irrigation for the Treatment of Postoperative wound infections following posterior spinal
fusion and instrumentation. Spine. 2010 Mar; 15;35(6):642-6
F075
An analysis of causal bacteria and antibiotic therapy in patients with pyogenic spondylitis
treated in the last decade
Ryoji Miyake, Hideaki Miyoshi, Fumio Hayashi
Takamatsu Minicipal Hospital, Takamatsu, Japan
82
Aim: Pyogenic spondylitis has frequently been noted in
aged or morbid patients with increasing incidence. Antibiotic therapy methods are changing as the causal bacteria
become resistant to those therapies, thereby resulting in
a difficulty in managing this disease. This study was performed to investigate the causal bacteria and evaluate antibiotic therapy methods in patients with pyogenic spondylitis.
Methods: A total of 91 patients with pyogenic spondylitis
were treated in this hospital from 2000 to 2013 and all of
them were included in this study. There were 52 males and
39 females. The age of the patients ranged from 38 to 84
years with an average of 64.2 years. The blood or the aspiration liquid were cultivated to detect bacteria. The bacterial detection rate, bacterial species, antibiotic types used
for treatment, and antibiotic sensitivity were assessed. The
relationship between bacterial detection rate and antibiotics before examination, the phase of disease development,
bone destruction or abscess was investigated.
Results: Bacteria were detected in 48.8% of all the patients.
In the untreated group,　bacteria were detected in 52.2%,
which is significantly higher than that in the antibiotic treat-
ed group. The bacterial detection rate was not significantly
different in each phase of disease development. Bacteria
were detected more frequently in patients with bone destruction or abscess than in those without such conditions.
Gram-positive bacteria were detected in 77.3% of the patients. Methicillin-resistant Staphylococcus aureus (MRSA)
was found in the majority of patients. Gram-negative species were detected in 22.7% of the patients. Cephem antibiotics sensitive to the causal bacteria were used in 67.5% of
these patients, while carbapenem antibiotics were used in
22.6% of patients with resistant bacteria. For patients with
MRSA, gluco-peptide was used as the first-line treatment,
but the use of linezolid was necessary in four patients.
Conclusions: MRSA increasingly recognized as a causal bacterium of pyogenic spondylitis. Resistant bacteria are also
detected in gram-negative species. The number of cases
requiring the use of carbapenem antibiotics is increasing.
Gluco-peptide is ineffective in some patients with MRSA,
and linezolid is necessary in four patients. However, it is
important to follow up patients for any adverse effects and
the emergence of resistant bacteria during treatment with
these broad spectrum antibiotics.
33rd Annual Meeting of the European Bone & Joint Infection Society
F076
Increasing rates of postoperative infections after spine surgery. With and without use of
implants
Jean-Paul Grabner von Rosenberg
St. Olavs Hospital, Ranheim, Norway
Introduction: Post operative infection is one of the most
devastating complications after spine surgery.
Objectives: In a prospective study we registered a rate of 2,
0% postoperative infections after spine surgery at the department of orthopaedic surgery, St. Olavs University Hospital in the period 1994-1997. Our objective was to register
the rate of postoperative infections the last ten years (19992010) and compare it with the period 1994-1997 in accordance to the changes regarding the surgical techniques
profile and the causative bacteria.
Methods: At the department of orthopaedic surgery, St.
Olavs University Hospital we registered all patients undergoing spine surgery (except cervical columna), and reoperations due to infections in less than 12 months after the
index operation, in the period 1999-2010.
The patients were identified through combining relevant
index and revisions codes (ICD, ICPM). Patients who did not
have a permanent address in Norway were excluded.
The results of culture of tissue samples taken during the reoperations were registered.
Results: Three patients were excluded. Postoperative infections were registered in 12/599 (2, 0%, 95% CI: 1, 2%–3,
5%) patients in the first period (1994-1997) compared to
112/1839 (6, 1%, 95% CI: 5, 1%–7, 3%) patients in the second period (1999-2010) (p<0,001 Pearson’s chi-square test).
Considering the changes regarding the surgical techniques
profile in the two periods the infection rate was distributed among the following groups as follows: extirpation of
nucleus pulposus prolaps (1/184 (0, 5 %) vs. 1/18 (5, 6 %)),
spine surgery without implants (5/157 (3, 2%) vs. 20/293
(6.8%)) and spine surgery with use of implants (6/258 (2,3
%) vs. 91/1531(5,9 %)) respectively. The increase in infection
rate was similar in the different surgical procedure groups
(p=0,586, logistic regression analysis). The following microbes were cultured in the two periods: Staphylococcus aureus: 8/15(53%) and 48/118 (41%), anaerobe bacteria: 2/15
(13%) and 22/118 (19%), and coagulase negative Staphylococcus spp: 2/15 (15 %) and 17/118 (14%), respectively.
Conclusion: We observed an increase in the rate of postoperative infections after spine surgery in the period 19992010 compared to the period 1994-1997. The increase in infection rate was observed in both patients operated without
an implant and in patients operated with use of an implant.
In both periods the S. aureus was the causative microbe in
approximately 50 % of the cases, and almost 20 % of the infections were due to anaerobe microbes. Possible explanations for the observed increase in the rate of postoperative
infections after spine surgery might be alterations in the
public health and environment. This includes an increase in
patient-related risk factors as diabetes mellitus and obesity,
displacement in the age composition and changes of the
environment in the operating theatres.
F077
Surgical approach in treatment of pyoinflammatory complications arising from
endocorrection of scoliosis
Vladimir Obolenskiy1, Alexander Ermolov2
City Hospital 13, Moscow; Rnrmu, Moscow, Russia
2
RNRMU, City Hospital 13, Moscow, Russia
1
Aim: to research the means of cutting short pyoinflammatory complications arising from endocorrection of scoliosis
(PCaES) with an option of retaining the corrective device.
Methods: A total of 48 patients that presented PCaES was
treated; the age group of 16-43 years (22.9 + 0.9); a postcorrection period of 1 month to 7 years.
In cases where a single fistula had been connected to one
attachment block, a fistulaectomy was performed, the block
was removed and a primary stitches were put.
In cases of local phlegmon the locus was drained, debrided
and a negative pressure wound therapy (NPWT) was ap-
plied which then had been changed once in 3-5 days; secondary stitches were put.
In cases of multiple fistulae and extensive purulence, all
metal structures were removed, the loci were drained, a
double drain/flush system was installed, the wound was
closed with layer-by-layer sutures.
Results: Of 48 patients, in 29 cases hardware removal was
followed by wound defect plasty; in one case hardware removal was followed by application of NPWT, the wound was
closed. In 11 cases one of corrective blocks was removed,
including 2 cases of using NPWT. In 6 cases fistula excision
September 11-13, 2014 - Utrecht - The Netherlands
83
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was followed by NPWT with preserving all the elements
of endocorrector. 2 patients refused to undergo a surgery.
There is no evidence of suture failures or wound abscesses
in any case of removal of corrective device and subsequent
wound closure; in cases where NPWT was employed the
pyoinflammatory process was successfully cut short, the
wound was closed and corrective device was kept in place.
Conclusion: There were no cases of sutures inconsistency
Abstracts free paper sessions
or wound suppuration after hardware removal and plasty;
after one block removal, recurrent fistula was reported in 3
cases; in all 9 cases of using NPWT we successfully managed
the suppurative inflammatory process and wound defect
closed, in 8 cases - with preserving the endocorrector. The
results obtained in the course of this study permit to recommend NPWT to cut short pyoinflammatory process and to
help keep the corrective device in place in case of PCaES.
F078
Adjuvant treatment of chronic osteomyelitis of the tibia following trauma using a medicated
bone graft substitute: a regional trauma-centre review
Saqib Noor1, Michael Cheeran David2, Gemma Humm3, Phillipa Bridgeman4, Deepa Bose4
Birmingham City Hospital, Birmingham, United Kingdom
2
The Royal Orthopaedic Hospital Nhs Foundation Trust, Birmingham, United Kingdom
3
Aintree University Hospital, Liverpool, United Kingdom
4
University Hospital Birmingham, Birmingham, United Kingdom
1
84
Introduction: Infection following traumatic injury of the tibia is challenging, with surgical debridement and prolonged
systemic antibiotic therapy well established as a management strategy. Local antibiotic delivery via cement beads
has shown improved outcome, but these often require further surgery to remove. A medicated bone graft substitute
(1) composed of 4% tobramycin-impregnated calcium-sulphate pellets is available for packing into bone defects. Concerns remain regarding the wound leakage from the sterile
effluent produced as it resorbs, along with the risk of acute
kidney injury following systemic absorption.
Aim: We present outcomes of 21 patients treated with 4%
tobramycin-impregnated calcium-sulphate pellets.
Methods: Medical notes were reviewed over a 30-month
period of every case of osteomyelitis of the tibia in which
the medicated bone graft substitute had been used as a
local antibiotic delivery agent and void filler. Excision of
tissue was performed back to bleeding bone. Metalwork,
whenever present, was removed, before the pellets were
packed into any contained defects or the intra-medullary
canal in those cases where an intramedullary nail had been
removed. Further bony stabilisation (n=9) and soft tissue
reconstruction (n=7) were undertaken as required. Intravenous vancomycin and meropenem were administered after
sampling. Meropenem was discontinued after 3 days in the
absence of any Gram-negative cultures, and vancomycin
continued for 1 week. Thereafter targeted antibiotic therapy
was given for between 6 weeks to 6 months, or ciprofloxacin
and rifampicin in culture negative cases.
Results: Average follow-up was 15 months. Wound complications were encountered in 52%. A wound discharge in the
early post-operative period was noted in 7 patients (33%)
independent of site of pellet placement, with 6 demonstrating wound healing complications. Of the 14 cases without
wound leak, 5 developed wound complications (p=0.06,
Fisher exact test), delayed wound healing and pin site infections. Union rate was 100%. One patient developed a transient acute kidney injury, and one refractory osteomyelitis.
Conclusion: Despite a high incidence of wound discharge
that might predispose to healing complications, antibioticloaded calcium-sulphate pellets are an effective adjunct in
treatment of chronic osteomyelitis of the tibia following trauma, and no significant nephrotoxic events were recorded in
our study.
(1) OSTEOSET®-T, Wright Medical Technology Incorporated, Arlington
TN, USA
33rd Annual Meeting of the European Bone & Joint Infection Society
F079
Ankle arthrodesis using ilizarov device in chronic osteomyelitis of tibiotalar joint
Leonardo Fisichella1, Haridimos Tsibidakis2, Domenico Fenga1, Francesco Guerreschi2, Michele Attilio Rosa1
University Of Messina - Section Of Orthopaedic And Traumatology, Messina, Italy
2
Azienda Ospedaliera Provincia Di Lecco - Hospital A.Manzoni, Lecco, Italy
1
Aim: The treatment of chronic osteomyelitis of the tibiotalar
joint is often complex and not easily solved. In these cases it
occurs the total destruction of the joint and ankle arthrodesis is a recognized treatment. Authors present their personal series and Ilizarov Method, for achieving arthrodesis
of ankle joint, is employed.
Methods: From January 1982 to December 2011, 43 patients were treated, 13 males- 30 females, mean age 67.3
years (42-80). In all the evaluated cases there was a chronic
osteomyelitis and an arthritic ankle joint was revealed after
several unsuccessful procedures of internal fixation. 15 patients were treated with monofocal technique removing up
to 2 cm; 28 patients were treated with bi-or tri focal bone
transport and removal of bone from 3 to 7 cm. The mean
follow-up was 3.8 years (2-5). The index AOFAS was used before and after treatment.
Results: The removed amount of bone tissue was between
2 and 7 cm. Average holding time of the apparatus was 18
months. 43 surgical revisions were provided with grafts at
the docking site, in 32 cases corrections of apparatus were
performed, 2 skin coverings were employed. Consolidation
occurred in all cases; infection recurred in 4 patients from 10
to 18 years. The average index of preoperative AOFAS was
42/100 while postoperatively was 83/100. Residual limb
length discrepancy was on average of 1.2 cm. Considering
all complications, and by a careful evaluation of literature,
Authors found out that the use of circular fixator, in cases of
osteomyelitis of the tibiotalar joint, provides stable fixation
with immediate loading and maintains the integrity of soft
tissues allowing possible “corrections in progress” to avoid
the risk of infection recurrence.
Conclusions: Circular External fixation according to the Ilizarov method turns out to be a safe method for arthrodesis
of the ankle joint in case of infection, as it allows to simultaneously treat both the bone component and the soft parts. It is
still a procedure which lasts for an heavily protracted amount
of time and it is combined with a low patient compliance.
However, it remains a convincing alternative to amputation.
85
F080
Vac instill and localised antibiotic instillation – safe and effective in the treatment of
musculoskeletal sepsis
James Tomlinson, Owain Evans, Rob Townsend, Maria Vincent, Ed Mills, Jonathan McGregor-Riley, Simon Royston,
Mick Dennison
Sheffield Teaching Hospitals, Sheffield, United Kingdom
Aim: To retrospectively assess the patients treated with vac
ulta antibiotic instillation in a unique case series performed
in a tertiary referral limb reconstruction unit.
Methods: We have now treated a number of patients off licence with antibiotic instillation under the guidance of the
microbiology department and the pharmacy committee.
All patients being treated with vac ulta were included in the
study. The underlying pathology treated, antibiotic treatment, length of treatment and organisms cultured were
all noted. Antibiotic and other complications were also recorded. Treatment was judged successful with resolution of
presenting symptoms, return of inflammatory markers to
normal levels and three negative foam cultures sent at time
of dressing change.
Results: There were 21 patients treated, with 13 male and
8 female patients. Length of treatment ranged from 1 to 10
weeks with a mean of 4.2 weeks. Follow up ranged from 1
to 42 months with a mean follow up of 17.9 months. The
most common pathogen was Staph. Aureus (11 cases). Enterobacter, ESBL, Strep Milleri, MRSA and Citrobacter were
also treated. There were no antibiotic reactions/allergies
encountered. Pathologies treated included osteomyelitis,
two stage amputation for infection, infected non-union and
infected metalwork. Treatment was successful in 19/21 patients. Infection recurred in 2/21 patients at 18 months and
2 years post treatment respectively.
Conclusion: The 90% treatment success rate is highly encouraging in this notoriously difficult group of patients to
treat. In this series vac instill was an effective treatment of
infection and allows antibiotic treatment to be targeted to
the infected tissues with localised high dose antibiotic treatment. This technique also allows a range of antibiotics to be
targeted locally and allows for treatment to be changed as
further cultures suggest.
September 11-13, 2014 - Utrecht - The Netherlands
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F081
F083
Cuadricetoplastia with mesh vicryl. Our experience
Osteomyelitis behaviour by using locking intramedullary osteosynthesis
Isidor Marchan, Alfredo Matamala, Christian Yela, Daniel Haro
University Hospital Mutua Terrassa, Barcelona, Spain
Gennadii Kolov, Mykola Grytsay
State Institution “Institute of Traumatology and Orthopedics of NAMS of Ukraine”, Kiev, Ukraine.
Introduction: It is common in prosthetic salvage surgery ,
the need for osteotomy cuadriceptoplastia or anterior tibial
tuberosity for better exposure of the joint. Traditionally, we
have used the simple suture reconstruction of the extensor
apparatus points. We present our experience in using vicryl
mesh for suturing the quadriceps.
