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1
Economical impact of the septic patient - How to
manage costs?
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FP02 – (#163) - Free Paper
COST-EFFECTIVNESS IN A DRG SYSTEM FOR 2-STEP EXCHANGE OF INFECTED TOTAL JOINT ARTHROPLASTY
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A. Fischbacher , K. Peltier , U. Furustrand-Tafin , O. Borens
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University of Lausanne, Lausanne, Switzerland
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CHUV-Lausanne, Lausanne, Switzerland
E-mail: [email protected]
Keywords: 2-Step Exchange, DRG, Cost-Effectivness
Aim
The costs related to the treatment of infected total joint arthroplasties represent an ever groving burden to
the society. Different patient-adapted therapeutic options like débridement and retention, 1- or 2-step
exchange can be used. If a 2-step exchange is used we have to consider short (2-4 weeks) or long (>4-6 weeks)
interval treatment. The Swiss DRG (Diagnose related Groups) determines the reimboursement the hopsital
receives for the treatment of an infected total arthroplasty.
The review assesses the cost-effectiveness of hospitalisation practices linked to surgical treatment in the twostage exchange of a prosthetic-joint infection. The aim of this retrospectiv study is to compare the economical
impact between a short (2 to 4 weeks) versus a long (6 weeks and above) interval during a two-satge
procedure to determine the financial impact.
Methods
Retrospectiv study of the patients with a two-stage procedure for a hip or knee prosthetic joint infection at
CHUV hospital Lausanne (Switzerland) between 2012 and 2013. The review analyses the correlation between
the interval length and the length of the hospital stay as well as with the costs and revenues per hospital stay.
Results
In average there is a loss of 40'000 Euro per hospitalisation for the treatment of prosthetic joint infection.
Revenues never cover all the costs, even with a short interval procedure. This economical loss increases with
the length of the hospital stay if a long-term intervall is choosen.
Conclusions
The review explores potential for improvement in reimbourement practices and hospitalisation practices in
the current Swiss healthcare setting. There should be alternative setups to decrease the burden of medical
costs by a) increase the reimboursment for the treatment of infected total joints or by b) splitting the hospital
stay with partners (rapid transfer after first operation from center hospital to level 2 hospital and retransfer for
second operation to center) in order to increase revenues.
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FP03 – (#132) - Free Paper
INCOME AND COSTS OF TREATING TIBIAL OSTEOMYELITIS IN THE UK – A COMPARISON OF LIMB SALVAGE
VERSUS AMPUTATION
J. Kendall, S. Jones, M. Mcnally
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Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
E-mail: [email protected]
Keywords: Osteomyelitis, Costs, Limb Salvage, Amputation
Aim
To compare the costs of treatment and income received for treating patients with tibial osteomyelitis,
comparing limb salvage with amputation.
Methods
We derived direct hospital costs of care for ten consecutive patients treated with limb salvage procedures and
five consecutive patients who underwent amputation, for tibial osteomyelitis. We recorded all factors which
affect the cost of treatment. Financial data from the Patient-Level Information and Costing System (PLICS)
allowed calculation of hospital costs and income received from payment under the UK National Tariff. Hospital
payment is based on primary diagnosis, operation code, length of stay, patient co-morbidities and
supplements for custom implants or external fixators.
Our primary outcome measure was net income/loss for each in-patient episode.
Results
The mean age of patients undergoing limb salvage was 55 years (range 34-83 years) whereas for amputation
this was 61 years (range 51-83 years). Both groups were similar in Cierny and Mader Staging, requirement for
soft-tissue reconstruction, anaesthetic technique, diagnostics, drug administration and antibiotic therapy.
In the limb salvage group, there were two infected non-unions requiring Ilizarov method and five free flaps.
Mean hospital stay was 15 days (10-27). Mean direct cost of care was €16,718 and mean income was €9,105,
resulting in an average net loss of €7,613 per patient. Patients undergoing segmental resection with Ilizarov
bifocal reconstruction and those with the longest length of stay generated the greatest net loss.
In the amputation group, there were 3 above knee and 2 below knee amputations for failed previous
treatment of osteomyelitis or infected non-union. Mean hospital stay was 13 days (8-17). Mean direct cost of
care was €18,441 and mean income was €15,707, resulting in an average net loss of €2,734 per patient. Length
of stay was directly proportional to net loss.
Conclusions
The UK National Tariff structure does not provide sufficient funding for treatment of osteomyelitis of the tibia
by either reconstruction or amputation. Average income for a patient admitted for limb salvage is €6,602 less
than that for amputation even though the surgery is frequently more technically demanding (often requiring
complex bone reconstruction and free tissue transfer) and the length of hospital stay is longer.
Although both are significantly loss-making, the net loss for limb salvage is more than double that for
amputation. This makes treatment of tibial osteomyelitis in the UK National Health Service unsustainable in
the long-term.
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FP04 – (#249) - Free Paper
HEALTH ECONOMICS OF THE SINGLE STAGE TREATMENT OF CHRONIC OSTEOMYELITIS; DEBRIDEMENT AND
FLAP VERSUS ANTIBIOTIC LOADED CALCIUM SULPHATE BEADS
H. Sharma, P. Dearden, K. Lowery, B. Gavin, A. Platt
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Hull Royal Infirmary & Castle Hill Hospital, Hessle, United Kingdom
E-mail: [email protected]
Keywords: Health Economics, Osteomyelitis, Single Stage, Calcium Sulphate Antibiotic Loaded Pellets
Aim
Chronic osteomyelitis is a challenging problem and a growing burden for the National Health Service.
Conventional method of treatment is 2 stage surgery, with debridement and prolonged courses of antibiotics.
Recently single stage treatment of chronic osteomyelitis is gaining popularity due decreased patient morbidity
and cost effectiveness. Dead space management in single stage treatment is accomplished by either a muscle /
myocutaneous or antibiotic loaded calcium sulphate beads.
We analysed the cost effectiveness of two dead space management strategies in single stage treatment of
osteomyelitis. Study is designed to analyse the health economics at 2 time points; 45 days post surgery and 2
years post surgery. We report preliminary results at 45 days post surgery.
Setting – Level 1 trauma centre and university hospital
Approval - Ethics committee approved study
Methods
10 patients in each group were retrospectively analysed through patient records. Each group was identified for
standard demographics, duration of procedure, hospital stay, type and duration of postoperative antibiotics,
number of out patient visits in first 45 days and recurrence of infection.
Results
Table attached details the results of both groups
In health technology assessment four quadrant model, CSB appears in quadrant II suggesting that it is more
cost effective.
Conclusions
Based on small data set and on assessment only evaluating cost, at 45 days assessment, antibiotic calcium
sulphate beads from a Health Economic Cost Effectiveness Analysis offers a better economic outcome. This is
holding constant the morbidity of the patients and effectiveness, assuming both treatments are standards of
care, which is best evaluated at 24 months.
Acknowledgements
Biocomposites for funding the cost of health economist.
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FP05 – (#85) - Free Paper
THE COST OF INFECTION IN SEVERE OPEN TIBIAL FRACTURES TREATED WITH A FREE FLAP
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U. Olesen , L. Lykke-Meyer , C. Bonde , H. Eckardt , U. Singh , M. Mcnally
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Rigshospitalet, Copenhagen, Denmark
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University Hospital Basel, Basel, Switzerland
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Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
E-mail: [email protected]
Keywords: Fractures,Free Flap, Cost Of Infection
References
1) Olesen UK, Juul R, Bonde CT, McNally M, Eckardt H. A review of forty five open tibial fractures covered with
free flaps. Analysis of complications, microbiology and prognostic factors.
Int Orthop. 2015 Mar 8
Aim
Open tibial fractures have a high infection risk making treatment difficult and expensive. Delayed skin closure
(beyond 7 days) has been shown to increase the infection rate in several studies (1).
We aim to calculate the cost of infection as a complication of open tibial fractures and to determine the effect
of delayed skin closure on this cost.
Methods
We retrospectively reviewed all records of patients treated with a free flap in our institution for an open tibial
fracture from 2002 to 2013.
We calculated direct costs of treatment by the DRG-values (2014 figures), based on length of stay (LOS),
diagnosis, orthopaedic and plastic surgical procedures and the corresponding reimbursement.
The primary goal was to establish the extra cost incurred by an infection, compared to treating an uninfected
open tibial fracture. The cost efficiency saving of early soft tissue cover was also investigated.
Results
We analysed 45 injuries in 44 patients. All patients were treated with debridement, stabilization, prophylactic
antibiotics and free flap cover. Infection increased the mean total LOS in hospital from 28.0 to 63.8 days. The
presence of an infection increased the cost of treatment from a mean of €49.301 for uninfected fractures
compared to a mean of €67.958 for infected fractures.
Achieving skin cover within 7 days of injury decreased the infection rate from 60% to 27% (total series rate
48%). The provision of early soft tissue cover (before 7 days) for all patients would have saved an average of
€18.658 per patient.
Conclusions
The development of an infection after a severe open tibial fracture greatly increases the cost of treatment.
Early soft tissue cover is one aspect of care which has been shown to improve clinical outcomes. This study
confirms that it will also reduce the cost of treating these complex fractures - underscoring the need for rapid
referral and an ortho-plastic setup to handle them.
We have only calculated the direct costs of treatment. Infected fractures will also consume extra costs in
rehabilitation and absenteeism from later infection recurrence and non-union. Therefore, our estimate of the
potential saving is likely to be conservative.
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FP06 – (#174) - Free Paper
DEVELOPMENT AND EVALUATION OF A PREOPERATIVE RISK CALCULATOR FOR PERIPROSTHETIC JOINT
INFECTION
T. Tan, M. Maltenfort, A. Chen, A. Shahi, A. Madden, J. Parvizi
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Rothman Institute, Philadelphia, United States
E-mail: [email protected]
Keywords: Risk Calculator, Periprosthetic Joint Infection, Preoperative, Prior Surgery, Drug Abuse
Aim
Considerable efforts have been invested into identifying risk factors for periprosthetic joint infection (PJI) after
total joint arthroplasty (TJA). Preoperative identification of risk factors for developing PJI is imperative for
medical optimization and targeted prophylaxis. The purpose of this study was to create a preoperative risk
calculator for PJI by assessing a patient’s individual risks for developing PJI with resistant organisms and
S.aureus.
Methods
A retrospective review of 27117 patients (43253 TJAs) from 1999 to 2014, including 1035 PJIs, was performed.
A total of 41 risk factors including demographics, comorbidities (using the Elixhauser and Charlson Index), and
the number of previous TJAs, were evaluated. Multivariate analysis was performed; coefficients of the models
were scaled to produce useful integer scoring. Predictive model strength was assessed employing area under
the curve (AUC) analysis.
Results
Among the 41 assessed variables, the following were significant risk factors in descending order of significance:
prior surgeries (p<0.0001), drug abuse (p=0.0003), revision surgery (p<0.0001), human immunodeficiency virus
(p=0.0004), coagulopathy (p<0.0001), renal disease (p<0.0001), congestive heart-failure (p<0.0001), psychoses
(p=0.0024), rheumatological disease (p<0.0001), knee involvement (p<0.0001), diabetes (p<0.0001), anemia
(p<0.0001), males (p<0.0001), liver disease (p=0.0093), smoking (p=0.0268), and high BMI (p<0.0001).
Furthermore, presence of heart-valve disease (p=0.0409), metastatic disease (p=0.0006), and pulmonary
disease (p=0.0042) increased the resistant organism PJIs. Patients with metastatic disease were also more
likely to be infected with S. aureus (p=0.0002). AUCs were 0.83 for any PJI, 0.86 for resistant PJI, and 0.84 for
S.aureus PJI models.
Conclusions
This large-scale single-institutional study has determined various risk factors for PJI. Some factors are
modifiable and need to be addressed before elective arthroplasty. It is imperative that surgeons are aware of
these risk factors and implement all possible preventative measures, including targeted prophylaxis, in
patients with high-risk of PJI. Continued efforts are needed to find novel and effective solutions to minimize
the burden PJI.
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Diagnostic tools in MSK infections
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FP07 – (#32) - Free Paper
SUPAR AS NEW BIOMARKER OF PROSTHETIC JOINT INFECTION : CORRELATION WITH INFLAMMATORY
CYTOKINES
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E. Galliera , L. Drago , C. Romano , M. Marazzi , C. Vassena , M. Corsi Romanelli
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Department of Biomedical, Surgical and Oral Science , Università degli Studi di Milano, and IRCCS Galeazzi
Orthopaedic Institute,, Milan, Italy
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Department of Biomedical Sciences for Health, Università degli Studi di Milano and IRCCS Galeazzi
Orthopaedic Institute,, Milan, Italy
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IRCCS Galeazzi Orthopaedic Institute,, Milan, Italy
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Department of Biomedical Sciences for Health, Università degli Studi di Milano,, Milan, Italy
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Department of Biomedical Sciences for Health, Università degli Studi di Milano, and U:O:C SMEL-1 Clinical
Pathology, IRCCS Policlinico San Donato, San Donato, Milan, Italy
E-mail: [email protected]
Keywords: Prosthetic Joint Infection, Serum Biomarker, SuPAR, Diagnosis
References
1. Parvizi J, Ghanem E, Menashe S, Barrack RL, Bauer TW. J Bone Joint Surg Am 2006; 88 Suppl 4:138-147
2. Donadello K, Scolletta S, Covajes C, Vincent JL. BMC Med 2010; 10:2.
3. Eugen-Olsen J. J Intern Med 2009; 270:29-31.
Aim
Post operative prosthetic joint infection (PJI) is the most common cause of failure of total joint arthroplasty,
requiring revision surgery , but a gold standard for the diagnosis and the treatment of PIJ is still lacking [1].
SuPAR, the soluble urokinase plasminogen activation receptor, has been recently described as a powerful
diagnostic and prognostic tool, able not only to detect sepsis but also to discriminate different grade of sepsis
severity [2,3]
This study aimed to examine the diagnostic value of SuPAR in post operative PJI, in order to explore the
possible application of this new biomarker in the early diagnosis of PJI.
Methods
The level of SuPAR have been measured in PJI patients and controls (patients undergoing prosthesis revision
without infection), and correlated with pro and anti inflammatory markers (CRP C-reactive protein, IL-6, IL-1
TNFα , IL-10, IL-12, IL-8, IL1ra and the chemokine CCL2).
Statistical analysis of Receiver Operating Characteristic (ROC) curves and Area Under the Curve (AUC) was
performed
Results
As described in Figure 1, serum SuPAR displayed a strongly significative increase in PJI patients compared to
not infected controls, and a significative positive correlation with C-reactive protein, IL-6, IL-1 and TNFα and
the chemokine CCL2.
SuPAR displayed a very good AUC , significantly higher than CRP and IL-6 AUC
Conclusions
This study clearly show that the measure of Serum level of SuPAR provide a extremely important benefit
because it is a precise indicator of bacterial infection , and the addition of SuPAR serum level measurement to
classical inflammatory markers can strongly improve the diagnosis of prosthesis joint infection
Acknowledgements
The authors acknowledge ViroGates, Denmark for providing suPARNOSTIC Standard Kit.
The authors would also acknowledge the Italian Ministero dell’ Istruzione, Università e Ricerca (MIUR) and
Italian Ministero della Salute for providing funds for this research project.
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FP08 – (#183) - Free Paper
BACTECTM BLOOD CULTURE BOTTLES AND PRIMARY PLATE CULTURES: IMPACTS ON TIME TO TARGETED
ANTIMICROBIAL THERAPY FOR PROSTHETIC JOINT INFECTIONS.
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C. Puzzolante , S. Warren , S. Zona , J. Howard , S. Palanivel , D. Mack
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Infectious Diseases Unit, Modena, Italy
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Azienda Ospedaliero-Universitaria Policlinico Modena, London, United Kingdom
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Royal Free London NHS Foundation Trust; Royal National Orthopaedic Hospital NHS Trust, Modena, Italy
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Infectious Diseases Unit, London, United Kingdom
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Royal Free London NHS Foundation Trust, London, United Kingdom
E-mail: [email protected]
Keywords: Bactec,Blood Culture Bottles,Beadmill Processing,Agar Plates,Diagnosis Of Prosthetic Joint Infection
Aim
Beadmill processing combined with automated blood culture bottle methods (BACTEC™) has a greater
sensitivity and specificity, and a shorter time to positivity compared with primary plates (PP) for prosthetic
joint infection (PJI) diagnosis but the clinical impact of Bactec on antimicrobial therapy has not yet been
evaluated. We compared time-to-positivity of Columbia agar with horse blood plates (BA) and chocolatized
horse blood plates (CHOC) versus anaerobic (ANA) and aerobic blood culture bottles (02) in patients with PJI.
We compared the contributions of the two methods to the commencement of effective and targeted
antimicrobial therapy.
Methods
Retrospective observational study from June 2013 to March 2014. Inclusion criteria were confirmed PJI (IDSA
criteria) with at least 2 perioperative samples. After beadmill processing BA and CHOC plates were incubated
for 2 days and discarded if negative, BactecTM bottles were incubated for 14 days and sub-cultured if positive.
MALDI-TOF (Microflex, Brucker) was used for identification and all isolates had sensitivities performed
(Phoenix, BD). Standard empirical antibiotic treatment was teicoplanin, piperacillin/tazobactam and amikacin.
We defined time to switch as difference between date of sample collection and date of commencing targeted
or effective therapy; prior antibiotic therapy was defined as the use of antibiotics within 14 days before
samples collection.
Results
Fifty cases were identified during the study period. 330 microbiological isolates were included: 24 (7.3%) were
considered contaminants; 153 isolates (50.0%) were detected both from BactecTM and PP; 152 (49.7%) from
BactecTM only; 1 isolate (0.3%) from PP only. 17 (34%) diagnoses of PJI was made exclusively by BactecTM.
The majority of isolates on BA and CHOC plates grew in the first 24 hours (81.2% and 77.5% respectively).
293/305 isolates from BactecTM (96.1%) grew in the first 2 days. Antibiograms were available after 2.5 days
from PP versus 4 days from BACTEC (p<0.0001). When we compared time to switch from empiric to targeted
therapy, no difference was seen between patients with positive BACTEC cultures only (median 4 days, range 215) versus patients with positive PP cultures, (median 5 days, range 2-9) (p=0.984). Where organisms were
resistant to empirical therapy, PP results did not contribute to switching to effective therapy. Prior antibiotic
therapy had no impact on time-to-positivity for both methods (R=-0.005, p=0.936).
Conclusions
Compared to BACTEC cultures for the diagnosis of PJIs, primary plate cultures did not provide additional
diagnostic information and did not significantly reduce the time to effective or targeted antimicrobial therapy.
Acknowledgements
Sources of funding: Nil
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FP10 – (#255) - Free Paper
USE OF SONICATION IN ‘ASEPTIC’ FAILURE OF ORTHOPEDIC PROSTHESIS
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B. Kocjancic , A. Lapoša , S. Jeverica , A. Trampuž , D. Dolinar
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University Medical Center Ljubljana, Department of Orthopaedic surgery, Ljubljana, Slovenia
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Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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Charité - Universitätsmedizin Berlin, Centre for musculoskeletal surgery, Berlin, Germany
E-mail: [email protected]
Keywords: Sonication, Culture-Negative PJI
Aim
INTRODUCTION:
Clear differentiation between aseptic failure and prosthetic joint infection remains one of the goals of modern
orthopaedic surgery. The development of new diagnostic methods enabled more precise evaluation of the
etiology of prosthetic joint failure. With the introduction of sonication an increasing number of culturenegative prosthetic joint infection were detected.
The aim of our study was to evaluate culture-negative prosthetic joint infections in patients who were
preoperatively evaluated as aseptic failure.
Methods
For the purpose of the study we included patients planed for revision surgery for aseptic failure.
Intraoperatively acquired samples of periprosthetic tissue and explanted prosthesis were microbiologicaly
evaluated using standard microbiologic methods and sonication. If prosthetic joint infection was discovered,
additional therapy was introduced.
Results
Between October 2010 and April 2013 54 patients were operated (12 revision knee arthroplasty, 42 revision
hip arthroplasty). 10 (18,6%) patients had positive sonication and negative periprosthetic tissue sample, 5
(9,2%) patients had positive tissue samples, but negative sonication, in 9 (16,7%) patients both tests were
positive and in 30 (55,5%) patients all microbiologic tests were negative. The microbiologic isolates of sonicate
fluid were in 12 cases coagulase-negative staphylococci, in 3 cases P.acnes in 3 cases mixed flora, in 1 case
enterococcus and in 1 case SA. From periprosthetic tissue cultures 5 samples have yielded coagulase-negative
staphylococci in 5 cases P.acnes in 2 cases mixed flora, in 1 case enterococcus and in 1 case SA were isolated.