Material and methods: We present 6 patients undergoing
surgery for prosthetic replacement ( septic and aseptic ) in
which we used a mesh of vicryl suture for quadriceps . The
mean age was 71 years. All had undergone multiple interventions.
All were immobilized with a splint in extension for 3 weeks
starting at 7 days passive physiotherapy, allowing active
movement from the third week.
We reviewed the following parameters: suture failure ( reoperation ) and range of motion.
Results: With a mean follow up of 30 months ( 8-36 ) , was
not observed any suture failure . As for the range of movement , there has been a shortage of middle extension of
3.5 degrees (-5° - 0°). The average flexural 101.7° (90 - 120°).
100x4 , 90, 120 .
Conclusion: Thought the vicryl mesh is an alternative to rebuilding cuadriceptoplastias in prosthetic replacement surgery with need for some gesture on the extensor apparatus.
F082
Surgical site infections following fracture fixation – incidence and microbiological profile
86
Priscila Rosalba Oliveira, Vladimir Cordeiro Carvalho, Cassia da Silva Felix, Adriana Pereira de Paula, Jocelio Furtado Tavares,
Jorge dos Santos Silva, Ana Lucia Lima
Hospital Das Clinicas - Universidade De Sao Paulo, Sao Paulo, Brazil
Aim: Describe incidence and microbiological profile of surgical site infections (SSI) following fracture fixation in a reference center for orthopedic care in Sao Paulo, Brazil.
Methods: All patients who underwent internal fixation of
closed or open fractures of the limbs from January 2005
to December 2012 were included. Those with closed fractures received antimicrobial prophylaxis for 24 hours with
cefazolin. Patients with open fractures underwent surgical
debridement, repair of cutaneous covering and external
fixation. Internal fixation was performed after improvement
of soft tissues. These patients received antimicrobial therapy for 14 days with cefazolin (Gustilo 1), or combination of
clindamycin and gentamycin (Gustilo 2 and 3). To determine
incidence of SSI, patients were followed for one year. Diagnosis of this complication followed criteria defined by the
Centers for Disease Control and Prevention (CDC). Only isolates obtained in culture from bone, soft tissue or exudate
collected after antisepsis and surgical debridement were
considered for microbiological characterization. Cumulative
antibiograms were performed in accordance with Clinical
and Laboratory Standards Institute (CLSI) standards.
Results: During this period, 11030 patients with fractures
were admitted. Among them, 9143 patients (83%) had
closed fractures and 1887 (17%) had open fractures. 379 patients had diagnosis of SSI related to topography of fracture,
overall SSI incidence was 3.45%. SSI incidence was significantly higher in patients with open fractures (12.3% versus
1.9%, p < 0.05). 529 agents were isolated and considered re-
lated to the infection. Most
frequent isolates were S.
aureus (26.3%), coagulasenegative
Staphylococci
(CoNS)(14.2%), Enterococcus spp. (11.4%), A. baumannii (11%) and P. aeruginosa (9.8%). Table 1 shows
susceptibility profiles.
Conclusions: Overall incidence of SSI related to fracture fixation was 3.45%. SSI
incidence was significantly
higher in patients with
open fractures. S. aureus ,
CoNS, Enterococcus spp., A.
baumannii and P. aeruginosa were most frequent isolates, with low antimicrobial
susceptibility rates.
Antimicrobial susceptibility profile
of most frequent isolates related to
SSI following fractute fixation
33rd Annual Meeting of the European Bone & Joint Infection Society
Locking intramedullary osteosynthesis (LIO) is the most effective method of long bones shaft fractures treatment. But
as with other implants in traumatology and orthopedics interlocking nails application does not exclude the possibility
of purulent complications and in some cases it can cause
osteomyelitis development.
According to literature sources the frequency of septic complications after LIO is 0.6-5.1% of all cases.
Work Objective. The objective of this work is to analyze behavior variants of the inflammatory process after BIOS and
patients treatment options with this complication.
Materials and Methods: We conducted a retrospective
analysis of medical records and X-ray images of 67 patients
with purulent complications after lower extremity bones
BIOS, who were treated in the bone-contaminated surgery
department. Among them 66% were men and 34% were
women aged from 17 to 52. 54% of patients had femoral
bone trauma and 45% had tibia trauma.
Results: The suppuration appeared in 1-24 months after
LIO, in 5.9 months on average. The microbiological data
analysis revealed the advantage of S.aureus in 40% of patients, among them 28.6% of MRSA.
In our group there were more young patients without significant comorbidities, which had BIOS with relation to fractures. Only 8.6% of them had purulent complication following a severe polytrauma. In 25.7% of patients LIO was used
following the external fixation device. LIO was conducted
in one stage with external fixation device removal, which
significantly increases the implant infection likelihood. LIO
usage for open fractures treatment caused not only suppuration in 14.3% of patients, but also led to osteomyelitis in
8.6% of patients.
In 51.4% of cases we observed instability of blocking screws,
in 77.8% - distal screws instability, which caused suppuration in most cases.
The main treatment method of purulent processes in this
group was sanitizing with metal construction removal. In
60% of consolidated fracture cases the treatment was completed on this stage. In other cases we conducted transosseous osteosynthesis, in 3.6% of them it was done not just for
bone fragments fixation, but also for the segmental bone
defect restoration.
Conclusions: Long-lasting fixation device instability and
BIOS after transosseous osteosynthesis with external fixation devices significantly increase the risk of septic complications. According to our data the distal blocking instability
was mostly often the cause of infection processes appearance.
The applied method allowed us to eliminate purulent processes of all patients in this group and to restore the extremities support ability; inflammatory process relapse was
observed for one patient only.
F084
The challenge of the infected pilon tibial non-union: treatment with radical resection, bone
transport and ankle arthrodesis
Annelien Brauns, Johan Lammens
Uzl, Pellenberg, Belgium
Aim: A significant number of patients with pilon tibial fractures develop complications, the most devastating being a
combination of infection and non-union with bone loss (Fig
1). The purpose of this study is to report how to deal with
these severe problems.
Methods: The results of the Ilizarov bone transport technique were retrospectively evaluated in eight patients. All
underwent an extensive resection and reconstruction aiming at an ankle arthrodesis.
Results: Only occasionally healing at the level of the docking site could be obtained at a first attempt. Six out of the
eight patients needed a reintervention using a new Ilizarov
procedure on one occasion and retrograde transcalcaneal
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87
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nailing in five patients, leading to a final healing in all of them.
Conclusions: If patients are prepared to participate in a
long term treatment with the risk of multiple interventions
a reconstruction can be performed, resulting in a limb with
an acceptable function, allowing all activities of daily life
and even a professional occupation. To obtain this final
result with a definite union at the docking site, retrograde
intramedullary nailing is considered a valuable and safe
procedure. A transcalcaneal guide pin during the Ilizarov
procedure can possibly advance the union of the docking
site, but this needs further investigation.
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References:
1. Ashman O. Injury, Int. J. Care Injured 2013;44 (1): 43-5.
2. Kugan R. Bone Joint J 2013;95-B(3):371-7.
3. Lavini F. Injury, Int. J. Care Injured 2010;41: 1191-1195.
4. Lovisetti G. Injury, Int. J. Care Injured 2013;44: 58-62.
5. Megas P. Injury, Int. J. Care Injured 2010;41: 294-9.
Acknowledgements: I would like to thank Johan Lammens
for his help in writing this article.
F085
Diversity of the clinical features of pyogenic spondylitis in patients treated in the last decade
Aims: Propionibacterium acnes is involved in bone and joint
infections (BJI) or device-related infections (DRI). Epidemiologically, five phylotypes were highlighted: IA, IB, IC, II and
III. We wanted to compare the distribution of phylotypes,
the possible genetic link, as well as clinical data between
isolates mostly involved in spine device-related infections
to those from environmental samples.
Methods: 88 isolates of P. acnes were selected: 58 spinal
infections isolated between 2000-2006, 4 prosthetic infections and 26 from the environment between 2007-2010.
Phylotyping was performed by sequencing the recA gene.
Molecular typing of isolates from spine infections was performed by comparing the profiles obtained by rep-PCR
(semi-automated technical DiversiLab bioMérieux). The
analysis of different clinical and laboratory patient data
was performed including reason for surgery, intraoperative
appearance, CRP and pathological findings. Patients were
separated into two groups: group 1 (n = 16) without signs of
infection, group 2 (n = 41) with signs of infection. One was
lost for this analysis due to the lack of information.
Results: 58% of the isolates belonged to phylotypes IA
among spine isolates, 37% to type IB and 3% to type II. No
correlation between phylotypes and clinico-biological presentation was highlighted. No type III was found. 3 of 4 isolates from prosthesis belonged to IA. The last one belonged
to phylotype IB. In contrast, the distribution of isolate phylotypes environment was varied with four IA, ten IB, three II
and nine III. The rep-PCR revealed different band patterns
for isolates of phylotype II but similar profiles divided into
five clusters for isolates belonging to type IA/IB.
Conclusions: This study reveals a predominance of phylotype IA in isolates involved in spine infections like in acne
strains. No correlation with clinical or biological data could
be established, for both groups with signs of infection or
not. The heterogeneity of phylotype strains of the environment contrasts with those involved in BJI or DRI highlighting the importance of a molecular epidemiological characterization of these strains by MLST.
Ryoji Miyake, Hideaki Miyoshi, Fumio Hayashi
Takamatsu Municipal Hospital, Takamatsu, Japan
88
Aim: Pyogenic spondylitis has frequently been noted in
aged or morbid patients, with an increasing incidence. The
clinical features of this disease are often atypical, thus resulting in a delay in making diagnoses or difficulty in treating some cases. This study was performed to assess the clinical features of pyogenic spondylitis cases that have been
treated in this hospital for a last decade.
Methods: A total of 103 patients with pyogenic spondylitis
were included in this study. They included 59 males, and 44
females. The age of the patient ranged from 38 to 84 years,
with an average age of 64.1 years. These patients were assessed with regard to their underlying diseases, mode of development for pyogenic spondylitis, clinical features and the
findings of examinations. The mode of disease development
was classified according to Kulowski’s criteria. Body temperature, blood analyses, pathological finding and magnetic resonance imaging (MRI) were included in this examination.
Results: Of the patients studied, 92 (89%) had underlying diseases such as diabetus mellitus, liver cirrhosis or cancer. Pyogenic spondylitis acutely occurred in 81 patients, while it sub-
acutely or chronically occurred in 22 patients (21%). Fourteen
patients had atypical symptoms, including stomachache, diarrehea and convulsions. These patients were diagnosed to
have either cholelithiasis, pancreatitis or pyelitis. 22 patients
(21%) had neither a high fever nor a positive finding for the
CRP. No bacteria were detected in 54 patients (52.4%). Although 96 patients (93%) were diagnosed to have pyogenic
spondylitis based on the pathological findings, the disease
was confused with a metastatic bone tumor by atypical cells
or an osteoporotic vertebral fracture by fibrosis. MRI revealed
characteristic findings in 87 patients, while in 16 patients
(16%) a primary diagnosis of either an osteoporotic vertebral
fracture or spondylosis deformance was made.
Conclusions: It is difficult to differentiate spondylitis from
metastatic bone tumors, spondylosis deformance or an osteoporotic vertebral fracture in patients with no inflammatory signs in the laboratory data. Spondylitis must be ruled
out if the patient demonstrate spinal pain, the inflammatory
signs and the MRI findings can be negative for the first few
months after onset in some patients.
F086
Is there a difference in phylotype of propionibacterium acnes strains in terms of origin: spinal
material, prosthetic devices and environment?
F087
Polyetheretherketone (peek) cages in surgical treatment of spondylodiscitis
Igor Novak, Miha Vodičar, Robert Košak, Matevž Gorenšek, Ludvik Travnik, Rok Vengust
University Medical Centre Maribor, Department Of Orthopedic Surgery, Maribor, Slovenia
89
Aim: To present a case series of patients who were surgically
treated for pyogenic spondylodiscitis with PEEK cage anterior column reconstruction.
Methods: Between 2009 and 2012 eleven patients with one
level pyogenic spondylodiscitis were treated operatively using PEEK cages for anterior column reconstruction. Eight
cases were lumbar, two thoracic and one cervical with average age at surgery of 57 (40-82) years. All patients underwent
clinical and radiological evaluation pre and postoperatively,
the latest follow up being on average 26 months (13-57
months) after surgery. Intravenous antibiotic therapy was
commenced according to sensitivity testing and was administered intravenously for at least 6 weeks after surgery.
Parameters assessed were comorbidity, causative organism,
time to solid bony fusion, angle of kyphosis, time of surgery,
blood loss, ambulatory status, neurologic work-up, and
functional outcome (Kirkaldy-Willis criteria).
Results: Mean time of surgery was 150 minutes and the
mean blood loss was 620 ml. Patients were able to walk
unaided 1,1 (1-2) day after surgery. Solid bony fusion was
achieved in 9 out of 11 patients (82%) on average 5 (4 – 8)
months postoperatively. Average deformity correction was
7 (0-18) degrees, with loss of correction of 4 (0-19) degrees
at latest follow-up. Functional outcome was assessed as excellent or good in 82 % of cases. At follow-up two patients
with diabetes mellitus, type II, had recurrence of infection.
Additional surgery with PEEK cage removal and autologous
bone grafting was employed in both cases with favorable
clinical and radiological outcome.
Conclusions: Despite few reports of favorable clinical results
after PEEK cage anterior column reconstruction in spondylodiscitis, results of our case series indicate that other kind of
anterior column support (autograft, titanium cages) might
be a better option when dealing with patients suffering
from diabetes mellitus and possibly other comorbidities.
References:
1. Mondorf Y. Acta Neurochir. 2009; 151: 1537-41.
2. Brase A. Acta Neurochir. 2010; 152: 2001-4.
3. Walter J. Eur Spine J. 2010; 19: 1004-9.
Guillaume Aubin1, Sarah Dellière1, Pascale Bémer1, Chloé Plouzeau2, Didier Tandé3, Stéphane Corvec1
Nantes University Hospital, Nantes, France
Poitiers University Hospital, Poitiers, France
3
Brest University Hospital, Brest, France
1
2
33rd Annual Meeting of the European Bone & Joint Infection Society
September 11-13, 2014 - Utrecht - The Netherlands
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F088
Single stage debridement, cement-interposition and stabilisation from posterior for
progressive, erosive spondylodiscitis
Lorin Michael Benneker, Emanuele Cattaneo, Hansjörg Sebald
University Of Bern, Orthopedic Department, Inselspital, Bern, Switzerland
90
Aim: The rate for haematogenous infections of the intervertebral disc is increasing as mostly elderly and immunocompromised patients are affected. Surgery is indicated if
the disease is progressive with destruction of the local with
instability and/or neurological impairment. Debridement of
intervertebral abscess, decompression of the spinal canal
and stabilisation of the segment is necessary. At the lumbar
spine the ventral approach allows a radical debridement of
the abscess but is less suited for stabilisation, especially in
cases with poor bone quality. Therefore often a two-stage
intervention with additional decompression and stabilisation from posterior is performed. In this study we report on
the mid- to long-term outcome of a single stage strategy
with debridement, cement-interposition and stabilisation
from posterior for progressive, erosive spondylodiscitis.