Conclusions
With the increasing number of patients requiring revision arthroplasty, a clear differentiation between aseptic
failure and prosthetic joint infection is crucial for the optimal treatment. Sonication of explanted material is
more successful in the isolation of pathogens compared to periprosthetic tissue cultures. Sonication of
explanted prosthetic material is helpful in the detection of culture-negative prosthetic joint infections.
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FP11 – (#224) - Free Paper
SYNOVIAL LEUKOCYTE ESTERASE, GLUCOSE AND C-REACTIVE PROTEIN IN THE DIAGNOSIS OF BONE AND
JOINT INFECTIONS
E. De Vecchi, F. Villa, S. Agrappi, M. Toscano, L. Drago
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IRCCS Galeazzi Orthopaedic Institute, Milan, Italy
E-mail: [email protected]
Keywords: Synovial Fluids, Prosthetic Joint Infections, Laboratory Diagnosis
Aim
Culture examination is still considered the gold standard for diagnosis of bone and joint infections, including
prosthetic ones, even if in up to 20-30% of cases, particularly prosthetic joint infections, it fails to yield
microbial growth. To overcome this limitation, determination of markers of inflammation and or infection
directly in joint fluid has been proposed.
Aim of this study was to evaluate the applicability of measurement of lecukocyte esterase (LE), C-reactive
protein (CRP) and glucose in synovial fluid for diagnosis of bone and joint infections.
Methods
Synovial fluids from 80 patients were aseptically collected and sent to laboratory for microbiological cultures.
After centrifugation at 3000 rpm for 10 minutes, pellet was used for cultures, while the surnatant was used for
determination of LE, CRP and glucose. LE and glucose were evaluated by means of enzymatic colorimetric
strips developed for urinanalysis. One drop of synovial fluid was placed on the LE and on the glucose pads and
the results were read after about 120 seconds. A LE test graded + or ++, and a glucose test equal to trace or
negative were considered suggestive for infection. CRP was measured by an automated turbidimetric method.
Results
On the basis of clinical findings, microbiological, haematological and histological analyses patients were
retrospectively divided into 2 groups. Group 1 comprised 19 infected patients (12 males, 7 females age: 70.6 ±
10.3 yrs, range: 47 - 88 yrs) while Group 2 included 61 aseptic patients (32 males and 29 females, age: 61.5 ±
16.3 yrs, range: 15 - 84). Sensitivity of the three tests was 89.5%. 84% and 73,7% for LE, CRP and glucose,
respectively. Specificity was 98.4%, 88.5% and 70% for LE, CRP and glucose, respectively. Positive and negative
predictive values were 94.4% and 96.8% for LE, 69.6% and 94.6% for CRP and 77.8% and 89.6% for glucose
test. When LE was combined with CRP, sensitivity increased to 94.7%, while no differences were observed for
LE combined with glucose.
Conclusions
Leukocyte esterase has proven to be a rapid, simple and inexpensive test to rule in or out bone and joint
infections. Combination of its measurement with that of CRP increased sensitivity. In conclusion, the
combination of leukocyte esterase and CRP may represent a simple and useful tool for diagnosis of bone and
joint infections.
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FP12 – (#161) - Free Paper
SONICATION CULTURES IMPROVED THE MICROBIOLOGICAL DIAGNOSIS OF INTRAMEDULLARY NAILASSOCIATED INFECTIONS
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C. Finelli , A. Dell Aquila , N. Miki-Rosario , H. Fernandes , F. Dos Reis , M. Cohen , R. Abdalla , C. Da Silva ,
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M.A. Murça , S. Nigro , M. Salles
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Universidade Federal de São Paulo, São Paulo, Brazil
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Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
E-mail: [email protected]
Keywords: Intramedullary Nail, Sonication, Microbial Diagnosis, Tissue Culture
Aim
Intramedullary nailing (IMN) has been frequently indicated to treat long bone open and closed fractures, but
infection following internal fixation may have devastating consequences, with higher costs. Treatment of
intramedullary nail-associated infections (IMNI) is challenging and based upon surgery and adequate antibiotic
administration, which requires the correct identification of causative microorganisms. However, there have
been difficulties for the microbial diagnosis of IMNI, as the peri-prosthetic tissue cultures may show no
microbial growth, particularly in patients with previous use of antibiotics. Sonication have shown higher
sensitivity and specificity for microbial identification on a variety of orthopedic implant-associated infections.
Aim: To compare clinical and microbiological results and sensitivity for the pathogen identification obtained by
conventional peri-implant tissue culture samples with culture of samples obtained by sonication of explanted
IMN implants, among patients presenting IMNI of long bones.
Methods
Methods: Longitudinal prospective cohort study performed at a tertiary public hospital, ongoing since August
2011. We analyzed all patients with indication for IMN implant removal, and orthopedic-implant associated
infections was defined according to previous publications addressing osteosynthesis-associated infections
(Yano 2014). Minimal of 2 samples from the peri-implant tissue were taken and sent under sterile conditions
to the laboratory for culture. Statistical analysis was performed McNemar’s test for related proportions.
Results
Results: We included 26 patients presenting clinical signs of IMNI, of which tissue and sonication cultures were
performed for 26 (100%) and 20 (77%) patients, respectively. Among them, 88% were male, with mean age
was 35.9 years (range, 19-59 yo). Causes of trauma were mainly motorcycle crashes accounting 54% of
accidents; tibia and fibula were affected in 65% and 27%, respectively. Gustilo open fracture classification was
grade II (35%) and IIIA (35%). First stage management with external fixation for fracture stabilization was
performed in 75% of trauma patients. Sensitivity of peri-prosthetic tissue culture and sonication was 80.7%
(21/26), and 95% (19/20) (p< 0.05), respectively. Only one infected patient presented negative tissue and fluid
cultures. Gram-positive cocci were isolated in 75% and 79% in tissue and sonication fluid cultures, respectively.
Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus sp., were isolated from tissue and
sonication culture in 43.5% and 36.3%, 8.7% and 22.7%, 13% and 13.7%, respectively. Polymicrobial infection
was diagnosed in 3.8% (1/26) and 15.8% (3/19), patients by tissue and sonication fluid cultures (p< 0,01),
respectively.
Conclusions
Conclusion: Sonication of retrieved infected intramedullary nails has the potential for improving the
microbiological diagnosis of IMNI.
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FP13 – (#271) - Free Paper
IS ARTHROCENTESIS ENOUGH TO DIAGNOSE ACUTE SEPTIC ARTHRITIS OF THE KNEE?
D. Santos, M. Oliveira, T. Torres, F. Santos, A. Costa, R. Pereira, M. Frias, G. Martins, A. Sarmento, P. Canela, A.
Dias, P. Carvalho, R. Freitas
1
CHVNGaia/Espinho, Porto, Portugal
E-mail: [email protected]
Keywords: Knee, Arthrocentesis, Septic, Arthritis
Aim
Acute septic arthritis of the knee may be a challenging diagnosis in the emergency department and must
always be excluded in any patient with knee pain and local or systemic signs of infection.
Arthrocentesis of
the suspected knee is mandatory, since the analysis of the synovial fluid gives useful information like the white
blood cell count (WBC)/mm3 or the polymorphonuclear cell percentage (PMP). These parameters will help the
clinician to make the decision to drain the joint in the operation room, without having to wait for the culture
or Gram stain, which may take several days to be available. The classical cutoff of 50,000 WBC/mm3 with more
than 90% of PMP may fail to include all the septic arthritis of the knee, since significant variation have been
described in recent years. The aim of this study was to evaluate the accuracy of WBC/mm3 and PMP in the
synovial fluid in the diagnosis of acute septic arthritis of the knee.
Methods
We reviewed the clinical data of patients diagnosed with acute septic arthritis of the knee admitted in our
center between January 2010 and December 2014, specifically the WBC/mm3 and the PMP of the synovial
joint fluid. The criteria for diagnosis of an acute septic arthritis of the knee was report of purulent material
when arhtrotomy or arthroscopy was performed or a positive culture of the joint fluid. The statistical
evaluation of the results was performed using Student’s t-test.
Results
48 patients matched the inclusion criteria. The mean WBC/mm3 was 44.333 (14.610-182.640) and the mean
PMP was 91,89% (86,4%-98,1%). 28 patients (58,33%) had a WBC/mm3 below 50.000 and 44 patients (91,67%)
had a PMP above 90%, both with no statistical significance.
Conclusions
Knee arthrocentesis is mandatory in every patient suspected to have an acute knee pyoarthrosis, since the
joint fluid analysis may show several abnormal findings.
Our results show that a considerable number of
patients may show a relatively low WBC/mm3 in the joint fluid in the presence of a knee pyoarthrosis. The
PMP may be a better criteria, but again failed to achieve statistical significance, probably because of the low
number of patients.
The synovial fluid analysis alone is probably misleading in the diagnosis of an acute septic
arthritis of the knee if the clinician is guided by the classical guidelines. The physical examination, medical
history, laboratory and imagiologic tests are all key elements in this challenging diagnosis.
15
Risk factors for infection
16
FP14 – (#253) - Free Paper
RISK FACTORS FOR INFECTION AFTER TOTAL KNEE ARTHROPLASTY AND PREVENTION STRATEGIES
S. Machado, M. Marta, P. Rodrigues, I. Pinto, R. Pinto, P. Oliveira
1
Centro Hospitalar São João, Oporto, Portugal
E-mail: [email protected]
Keywords: Arthroplasty, Knee, Infection, Prevention
References
1. Horan TC, Gaynes RP, Martone WJ, Jarvis WR, Emori TG. CDC Definitions of Nosocomial Surgical Site
Infections, 1992: A Modification of CDC Definitions of Surgical Wound Infections. Infect Control Hosp
Epidemiol. 1992; 13: 606-608
Aim
Because life expectancy is increasing, the number of primary knee arthroplasties performed is projected to
increase 673% by 2030, according to Westrich et al. Also, Toulson et al. in a recent study predict that the
incidence of deep infection associated with primary total knee arthroplasty ranges from 1% to 2%.
Periprosthetic knee infection is one of the most dramatic and difficult to manage complications following total
knee arthroplasty. Therefore, periprosthetic knee infection will continue to be a significant complication and
an economic burden in the future. Our objective was to identify the risk factors that may provide greater
likelihood of infection and thus select high-risk patients and to take maximum prevention strategies.