Methods: In a retrospective, single center case series patients were evaluated who were surgically treated for progressive, erosive spondylodiscits. The single stage strategy
consists of a lamino- and recessotomy for decompression,
debridement of the disc space and the affected bone
through anulotomy, filling of the resulting defect with an
antibiotic containing cement spacer and bisegmental stabilisation with transpedicular screw fixation.
Results: From 1997 to 2012 62 patients (34m, 28f, mean age
70y (32-92)) were treated with this technique. 41 patients
were available for a minimal follow up of one year (mean
FU 23.2 mths). 2 patients required additional debridement
from ventral for persisting infection in all other the infection was treated successfully with the posterior intervention
alone. Mean operation time was 164 min, blood loss 812 ml,
length of hospital stay 11.7 days. 2 patients died during initial hospitalisation, 12 patients during follow up; in 4 cases
the cause of death was unknown in the other cases not related to the infection. 8 of the 14 patients with neurological
impairment recovered completely. 11 patients required a
secondary intervention of the spine (1x hematoma, 1x revision of a dural tear, 2x persisting infection with debridement of the psoas abscess from anterior, 2x spondylodiscitis
with a different germ at different level, 3x implant loosening/failure, 2x adjacent segment disease).
Conclusion: The single-stage strategy with debridement,
cement-interposition and stabilisation from posterior is a
valid option for he treatment of progressive, erosive spondylodiscitis of the lumbar spine. The complication rate is
relatively low and the rate of persisting infection with 3.2%
comparable with the results of two-stage procedures.
F089
Spinal infections: comparative microbiology diagnosis using peri-implant tissue culture and
sonicate-fluid culture of removed implants
Mauro Salles, Maysa Yano, Ricardo Umeta, Osmar Avanzi, Cely Barreto, Stanley Nigro, Aparecida Murça
Santa Casa De Sao Paulo School Of Medicine, Sao Paulo, Brazil
Objectives: Spinal wound infection occurs in up to 7% following spinal implant surgery, and diagnosis spinal-associated infection (SAI) is difficult to accomplish as deep and
late infections may not show overt signs and symptoms.
We aim to compare the sensitivity and specificity, positive
predictive value (PPV) and negative predictive value (NPV)
of conventional peri-implant tissue culture samples with
culture of samples obtained by sonication of explanted implants.
Methods: A prospective cohort study from August 2011
to September 2013 was performed at the Orthopedic Department of Santa Casa de Sao Paulo School of Medicine,
among patients undergoing partial or total spinal implant
surgical removal due to any reason. Diagnosis of implant
associated infection was based upon standard criteria of in-
fection previously published, accompanied by clinical signs
and symptoms of infection. A minimal of 2 samples of the
peri-implant tissue were taken and sent under sterile conditions to the laboratory. The removed implants were packed
into plastic sterile containers and covered with Ringer’s
solution, vortexed for 30 seconds and sonicated for 5 minutes (frequency, 40 kHz; power density, 0.22 W per square
centimeter). The sonicated fluid was then cultured and
the microorganisms isolated were identified according to
standard method. Statistical analysis was performed using
McNemar test.
Results: From 26 patients with removed spinal implants,
68% had criteria for postoperative infection, 62.5% were
male with a mean age of 46 years old. Mean time of implantation was 31 months and reasons for surgery were
33rd Annual Meeting of the European Bone & Joint Infection Society
degenerative spinal disease in 45.8%, closed fracture in
25% and spinal deformity in 29.2%. The sensitivity for periprosthetic tissue culture and sonicate-fluid culture was 47%
(CI95%:0.26-0.69) and 94.1% (CI95%:0.73-0.98) respectively
(P=000.1). The specificity for peri-prosthetic tissue culture
and sonicate-fluid culture was 85.7% (CI95%:0.48-0.97) and
100% (CI95%:0.64-1.0) respectively. PPV for peri-prosthetic
tissue culture and sonicate-fluid culture was 88.8% (CI95%:
0.48-0.97) and 100% (CI95%:0.73-1.0) and NPV for periprosthetic tissue culture and sonicate-fluid culture was 40%
(CI95%:0.26-0.69), and 87,5% (CI95%:0.73-1.0) respectively
(P=000.1). Staphylococcus aureus and Coagulase-negative
Staphylococci were identified in 37.5% and 12.5% in the
sonicate-fluid culture and 33.3% and 11.1% in peri-implant
tissue culture. Gram negative Bacilli were detected in 43.5%
and 6.25% were polymicrobial infection in the sonicatefluid culture.
Conclusion: In the present study, sonicate-fluid cultures improved the microbiological diagnosis of spinal implant associated infections.
F090
Spondylodiscitis in childhood in concepcion, Chile. Review of 10 years
Pablo Schaufele1, Andres Ibieta1, Daniel Pineda2, Consuelo Peirano3,Claudio Figueroa3
1
Guillermo Grant Benavente´S Hospital - University Of Concepción, Concepción, Chile
2
Guillermo Grant Benavente´S Hospital, Concepción, Chile
3
University Of Concepción, Concepción, Chile
Aim: Spondylodiscitis (SD) is one of the less frequent localizations among osteoarticular infections and also less
known, so we decided to analize its behaviour in our unit.
Material and method: A retrospective study of 14 records
was carried out, 9 with diagnosis of entrance of SD and 5
with diagnosis of another pathology that turned out to be a
SD, between the years 2004 and 2013 in our unit.
Results: 9 only fulfilled the requirements to be classified
as SD (Clinic features of infection and spine localization,
laboratory exams and Tc-99 bone scintigraphy alterations).
4 males and 5 females, 2 had clinically predisposing conditions (trauma), aged between 1 and 13 years (average 6,9
years). The half time of clinical evolution foresaw to diagnosis it was of 9,7 days (range between 1 and 45 days), with
5 wrong inicial diagnosis. The results come in two groups
(bimodal): children under 4 and over 8 years. Two different
clinical patterns were presented: in children under 4 years,
rigid column (100%), refusal to walk and sit (75%) and abdominal pain (25%) in T10-T11; about 8 years, back and
buttock pain (80%), fever (75%). Fever appeared in 44% of
the cases and mild fever in 22%. 44.4% had moderate leukocytosis, 66.7% CRP> 20mg/dl and 33.3% over 40mmHr
ERS. Blood cultures were positive in 60% and the Staphylococcus aureus was the only bacteria found (100%). The
most common localizations were L4-L5 and L5-S1. The xray diagnosis was abnormal in 22% of the cases. The TC-99
bone scintigraphy was positive in 78%, and 100% on the 5th
day. All received antibiotic treatment (oxacillin + amikacin
in 78% of patients) and immobilization only 1 (11%). All of
them experienced rapid improvement following initiation
of treatment. The radiological monitoring performed in 5
patients at 8 months on average (range 3-14), showed decreased disc space in 20% of the children (1). In the clinical
follow-up (5 patients) all were asymptomatic.
Conclusions: Blood cultures may be obtained prior to the
administration of antibiotics. The Staphylococcus aureus
is by far the most frequent germ involved in this process,
and may guide the empiric antibiotic therapy. The precocious antibiotic treatment solves the case without sequels.
The SD is an uncommon pathology in children that makes it
often not recognized initially. Wrong diagnosis such as appendicitis, transient synovitis of the hip, sacroiliitis, etc. can
be avoided if SD is sought in a systematic way.
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F091
Spondylodiscitis in toddlers – a report of two cases
Marko Pokorn
University Medical Centre Ljubljana, Department Of Infectious Diseases, Ljubljana, Slovenia
92
Background: Spondylodiscitis is rare in childhood. It is usually a hematogenous infection, most frequently caused by
Kingella kingae and Staphylococcus aureus. The disease can
provide a diagnostic challenge and in toddlers it is usually
recognised after more than 3 weeks’ duration.
Methods: Two children, aged 15 and 16 months were admitted to our Department with an average 3 weeks’ (14-28 days)
duration of refusal to walk, unexplained pain and fever episodes. Both children had normal WBC counts and CRP levels
and received ibuprofen for 7-14 days for presumed synovitis.
ESR in both patients was elevated on admission (48 and 70
mm/h, respectively). Bone scan demonstrated increased uptake in lumbar spine and MR has shown destruction of intervertebral disc with changes in adjacent vertebrae in region L
1-2 and L 4-5, respectively. Blood cultures were negative and
invasive diagnostic procedures were not performed.
Results: Both children were treated with flucloxacillin, 3
weeks IV followed by 3 weeks of oral treatment. The patient
with changes in L 1-2 region also had lumbar spine immobilized for 6 weeks. Both children made an uneventful recovery and were normal at follow-up 6 months after completion of treatment.
Conclusion: In a toddler with fever, unexplained pain and
refusal to walk, spondylodiscitis should be suspected, es-
pecially with elevated ESR. NSAIDs should not be given to
these children as this prolongs time-to-diagnosis.

hospital costs appear still sustainable in specialized centers
and, on the average, adequately covered by current reimbursement policy in Italy; however, it should be noted that
this analysis did not include rehabilitation costs, home care,
work loss compensation, etc.. With an estimated 3,600 new
PJIs per year in Italy, considering all patients treated according to a two-stage approach, an estimated overall direct
hospital cost of approximately 52,000,000 euros/year is to
be expected.
F093
A prospective clinical outcome study of a new biphasic absorbable composite carrier with
Gentamicin in the treatment of chronic osteomyelitis
Martin McNally1, Jamie Ferguson2, Ryan Giordmaina2, Neal Jacobs2, Marion Sutherland2, David Stubbs2, Andrew Woodhouse2
Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
2
Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford, United Kingdom
1
Spondylodiscitis L1-2
F092
Economical impact of two stage hip or knee revision surgery in an italian orthopedic center:
an “activity based costing” analysis
Marco Pozzi1, Lorenzo Drago1, Vitantonio Colucci2, Delia Romanò1, Carlo Luca Romano1
Istituto Ortopedico Irccs Galeazzi, Milano, Italy
2
Università Carlo Cattaneo – Liuc, Castellanza (Va), Italy
1
Aim: A better understanding of peri-prosthetic infection
(PJI) management costs is a key factor to evaluate current
reimbursement policies and may play an important role in
treatment choice. Activity Based Costing (ABC) is a well established methodology to calculate average hospital costs
of different surgical procedures. In the present study, we applied ABC analysis to two-stage hip and knee revision procedures, performed according to a standard protocol.
Methods: Twenty-four two-stage joint revision procedures
(12 hips and 12 knees), randomly chosen among those performed in our department during years 2010-2011, were
included in this retrospective study. All procedures were
performed by the same surgical team and according to a
similar protocol, including preformed hip or knee spacer,
euros, compared to 11,931.8 for two-stage knee revision;
charging 19% indirect costs, overall revision costs raised to
14,676.61 and 14,198.8 euros, respectively. Current standard
reimbursements in Lombardia Region, both for first (euros:
4,455.00) and second stage (from 8,898.00 to 11,904.00 euros), appear roughly in balance with the calculated mean
hospital costs at our facility.
Conclusions: Calculated costs of hip or knee two-stage revision did not differ significantly. This study shows that, even
if economical impact of peri-prosthetic infections is high,
followed by a cementless revision prosthesis, 8 to 12 weeks
after first operation. Based on clinical charts and records,
patient management was divided in: 1) Unit Care (analyzed
costs: a) Personnel; b) Drug administration; c) Medication;
d) Exams; e) Blood sampling); 2) Surgical Intervention (analyzed costs: a) Personnel; b) Drug administration; c) Implant;
d) Other materials).
Results: Average hospital stay: 10.8 days (range: 6 to 20) for
hip and 13.3 days (8 – 18) after knee first stage procedure,
with mean calculated direct costs of 4,780.9 and 4,542.2 euros, respectively; average hospital stay for second stage: 7
days (5 - 8) for hip and 8.2 days (4 - 17) for knee, with an
average cost of 7,552.4 and 7,389.5 euros, respectively.
Overall, direct cost of a two-stage hip procedure: 12,333.3
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: To assess the efficacy and safety of a composite Calcium Suphate and Hydroxyapatite bone void filler with
Gentamicin (Cerament™ G) in the eradication of chronic infection and to investigate the completeness of healing of
cavitary bone defects after surgery.
Methods: 41 patients with Cierny-Mader Stage III and IV osteomyelitis were treated with debridement, implantation of
the carrier, soft tissue closure and systemic antibiotics for 6
weeks. Serum Gentamicin levels were measured in 11 patients for 5 days after surgery.
Clinical outcome and radiographic bone defect filling were
assessed by blinded observers at final follow-up (mean 13.2
months; range 9-17).
Results: There were 25 men and 16 women with mean age
55yrs (27-84) and with chronic osteomyelitis present for a
mean of 10.4 yrs (range 0.5-68). 32 had undergone previous surgery. There were 8 CM IIIA cases, 27 CM IIIB and 6 CM
IVB cases. There were 19 tibias, 8 femurs, 6 humeri, 4 radii, 2
clavicles, 1 calcaneum and 1 talus. 12 required free muscle
flaps for closure.
Cultures revealed Staph aureus in 9, CoNS in 3, Klebsiella in
3, Enterococci in 2, MRSA in 2, Enterobacter in 2, Corynebacteria in 2, Propionibacteria in 2 and one each of Pseudo-
monas, Salmonella, Streptococci, Clostridia, Morganella and
Achromobacter . Four cases were classed as Gentamicinresistant.
39 wounds healed with no wound ooze. One had fluid leakage for 9 days and one for 6 weeks. One patient suffered a
fracture through the bone defect after trauma at 6 weeks
post-surgery. One developed a sterile seroma treated conservatively. There was no recurrence of infection during the
follow-up period. Serum Gentamicin levels rose to a maximum of <2mg/l at 24 hours after surgery.
Bone ingrowth was assessed at 6, 12, 26 and 52 weeks. The
Calcium Sulphate phase dissolved within 12 weeks in all cases. The hydroxyapatite remained visible for many months and
osteogenesis was observed. At 6 months, 75% had complete
defect filling and new bone formation continued through the
whole follow-up period. Only two patients, with completely
uncontained defects had poor defect filling. There was no
toxicity or other adverse reaction to the material.
Conclusions: This new carrier provides safe and effective
delivery of antibiotics into bone defects. It was associated
with good early clinical outcomes in this series. Unlike other
absorbable carriers, wound leakage was uncommon and
good bone ingrowth was observed in almost all cases.
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F094
the very low infection rate identified in our patients, we see
no reason to change our current practice of extended anti-
Acute osteomyelitis in Ugandan children
Antonio Loro
Corsu Rehabilitation Hospital, Kampala, Uganda
Aim: In developing countries osteomyelitis, though extremely common in its chronic form, is rarely seen at its onset. Traditional bone setters are usually the first caretakers,
causing delay in presentation and, often, compounding the
disease evolution. There are different clinical expressions
of the disease at presentation and it is difficult to classify
it, since there is no consensus on what acute means. This
clinical study was undertaken in order to show that the term
acute refers to clinical rather then chronological aspects of
the disease and to emphasize the need to explore the infected bone in urgency since radical debridement alters the
evolution of the disease.
Methods: This study focuses on 30 children, with an average age of 12 years. Delay in presentation was commonly
seen. Swelling and local tenderness were mostly reported
; fever was not a prominent symptom. Long tubualr bones
were routinely involved. Radiographs showed round osteolytic lesions in the medullary cavity; small sequestra were
94
F096
seen in three cases and bone erosions in two. Bone exploration for decompression, pus swab and biopsy was carried
out through a cortical window. Post-operatively the bone
cavity was packed with gauzes and the wound dressed, under sedation, 48 hours later, with delayed suture. Antibiotic
therapy was usually given for 2 weeks; cloxacillin was routinely administered. There was need for wound review in
two patients. Children were followed-up for 6 months.
Results: Healing was obtained in 28 patients, while two cases evolved in chronic osteomyelitis. Staphylococcus aureus
was grown in most cases.
Conclusions: Radical debridement and antiobiotic therapy
are the mainstays of treatment of acute osteomyelitis, where
acute refers to clinical aspects, not duration of symptoms.
Endomedullary abscess require bone exploration ; it should
be done as early as possible. This reduces the risk for chronic
osteomyelitis to follow. There is no need for long term antibiotic coverage if bone debridement has been radical.
F095
Extended antibiotic prophylaxis is associated with low rate of infection after tumor resection
and endoprosthetic reconstruction involving the proximal femur
Werner Hettwer, Thea Hovgaard, Peter Horstmann, Michael Mørk Petersen
National University Hospital, Copenhagen, Denmark
Aim: Endoprosthetic reconstruction after tumor resection
involving the proximal femur is associated with substantial
risk of periprosthetic joint infection (PJI), however the optimal duration of antibiotic prophylaxis for this patient population is unknown. We wish to report our experience with
extended post-operative iv. antibiotic prophylaxis in these
high risk patients.
Material and methods: We performed a retrospective review of all adult patients who underwent endoprosthetic
reconstruction of the proximal femur after tumor resection
for primary or metastatic bone disease in our department
during a 4-year period from 2010 to 2013. All post-operative
emergency medical contacts or orthopaedic hospital admissions, which are registered in our country-wide, national
electronic medical record system, were reviewed to establish rate and type of relevant complications encountered.
118 patients (64 f, 54 m) with a mean age of 65 years (range
16 – 92) received a total of 124 implants. In 45 patients conventional resection at the level of the femoral neck and
cementented long stem protheses were used, 7 patients
required a total femur replacement and the remaining 72
patients underwent proximal femoral replacement.
biotic prophylaxis for high risk patients until very convincing evidence to the contrary becomes available.
Results: Mean survival was 33 months (range 0.5 – 120)
and 39 patients remain alive (33%). We identified 18 major
complications (15%): 12 dislocations (10%), 5 periprosthetic
joint infections (4%), one mechanical complication (1%) and
one local recurrence (1%) resulting in a total of 23 revision
procedures. Two-stage revision was performed successfully
in 3 of the 4 patients with infection. One patient revised for
local recurrence and impending periprosthetic fracture, remains on oral antibiotic treatment due to cultures positive
for propioni bacteria.
Discussion: There is large variation between published infection rates after tumor related endoprosthetic reconstruction, from 0 – 25 % and similar inconsistency in reported
post-operative antibiotic prophylaxis from none to over 7
days. In keeping with findings of a recent systematic review,
suggesting long term antibiotic prophylaxis to be more effective in decreasing risk of PJI in patients undergoing tumor
resection and endoprosthetic reconstruction of the lower
limb, we found an infection rate well below the published
average as well. Despite obvious limitations of our study
(retrospective design, risks associated with antibiotic ”overuse” and relative heterogeniety of the patient cohort), given
33rd Annual Meeting of the European Bone & Joint Infection Society
A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless
hip prostheses
Danielle Neut1, René Dijkstra1, Jonathan Thompson2, Claire Kavanagh3, Henny van der Mei1, Henk Busscher1
1
University Medical Center Groningen, Groningen, Netherlands
2
Depuy Synthes Joint Reconstruction, Leeds, United Kingdom
3
Depuy Ireland, Cork, Ireland
Aim: A degradable, gentamicin-loaded prophylactic coating
for hydroxyapatite(HA)-coated cementless hip prostheses is
developed with similar antibacterial efficacy as offered by
gentamicin-loaded cements for fixing traditional, cemented
prostheses in bone.
Methods: We describe the development pathway from in
vitro investigation of antibiotic release and antibacterial
properties of this gentamicin-HA-coating in different clinically relevant in vitro models to an evaluation of its efficacy
in preventing implant-related infection in rabbits. Bone ingrowth in the absence and presence of coating was investigated in a canine model.
Results: The gentamicin-HA-coating showed high burst release with antibacterial efficacy in agar-assays completely
disappearing after 4 days, minimizing risk of inducing antibiotic resistance. Gentamicin-sensitive and gentamicinresistant staphylococci were eradicated by the drug-loaded
coating in a simulated prosthesis-related interfacial gap.
Gentamicin-HA-coatings prevented growth of bioluminescent staphylococci around a miniature-stem mounted in
bacterially contaminated agar, as observed using bio-optical imaging. Gentamicin-HA-coated pins inserted in bacteri-
ally contaminated medullary canals in rabbits caused a statistically significant reduction in infection rates compared
to HA-coated pins without gentamicin. Bone ingrowth to
gentamicin-HA-coated pins in condylar defects in Beagle
dogs was not impaired by the presence of the degradable,
gentamicin-loaded coating.
Conclusion: The gentamicin-HA-coating constitutes an
effective strategy for infection prophylaxis in cementless
prostheses.
Acknowledgements
This study was funded in part by the University Medical
Center Groningen, The Netherlands, DePuy Synthes, United Kingdom and SASA BV, The Netherlands. Authors were
employed by their own organizations. HJ Busscher is also
director-owner of SASA BV. The authors declare no potential
conflicts of interest with respect to authorship and/or publication of this abstract. Opinions and assertions contained
herein are those of the authors and are not construed as
necessarily representing views of the funding organizations
or their respective employers.
F097
Influence of high temperature on the formation of crystalline degradation products of
vancomycin released from local carriers of antibiotics used in orthopedics
Pavel Melicherčík1, Eva Klapková2, Judl Tobiáš1, Karel Kotaška2, van Landor1
1
Charles University, Department Of Orthopaedics, First Faculty Of Medicine, Motol University Hospital, Praguq, Czech Republic
2
Charles University, Department Of Medical Chemistry And Biochemistry, Second Faculty Of Medicine, Motol University Hospital,
Prague, Czech Republic
Aim: Vancomycin is increasingly being used as a topical antibiotic because of the development of methicillin resistance
in bacterial strains. Consequently, resistance to Vancomycin
has recently been on the rise. One possible explanation for
this phenomenon could be the thermal degradation of Vancomycin to antibacterially inactive crystalline degradation
products (CDP-1s).
Previous experiments, we have verified the formation of CDP1s and their gradual release from carriers in exceeding concentration of the active form of Vancomycin (factor B).
We know that the factor B and CDP-1s are released from polymethylmethacrylate to a much lower level than a bone grafts.
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Therefore, the aim of this study was to demonstrate the effect of polymerization on the formation of CDP-1s.
Recent studies we have found that high temperature does
not affect the increased production of CDP-1s.
Methods: Obtained from 20 samples stored in a thermostat
at 80°C, CDP-1s and the active form of Vancomycin released
from bone grafts into the buffer solution were measured using the high-performance liquid chromatography method
at progressive intervals.
Results: The active form of Vancomycin and CDP-1s was released from bone grafts at temperature of 80°C at almost
the same levels, as bone grafts with vancomycin at temperature of 37°C.
Conclusions: On the basis of the in vitro experiment, we
confirmed the tendency of Vancomycin to convert to antimicrobially ineffective CDP-1s in the same amount as at
temperature of 37°C and at a temperature arising in the po-
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lymerization of the bone cement, 80°C.
Levels of the factor B released from polymethylmethacrylate was in minimal concentration after 9 days. Because of
bone cement most of the antibiotics are incorporated inside
the material and release only a small proportion of vancomycin from the carrier surface.
This work was supported by institutional grant No.
00064203 from the Ministry of Health of the Czech Republic
for the conceptual development of research organizations
(Motol University Hospital, Prague, Czech Republic), Internal Grant of the Motol University Hospital, Prague, Czech
Republic, “Modern Therapy” for the project „Local treatment
of osteomyelitis with antimicrobial peptides released from
local carriers used in orthopaedics“, No. 9777 and grant No.
NT/14218 from the Internal Grant Agency of Ministry of
Health of the Czech Republic.
F098
Do intra-articular steroid injections increase infection rates in subsequent arthroplasty
surgery? A systematic review and meta-analysis of comparative studies
Charalambos Charalambous, Apostolos Prodromidis, Tariq Kwaees
Blackpool Victoria Hospital, Blackpool, United Kingdom
96
Aim: Intra-articular steroid injections are widely used for
therapeutic or diagnostic purposes in the management of
joint arthritis. Concerns have been previously raised regarding the safety of such injections, suggesting that they may
increase the infection rate in subsequent arthroplasty surgery. We carried out a meta-analysis of studies examining
the relation between intra-articular steroid injections and
infection rates in subsequent joint arthroplasty.
Methods: A literature search was undertaken with no language restriction in various databases from their year of inception to February 2014. Eight studies looking at total hip
and knee arthroplasty were included for analysis.
Results: Meta-analysis showed that steroid injection prior to
joint arthroplasty had no significant effect on either deep
infection rates (Risk Ratio=1.87; 95%CI 0.80-4.35; P=0.15)
or superficial infection rates (Risk Ratio=1.75; 95%CI 0.76 –
4.04; P=0.19).
Conclusions: Our results suggest that overall intra-articular
steroid injections do not lead to increased superficial or
deep infection rates of subsequent joint arthroplasty. Further large size cohort studies, using standardized injection
protocols, would be of great value in specifically further
examining whether steroid injections close to the time of
arthroplasty are safe.
F099
Pan american guidelines for the treatment of infections in lower limbs neuropathic ulcers
Alexandre Godoy-Santos1, Ana Lucia Lima1, Priscila Rosalba1, Tulio Diniz-Fernandes1, Sergio Cimerman2, Eduardo Savio3
University Of São Paulo, São Paulo, Brazil
2
Instituto Infectologia Emilio Ribas, São Paulo, Brazil
3
Florida University, Miami, United States
1
Objective: to describe the construction of the Pan American guidelines for the treatment of infections in lower limbs
neuropathic ulcers.
Methods: we selected 21 different specialists PhD from
North America, Central America and Latin America to study
the current literature and build the Pan American consensus for the treatment of infection in lower limb neuropathic
ulcers. The scientific coordinators conducted a literature
review. Participants were divided into specialists groups orthopedic surgeon, infectious disease, radiology, vascular
surgeon, plastic surgeon, endocrinologist and pathologist
- to make critical review of the scientific material selected.
All physicians participated in a face meeting, the 7 working
groups presented their lecture with rational content and
the consensus was written.
Results: This work resulted in a 46 pages publication in Rev.
Panam. Infectol. which established criteria and definitions,
standardized classification system and diagnostic methods
and, also, established the principles of treatment for infections in lower limbs neuropathic ulcers.
In Chapter I, the authors present the three most frequent
comorbidities related to its genesis: the Diabetes Mellitus,
Hansen’s Disease and chronic alcoholism. For patients with
these diseases, it is necessary
Multidisciplinary training groups approach with well-established treatment protocols, close monitoring and prevention and education that can help reduce amputations.
In Chapter II, the authors discuss the diagnostic investigation in neuropathic ulcers of the lower limbs. Classified according to the classification system of diabetic foot ulcers
International Consensus (PEDIS). The authors discuss the
collection of samples for microbiological analysis, evaluation and vascular imaging research.
Chapter III discuss the treatment of infections in neuropathic ulcers of the lower limbs. The authors emphasize that the
success of the treatment of infections in ulcers, the patient
should have their disease well controlled base (Diabetes
Mellitus, Hansen’s disease and chronic alcoholism).
Regional also presents alternatives for initial empirical
choice based on PEDIS classification and origin of the patient (community or health services or hospital).
Conclusion: This design of work task force was well designed
and represents an effective form of updated knowledge organization and definition of principles to be followed in different regions of the world in order to best patient care with
infection in lower limbs neuropathic ulcers.
F100
The choice of organ-sparing surgical method in patients with surgical complications of the
neuropathic form of the diabetic foot syndrome
Vladimir Obolenskiy1, Viktor Protsko2, Pulad Leval3, Darya Ermolova1
City Hospital 13, RNRMU, Moscow, Russia
2
Rufp, Moscow, Russia
3
City Hospital 13, Moscow, Moscow, Russia
1
Deep infection rate meta-analysis
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: to present a review and to estimate the prospects of
using organ-sparing surgical methods in the treatment of
patients with surgical complications of the neuropathic
form of the diabetic foot syndrome (SC NF DFS).
Materials and methods: 1) For the purpose of stimulation
of regeneration after wound debridement in patients with
stage 1 – 2 neuropathic trophic ulcers (according to Wagner’s classification), we use applications of flat clots of platelet-rich autologous conditioned plasma. 2) In patients with
stage 2 neuropathic ulcers caused by deformation of the
anterior foot bones, we employ corrective mini-osteotomy.
3) For stage 3 associated with destruction of the metatar-
sal bones and the metatarsophalangeal joints, we perform
resection of the affected bones, subsequently filling the
defects with a collagen sponge, impregnated with an antibiotic*), and then closing the wound with primary suture.
For patients with Charcot foot syndrome following resection of the affected bones: 4) we fill the defect with a collagen sponge, impregnated with an antibiotic, and then close
the wound with primary suture; 5) or stabilize the mid-foot
using compressive screws; 6) or use extrafocal corrective
osteosynthesis using Ilizarov’s method. 7) If saving the foot
is unfeasible, we amputate using Pirogov’s technique and
osteosynthesis using Ilizarov’s method.
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Results: No recurrence of trophic ulcers or osteomyelitis of
the foot bones was observed during a 1.5-year follow-up in
any of the patients treated according to Options 1 – 4 and
7. There was one case of septic instability of a compressive
screw after more than one month in the Option 5 group,
the screw was then removed. In the Option 6 group, there
was one case of an unstable bone fragment; its removal was
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necessary.
Conclusions: The described methods appear promising in
the treatment of patients with SC NF DFS; their effectiveness
may be assessed after randomized trials are completed.
*) Collatamp EG
F101
No-Air-Plasma currents and ozone therapy in treatment of patients with diabetic foot
syndrome
Results: During this period, 52 patients were treated. Diabetes mellitus (DM) was the main diagnosis associated with
neuropathy (85%), followed by leprosy (8%). There was a
predominance of males (77%) and mean age was 58 years.
Regarding the surgical debridement, 41% of patients suffered partial amputation and 8%, total amputation. 109 bacterial isolates were identified as causative agents of infection, mean 2 isolates per patient. There was a predominance
of Gram-positive cocci (51%), followed by Gram-negative
bacilli (GNB) (47%). Most prevalent agents were Staphylococcus aureus (18%), Enterococcus faecalis (18%) and
coagulase-negative Staphylococci (CoNS) (14%). Among S.
aureus isolates, prevalence of methicillin-resistant (MRSA)
was 48%, but with 100% susceptibility to sulfamethoxazole/trimethoprim (SMT/TMP). Among CoNS, 77% were
methicillin-resistant (MRCoNS), also with 100% susceptibil-
ity to SMT/TMP . All isolates of E. faecalis were susceptible to
ampicillin and vancomycin. Among BGN, predominated the
Enterobacteriaceae (77%), with 89% susceptibility to ciprofloxacin and piperacillin/tazobactam and 100% susceptibility to carbapenems. All patients received antimicrobial
treatment guided by antibiograms for 6 months after debridement. After 6 months follow-up, 75% of patients were
in remission, without signs of infection.