Methods
Case-control study, between infected and non infected patients, undergoing primary total knee arthroplasty
between January 2008 and January 2013. The risk factors evaluated were: duration of hospital stay, surgery
duration, prophylactic antibiotics and timing for administration, volume of blood transfusion, autologous blood
recovery system use, anesthetic technique, ASA classification, Diabetes Mellitus, Obesity (BMI>30),
immunosuppression and history of any infection in the month preceding surgery. The presence of infection
was defined by the criteria of the Center for Disease Control for Nosocomial Surgical Site Infections1. Statistical
analysis IBM SPSS Statistics 20 (Fisher's exact test, Mann-Whitney U test and Student's t-test). Statistical
significance for p ≤ 0.05.
Results
We evaluated 540 patients with a mean follow-up of 56 months. We identified 21 deep infections (3,8%), and
35 superficial wound infections and found a positive correlation between infection and obesity (p <0.01),
immunosuppression (p <0.01), volume of blood transfusion (p=0.02), history of any infection in the month
preceding surgery (p <0.01). We found a negative correlation with the use of a autologous blood recovery
system (p <0.01). Other factors, commonly referred in the literature, showed no association or did not reach
statistical significance.
Conclusions
The incidence of periprosthetic knee infection after primary total knee arthroplasty stays high. The presence of
obesity, immunosuppression, blood transfusion, history of any infection in the month preceding surgery were
identified as significant risk factors for infection to occur. The identification, modification or eviction of the risk
factors implied are essential to reduce and prevent infection in arthroplasty.
17
FP15 – (#39) - Free Paper
PROSPECTIVE EVALUATION OF THE INCIDENCE OF HAEMATOGENOUS PROSTHETIC JOINT INFECTIONS (H-PJI)
FOLLOWING BLOODSTREAM INFECTIONS (BSI)
1
1
1
1
1
1
2
2
S. Nguyen , M. Valette , P. Choisy , P. Cornavin , P. Patoz , N. Blondiaux , F. Vuotto , D. Descamps , E.
1
Senneville
1
Dron Hospital, Tourcoing, France
2
Bethune Hospital, Bethune, France
E-mail: [email protected]
Keywords: Bloodstream Infection, Prosthesic Joint Infection, Haematogenous Infection
References
1-Ainscow et al. J Bone Joint Surg Br. 1984; 66(4):580-2.
2-Uçkay et al. J Infect. 2009;59(5):337-45
Aim
In France, 5% of men and 7% of women aged more than 60 years have a joint prosthesis (JP). The incidence of
H-PJI following BSI remains unknown (1-2). The aim of this study was to determine prospectively the clinical
characteristics of patients with JP and the incidence of H-PJI following a BSI.
Methods
A prospective observational multicentric study was performed in two French General Hospitals, from
December 2012 to April 2015. Each patient with JP, in whom a BSI was diagnosed, was evaluated prospectively
by an ID specialist. Data regarding clinical and microbiological characteristics were collected. A follow-up by
phone call was performed monthly during 6 months to determine the incidence of H-PJI following BSI.
Results
During the study period, 97 patients of mean age ± SD of 82.1 ± 10.4 years were identified, with a
predominance of women (n=61). Nineteen patients (20%) had neoplasia, and 32 diabetes mellitus (33%). Most
patients had one (n=61 ; 63%) or two JP (n=29 ; 30%) ; with a predominance of hip arthroplasty (n=77 ; 79%).
Predominant pathogens were E. coli (n=41 ; 42%), S. aureus (n=23 ; 23%) and S. pneumoniae (n=8 ; 8%).
At the onset of BSI, the JP was concomitantly infected in 10 (10.3%) patients (including 8 S. aureus, 1 E. coli
and 1 P. mirabilis), thus 87 were studied for the incidence of H-PJI following BSI of another source. Among
these 87 patients, no H-PJI was detected, with a complete 6-month follow-up available for 29 patients (34%),
incomplete follow-up for 26 patients (30%), loss of follow-up for 3 patients (3%), and death occurring in 29
patients (34%). The comparison between the patients with no H-PJI detected (« No Event Group ») and the
deceased patients (« Death Group ») showed that patients of the « No Event Group » had a lower rate of
neoplasia (14% vs 34% ; P=0.025).
Conclusions
Our preliminary results show that patients with JP in whom a BSI occurred were old, and had a high mortality
rate. In our study, the incidence of secondary H-PJI appears to be low, since no event was detected during the
follow-up. The incidence of H-PJI may have been underestimated due to the high mortality rate.
Acknowledgements
We would like to thank Dron Hospital and Bethune Hospital medical teams.
The authors declare that there are no conflicts of interest.
18
FP16 – (#40) - Free Paper
SUPPRESSIVE ANTIBIOTIC THERAPY BY ORAL CYCLINES FOR PROSTHETIC JOINT INFECTIONS
1
1
1
1
1
2
1
S. Nguyen , M. Pradier , M. Valette , P. Choisy , M. Digumber , H. Migaud , E. Beltrand , E. Senneville
1
Dron Hospital, Tourcoing, France
2
Lille University Hospital, Lille, France
E-mail: [email protected]
1
Keywords: Prosthetic Joint Infection, Suppressive Antibiotic Therapy, Cycline
References
1-Osmon et al. Clin Infect Dis. 2013;56(1):e1-e25
Aim
There is currently no consensus on the use of suppressive antibiotic therapy (SAT) in prosthetic joint infections
(PJI) (1). We describe herein the experience of a French Reference Centre for Complex Osteo-Articular
Infections on use of oral cyclines (doxycline and minocycline) for SAT.
Methods
A retrospective analysis was performed on consecutive patients with PJI who received oral cyclines
(doxycycline or minocycline) for SAT between January 2006 and June 2014. All patients had surgical
management, followed by systemic antibiotic treatment and SAT instauration thereafter. Remission was
defined as an asymptomatic patient with a functioning prosthesis.
Results
Seventy-nine patients with a mean age of 63.8 ± 16.8 years were included. Sixteen patients (20%) had
neoplasia, 9 (11%) diabetes mellitus, 10 (13%) rheumatoid arthritis, and 6 patients (8%) were receiving
corticosteroids or chemotherapy.
There were 37 knee (47%), 36 hip (46%), 4 elbow (5%), and 2 shoulder (3%) infections, with a mean delay from
implantation of 7.37 ± 6.94 months (range 1-27). Surgical management consisted in debridement and implant
retention for 60 patients (76%), or in implant exchange for 19 patients (24%).
Main pathogens were coagulase-negative staphylococci (37%) and Staphylococcus aureus (41%) ; 23 patients
had polymicrobial infection (29%).
The most frequent initial antibiotic regimens debuted before SAT were rifampicin combinations (70%). Mean
duration of curative antibiotic therapy was 103 ± 75 days.
Indications of SAT were (i) patients unsuitable for or refusing further surgery (n=23), suboptimal (ii) surgery
(n=26) or (iii) curative antibiotic therapy (n=11), (iv) complex orthopaedic surgery (n=11), and (v)
immunosuppressive status (n=8). Seventy-three patients received doxycycline and 6 patients received
minocycline as SAT (n=48). Mean SAT duration was 625± 536 days (range 30-2900), with a mean follow-up of
765 ± 572 days.
Adverse events were reported in 13 patients (16%), leading to SAT discontinuation in 5 (6%).
During follow-up, 59 patients were considered in remission (75%), and 20 failed including 13 relapses (16%)
and 7 reinfections (9%). Among failure patients, 10 pathogens resistant to doxy/minocycline were identified,
including 5 with acquisition of cycline resistance.
Conclusions
In our study, SAT with cyclines is associated to a 75% remission rate, with an acceptable tolerability.
Further studies are warranted to determine ideal regimens and optimal duration of SAT.
Acknowledgements
We would like to thank Dron Hospital and Lille University Hospital medical teams.
The authors declare that there are no conflicts of interest.
19
FP17 – (#26) - Free Paper
LIQUID ANTIBIOTICS IN BONE CEMENT - AN EFFECTIVE WAY TO IMPROVE THE EFFICIENCY OF ANTIBIOTIC
RELEASE IN ANTIBIOTIC-LOADED BONE CEMENT
S. Lee, C. Hu, Y. Chang
1
Chang Gung Memorial Hospital, Taoyuan, Taiwan
E-mail: [email protected]
Keywords: Liquid Antibiotic, Musculoskeletal Infection, Antibiotic-Loaded Bone Cement
References
Liquid antibiotics in bone cement: an effective way to improve the efficiency of antibiotic release in antibiotic
loaded bone cement. Bone Joint Res. 2014 Aug;3(8):246-51. doi: 10.1302/2046-3758.38.2000305.
Aim
The objective of this study was to compare the elution characteristics, antimicrobial activity and mechanical
properties of antibiotic-loaded bone cement (ALBC) loaded with powdered antibiotic, powdered antibiotic
with inert filler (xylitol), or liquid antibiotic, particularly focusing on vancomycin and amphotericin B.
Methods
Cement specimens loaded with 2 g of vancomycin or amphotericin B powder (powder group), 2 g of antibiotic
powder and 2 g of xylitol (xylitol group) or 12 ml of antibiotic solution containing 2 g of antibiotic (liquid group)
were tested.
Results
Vancomycin elution was enhanced by 234% in the liquid group and by 12% in the xylitol group compared with
the powder group. Amphotericin B elution was enhanced by 265% in the liquid group and by 65% in the xylitol
group compared with the powder group. Based on the disk-diffusion assay, the eluate samples of vancomycinloaded ALBC of the liquid group exhibited a significantly larger inhibitory zone than samples of the powder or
the xylitol group. Regarding the ALBCs loaded with amphotericin B, only the eluate samples of the liquid group
exhibited a clear inhibitory zone, which was not observed in either the xylitol or the powder groups. The
ultimate compressive strength was significantly reduced in specimens containing liquid antibiotics.
Conclusions
Adding vancomycin or amphotericin B antibiotic powder in distilled water before mixing with bone cement can
significantly improve the efficiency of antibiotic release than can loading ALBC with the same dose of antibiotic
powder. This simple and effective method for preparation of ALBCs can significantly improve the efficiency of
antibiotic release in ALBCs.
Acknowledgements
We thank H.Y. Hsu for performing the bioassay.
20
FP18 – (#8) - Free Paper
BACTERIAL CONTAMINATION OF DIATHERMY TIPS USED DURING ORTHOPAEDIC PROCEDURES
A. Abdulkarim, A. Moriarity, P. Coffey, E. Sheehan
1
Midland Regional Hospital, Tullamore, Ireland
E-mail: [email protected]
Keywords: Infection,THR, Diathermy,Arthroplasty
References
The role of diathermy in orthopaedic surgical practice has increased since its introduction. It is widely used for
underlying tissue dissection, cutting, and haemostasis. Previous studies have compared electrosurgical and
scalpel incisions in terms of wound infection, wound-related pain, and blood loss. There are well documented
hazards associated with diathermy use including burns injury, electrocution, hypoxic stress, inhalation of
diathermy plume, and gene mutation. No single study to date has focused on the potential for diathermy tips
to cause wound contamination and infection. We sought to identify whether diathermy tips could be possible
sources of infection in orthopaedic procedures.