Conclusions: In patients with CO secondary to NFI, DM and
leprosy were the most prevalent etiologies related to the
neuropathy. S. aureus, E. faecalis and CoNS were the most
frequent agents. Occurrence of MRSA and MRCoNS was
high, but with 100% susceptibility to SMT/TMP. Extensive
surgical debridement associated with prolonged antimicrobial therapy led to infection remission in 75% of patients
after 6 months follow-up.
Vladimir Obolenskiy1, Alexander Molotschnikov2
City Hospital 13, RNRMU, Moscow, Russia
2
City Hospital 13, Moscow, Russia
1
98
Aim: to determine the effect of joint use of NO-air-plasma
currents (APC) and ozone therapy (OT) on cellular elements
and the level of bacteriological contamination of wounds
occurring as a result of diabetic foot syndrome (DFS).
Methods: A total of 160 patients suffering from purulo-necrotic feet wounds arising from DFS. Patients’ average age
was 63,9+9,7 years, with men slightly outnumbering women, 57,1 vs. 42,9%, respectively. Predominant conditions
neuro-ischemic form of DFS (>87%).
The main group consisted of 57 (35,6%) patients that underwent corrective surgery on major vessels of lower limbs and
treated daily with APC and OT. The wound then was dressed
with water-soluble ointment.
The first control group consisted of 75 (46,9%) patients
that did not undergo corrective surgery on major vessels of
lower limbs, the second group consisted of 28 (17,5%) patients with corrective vascular measures. Treatment in these
groups involved daily changes of wound dressings and application of water-soluble ointment.
Results: Proliferation activity of fibroblastic cells, collagenogenesis and mitotic activity of epithelial cells in the main
group exceeded the same indexes in the first control group
more than two times and more than 1,5 times in the second
control group. Microbiological contamination of wound in
the main group on the 4-5 day declined down to 103-105
CFM/cm2, however in both control groups this score remained >105 for up to 12 days.
Conclusion: Sequenced application of APC and OT in treatment of patients with DFS is characterized with pronounced
bactericidal effect and boosts epithelialization process,
making it two times faster.
*) «Plazon» & UOTA 60-01 «Medozon»; made in Russia.
F102
Clinical and microbiological characterization of patients with osteomyelitis secondary to
neuropathic foot infection
Priscila Rosalba Oliveira, Alexandre Leme Godoy-Santos, Guilherme Honda Saito, Rafael Trevisan Ortiz, Vladimir Cordeiro
Carvalho, Tulio Diniz Fernandes, Ana Lucia Lima
Hospital Das Clinicas - Universidade De Sao Paulo, Sao Paulo, Brazil
Objective: To describe the clinical and microbiological characteristics of 52 patients with chronic osteomyelitis (CO) secondary to neuropathic foot infection (NFI) admitted to a referral center for Orthopaedics and Traumatology in Sao Paulo,
Brazil
Methods: Retrospective analysis of medical records of patients admitted for treatment of CO secondary to NFI between
January 2005 and December 2013. Cases with of previous
surgical manipulation of the affected foot were excluded. All
patients underwent surgical debridement, that could include
partial or complete amputation, in association to antimicrobial therapy. Only isolates obtained in culture from samples
collected after antisepsis and debridement were considered
for microbiological characterization. Cultures and susceptibility tests were performed in accordance with Clinical and
Laboratory Standards Institute (CLSI) standards.
33rd Annual Meeting of the European Bone & Joint Infection Society
F103
The evaluation of appropriateness of initial empiric therapy in diabetic foot infections
according to culture results
Pınar Aysert Yıldız, Tugba Özdil, Murat Dizbay, Özlem Güzel Tunçcan, Kenan Hızel
Gazi University Faculty Of Medicine, Ankara, Turkey
Aims: Diabetic foot infections (DFI) are common in patients
with diabetes and are associated with high morbidity and
risk of lower extremity amputation. Appropriateness of initial empiric antibiotic therapy has protective effect on the
lower extremity loss. In this study, we aimed to evaluate the
appropriateness of initial empiric antibiotic therapy according to culture results (microorganisms and antibiotic susceptibility test).
Methods: Records of the patients with DFI who admitted
to the hospital between 2005 and 2013 were retrospectively analyzed. The patients with PEDIS score 3 and 4 were
included in the study. Demographic and clinic characteristics of the patients were recorded. Initial empiric antibiotic
treatments and subsequent culture results were evaluated.
The reasons for inappropriate initial empiric therapy were
determined.
Results: Totally, 83 patients with DFI were included in the
study. Of them, 23 (27.7%) were female and 60 (72.3%)
male. Mean age of the patients was 60.7 years. Culture results revealed that the causative agents were polymicrobial
in 21 (25%) of the patients. Totally 104 microorganisms in
83 patients were yielded. Of them, 57 (55%) were grampositive, and 47 (45%) gram-negative microorganisms. The
most common isolated microorganisms are staphylococci
(32.5%), pseudomonas (14.4%), streptococci (13.4%) and
E. coli (10.5%). Methicillin resistance among staphylococci
were found as 25.7%. Extended spectrum beta-lactamase
positivity was 27.3% among Escherichia coli isolates. The
traetment was started empirically in 72 (86.7%) of the patients before culture results. Empirically started antibiotics
were mainly piperacillin-tazobactam (66%), ampicillin-sulbactam (29%). The initial empiric antibiotic treament was
inappropriate in 17 (20.4%) patients. The reasons for inappropriate empiric therapy were the presence of resistant
microorganisms to the initial antibiotics (82.3%), and the
microorganisms that are not covered by initial antibiotics
(17.7%).
Conclusions: In this study, there was an inappropriateness
in the selection of initial empiric antibiotic treatment in 20%
of the patients. The presence of resistant microorganisms,
such as methicillin-resistant staphylococci and ESBL-positive E. coli, or not covering of Pseudomonas aeruginosa by
initial antibiotics were main reasons for the inappropriateness. Therefore, in patients with DFI (PEDIS 3 and 4), the covering of above microorganisms in initial empiric antibiotic
treament could be a good approach.
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F104
Infections of charcot feet with pseudomonas aeruginosa – the underestimated threat
Ulrich Illgner1, Andreas Uekoetter2, Hans Henning Wetz3
Clinic For Rheumaorthopaedic Surgery St Josef Stift Sendenhorst, Sendenhorst, Germany
2
Labor Loer Muenster, Muenster, Germany
3
Clinic For Technical Orthopaedic Surgery And Rehabilitation Muenster, Muenster, Germany
1
Background: Patients with Charcot neuroarthropathy (CN)
present a high risk of ulcers with secondary bone infections
or sepsis. The anticipated rising number of these patients
especially due to the raising number of diabetic patients
represents a social-economic threat to public health systems. Infections with Pseudomonas aeruginosa represent
a severe threat to the patients. Clinical studies are missing.
Aim and Hypothesis: Infections with P. aeruginosa cause a
longer stay in hospital and more operations than infections
with other bacteria.
Methods: All patients who underwent surgery of Charcot neuroarthropathy (CN) of the feet between 1996-2006
(n=205) in our clinic were included. Residence time in hospital and number of surgeries in patients with infections due
to methicillin resistant Staphylococcus aureus (MRSA) vs. P.
aeruginosa were compared to infections with other bacteria.
100
All patients were scanned for MRSA and were isolated when
tested positive and treated according to a defined algorithm.
Results: 79 intra-operative samples exhibited bacterial
growth: 12 cases of MRSA, 14 cases of P. aeruginosa and 53
other bacteria. Patients with deep infections due to P. aeruginosa stayed significantly longer in hospital (52d vs. 35d,
p < .041) and needed significantly more surgery (1.71 vs.
1.28 surgeries, (p < .027). There was no significant difference
between patients with MRSA infections to those without
MRSA or P. aeruginosa.
Conclusion: Infections with P. aeruginosa caused significantly more operations and a longer stay in hospital. Rapid
debridement is the basic treatment. A specific algorithm
for isolation, surgical and antibiotic treatment for P. aeruginosa infections is proposed as a similar algorithm for MRSA
showed to be successful.
F105
Positive bone biopsy culture: spread of the infectious process to the site of a major limb
amputation
Danguole Vaznaisiene1, Rita Sulcaite1, Aukse Mickiene1, Daiva Jomantiene1, Arturas Spucius1, Anatolijus Reingardas1, Kestutis
Balanaska1, Rolandas Sleivys1, Vytautas Kymantas1, Linas Velicka1, Kristina Rysevaite1, Dainius Pauza1, Eric Senneville2
1
Lithuanian University Of Health Sciences, Kaunas, Lithuania
2
Centre Hospitalier Gustave Dron, Tourcoing, France
Aim: to assess the prevalence of positive bone biopsy culture performed at the level of a major limb amputation
(BBA), to compare BBA culture results with the results of the
culture of a bone biopsy performed concomitantly at the
foot wound site (BBF), responsible for the amputation, to
evaluate the possibility of the conservative surgery, and to
clarify the potential spread of ascendant infection.
Methods: Prospective cohort study, aiming to confirm the
results of the pilot study, which showed the ascendant
spread of infection to the site of a major limb amputation
(1). Concomitant BBA and BBF cultures were performed
during limb amputation at our institution during the period
2012-2013 by the methodology described in the literature
(2). A positive culture was defined as the identification of at
least 1 bacteria not belonging to the skin flora or at least 2
bacteria belonging to the skin flora with the same antibiotic
susceptibility profiles, or bacteria belonging to the skin flora
>10 KFV/g or the same bacteria belonging to the skin flora
in two different sites. Taking into account that radical surgery is usually performed at our institution, and to search
for possible ascendant spread of infection, during amputation above the knee, bone biopsy was performed and in the
site of presumed below the knee operation (for diabetics
and/or cases of evident osteomyelitis) with distinct tools.
Results: 1. 110 patients (60M/50F) of mean age 75.4 years
who had major limb amputation including 34 diabetics were
included. BBA culture was positive in 14 (12.73%) cases. In
50% of cases the same microorganisms were identified from
BBA and BBF cultures, without any significant difference
between the species of the isolated bacteria. Compared
with the results of the pilot study (positive BBA in 42.1%,
and positive BBF in 69.6% of cases, respectively (2)), positive
BBA culture was observed less often in this study probably
due to more common radical surgery. 2. During 18 above
the knee amputations, bone biopsies were performed in
the planned site of amputation below the knee (BBP). In 8
cases (44.4%) BBP culture was positive. The microorganisms
identified from BBP were the same as identified in the BBF
culture in 7 (87.5%) cases. In 7 (87.5%) BBP positive cases
BBA culture was negative. In 1 (12.5%) case the same bac-
33rd Annual Meeting of the European Bone & Joint Infection Society
teria were identified in the BBA, BBP and BBF. In 3 (16.67%)
cases bacteria identified in BBF were not found in BBP or in
BBA. In these three cases the amputation below the knee
could have been used as a radical surgery. The other BBP
negative cases were ignored due to negative BBF in these
cases. The reason for above the knee amputation was probably peripheral vascular disease in these cases.
3. Taking into account all positive BBP cases, the positive
bone biopsy culture at the level of a major limb amputation
was detected in 21 (19.1%) cases. In 14 (66.7%) of these cases,
the same microorganisms were identified at the distal site.
Conclusions: Our results confirm that foot infection may
spread silently to the overlying bone where a major limb
amputation will be performed. In most cases presumed
below the knee amputation would be a conservative and
required antibiotic therapy according to the results of bone
biopsy.
References
1. Vaznaisiene D. et al. Major amputation of lower extremity: prognostic value of positive bone biopsy cultures. OTSR 2013; 99(1):88-93.
2. Senneville E. al. Culture of percutaneous bone biopsy specimens for
diagnostic of diabetic foot osteomyelitis: concordance with ulcer
swab cultures. Clin Infect Dis 2006;42:57-62.
Acknowledgement
Science Foundation of Lithuanian University of Health Sciences
F106
Daptomycin effectiveness for the treatment of musculoskeletal infections
Marianthi Papanagiotou, Zoe Dailiana, Nikolaos Karamanis, Aaron Venouziou, Socrates Varitimidis, Konstantinos Malizos
Orthopaedic Department, Larrissa University Hospital, Larissa, Greece
Aim: Daptomycin is indicated for the treatment of musculoskeletal infections due to gram-positive pathogens. The
aim of the study was to evaluate the efficacy and safety of
intravenously administrated daptomycin for the treatment
of musculoskeletal infections and to compare the therapeutic outcome between patients with soft tissue infections to
those who had bone involvement.
Method: Two hundred and nineteen (219) patients (82 female-137 male) with infections of the upper and lower
extremity were treated with intravenous administration of
daptomycin. A total of 161 soft tissue infections (85 superficial and 76 deep) and 58 bone infections [septic arthritis (10), osteomyelitis (8), bone implant related (40)] were
treated. Previous failed antibiotic therapy had been administrated in 53 cases. During hospitalization, 148 patients
underwent surgical procedures for the treatment of their
infection (all patients with bone involvement and in 56% of
those with soft tissue infections). Simple incision and drainage was performed in 57 of them, and more radical soft tissue and/or bone debridement in 91. Cultures (swab, tissue
and /or bone) were received in 132 patients. Daptomycin
was administrated initially empirically as a monotherapy
in 119 patients, while in the other 100 antibiotics to cover
Gram(-) pathogens were added.
Results: Cultures were positive in 99 of the 132 cases. For
the majority of the infections (72) Gram (+) cocci were responsible, while in 27 cases more than one pathogens were
isolated. Infection was cured in 93.1% of the cases while in
the other 6.9% further procedures and antibiotic exchange,
due to Gram(-) resisted pathogens required. No difference
between treatment success rates was noted between bone
and soft tissue infections The mean daptomycin administration period was 6 days in cases of soft tissue infections and
15 days in cases with bone involvement, while the mean
administration dose was 5,4 mg/kg and 6,7 mg/kg respectively. Two patients revealed adverse events possibly related
to daptomycin (simple rush and anaphylactic reaction) and
in one of them drug administration was interrupted.
Conclusion: The majority of musculoskeletal infections
are Gram(+) related. Empiric daptomycin administration
concomitantly with antibiotics to cover Gram (-) bacteria,
proved effective and safe for the treatment of musculoskeletal infections. However for the treatment of bone sepsis
higher doses of the drug and prolonged administration
periods in addition with radical surgical intervention are
required.
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101
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F107
Development of novel daptomycin-loaded poly-ε-caprolactone microparticles for skeletal
drug delivery – in vitro antibacterial activity and biocompatibility
Inês Santos Ferreira1, Bertrand Bétrisey2, Lídia Gonçalves1, Ana Bettencourt1, António Almeida1, Judith Kikhney3, Annette Moter3,
Andrej Trampuz4
1
Institute For Medicines Research (Imed.Ulisboa), Faculdade De Farmácia, Universidade De Lisboa, Lisboa, Portugal
2
Infectious Diseases Service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
3
Center For Biofilms And Infection, German Heart Institute Berlin, Berlin, Germany
4
Center For Musculoskeletal Surgery, Charité-Free And Humboldt University Of Berlin, Berlin, Germany
102
Aim: Poly-ε-caprolactone has been widely used for controlled drug delivery due to its biocompatibility and biodegradation. Recently it has been widely used in development of nano and micro-particulate bone biomaterials for
local antibiotic delivery. Our aim is to develop a biomaterial
with improved antibiotic release profile by incorporation of
daptomycin-loaded poly-ε-caprolactone microparticles.
Methods: Daptomycin-loaded microparticles (MP) using
poly-ε-caprolactone (PLC) were prepared by double-emulsion w1/o/w2-solvent evaporation method. Particles’ morphology (transmission electron microscopy-TEM), encapsulation efficiency (EE), surface charge (zeta potential), size
distribution, in vitro release profile and biocompatibility
with osteoblasts were assessed. All batches were prepared
in triplicate and plain particles were used as controls.
Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of antibiotic-loaded MP were determined by isothermal microcalorimetry at 37ºC. MP suspensions were prepared in Mueller-Hinton broth supplemented
with 50mg/L Ca2+. Staphylococcus aureus (ATCC 29213 and
ATCC 43300; 1-5×10^5 CFU/mL) was used and measurements
of heat flow (W) were performed for 24 hours at 10 seconds
intervals. All samples were tested in triplicates. Interaction between planktonic bacteria and fluorescence labeled particles
was characterised by fluorescence microscopy.
Results: Daptomycin-loaded MP presented a micrometer
size range, confirmed by TEM, high EE values and a con-
trolled drug release profile. The biocompatibility assessment showed a high percentage of viable osteoblasts after
prolonged incubation with daptomycin-loaded MP. Daptomycin-loaded PCL-MP were able to inhibit bacterial growth
at a concentration of 2.7 mg/mL for S. aureus ATCC 29213
and 5.3 mg/mL for S. aureus ATCC 43300. Additionally, plain
MP led to a change in growth profile characterised by a reduction of maximum amount of heat produced proportional to particle concentration in the samples. This peak height
suggests that the carrier itself affects bacterial growth. Fluorescence microscopy revealed the formation of clusters of
bacteria and microparticles.
Conclusions: New daptomycin-loaded PCL-MP were developed and showed adequate antibacterial activity. Daptomycin-loaded PCL-MP may be of interest for local drug delivery
to the bone due to their biocompatibility with osteoblasts
and to the their interaction with bacteria. These are promising and exciting results regarding the improvement of local
antibiotic delivery for treatment of bacterial bone infections
caused by Gram-positive bacteria.
Acknowledgements
Work supported by the Portuguese government (Fundação para a Ciência e a Tecnologia) and FEDER: SFRH/
BD/69260/2010 (PhD grant given to Inês Santos Ferreira),
research project EXCL/CTM-NAN/0166/2012 and PEst-OE/
SAU/UI4013/2011.
F108
No need for prolonged intravenous antibiotics in bacteremic bone and joint infections of
childhood
Markus Pääkkönen1, Pentti Kallio2, Markku Kallio2, Heikki Peltola2
Turku University Hospital, Turku, Finland
2
University Of Helsinki, Helsinki, Finland
1
Aim: Short intravenous course of 2-4 days followed by oral
administration has recently been introduced as the treatment of choice for childhood hematogenous bone and joint
infections.1,2 Children tolerate high oral doses of frequently
administered beta-lactams or clindamycin remarkably well
during the total 2-3-week administration that is usually
sufficient in uncomplicated cases2-5 Still, no study has yet
analyzed short term intravenous treatment in patients with
positive blood cultures.
Methods: 265 children previously healthy children age 3
months to 15 years with a culture proven bone and/or joint
infection were prospectively enrolled as part of a treat-
33rd Annual Meeting of the European Bone & Joint Infection Society
ment trial.5 Blood cultures were taken on admission from
all patients. Patients were given first-generation cephalosporin (150mg/kg/day divided in four equal doses, q.i.d.)
or clindamycin (40mg/kg/day q.i.d.). Intravenous administration was changed to oral once clinical recovery and descending C-reactive protein (CRP) was observed. The total
antibiotic course lasted 10-30 days according to randomization, that was part of the main trial.5 The same dose and frequency were used in both intravenous and oral administration. A subanalysis on patients with or without bacteremia
was performed regarding the length of intravenous therapy. The end-point was all potential permanent sequelae or
recurrence of infection during the one-year follow-up. T-test
was used to calculate p-values.
Results: 157 patients (59%) had bacteremia. The antibiotic
was administered intravenously for 4 ± 0.3 and 4 ± 0.2 days
(mean ± standard error of mean, SEM) in the non-bacteremic and bacteremic cases, respectively, and there was
no difference between the groups (p=0.97). CRP and the
erythrocyte sedimentation rate normalized equally (p=076,
p=0.63). There was no difference between groups in the low
sequelae rate.
Conclusions: Short term intravenous antibiotic treatment
followed by oral therapy is sufficient in children with an
acute bone and/or joint infection also when blood cultures
prove positive. Key to successful short term treatment is
frequent high-dose administration of well absorbing antibiotics. Prolonged intravenous treatment may be needed
in cases in neonates, children with underlying illnesses or
when complications arise.
References:
1. Peltola et al. N Eng J Med 2014; 370: 352-60.
2. Pääkkönen et al. Pediatr Clin North Am 2013; 60: 425-36.
3. Kolyvas E, Ahronheim G, Marks MI, Glendill R, Owen H, Rosenthal L.
Oral antimicrobial therapy of skeletal infections in children. Pediatrics 1980; 65: 867-71.
4. Tetzlaff TR, McCracken GH Jr, Nelson JD. Oral antimicrobial therapy
for skeletal infections of children. II. Therapy of osteomyelitis and
suppurative arthritis. J Pediatr 1978; 92: 485-90.
5. Peltola H, Pääkkönen M, Kallio P, Kallio MJT. Clindamycin vs first-generation cephalosporins for acute osteoarticular infections of childhood – prospective quasi-randomized controlled trial. Clin Microbiol
Infect. 2012; 18: 582-9.
F109
Mechanical properties of a bioactive glass granules/morselized allograft mixture in confined
compression
Dennis Hulsen , Jan Geurts , Bert van Rietbergen , Chris Arts
1
Eindhoven University Of Technology, Maastricht University Medical Centre, Son, Netherlands
2
Maastricht University Medical Center, Maastricht, Netherlands
3
Eindhoven University Of Technology, Eindhoven, Netherlands
4
Maastricht University Medical Center, Eindhoven University Of Technology, Maastricht, Netherlands
1
2
3
4
Aim: Disadvantages of natural bone graft materials are its
limited availability and the donor-dependency of both mechanical properties and biological regenerative potential.
Synthetic materials are an appealing alternative. Bioactive
glass (BAG) is an osteoconductive material that possesses
antibacterial properties, but has rarely been used in loadbearing applications so far. In order to assess their applicability in load-bearing defects, we here measured the mechanical properties of BAG allograft mixtures in confined
compression conditions for different mixture ratios.
Methods: S53P4 BAG granules and human morselized cancellous allograft were mixed in five different volume ratios
(0, 25, 50, 75, and 100 volume % BAG). Five samples of 3 mL
graft material mixtures were prepared per group. Sample
material was impacted into a cylindical container using a
drop weight (Walschot, 2010) and impaction strain was
measured. Impacted samples were thereafter subjected to
cyclic compression mimicking pelvic stress levels during
walking. During and after loading, loading strain, elastic
stiffness, and creep strain of the sample were determined.
Following confined compression, micro computed tomography scans of the samples were made to determine graft
layer porosity.
Results: Impaction strain decreased with increasing BAG
volume content from 0.6 for pure allograft to 0.3 for pure
BAG. Elastic stiffness increased from 116 MPa for pure allograft to 654 MPa for pure BAG. Both loading strain (0.23
for pure allograft, 0.01 for pure BAG) and creep strain (0.09
for pure allograft, 0.01 for pure BAG) decreased with increasing BAG volume content. Finally, porosity decreased with increasing BAG volume content, from 66% for pure allograft
to 15% for pure BAG.
Conclusions: When including allograft only, good impactability was obtained, but the stiffness in confined compression was lowest, whereas the creep was rather high.
When including BAG only, the impactability is less which
can lead to a less favorable filling, but the stiffness and creep
properties are improved. Based on these results, we propose a 1:1 BAG granules/allograft volume mixture in reconstruction for load-bearing bone defects. This will still result
in favorable mechanical behavior of the graft layer, while
decreasing the amount of donor material that is required.
Acknowledgements
This study was sponsored in kind (materials) by BonAlive
Biomaterials Ltd. No additional disclosures from all authors.
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References
Walschot LH, Schreurs BW, Buma P, Verdonschot N. Impactability and
time-dependent mechanical properties of porous titanium particles for
Abstracts free paper sessions
application in impaction grafting. J Biomed Mater Res B Appl Biomater
2010 Oct;95(1):131-40.
F110
Iliopsoas abscess: treatment & surgery
ics was the preferred treatment for most authors and was
performed in 116 (87.9%) of cases with an average of 1.6
procedures (up to 6). The graft was preserved in majority of
cases with only 10 (7.6%) being removed. This included one
infected case presenting within 7 days of the index procedure and nine cases after 7 days. Continuous joint irrigation
was undertaken in 22 (16.7%) cases, of which almost half
required an additional formal arthroscopic procedure.
Functional outcomes after the treatment for infection were
not consistently reported across studies. Where reported,
range of motion was maintained in majority of patients
with 40% having knee laxity (Lachman and/or Pivot shift
test positive). A median Lyshom score of 88 (range 14-100)
was measured in 65.2% of patients.
Conclusion: Arthroscopic debridement with intravenous
antibiotics with primary intention of graft preservation in
most frequently employed and is our recommendation.
Graft removal should be strongly considered in late presentations. Conservative treatment with continuous irrigation
and antibiotics required a surgical intervention in nearly
half of the procedures.
Taj Haubuf
Aarhus University Hospital, Aarhus, Denmark
104
Abscesses in the iliopsoas muscles have occult clinical characteristics that may cause diagnostic delay, resulting in
mortality and morbidity.
Aim: To describe our experience with treating iliopsoas abscesses.
Methods: Between 2008 and 2014, 22 patients with iliopsoas abscess (one bilateral) were treated. Retrospectively,
the records and radiological examinations were reviewed to
explore clinical features, microbiology and treatment.
Results: Median age was 41(1-85) years. Fourteen patients
had co-morbidities: rheumatic-/dermato-/hemato-/neurologic disorders, addiction, hepatitis, COPD, uremia, c. recti
and ischemic heart failure.
In nineteen patients blood cultures were taken and 18 were
positive: Salmonella were cultured in 1 patient, Enterococcus in another and Staph. Aureus were cultured in 16 patients, of whom one had MRSA. Aspiration from one patient
showed Tuberculosis. Fifteen patients had sacroiliitis. Nine
patients had other infectious foci included endocarditis,
abscesses in lung, labia and extremities, osteomyelitis and
arthritis in hip and knee. No patients had spondylodiscitis.
Radiological elucidation included MR scan solely in 14 cases, CT scan solely in 4 cases. In 4 cases CT scans were supplemented with MR scans. Median time from admission to
operation was 8days (1-33).
All patients were operated in lateral position with an incision along the iliac crest. After drainage pulse lavage, local
antibiotic fleece and suction drain were used. Surgery was
chosen over ultrasound drainage do to sacroiliitis and other
infectious foci.
Two patients died from the infection. Three other patients
died from deterioration of their general condition due to comorbidity. So far no patient had recurrence.
Results: Patients with iliopsoas abscess represent a complex
clinical and diagnostic challenge and may benefit from a multidisciplinary approach. However, surgical drainage is simple.
F111
Management of bacterial septic arthritis following acl reconstruction with autologous
hamstring grafts: a systematic review
Kenan Kursumovic, Charalambos Panayiotou Charalambous
Blackpool Victoria Hospital, Blackpool, United Kingdom
Background: Septic arthritis following Anterior Cruciate
Ligament (ACL) reconstruction is a serious complication.
However, cases are rare and often difficult to diagnose with
no best practice guidance on their management.
Aim: To review the literature on the management of bacterial septic arthritis following ACL reconstruction with an autologous Hamstring graft.
Method: A systematic review of the literature on PubMed and
EMBASE databases was performed. Selected articles were reviewed for additional relevant studies. 764 publications were
initially identified, of which 28 were eligible for full text review and 15 fulfilled the inclusion criteria. All were retrospective studies except for one prospective case control study.
Inclusion criteria required that all studies had three or more
reported cases of bacterial septic arthritis with a Hamstring
graft. Where a mixture of infected ACL graft types was described, data was extrapolated to obtain values for Hamstring grafts only. Authors were contacted for additional
breakdown of data.
Results: 132 cases of infected Hamstring graft ACLs were
identified with a mean (standard deviation) patient age of
26 (+/-9) years and follow up of 40 (+/- 24) months. Mean
time to presentation from index procedure was 21 (+/-40)
days, with 63 (47.7%) and 130 (98.5%) presenting within two
weeks and two months, respectively. The most common
organism was coagulase negative staphylococcus (n=68,
51.5%), followed by staphylococcus aureus (n=28, 21.2%).
Arthroscopic debridement with intravenous antibiot-
33rd Annual Meeting of the European Bone & Joint Infection Society
F112
Tuberculous osteomyelitis in children and adolescents
Antonio Loro
Corsu Rehabilitation Hospital, Kampala, Uganda
Aim: Tuberculous osteomyelitis of the long bones in children is quite uncommon, though not rare in countries
where tuberculosis is endemic. The diagnosis is challenging
and, often, delayed since clinically and radiographically the
specific infection may ¬mimic generic, aspecific osteomyelitis or other bone disorders. Diagnostic delay is, therefore,
quite common. From 2010 to 2013 all the patients admitted with a diagnosis of osteomyelitis underwent an intraoperative biopsy in order to estimate the prevalence of the
disease and to evaluate if there were clinical or radiological
aspects which, preoperatively, could suggest it.
Methods: In the last four years 51 patients, 27 males and
24 females, were treated for tuberculous osteomyelitis in
our institution. Their average age at presentation was 9.7
years; the youngest patient was 18 months old and the
oldest 16 years. Ten patients presented with multiple sites
involvement. Plain radiographs of the affected segments
were always obtained. Findings were extremely variable:
cystic lesions, sequestration (with and without involucrum),
pathological fractures, medullary sclerosis, periosteal reaction. There was a moderate anaemia in all the patients and
the ESR was raised in 22 patients; it was above 100 mm/hr
in five patients with multiple sites involvement. HIV test
proved negative in 20 kids. Surgery was performed in all of
them; biopsy specimen consisted of pyogenic membranes
and bone chips harvested from the sequestrum.
Results: In total 61 bones were involved. Tibia (27) and femur (15) were the most involved segments, followed by
humerus (10) and fibula (2), radius (2), clavicle (2) and metatarsals (2). Clinical signs were quite aspecific, with swelling,
local tenderness, pus discharging sinuses, exposed sequestra. Radiographic findings were extremely variable and laboratory tests were not diriment in suggesting a diagnosis
of tuberculosis. The index case was not found for any of the
patients. Diagnostic delay varied from 3 months to 5 years;
it was 11 months on average. Histology was the clue for the
diagnosis. All the children were cured with surgery and 8
months long medical therapy (rifampicin, isoniazid, pyrazinamide and ethambutol). Permanent sequelae included
fused joints, limb length discrepancy, angular deformity.