Aim
To determine the prevalence of bacterial contamination of diathermy tips during orthopaedic surgery and to
assess any correlation with surgical site infections.
Methods
From July 2013 to September 2013, the diathermy tips from 86 consecutive orthopaedic procedures using
diathermy were cultured using direct and enriched media. None of the diathermy tips were used for the skin
incision. All patients underwent an orthopaedic procedure for a non-infected condition. For each procedure an
unused control diathermy tip was placed on the instrument table at the beginning of the procedure and
processed similarly. All patients were followed for any postoperative complications.
Results
108 diathermy tips from 86 orthopaedic procedures were cultured. None of the tips cultured directly on blood
agar demonstrated bacterial growth. Following enrichment culture, 6 (5.6%) of the procedure diathermy tips
and 1 (0.92%) of the control tips demonstrated bacterial growth. Coagulase-negative staphylococci (83.3%)
and proprionibacterium (16.7%) were cultured from the tips. 1 of the patients who had bacterial growth from
the diathermy tip developed a superficial surgical site infection.
Conclusions
Surgical site infections contribute substantially to orthopaedic surgical morbidity and mortality each year. The
prevention of these infections encompasses careful operative technique, preoperative antibiotics, and a
number of important measures to minimize the risk of bacterial contamination posed by operative staff, the
operating theatre environment, and the patient’s endogenous skin flora. Identifying potential bacterial sources
is an important component of surgery. The two bacteria cultured in our study (coagulase-negative
staphylococci and proprionibacterium) are both well known major culprits in orthopaedic infections,
responsible for up to 70% of early and late peri-prosthetic infections. Our study suggests diathermy tips and
the tissue coagulated by its use may not be as sterile as previously thought. There may be benefit in changing
the diathermy tips during orthopaedic procedures as they may represent a possible source of bacterial
contamination.
Acknowledgements
Microbiology Department at the Midland Regional Hospital Tullamore, Ireland
21
FP19 – (#33) - Free Paper
UNACCEPTABLY HIGH INFECTION RATE AFTER LOCAL INFILTRATION ANALGESIA WITH CORTICOSTEROIDS IN
PRIMARY TOTAL KNEE ARTHROPLASTY
B. Nijsse, L. Kadic, M. De Waal Malefijt, B. Schreurs
1
Radboud UMC, Nijmegen, The Netherlands
E-mail: [email protected]
Keywords: PJI, LIA, Corticosteroid
References
1) Reilly K A, Beard D J, Barker K L, Dodd C A, Price A J, Murray D W. Effi¬cacy of an accelerated recovery
protocol for Oxford unicompartmental knee arthroplasty--a randomised controlled trial. Knee 2005; 12: 351-7.
2) Kadic L, Niesten E, Heijnen I, Hofmans F, Wilder-Smith O, Driessen J J, Malefijt M C. The effect of addition of
pregabalin and s-ketamine to local infiltration analgesia on the knee function outcome after total knee
arthroplasty. Acta Anaesthesiol Belg. 2012; 63: 111-4.
3) Salerno A, Hermann R. Efficacy and safety of steroid use for postoperative pain relief. Update and review of
the medical literature. J Bone Joint Surg (Am). 2006; 88: 1361-72.
4) Marsland D, Mumith A, Barlow IW. Systematic review: The safety of intra-articular corticosteroid injection
prior to total knee arthroplasty. The Knee 2014; 21: 6-11
Aim
Local infiltration analgesia (LIA) is promoted as an effective treatment modality for pain control after total
knee arthroplasty (TKA) (1). A mixture of drugs is used to provide a multimodal analgesic effect. Previous
studies reported that the use of these drugs is safe. After we carefully implemented a LIA study protocol in our
practice, concerns raised about patient safety with probably higher infection rates. This forced us to perform
an interim analysis after the first 58 cases.
Methods
58 patients underwent a unilateral TKA with a standardised LIA protocol (2), which consisted of a mixture of
ropivacaine, epinephrine, and triamcinolone acetonide. Complications, knee function and patient satisfaction
scores were prospectively recorded during regular outpatient control.
Results
Four patients (6.9%) presented with signs of periprosthetic joint infection (PJI) within two months after
surgery. Baseline characteristics were similar between the infected and non infected group. All infections were
treated with debridement and retention, and antimicrobial treatment was started. One patient who suffered
an infection died during followup. At two years followup all implants could be retained. Knee function and KSS
score were acceptable for the patients who suffered PJI.
Conclusions
There is no consensus on the combination of drugs used for LIA. The application of corticosteroids in LIA is
reported to be safe (3), but arguable results about the injection of local corticosteroids around knee
arthroplasty surgery in the past have raised suspicion in literature (4). Combined with our unacceptable high
rate of PJI, we believe that the current body of evidence, with small heterogeneous series, does not support
the safe use of corticosteroids in LIA.
Acknowledgements
we have no conflicts of interest to declare.
22
FP20 – (#261) - Free Paper
LAMINAR AIRFLOW REDUCES MICROBIAL AIR CONTAMINATION IN COMPARISON TO TURBULENT AIRFLOW
DURING SIMULATED TOTAL HIP ARTHROPLASTY SURGERY
1
2
3
3
4
5
6
1
1
C. Ravn , A. Overgaard , N. Knudsen , J. Nielsen , M. Olsen , J. Toftum , M. Kemp , L.H. Frich , S. Overgaard
1
Dep. of Orthopaedic Surgery and Traumatology, Odense University Hospital - Institute of Clinical Research,
University of Southern Denmark, Odense, Denmark
2
Dep. of Orthopaedic Surgery, Herlev University Hospital, Copenhagen, Denmark, Copenhagen, Denmark
3
Fournais Energi Aps, Vedbaek, Denmark, Copenhagen, Denmark
4
JRV A/S, Greve, Denmark, Copenhagen, Denmark
5
Dep. of Civil Engineering, Technical University of Denmark, Lyngby, Denmark, Copenhagen, Denmark
6
Dep. of Clinical Microbiology, Odense University Hospital - Institute of Clinical Research, University of
Southern Denmark, Copenhagen, Denmark
E-mail: [email protected]
Keywords: Surgical Site Infection, Laminar Airflow, Active Sampling, Contamination
References
Stocks GW. Predicting bacterial populations based on airborne particulates: a study performed in nonlaminar
flow operating rooms during joint arthroplasty surgery. American journal of infection control 2010;38(3):199204.
Aim
To compare the number of airborne bacteria and particles under laminar airflow (LAF) versus turbulent airflow
(TAF) with 100% and 50% reduced fresh air exchange during simulated total hip arthroplasty (THA)
Methods
Two equally dimensioned operating rooms (OR) build in 2009 with modern ventilation systems of LAF and TAF
respectively were used during 32 simulated THA-operations under four different ventilation conditions: LAF or
TAF with either full (n=8+8) or 50% reduced (n=8+8) fresh air exchange volume.
We followed a protocol controlling the complete perioperative setup including interior cleaning, sterile
materials, OR-personnel procedures, surgical clothing, instruments and 50-minute surgical procedure on a fullsized dummy at 37°C.
Microbial contamination was determined intra-operatively by ISO-validated Microbiological Active Sampler
(MAS-100, Merck, 100 L/min) at two 10-minute intervals in 30 cm distance of the operating field. Blood-agar
plates from each operation were incubated for 2 days at 35°C and the microbial concentration was determined
by viable counting of colony-forming units (CFU) per m3 air.
Furthermore airborne particulate (0,5-10 µm) was sampled with ISO-validated light scattering particle analyzer
(MET-one, Beckman Coulter, 28,3 L/min) during the 50-minute surgical procedure (1,42 m3/operation). Large
particle sizes (>5 µm) are correlated with microbial contamination (Stocks, 2010). According to standards
large-sized particle number must not exceed a 2.900/m3-threshold for cleanroom operations.
Results
Microbial air concentration (mean CFU/m3 ±standard deviation) under LAF conditions with full and 50%
reduced fresh air exchange were 0,4±0,8 and 0,4±0,4 respectively, whereas air contamination under TAF
conditions were significantly higher with 7,6±2,0 and 10,3±8,1 (p<0,05).
Large (>5 µm) airborne particulate (mean no./m3 ±standard deviation) under LAF conditions with full and 50%
reduced fresh air exchange were 1.581±2.841 and 1.018±1.084 respectively, whereas particulate under TAF
conditions were 7.923±5.151 and 6.157±2.439 respectively.
Conclusions
Microbial air contamination was significantly lower under LAF ventilation compared to TAF during simulated
THA under both full and 50% reduced fresh air exchange in modern operating theatres used in daily clinic. The
number of particles measured under TAF conditions exceeded the threshold for cleanroom operations in
12/16 simulated operations. These findings indicate that LAF reduces the airborne microbial risk factor of
surgical site infection in comparison to TAF.
Acknowledgements
The study was in part managed by Clean Energy, Denmark and funded by the Danish Energy Agency under
Ministry of Climate, Energy and Building
23
FP21 – (#211) - Free Paper
OPERATING ROOM VENTILATION AND RISK OF REVISION DUE TO INFECTION AFTER THA
H. Langvatn, H. Dale, L. Engesæter, J. Schrama
1
Haukeland University Hospital, Bergen, Norway
E-mail: [email protected]
Keywords: Total Hip Arthroplasty, Prosthetic Joint Infection, Operating Room Ventilation, Laminar Airflow,
Revision Due To Infection
Aim
The aim of this study was to validate the information on operating room ventilation reported to the Norwegian
Arthroplasty Register (NAR). We then wanted to assess the influence of operating room ventilation on the rate
of revision due to infection after primary THA performed in operating rooms with conventional ventilation,
“greenhouse”–ventilation and Laminar Airflow ventilation (LAF).
Methods
We identified cases of THA revisions due to deep infection and the type of ventilation system reported to the
NAR from the primary THA. We included 5 orthopaedic units reporting 17947 primary THAs and 136 (0.8%)
revisions due to infection during the 28 year inclusion period from 1987 to 2014. The hospitals were visited
and the current and previous ventilation systems were evaluated together with the hospitals head engineer,
and the factual ventilation on the specific operating rooms was thereby assessed. The association between
revision due to infection and operating room ventilation was estimated by calculating relative risks (RR) in a
Cox regression model.