Conclusions: The 51 patients under review were part of 707
children who had been admitted, from 2010 to 2013, with
a diagnosis of generic haematogenous osteomyelitis. The
prevalence of 7.2% should alert the clinician about the diagnosis of tuberculous osteomyelitis of long bones, even in
small children. Since there are no diriment clues offered by
clinical history, laboratory tests or radiograms intraoperative biopsy is mandatory in any case of generic, pyogenic
osteomyelitis in areas where tuberculosis is endemic.
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F113
F114
Gentamicin-collagen sponges to prevent surgical-site infection following hip arthroplasty in
patients with femoral neck fracture
Increased risk of revision for infection in total hip prosthesis in patients with rheumatoid
arthritis
Marianne Westberg1, Frede Frihagen1, Wender Figved2, Bjarne Grøgaard1, Haldor Valland3, Helge Wangen4, Finnur Snorrason5
1
Oslo University Hospital, Ullevål, Oslo, Norway
2
Bærum Hospital, Bærum, Norway
3
Diakonhjemmet Hospital, Oslo, Norway
4
Elverum Hospital, Elverum, Norway
5
Drammen Hospital, Drammen, Norway
Johannes Cornelis Schrama1, Anne Marie Fenstad2, Havard Dale2, Leif Havelin2, Geir Hallan2, Soren Overgaard3, Alma B
Pedersen4, Johan Karrholm5, Goran Garellick5, Pekka Pulkkinen6, Antti Eskelinen7, Keijo Makela8, Lars Birger Engesaeter2, Bjorg
Tilde Fevang2
1
Haukeland University Hospital, Bergen, Norway
2
The Norwegian Arthroplasty Register, Haukeland University Hospital, Bergen, Norway
3
Institute Of Clinical Research, University Of Southern Denmark, Odense, Denmark
4
Department Of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
5
The Swedish Hip Arthroplasty Register, Gothenburg University, Molndal, Sweden
6
Department Of Public Health, University Of Helsinki, Helsinki, Finland
7
The Coxa Hospital For Joint Replacement, Tampere, Finland
8
Department Of Orthopaedics And Traumatology, Turku University Hospital, Turku, Finland
Aim: Surgical-site infection (SSI) is a feared complication in
hip arthroplasty, especially following femoral neck fracture
in the elderly, associated with substantially increased morbidity, mortality and costs. Gentamicin-containing collagen
sponges are widely used for prevention of SSI, but their effectiveness in joint replacement surgery remains unclear.
The aim of this trial was to evaluate the effect of using local
application of gentamicin-containing collagen sponges in
addition to systemic antibiotic prophylaxis to reduce early
SSIs following hemiarthroplasty in patients with femoral
neck fractures.
Methods: In this multicenter, double-blind controlled trial,
we randomly assigned 694 patients with femoral neck fracture undergoing a hemiarthroplasty to receive either two
gentamicin-containing collagen sponges into the hip joint
at the end of the operation (the gentamicin-collagen group)
or no intervention (the control group) in addition to standard prophylactic intravenous antibiotics with cephalotin.
The primary end point was SSI within 30 days after surgery.
All analyses were based on intention-to-treat.
Results: There was no significant difference in SSI between
the gentamicin-collagen group (16 of 329 [4.9%]) and the
control group (19 of 355 [5.4%], relative risk, 0.91; 95% confidence interval, 0.48 to 1.79; p=0.77). No significant differences were observed between the gentamicin-collagen
group and the control group, respectively, in superficial SSI
(2 of 329 [0.6%] versus 3 of 355 [0.8%]; p=1.00) and deep
SSI (14 of 329 [4.3%] versus 16 of 355 [4.5%]; p=0.87). There
were no significant differences between the groups regarding type of bacteria isolated.
Discussion: This is the first randomized controlled trial studying the prophylactic use of gentamicin-collagen sponges in
joint replacement surgery. Several studies have evaluated
the effectiveness of collagen-gentamicin sponges used as
prophylaxis, especially in cardiac surgery, and the results
are conflicting 1-4. Differences in microbiological spectra
may have contributed to the different study outcomes. Furthermore, there has been some debate on the surgical technique for implantation of the collagen-gentamicin sponges.
In two of the studies, they were pre-soaked in saline to facilitate implantation2, 3. This may have affected the results, as
wetting the sponges may reduce the gentamicin content in
the sponges. Finally, the causes of SSI are multifactorial and
unknown factors may have influenced the results.
Conclusions: In this randomized multicenter trial involving
elderly patients treated with a hemiarthroplasty because of
femoral neck fracture, locally administered collagen-gentamicin sponges did not reduce the incidence of SSI compared to no intervention.
Reference List
1.Friberg O, Svedjeholm R, Soderquist B, Granfeldt H, Vikerfors T, Kallman J. Local gentamicin reduces sternal wound infections after
cardiac surgery: a randomized controlled trial. Ann Thorac Surg
2005;79(1):153-162.
2. Bennett-Guerrero E, Ferguson TB, Jr., Lin M et al. Effect of an implantable gentamicin-collagen sponge on sternal wound infections following cardiac surgery: a randomized trial. JAMA 2010;304(7):755762.
3.Bennett-Guerrero E, Pappas TN, Koltun WA et al. Gentamicin-collagen sponge for infection prophylaxis in colorectal surgery. N Engl J
Med 2010;363(11):1038-1049.
4.Schimmer C, Özkur M, Sinha B et al. Gentamicin-collagen sponge reduces sternal wound complications after heart surgery: A controlled,
prospectively randomized, double-blind study. J Thorac Cardiovasc
Surg 2012;143(1):194-200.
Aim: The major objective of the present study was to investigate the risk of revision for infection after primary total hip
replacements (THRs) in patients with rheumatoid arthritis
(RA) during a 16-year period. We compared RA patients
with osteoarthritis (OA) patients in order to detect any differences in the risk of revision for infection and to compare
change over time in this risk for the two patient groups. Furthermore, we studied the time from primary implantation
to revision for infection in the two groups and evaluated the
THRs fixated with antibiotic loaded cement and the uncemented THRs separately.
Methods: We identified 13,384 THRs in RA patients and
377,287 THRs in OA from 1995 until 2011 in the dataset of
the Nordic Arthroplasty Register Association (NARA). Survival analyses with revision for infection as endpoint were
performed using Kaplan-Meier survival curves and multiple
Cox regression to calculate the relative risk (RR) adjusted for
diagnosis, age, gender, type of fixation and year of primary
surgery. An extended Cox model was used to estimate RR
F115
Implant sonication as a diagnostic tool for infection in revision surgery
Floor van Diek1, Miranda van Hooff1, Christiaan Albers2, Jacques Meis3, Jon Goosen1
1
Sint Maartenskliniek, Nijmegen, Netherlands
2
Radboudumc, Nijmegen, Netherlands
3
Canisius-Wilhelmina Ziekenhuis, Nijmegen, Netherlands
Aim: Sonication of removed implants enables microbiological analysis of the so-called biofilm. The objective of this
study was to determine the diagnostic accuracy of sonication in detecting prosthetic-joint infection (PJI) in revision
arthroplasty suspected for a septic cause or not.
Methods: Patients who underwent prosthetic revision surgery for any reason were enrolled. Cases were scored as
early or late suspected or unsuspected PJI according to the
criteria for PJI postulated by the Musculoskeletal Infection
33rd Annual Meeting of the European Bone & Joint Infection Society
within various follow-up intervals in uncemented and antibiotic loaded cement THRs.
Results: RA patients with THR had a 1.3 times (CI 1.0-1.6)
higher risk of revision for infection than OA patients. We
found a more increased risk of revision for infection from
2002 onward in RA patients compared to OA patients. The
risk of revision for infection during the first three months
postoperatively and from 8 years postoperatively on was
higher in RA patients with THRs fixated with antibiotic loaded cement than in OA patients. In the uncemented THRs
there was a trend to a continuously slightly higher risk in RA
compared to OA.
Conclusions: The overall risk of revision for infection after
THR was higher in RA patients. After the year 2001, the risk
of revision for infection in RA was more increased than in OA
patients. The risk of early and late infection leading to revision was increased in RA with THRs with antibiotic loaded
cement fixation compared to OA. This is in contrast to the
findings in the uncemented THRs.
Society (MSIS). Peri-operatively, six tissue biopsies were obtained and the removed implants were sent for sonication.
Biopsies were taken as golden standard for diagnosis of PJI
and were considered positive if in two or more specimens
the same microorganism was cultured. Sonication was
positive when at least 50 colony-forming units per milliliter
were observed. Compared with the cultures, sensitivity and
specificity of sonication results were determined in case of
suspected and unsuspected PJI.
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Results: Two-hundred-and-fifty-four revision implant surgeries were enrolled. In 49 cases of early suspected PJI debridement and retention of the prosthesis with exchange of
the mobile parts was performed. In 41 late suspected cases
a two-stage and in 164 unsuspected cases a one-stage revision arthroplasty was performed. Compared with tissue
cultures, the sensitivity of the sonication-fluid analysis was
relatively low: 0.77 [95%CI 0.63-0.92] in the late suspected, 0.64 [95%CI 0.63-0.92] in the early suspected and 0.10
Abstracts free paper sessions
[95%CI 0.05-0.15] in the unsuspected cases of PJI. The specificity was high in all three groups (0.96 [95%CI 0.63-0.92] in
the early suspected group versus 1.00 in the other groups).
Conclusion: Based on our results, sonication is a highly specific test for diagnosing PJI. A positive sonication is highly
associated with PJI in all kinds of revision cases. Nonetheless, a negative sonication does not rule out PJI. Sonication
is a useful indicator but cannot be considered as determining diagnostic tool in PJI yet.
F116
Normal C-reactive protein levels do not exclude prosthetic joint infection
Daniel Pérez-Prieto1, María Eugenia Portillo2, Carlo Gamba3, Juan Pablo Horcajada3, Lluisa Sorlí3, Albert Alier3, Lluís Puig-Verdié3,
Joan Carles Monllau3
1
Hospital Del Mar, Barcelona, Spain
2
Laboratori De Referència De Catalunya, Barcelona, Spain
3
Parc De Salut Mar, Barcelona, Spain
108
Introduction and Aim: Diagnosis of Prosthetic Joint Infection (PJI) could be difficult especially in low grade infections.
Several authors (Della Valle 2011, Parvizi 2010) consider
Erythrocyte Sedimentation Rate (ESR) and, in particular, CReactive Protein (CRP) basic to diagnose PJI, in such a way
that negative CRP excludes infection. The hypothesis of the
present work is that there are some PJI in which the CRP
could be normal.
Material and Methods: all PJI accounted in a University Hospital between 2012 and 2013 were retrospectively revised.
Only infections with positive cultures were included. Altogether there were 32 cases; the most common of them were
Total Knee Arthroplasty (TKA) with 17 cases (53%); hip arthroplasties represent 37% of all cases, 10 were Total Hip Arthroplasty (THA) and 1 was a Hemi-Arthroplasty (H-HA); the
rest were 3 shoulder arhtroplasties (2 Reverse Shoulder Arthroplasty, RSA, and 1 Hemi-Arthroplasty, S-HA) and 1 Total
Elbow Arthroplasty (TEA). The levels of CRP prior to surgery
as well as the infective germen were collected.
Results: mean age of the sample was of 68.57 years old.
There were 13 male (40%). Cultures showed 11 Coagulase
Negative Staphilococci (CNS), 6 Staphilococcus aureus (1
MRSA), 5 Propionibacterium acnes, 8 infections due to Gram
negative bacteriae and 2 infectionts due to streptococci. It
was not possible to obtain preoperative CRP levels in 2 patients (1 TKA and 1 RSA). Preoperative CRP levels were lower
than 0.8 mg/dl in 9 patients (28%): 5 SCN (3 THA, 1 RSA and
1 TEA), 2 Propionibacterium acnes (1 THA and 1 S-HA) and 2
Staphilococcus aureus (2 TKA).
Conclusions: preoperative CRP has been of little value in the
diagnosis of PJI, particularly in those of low grade as some
authors have recently published (Piper 2010). Additionally,
in the present study it has been found negative-CRP PJIs in
TKA or THA even with virulent bacteriae. Then again, we believe the CRP is useful in the follow up of PJI but should be
considered with caution for its diagnosis and in any case can
exclude infection.
F117
Prosthetic and periprosthetic staphylococcal strains recovered from sonication fluid and
tissue cultures of revisions of total hip and knee replacements
Panagiotis Lepetsos1, Dimitrios Argyris2, Spyridon Kamariotis2, Sofia Tani3, Athanasios Adamopoulos2, Maria Koursopoulou2,
Sofia Katara2, Moyssis Lelekis4,Antonios Stylianakis2
1
D’ Orthopaedic Department, Kat-Hospital, Kifissia, Athens, Greece
2
Laboratory Of Implant Infections-Microbiology Department, KAT-Hospital, Kifissia, Athens, Greece
3
Operating Room, Kat Hospital, Kifissia, Athens, Greece
4
Internal Medicine Department, Kat-Hospital, Kifissia, Athens, Greece
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: To study the staphylococcal strains recovered by sonication of septic loosened hip and knee arthroplasties components and the respective periprosthetic tissue cultures,
on species level and resistance profile.
Methods: From 10/2012 till 3/2014, we prospectively included patients who underwent revision of total hip and
knee arthroplasties. The explanted prostheses were sonicated according to the Trampuz’s method*. Five periprosthetic
tissue specimens of every arthroplasty were cultured according to the laboratory practice. Polymicrobial infections,
but not mixed staphylococcal infections were excluded to
prevent cross contamination among the examined isolates.
The identification and susceptibility testing of staphylococcal isolates were performed by an automated system**.
Strips with different concentrations of proper antibiotics***
were used for confirmation of rare resistance phenotypes
previously found by the automated system and measuring
the MIC levels of daptomycin and vancomycin.
Results: We included 22 patients with hip (n1=16) and knee
(n2=6) prosthesis removal with confirmed prosthetic joint
staphylococcal infections (PJSI). Twenty-four CoagulaseNegative Staphylococcus (11 methicillin-resistant, MR-CNS)
and 7 Staphylococcus aureus isolates (2 methicillin-resistant,
MRSA) were identified from the sonication fluid cultures, in
contrast to 13 CNS (4 MR-CNS) and 2 methicillin-sensitive S.
aureus (2 MSSA) isolates from tissue cultures. In 7 patients
the staphylococcal isolates (1 MSSA, 3 MR-CNS and 3 MSCNS) were recovered only from the sonication fluid cultures.
The same results of identification and susceptibility testing
were received by both cultures from the five patients’ equal
numbered staphylococcal isolates. One identification species
level discrepancy was observed between sonication fluid
(S. saprophyticus) and tissue cultures (S. epidermidis). Five
staphylococcal species mixed infections were detected only
by sonication. Furthermore, by sonication, heterogenous resistance populations of two prosthetic staphylococcal strains
(S. epidermidis and S. aureus) and none of the periprosthetic
staphylococcal ones were detected. Two prosthetic MR-S.
epidermidis isolates (MRSE) were resistant to teicoplanin too,
four MRSE had vancomycin MIC=4mg/L while the respective
perisprosthetic isolates were sensitive to teicoplanin and had
vancomycin MIC=2mg/L. All staphylococcal isolates were
sensitive to rifampicin and daptomycin.
Conclusions: The prosthetic staphylococcal strains had
higher vancomycin MIC values and were more resistant
than the respective periprosthetic ones, especially to oxacillin and teicoplanin. The sonication method detects strains
causing PJSI and resistance heterogeneity of prosthetic
staphylococcal populations that were not recognized by
the tissue cultures. The sonication may contribute to better
diagnostic and therapeutic results.
References
* Trampuz et al. NEJM 2007; Aug 16;357(7):654-63
** VITEK 2, Biomerieux
*** E-test, Biomerieux
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F118
The ”true” incidence of prosthetic joint infection after 32,896 primary total hip arthroplasty:
a prospective cohort study
Per Hviid Gundtoft1, Søren Overgaard2, Henrik Carl Schønheyder3, Jens Kjølseth Møller4, Per Kjærsgaard-Andersen5, Alma Becic
Pedersen6
1
Department Of Orthopedic Surgery, Kolding Sygehus & Department Of Orthopaedic Surgery And Traumatology, Odense
University Hospital, Vejle Oest, Denmark
2
Department Of Orthopaedic Surgery And Traumatology, Odense University Hospital & Institute Of Clinical Research, University
Of Southern Denmark, Odense, Denmark
3
Department Of Clinical Microbiology, Aalborg University Hospital & Department Of Clinical Medicine, Aalborg University,
Aalborg, Denmark
4
Department Of Clinical Microbiology, Vejle Hospital, Vejle, Denmark
5
Department Of Orthopedic Surgery, Vejle Hospital, Vejle, Denmark
6
Department Of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
Background and purpose: Risk of prosthetic joint infection in patients with total hip arthroplasty (THA) is often
assessed based on register data. However, previous studies
have shown that arthroplasty registries may underestimate
the incidence of prosthetic joint infection. The purpose of
this study was to estimate the “true” incidence of prosthetic
joint infection following primary THA using multiple data
sources and subsequent to compare this estimate with the
incidence reported by the national registers.
Material and Methods: The Danish Hip Arthroplasty Register (DHR) was searched for primary THAs performed be-
tween January 1, 2005-December 31, 2011 in the Danish
provinces Jutland and Funen. Both DHR and the Danish National Register of Patients (NRP) were searched to identify
the first revision following the primary THA. The revisions
were classified as due to prosthetic joint infection or due to
other causes than infection using an algorithm incorporating intraoperative cultures, aspiration of joint fluid, plasma
C-reactive protein, prior use of antibiotics, and clinical findings as described in the medical record. We calculated cumulative incidence proportion (CIP) of prosthetic joint infection with 95% confidence interval (CI).
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
Results: 32,896 primary THAs were identified of which 1,546
were reported to the DHR and/or NRP with a first time revision. For the DHR the 1-year CIP of prosthetic joint infection
was 0.51 % [CI 0.44; 0.59] and for the NRP 0.48 % [0.41; 0.56].
The 5-year CIP was for the DHR 0.64 % [0.51; 0.79] and for
the NRP 0.57 % [0.45; 0.71]. The corresponding 1- and 5-year
CIPs estimated by the algorithm were: 1-year 0.86 % [0.77;
0.97] and 5-year: 1.03 % [0.87; 1.22]. Thus, the “true” inci-
Abstracts free paper sessions
dence of prosthetic joint infection in primary THA is approximately 40 % higher when using several clinical data sources
than the incidence derived from the national registers.
Conclusion: The “true” incidence of prosthetic joint infection
in primary THA is significantly higher than reported routinely to the Danish National Registers and can be estimated by
using multiple data sources.
F119
Elisa-based detection of gentamicin and vancomycin
Jim Odekerken, Geert Walenkamp, Jacobus Arts, Tim Welting
Maastricht University, Maastricht, Netherlands
110
Aim: Gentamicin and vancomycin are used in local release
systems (due to their potential systemic toxicity) for the
treatment of osteomyelitis. The most commonly used local
release system is antibiotic containing bone cement. Monitoring the systemic and local antibiotic load is an important
clinical monitoring step. Current clinical diagnostics mainly
offer two possible approaches, a fluorometric assay or detection by liquid chromatography. Both methods are heavily influenced by protein presence. Due to these technical
limitations in detection methods, detection of antibiotic
compounds in serum or wound exudate is troublesome. We
therefore explored the use of an enzyme linked immunosorbent assay (ELISA)-approach for the detection of gentamicin and vancomycin.
Methods: A purified gentamicin- or vancomycin-protein
conjugate was coated to the surface of a microtiterplate.
The calibration curve for both antibiotics was prepared
with a range of 0.1–500 ng/ml. The incubation period of the
calibration curve in the microtiter plate was combined with
the antibiotic specific primary antibody in the same well.
The antibody fraction attached to the coated surface was
detected by the use of an HRP-conjugated secondary antibody and subsequent conversion of a tetramethylbenzidine
(TMB) substrate (measured at 450 nm in an ELISA plate read-
er). The intensity of the 450 nm signal is inversely correlated
to the concentration of the antibiotic in a sample.
Results: The established calibration curve allowed a detectable range between 2-300 ng/ml for gentamicin and 10-500
ng/ml for vancomycin. To determine whether this ELISA allows the detection of gentamicin and vancomycin in highprotein containing samples, we spiked wound exudate with
5 µg/ml gentamicin and human serum with 50 µg/ml vancomycin. After sample dilution we were able to measure 4.5
ng/ml gentamicin in the diluted wound exudate and 53.5 ng/
ml vancomycin in the diluted human serum, corresponding
to 4.5 µg/ml gentamicin and 53.5 µg/ml vancomycin in the
crude samples. Importantly, no cross-reactivity was observed
for vancomycin in the gentamicin ELISA and vice versa.
Conclusions: Our results show that ELISA provides a highly
sensitive method to measure antibiotic levels in wound exudate and serum. In contrast to the in literature described
fluorescent detection methods, the herein described ELISAs
are about 50x more sensitive. Since our ELISA-based method is compatible with high-protein containing samples,
measurements in wound exudate and serum are no longer
a practical obstacle. The application of these ELISAs may
contribute to an improved antibiotic regimen in the clinic
for osteomyelitis treatment.
F120
The incidence of late prosthetic joint infections
Kaisa Huotari1, Mikko Peltola2, Esa Jämsen3
1
Helsinki University Central Hospital, Helsinki, Finland
2
Centre For Health And Social Economics CHESS, National Institute For Health And Welfare, Helsinki, Finland
3
Coxa, Hospital For Joint Replacement, Tampere, Finland
33rd Annual Meeting of the European Bone & Joint Infection Society
Aim: Late hematogenous prosthetic joint infections (PJI) are
an expanding medical challenge, as more and more joint
replacements are performed annually and the expected
lifespan of patients with joint prostheses is increasing. The
objective of this study was to analyze the incidence of late
PJI and its temporal trends in a nationwide population.
Methods: 112,708 primary hip and knee replacements
(50,272 (44.6%) hips and 62,436 (55.4%) knees) performed
due to primary osteoarthritis between 1998 and 2009 were
followed for median of 5.0 years (range, 0-13 years), using
data from nationwide Finnish health registers. Late PJI was
defined as a PJI that was detected >2 years postoperatively
and PJI detected >5 years postoperatively were considered
very late. Cumulative incidence, incidence rate, and their
95% confidence intervals at different stages of follow-up
were calculated. Poisson regression was used to analyze
temporal trends.
Results: During the follow-up of 619,299 prosthesis-years,
1,345 PJIs were registered (cumulative incidence 1.20%;
95% CI, 1.13-1.26%). The mean age of the patients at the
time of the primary operation was 69.1 years (range, 21-102
years). 29.2% of the patients were under 65 years of age. Of
the joint replacements performed, 36.1% were for males
and 63.9% for females.
The incidence of late PJI was 0.069%/ prosthesis year (95%
CI, 0.061-0.078%), and it was greater following knee than hip
replacement (0.080% vs. 0.057%, P=0.006). The incidence of
very late PJI was 0.051%/ prosthesis-year (95% CI, 0.42-0.63):
0.058% for knees and 0.044% for hips, P=0.172. The incidence
of late PJI varied between 0.041% and 0.107% between the
observation years without any observable temporal trend
(incidence rate ratio [IRR] 0.98; 95% CI, 0.93-1.03). In very late
PJI, there was an increasing trend from 0.026% in 2004 to
0.056% in 2010 (IRR 1.11; 95% CI, 1.02-1.20).
The proportion of late PJI treated with prosthesis removal or
prosthesis exchange declined from 71.4% (5/7) in 2000 to
38.9% (21/54) in 2010, P=0.003. The trend was similar in very
late infections (from 100% [2/2] to 19.2% [5/26], P<0.001).
Conclusions: In our nationwide study, the incidence of late
PJI was approximately 0.07%/ prosthesis-year: higher for
knee than hip replacements. The proportion of late and very
late PJIs treated with debridement and implant retention increased during the study period. The incidence of very late
PJI seemed to increase.
F121
Osteoconductive properties of cancellous bone grafts loaded with tobramycin or vancomycin
Dennis Link1, Arlinke Bokhorst1, Heinz Winkler2, Henriette Valster1
Emcm B.V., Nijmegen, Netherlands
2
Osteitis Zentrum, Privatklinik Döbling, Vienna, Austria
111
1
Aim: Infections in bone require removal of all foreign material and thorough debridement of the infected site, thus osseous defects remain as a consequence. For reconstruction
of these defects, bone grafts are used successfully in orthopaedic, dental and trauma surgery. However, bone grafts are
at risk of becoming infected themselves, especially in septic
indications, and are usually applied only in a second stage
procedure after all signs of infection have seized. Impregnating cleaned allograft bone with high loads of antibiotics
provides local concentrations that are likely to decontaminate the surrounding and as such allows reconstruction in
a single stage procedure. Furthermore, high concentrations
of antibiotics show a variably cytotoxic effect and therefore
may be suspected to interfere with incorporation of the
grafted bone. Therefore, the aim of this animal experiment
was to investigate the osteoconductive effect of bone chips
impregnated with high loads of tobramycin or vancomycin.
Methods: Ten Dutch milk goats (60–70 kg, age 23–28
months) underwent pedicle screw instrumented posterolateral fusion. Teflon cassettes with a height of 8mm were
filled with purified bone chips of human origin and were
placed next to the prepared transverse processus. At one
side of the spine the chips were impregnated with tobramycin (0,4g per 1,8g of bone) or vancomycin 1g per 1.8g)
and on the contralateral side with non-loaded bone chips
as a control. After 12 weeks of implantation all samples were
explanted, fixated in formaldehyde and embedded in polymethylmetacrylate. After sectioning and staining, they were
qualitatively analyzed using light/fluorescence microscopy.
Results: Newly formed bone migrated from the transverse
process towards the overlying muscle. No statistically significant differences were found regarding the height (between
2 and 6 mm) and the area of new bone (between 10 and
12% of total area) for bone chips impregnated with tobramycin, vancomyin or non-loaded cancellous bone chips.
Conclusions: The study indicates that impregnation of cancellous bone chips with vancomycin or tobramycin does
not adversely affect their osteoconductive properties compared with non-loaded bone chips.
September 11-13, 2014 - Utrecht - The Netherlands
Abstracts free paper sessions
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F122
Does cemented or cementless single-stage exchange of periprosthetic hip infections provide
higher infection eradication rates than two-stage? A systematic review
David George1, Nicola Logoluso2, Sara Scarponi2, Lorenzo Drago2, Fares Haddad1, Carlo Luca Romano2
1
University College London Hospitals, Department Of Trauma And Orthopaedics, London, United Kingdom
Istituto Ortopedico Irccs Galeazzi, Milano, Italy
2
Aim: The best surgical modality for treating chronic periprosthetic hip infections remains controversial, with a lack
of randomised comparative studies available. This systematic review of the literature compares the infection eradication rate after a single-stage hip exchange arthroplasty to a
two-stage exchange.
Methods: Full-text papers and those with an abstract in
English published from 1974 to 2013, identified through international databases, were reviewed. Those reporting the
success rate of infection eradication after a single-stage or
two-stage exchange were included, with a minimum followup of 12 months and sample size of 5 patients.
Results: Nearly all studies available were a case-series (Level
of evidence IV). Twenty original articles reporting the results
after single-stage (n=1221), and 63 papers reporting twostage hip exchange (n=3360) were included. The average
infection eradication rate was 81.7% after a single-stage,
at a mean follow-up of 67.3 months and 91.1% after a twostage, at 58.4 months, (p<0.0001). Comparing studies with
a 36 months minimum follow-up, the respective average
infection eradication rate was 92.1% and 94.8% (p=0.16).
Considering a single-stage cementless exchange (n=81),
the average infection eradication rate was 91.4% at a mean
follow-up of 81 months, compared to 80.9% after a singlestage cemented exchange at 64 months (p = 0.017), and to
94.6% after a two-stage cementless at 51 months follow-up
(p = 0.29).
Conclusions: The methodological limitations of this study
and the heterogeneous material in the studies reviewed
notwithstanding, this systematic review shows that, on average, a two-stage exchange is associated with a higher rate
of eradication of infection than a single-stage exchange for
periprosthetic hip infections, while analysis of some subgroups of patients failed to confirm the difference.
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none
Analysis of the yield of a 14 days incubation protocol for tissue biopsies in orthopaedic
device-associated infections
Peter Wahl1, Nora Schwotzer2, Dominique Fracheboud3, Emanuel Gautier3, Christian Chuard3
Cantonal Hospital Winterthur, Winterthur, Switzerland
2
University Hospital Center Lausanne, Lausanne, Switzerland
3
Hfr Fribourg - Cantonal Hospital, Fribourg, Switzerland
1
Aim: Microbiological cultures of tissue samples remain the
mainstay for the diagnosis of infection. Prolonging incubation and increasing the number of samples has been proposed to optimize sensitivity of cultures, in order to detect
slow-growing bacteria present in orthopaedic implantassociated infections. This study assesses the yield of a 14
days incubation protocol for tissue biopsies from joint replacement and internal fixation device revisions in a general
orthopaedic and trauma surgery setting.
Methods: Retrospective analysis of a prospectively collected cohort of cases of orthopaedic and trauma revision
surgery from a single institution, where tissue biopsies had
been sampled between August 2009 and March 2012. Only
the first revision was considered.
Results: A total of 499 tissue biopsies had been sampled
in 117 cases. At least one sample showed microbiological
growth in 70 cases (60%). Among these 70 cases, 58 (83%)
were classified as infections, whereas 12 (17%) were considered as contaminants. The median time to positivity was 1
day (range 1-10) in case of infection, and 6 days (range 1-11)
in case of contamination. Cultures were positive within 7
days of incubation in 56 (96.6%) of the cases of infection.
Conclusion: This study shows a benefit for prolonging microbiological culture incubation up to 7 days, but not beyond.
While longer incubation might be of interest in particular
situations, where the prevalence of slow-growing and anaerobic bacteria is higher, it does not appear to be productive in
this setting of general orthopaedic and trauma surgery.
33rd Annual Meeting of the European Bone & Joint Infection Society
September 11-13, 2014 - Utrecht - The Netherlands