Results
73% of the primary THAs were performed in a room with LAF, in contrast to the reported 80 % of LAF. There
was similar risk of revision due to infection after THA performed in operating rooms with laminar air flow
compared to conventional ventilation (RR=0.7, 95 % CI: 0.2–2.3) and after THA performed in operating rooms
with “greenhouse”-ventilation compared to conventional ventilation (RR=1.2, 0.1–11).
Conclusions
Surgeons are not fully aware of what kind of ventilation there is in the operating room. This study may indicate
that, concerning reduction in incidence of THA infection, LAF does not justify the substantial installation cost.
The numbers in the present study are too small to conclude strongly. Therefore, the study will be expanded to
include all hospitals reporting to the NAR.
Acknowledgements
We report no conflict of interests.
24
FP22 – (#46) - Free Paper
TRANSFUSION OF RED BLOOD CELL UNITS STORED MORE THAN 14 DAYS INCREASES THE RISK OF INFECTION
AFTER JOINT ARTHROPLASTY.
1
2
3
1
1
1
3
E. Tornero , A. Pereira , L. Morata , S. Angulo , D.M. García-Velez , S. García-Ramiro , A. Soriano
1
Department of Traumatology and Orthopaedic Surgery, Hospital Clinic of Barcelona., Barcelona, Spain
2
Service of Hemotherapy and Hemostasis. Hospital Clínic of Barcelona, Barcelona, Spain
3
Service of Infectious Diseases. Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
E-mail: [email protected]
Keywords: Prosthetic Joint Infection, Red Blood Cell, Transfusion.
References
1. Flegel WA, Natanson C, Klein HG. Does prolonged storage of red blood cells cause harm? Br J Haematol
2014;165(1):3–16.
2. van de Watering L. Red cell storage and prognosis. Vox Sang 2010;100(1):36–45.
3. Pereira A. Deleterious consequences of allogeneic blood transfusion on postoperative infection: really a
transfusion-related immunomodulation effect? Blood 2001;98(2):498–500.
Aim
Stored red blood cells (RBCs) undergo a variety of changes that impair their post-transfusion viability, but the
detrimental effect of such lesion at the clinical level is a matter of debate (1) and there is no data about the
incidence of postoperative infection, a complication frequently associated with transfusion of stored RBCs (2).
Methods
We reviewed 9906 patients who underwent a primary or revision arthroplasty between January 2000 and
December 2012. Of these, 1153 (11.6%) received transfusion during surgery or within the first 6h after surgery
(early transfusion, ET) and 920 (9.3%) received transfusion only between 24 and 96 hours after surgery (late
transfusion, LT). Primary end-point was prosthetic joint infection (PJI) within the first year. Demographics,
joint, type of surgery, duration of surgery, number and length of storage of transfused RBCs were collected.
Ethical Committee approved the study.
Results
The median age was 74.9 (IQR:68.3-80.1) years and 1546 (74.6%) were female. There were 914 (44.1%) hip
and 1117 (53.9%) knee arthroplasties and 428 (20.6%) were revision surgeries. The median duration of surgery
was 105 (IQR:80-145) minutes. A total of 100 (4.8%) patients had a PJI. Figure 1 shows the PJI rate according to
the number of RBC units transfused and the proportion of such units that had been stored for more than 14
days, both in the ET-group (Fig. 1A) and the LT-group (Fig. 1B). In the ET-group, the fact that >50% of
transfused RBCs had been stored >14 days was an independent predictor of PJI (OR:2.50, 95%CI:1.44-4.33,
Hosmer-Lemeshow test P=0.972).
Conclusions
Stored RBC occlude the microcirculation (1), thereby precluding a good oxygenation of the surgical wound and
the arrival of leukocytes and prophylactic antibiotics. Both factors are involved in the progression from wound
bacterial contamination to wound infection and are particularly operative in the few hours following surgery
(5). It is biologically plausible that transfusion of old RBC in this early, critical period results in more wound
infections as compared to RBCs transfused later.
25
FP23 – (#227) - Free Paper
QUALITY OF LIFE AFTER STAGED REVISION FOR INFECTED TOTAL HIP ARTHROPLASTY: A SYSTEMATIC
REVIEW.
1
2
3
4
L. Rietbergen , J. Kuiper , S. Walgrave , S. Colen
1
Centre for Orthopaedic Research Alkmaar, MCA, Alkmaar, The Netherlands
2
Medisch Centrum Alkmaar, Alkmaar, The Netherlands
3
KU Leuven, Leuven, Belgium
4
Hümmling Hospital, Sögel, Germany
E-mail: [email protected]
Keywords: Quality Of Life, Hip, Prosthetic Joint Infection, Two Stage Revision, QoL
Aim
The aim of our review was to assess (health related) quality of life ((HR)QoL) after one-stage or two-stage
revision for prosthetic joint infection (PJI). Although it is generally accepted that staged revisions are very
strenuous for patients, little is known about the (HR)QoL after these procedures.We compared (HR)QoL scores
with normative population scores to assess the magnitude of this problem.
Methods
Two authors performed a computerized systematic search in Embase, Cochrane and Pubmed. We included
articles that reported: validated (HR)QoL questionnaires, one-stage or two-stage revision for PJI after total hip
arthroplasty (THA), a minimum follow-up of 24 months and a minimum of ten patients. Methodological quality
of all papers was assessed using the MINORS score. The systematic review was conducted according to the
PRISMA statement.
Results
The search produced 11195 hits. After selection, based on title and abstract, 18 full text papers were reviewed.
Six articles were excluded. Twelve papers were selected for final assessment. All papers described two-stage
revisions. The mean MINORS score for these studies was 9.8, indicating moderate study quality.
Seven articles reported WOMAC scores, with a total of 185 patients (74% response rate) having a mean
general score of 73, with a mean follow-up of 65 months. The normative total WOMAC score for the general
population (age 60-64) is 82.9, with a score of 100 being the best possible outcome.
Four articles described Short Form 36 (SF-36) results on a total of 159 patients (71.9% response rate). In these
studies the physical component score (PCS) of the SF-36 was on average 39.6 and the mental component score
(MCS) was on average 50.9, with a mean follow-up of 41 months. Normative data for the US population (age
55-64) are a PCS of 47.2 and an MCS of 51.8.
Four articles reported Short Form 12 (SF-12) scores on a total of 138 patients, with a mean PCS of 33.6 and a
mean MCS of 51.7, with a mean follow up of 72.5 months. Normative data for the Dutch population (age 5565) are a PCS of 48.3 and an MCS of 52.8. A score of 100 represents best possible health for both SF
questionnaires.
Conclusions
Patients that underwent two-stage revision for hip PJI have substantially lower (physical component) (HR)QoL
scores, when compared to the general population.
26
FP24 – (#83) - Free Paper
COULD AN ISOLATION WARD REDUCE THE RATE OF NOSOCOMIAL TRANSMISSION OF MULTIRESISTANT
BACTERIA?
M. Militz, R. Werle, D. Meier, S. Hungerer, V. Buehren
1
Trauma Center Murnau, Murnau, Germany
E-mail: [email protected]
Keywords: Multiresistance, Isolation
Aim
To prevent nosocomial transmission (NT) of multiresistent germs (MRG) the German Robert Koch Institute
(RKI) recommends to isolate patients with MRG.
At a so-called normal ward isolating patients is a challenging and stressful procedure for both patients and
hospital staff.
The present study proposes the hypothesis that, compared to normal wards, an isolation ward reduces the
nosocomial infection rate.
Methods
After an isolation ward with twelve beds has been established in 2005, patients with MRG on the wards of the
department for spinal cord injury as well as on the isolation ward were monitored using a prospective
screening and meeting the requirements of the RKI. Apart from detecting transmitter of MRG the NT of these
bacteria was identified and registered between 2006 and 2013.
The total length of a patients stay in the hospital, the number of isolation days and the rate of NTs were
documented. The quotient of MRG load per ward and the number of NTs per ward were compared.
Results
In the investigation period of eight years 262175 patient days, 33416 isolation days and 33 transmissions were
registered.
On the spinal cord injury ward 223167 of the patient days, 1120 of the isolation days and 29 of the NTs were
documented. On the isolation ward 39008 of the patient days and 32296 of the isolation days with four of the
transmissions were registered.
The mean load of MRG resulted from the quotient of the number of days with MRG per 100 patient days.
The effective nosocomial frequency of transmission resulted from the quotient of the mean load of MRG to
the number of transmissions.
As a result, the frequency of transmission on the isolation ward was significantly lower (p=0,001) in
comparison to the spinal cord injury ward.
Conclusions
The presented results suggest that, despite multiple higher loads of MRG, constructional measures combined
with contact isolation facilitate a reduction of NT rates of MRG.
The reservation must be made, however, that in case of known MRG the screening was performed under
isolation conditions, with unkown MRG without meeting requirements of isolation.
The present comparison of NT rates on an isolation ward and a normal spinal cord injury ward emphasizes the
importance and function of an isolation ward through constructional (physical) separation and pooling of
professional competency for successful management of MRG in healthcare facilities.
27
FP25 – (#17) - Free Paper
TREATMENT OF OPEN FRACTURES OF THE TIBIA WITH LOCKED INTRAMEDULLARY NAIL WITH A CORE
RELEASE OF ANTIBIOTICS (SAFE DUALCORE UNIVERSAL).
N. Craveiro-Lopes, C. Escalda, M. Leão
1
Garcia de Orta Hospital, Almada, Portugal
E-mail: [email protected]
Keywords: Open Fractures, Bone Infection, Bone Cement With Antibiotic
Aim
The aim of this study was to compare the clinical and radiographic results of a interlocking nail with a releasing
antibiotic core of PMMA with a standard interlocking nail for the treatment of open fractures of the tibia.
Methods
Prospective, controlled trial, randomized by surgeon preference, including 30 patients with open fractures of
the tibia. Patients were divided into two groups according to the treatment method: Group I (STD), consisting
of 14 patients treated by delayed interlocking standard nailing, after an antibiotic treatment and bed rest.
Group II (SAFE) comprising 16 patients treated with a interlocking intramedullary nail with a core of PMMA
cement with antibiotics, 5 of which had a temporary stabilization with an external fixator. Antibiotics chosen to
impregnate the SAFE nail in cases without prior bacteriology were vancomycin (2gr) and flucloxacillin (2gr)
Results
There were no statistically significant differences between groups with respect to demographic data (age,
gender), type of fracture and degree of exposure (p>0,05). The mean follow-up was 2.4 years (5 months to 4
years) for the STD group and 2.1 years (4 months to 3 years) for the SAFE group. 15 of the 30 patients had
positive bacteriology, including 13 cases with aggressive agents predominating Enterobacter, Enterococcus,
Pseudomonas and MSSA groups.
The infection rate after nailing was 43% (6/14 patients) for the STD group and 6% (1/16 cases) to the SAFE
group, a statistically significant difference (p=0.02)
The mean time to union was 7.5 months (3 months to 1.5 years) for the STD group and 4.5 months (2 months
to 8.5 months) for the SAFE group, a statistically significant difference (p=0.02). The complication rate was 64%
(9/14) in the STD group and 25% (4/16) for the SAFE, including a infection rate of 43% in the STD group and 6%
in the SAFE group, a statistically significant difference (p=0.03).
Conclusions
We observed that the open fractures of the tibia treated with SAFE nails presented a statistically significant
lower rate of infection, faster consolidation and fewer complications compared with treatment with deferred
standard nails. Compared to similar devices available on the market, it has the advantage of allowing selection
of the type and dose of antibiotics, it allows fixation with screws of intermediate bone segments, it shorten the
period of hospitalization and treatment time, reducing the costs associated with the treatment of this
pathology
28
FP26 – (#15) - Free Paper
A REVIEW OF 45 OPEN TIBIAL FRACTURES COVERED WITH FREE FLAPS. ANALYSIS OF
COMPLICATIONS, MICROBIOLOGY AND PROGNOSTIC FACTORS
1
1
1
2
U. Olesen , C. Moser , C. Bonde , M. Mcnally , H. Eckardt
1
Rigshospitalet, Copenhagen, Denmark
2
Nuffield Orthopeadic Centre, Oxford, United Kingdom
3
University Hospital, Basel, Switzerland
E-mail: [email protected]
3
Keywords: Open Fractures, Complications, Timing Of Surgery, Microbiology, Antibiotics
References
1. Gustilo RB, Anderson JT. (1976) Prevention of infection in the treatment of one thousand and twenty-five
open fractures of long bones: retrospective and prospective analyses. J Bone Joint Surg Am 58:453-458.
2. D'Alleyrand JC, Manson TT, Dancy L, et al. (2014) Is time to flap coverage of open tibial fractures an
independent predictor of flap-related complications? J OrthopTrauma 28:288-293.
3. Pollak AN, McCarthy ML, Burgess AR (2000). Short-term wound complications after application of flaps for
coverage of traumatic soft-tissue defects about the tibia. The Lower Extremity Assessment Project (LEAP)
Study Group. J Bone Joint Surg Am 82:1681-1691.
4. Gopal S, Majumder S, Batchelor AG, et al. (2000) Fix and flap: the radical orthopaedic and plastic treatment
of severe open fractures of the tibia. J Bone Joint Surg Br 82:959-966.
5. Sinclair JS, McNally MA, Small JO, et al. (1997) Primary free-flap cover of open tibial fractures. Injury 28:581587.
6. Patzakis MJ, Wilkins J. (1989) Factors influencing infection rate in open fracture wounds. Clin Orthop Relat
Res 243:36-40.14
7. Hohmann E, Tetsworth K, Radziejowski MJ, et al. (2007) Comparison of delayed and primary wound closure
in the treatment of open tibial fractures. Arch Orthop Trauma Surg 127:131-136.
8. Cierny G 3rd, Byrd HS, Jones RE (1983) Primary versus delayed soft tissue coverage for severe open tibial
fractures. A comparison of results. Clin Orthop Relat Res. 178:54-63.
9. Hertel R, Lambert SM, Müller S, et al. (1999) On the timing of soft-tissue reconstruction for open fractures of
the lower leg. Arch Orthop Trauma Surg 119:7-12.
10. Crowley DJ, Kanakaris NK, Giannoudis PV. (2007) Debridement and wound closure of open fractures: the
impact of the time factor on infection rates. Injury. 38:879-889
13. Sheehy SH, Atkins BA, Bejon P, et al. (2010) The microbiology of chronic osteomyelitis: prevalence of
resistance to common empirical anti-microbial regimens. JInfect 60:338-343.
14. Hauser CJ, Adams CA Jr, Eachempati SR. (2006) Surgical Infection Society guideline: prophylactic antibiotic
use in open fractures: an evidence-based guideline. Surg Infect (Larchmt) 7:379-405.
15. Saveli CC, Belknap RW, Morgan SJ, et al. (2011) The role of prophylactic antibiotics in open fractures in an
era of community-acquired methicillin-resistant Staphylococcus aureus. Orthopedics. 34:611-616.
16. Zalavras CG, Patzakis MJ. (2003) Open fractures: evaluation and management. J Am Acad Orthop Surg
11:212-219.
17. Christy MR, Lipschitz A, Rodriguez E, et al. (2014) Early postoperative outcomes associated with the
anterolateral thigh flap in Gustilo IIIB fractures of
Aim
Treatment of open fractures is complex and controversial.
The purpose of the present study is to add evidence to the management of open tibial fractures, where tissue
loss necessitates cover with a free flap. We identified factors that increase the risk of complications. We
questioned whether early flap coverage improved the clinical outcome and whether we could improve our
antibiotic treatment of open fractures.
29
Methods
From 2002 to 2013 we treated 56 patients with an open tibial fracture covered with a free flap. We reviewed
patient records and databases for type of trauma, smoking, time to tissue cover, infection, amputations, flap
loss and union of fracture. We identified factors thatincrease the risk of complications. We analyzed the
organisms cultured from open fractures to propose the optimal antibiotic prophylaxis.
Follow-up was minimum one year. Primary outcome was infection, bacterial sensitivity pattern, amputation,
flap failure and union of the fracture.
Results
When soft tissue cover was delayed beyond 7 days, infection rate increased from 27% to 60% (p<0.04). Highenergy trauma patients had a higher risk of amputation, infection, flap failure and non-union. Smokers had a
higher risk of non-union and flap failure. The bacteria found were often resistant to Cefuroxime,
aminoglycosides or amoxicillin, but sensitive to Vancomycin or Meropenem.
Conclusions
Flap cover within one week is essential to avoid infection. High-energy trauma and smoking are important
predictors of complications. We suggest antibiotic prophylaxis with Vancomycin and Meropenem until the
wound is covered in these complex injuries.
Acknowledgements
The authors wish to thank Christian E Forrestal for secretarial assistance, spreadsheets and figures, MD Maria
Petersen for academic feedback and typography.
Table: Culture results. Depicts the organisms isolated from the wounds, their number N and the number of
bacteria that were fully susceptible to antibiotics according to the culture results in falling order on day 2-30
from the trauma. Most organisms were resistant to
Cefuroxime. A blank space denotes that the organism was not tested against this antibiotic. A “0” denotes that
the organism was not fully sensitive to the antibiotic.
Bacteria
N Vanco Mero Linez Genta Sulfa Amp Moxi Ery Rif Cipro Cefur Azit Metro
Enterococcus species
11 11
7
9
9
5
5 1
0
2
Coagulase neg.
9
9
9
5
3
2 8
3
3
staphylococci (CoNS)
Enterobacteriaceae
6
5
5
5
1
5
1
Miscellaneous
6
5
6
3
5
2
4
2
2
2
2
Other pseudomonas
4
2
2
3
0
3
Anaerobic bacteria
2
2
1
2
Staphylococcus aureus
2
2
2
2
1 2
2
2
Haemolytic streptococci
1
1
1
1
1
1
1
Corynebacterium species 1
1
0
1
0
0
0
1
0
Pseudomonas aeruginosa 1
1
1
0
Total
43 29
24
24
15
14
13
13 12 11 10
9
9
2
30
The bone defect in septic surgery
31
FP27 – (#135) - Free Paper
A COMPARATIVE STUDY OF THREE BIOABSORBABLE ANTIBIOTIC CARRIERS IN CHRONIC OSTEOMYELITIS: 313
PATIENTS WITH MINIMUM 1 YEAR FOLLOW-UP
M. Mcnally, J. Ferguson, J. Kendall, M. Dudareva, M. Scarborough, D. Stubbs
1
The Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
E-mail: [email protected]
Keywords: Osteomyelitis, Local Antibiotics, Outcomes, Absorbable
Aim
To evaluate the clinical outcome of three different local antibiotic delivery materials, used as bone defect
fillers after excision of chronic osteomyelitis.
Methods
We reviewed all patients receiving Collagen Fleece with Gentamicin (Septocoll E)(n=74), Calcium Sulphate with
Tobramycin pellets (Osteoset T)(n=166) or Calcium Sulphate/Hydroxyapatite biocomposite with Gentamicin
(Cerament G)(n=73) for dead space filling after resection of C-M Stage III and IV chronic osteomyelitis. Data
was collected on patient comorbidities, operation details, microbiology, postop complications and need for
plastic surgery or external fixation. All operations were performed by two surgeons. All patients had similar
systemic antibiotic therapy and rehabilitation.
Primary outcomes were recurrence rate, fracture rate and wound leakage rate.
Results
All three groups had very similar mean age and range, microbiological cultures, need for free muscle flaps or
local flaps, proportion of femur, tibia and upper limb bones and use of external fixation. There were small
differences in the proportion of C-M Class B hosts and anatomic Type IV cases, between the groups. All
patients were followed up for at least one year. Mean follow-up was 1.75 years for Septocoll E, 1.96 years for
Osteoset T and 1.78 years for Cerament G.
After surgery, there were fewer prolonged wound leaks with Cerament G (leakage persisting for more than 2
weeks). Fracture rates and infection recurrence were twice as common with Osteoset T compared with
Cerament G at between one and two years after operation (see Table).
Conclusions
The use of a biocomposite material delivering local aminoglycoside was associated with lower recurrence rates
and few wound problems, compared with collagen or calcium sulphate alone. This may reflect the higher
levels of antibiotic in the defect and controlled release profile. The improved recurrence rate was despite a
higher percentage of compromised Class B hosts.
Septocoll E Osteoset T Cerament G
Number
74
166
73
Mean Age (range)
48.2(19-80) 45.6(16-82) 52.0(21-84)
C-M Type III %
82.5
79.4
87.8
C-M Host Class B %
74.3
65.7
83.3
Total wound leakage %
17.6
20.5
9.6
Fracture rate %
2.7
3.6
1.4
Recurrence rate %
6.6
8.4
4.1
32
FP28 – (#121) - Free Paper
CERAMENT BONE VOID FILLER WITH GENTAMICIN INCREASES BONE FORMATION AND DECREASES
DETECTABLE INFECTION IN A RAT MODEL OF DEBRIDED OSTEOMYELITIS.
1
1
1
2
1
1
A. Dvorzhinskiy , G. Perino , R. Chojnowski , M. Van Der Meulen , F. Ross , M. Bostrom , X. Yang
1
Hospital for Special Surgery, New York, United States
2
Cornell University, New York, United States
E-mail: [email protected]
1
Keywords: Osteomyelitis, Cement, Debridement, Osteoconduction, Void
References
1. Lew et al. Lancet. 2004.
2. Eckardt et al. CORR. 1994.
3. Sutton S. J. Validation Technol. 2011
Aim
To test the hypothesis that: CERAMENT[™]|G (C-G) would improve new bone growth and decrease infection
rate after debridement as compared with 1) CERAMENT|BONE VOID FILLER (CBVF) and 2) no void filler in a rat
osteomyelitis model.
Methods
72 Sprague Dawley rats were injected with 1.5 x 10^6 CFU of S. aureus into a drill hole in the right tibia. After 3
weeks, the osteomyelitic defect was debrided, and filled with either: 1) C-G (n=32), 2) CBVF (n=20), or 3)
nothing (n=20). 6 weeks after the second surgery, 20 rats from each group were sacrificed and the right tibias
were harvested. A long-term group (n=12) of C-G treated rats were also sacrificed at 6 months after the
second surgery. The tissues were sonicated and the colony forming units in the sonicate were quantified by
serial dilutions and culture. MicroCT was used to quantify the new bone growth (BV/TV) in the debrided
osteomyelitic void. Histological samples were analyzed for the presence of a neutrophil response by a blinded
pathologist.
Results
(*: p<0.05)
Positive cultures in:
o 30% of animals treated with CBVF
o 25% of animals treated with no void filler
o 0% of animals treated with C-G (*)
Neutrophil reaction in:
o 35% of animals treated with CBVF
o 50% of animals treated with no void filler
o 0% of animals treated with C-G (*)
The BV/TV in:
o C-G treated rats was 24% greater than CBVF treated rats (*)
o C-G treated rats was 94% greater than rats treated with no void filler (*)
o CBVF treated rats was 56% greater than rats treated with no void filler (*)
Animals sacrificed at 6 months which were treated with C-G did not have any evidence of infection by culture
or histology. The bone mass of the implanted limb was higher than the contralateral (non-operated) side.
Conclusions
CERAMENT|G decreased the rate of infection and increased new bone growth as compared with both CBVF
and no void filler in a debrided osteomyelitic environment. Animals treated with C-G at 6 months showed no
evidence of infection and retained a higher bone mass relative to the contralateral (non-operated) side.
This study supports the use of CERAMENT|G as a readily available void filler which could be used in
osteomyelitic environments after debridement.
Acknowledgements
This study was generously funded by BONESUPPORT AB.
33
FP29 – (#123) - Free Paper
BONE DEFECTS TREATMENT TACTICS IN CASE OF INFECTIONS FOLLOWING THE OSTEOSYNTHESIS.
M. Grytsai, O. Linenko, G. Kolov, V. Tsokalo, A. Hordii, V. Sabadosh, A. Pecherskiy
1
Institute of travmatology and orthopedics, Kyiv, Ukraine
E-mail: [email protected]
Keywords: Bone Defect, Osteomyelitis, Free Bone Grafting, Distraction Method
References
A large percentage of patients with long bones osteomyelitis have significant bone defects that require bone
grafting to eliminate the pathological process and to restore the extremity function.
The research goal was to generalize the results of treating patients with long bones post-osteomyelitis defects
by using free and non-free bone grafting.
Aim
This article is based on the analysis of surgical treatment peculiarities of 641 patients with post-osteomyelitis
long bones defects. The average age of patients at the time of hospital admission was 32,4 ± 0,7 and ranged
from 4 to 70 years. Most of them were people of active working age (476 (74.3%)) and male (523 (81.1%)).
In this observation group 566 (88.3%) patients had the osteomyelitis process of the traumatic origin, including
post-surgical (n = 155) and post-gunshot injuries (n = 13). Chronic hematogenous osteomyelitis was diagnosed
in 75 (11.7%) patients. Most patients had lower extremity bones problems, including 444 tibia defects and 142
femoral bone defects. Much fewer patients had the osteomyelitis process of the upper extremity (humerus,
radius, ulnar bone - 18, 19 and 18 respectively).
Methods
Purulent necrotic process was accompanied by nonunion bone fragments in 160 (24%) patients, delayed union
in 95 (14.6%) patients, false joint in 178 (27.6%) patients, segmental bone defect in 75 (11 5%) patients and
bones union with edge defects and cavities in 143 (22.3%) patients.
340 (53%) patients were operated using the method of free bone grafting, and 301 (47%) patients were
operated using the distraction method.
Results
The need to use the bilocal for external fixation on upper extremities occurs quite seldom (twice in our
observations). Even when there is an upper extremity bone defect of several centimeters the preference
should be given not to bilocal external fixation.
When treating the lower extremities taking the above mentioned into consideration, segmental defects
predominated, that is why the bilocal distraction-compression method of surgical treatment prevailed (98.6%).
Conclusions
Thus, the main method of upper extremities long bones defects replacement is free bone grafting with
segment fixation by the external fixation device, for lower extremities the is not-free main Ilizarov method,
which allows to get positive results in 84.6% of patients with femoral bone problems and in 96.4% of tibia
problems, mainly due to one-step treatment, directed simultaneously to inflammatory process elimination and
maximum possible anatomical and functional restoration of the affected extremity.
34
FP30 – (#78) - Free Paper
INDICATIONS FOR BONE-DEFECT-RECONSTRUCTION WITH THE MASQUELET-TECHNIQUE
R. Schoop, G. Ulf-Joachim, S. Maegerlein, M. Borreé
1
BG Unfallkrankenhaus Hamburg, Hamburg, Germany
E-mail: [email protected]
Keywords: Bone Defect-Reconstruction, Masquelet
Aim
For which patients is bone-defect-reconstruction with the Masquelet-technique suitable?
Methods
Between 11/2011 and 1/2015 we treated 27 Patients (4 female/ 23 male) with bone-defects up to 150mm
after septic complications with the Masquelet-technique.
Reason of the bone defects were infected-non-unions of lower extremity, chronic osteomyelitis, infected kneearthrodesis, chronic upper-ancle-empyema and infect-defect-non-union of the humerus. On average the
patients were 47,5 (18-74) years old. The mean bone-defect-size was 62,6 mm (25-150). 26 of the 27 patients
came from other hospitals, where they had up to 20 (mean 4,9) operations caused by the infection. The time
before transfer to our hospital was on average 177days (6-720). 25 patients receaved flaps because of soft
tissue-defects (7 free flaps, 18 local flaps).
13 patients suffered a polytrauma.
In 5 cases the femur, in 3 cases a knee-arthrodesis, in 18 cases the tibia and in 1 case the humerus was
affected by infection resulting in bone defects.
Indication for the Masquelet-technique was low-/incompliance in 10 cases due to higher grade of traumatic
brain injury and polytrauma and difficult soft-tissue conditions, in 6 times after problems with segmenttransport and in 1 case as dead space management.
Positiv microbial detection succeeded in 19 patients at the first operation although most of the patients
underwent long term antibiotic therapy. Mainly we found problematic bacteria. At the time of defect
reconstruction with spongious graft we found persistant bacteria in 4 cases.
The first operation aimed treating the infection with radical sequestrectomy, removal of foreign bodies and
filling the defect with an antibiotic loaded cementspacer as well as external fixation. 6-8 weeks later we
removed the spacer and filled the defect with autologous bonegraft. In 2 cases we needed 2 bone grafts to fill
the defect. In 9 cases we removed the fixateur and stabilized the defect with an internal anglestable plate.
All patients were examined clinically and radiologically every 4-6 weeks in our outpatient-department for
osteitis until full weight bearing and later every 3months
Results
In 22 of 27 cases the infection was clinically treated successfully. 5 patients are allowed for full weight bearing
(all with secondary internal plates). No patient underwent amputation.
There were 4 recurrences of infection, 9 instabilities needing internal stabilization and further bonegraft.
Conclusions
For patients with low-/incompliance for various reasons and for those with difficult soft tissue conditions
following flaps the Masquelet technique is a valuable alternative to the normal autologious spongegraft and to
the segmenttransport. Internal fixation seems necessary.
35
FP31 – (#188) - Free Paper
SURGICAL TREATMENT OF INFECTED TUMOR MEGAPROSTHESES WITH STAGED RECONSTRUCTION
1
2
1
2
J. Benevenia , F. Patterson , K. Beebe , S. Rivero
1
Rutgers New Jersey Medical School, Newark, United States
2
Rutgers New Jersey Medical School, New Jersey, United States
E-mail: [email protected]
Keywords: Musculoskeletal Oncology, Infection, Megaprosthesis
Aim
Limb salvage in musculoskeletal tumor surgery may be complicated by infection. With the advent of modern
techniques and medical management limb sparing surgeries can be considered as an alternative to ablation.
Methods
Between 1992 and 2014, 17 patients were treated for infected megaprostheses after being surgically treated
for musculoskeletal tumors. There were nine females and eight males. The mean time from the index
procedure until infection was 30 months. Following radical debridement, the resultant skeletal defect
averaged 30 cm. Patients were treated with local antibiotics in polymethyl methacrylate (PMMA) spacers and
endoprostheses as well as IV antibiotics for a minimum of six weeks followed by oral antibiotics for an
additional six weeks. The initial tumor procedure involved the femur in eleven patients, the tibia in two, the
acetabulum in one, the humerus in two, and the ulna in one. Patients had repeat cultures before two-stage
reimplantation when their WBC, ESR, and CRP returned to normal. Patients were reimplanted when final
cultures were negative.
Results
Thirteen patients were treated using a two-stage protocol with customized intraoperative antibiotic
impregnated PMMA spacers including intramedullary nails for a mean of 10 months and the other four
patients had a one-stage procedure. These four patients included two patients with a total femur replacement
and two patients with an allograft-prosthetic composite of the proximal humerus and ulna. The organisms
cultured were gram positive in 14 cases, mixed gram positive and negative in one case, and two patients had
no growth on cultures but histologic evidence of acute infection. Reimplantation was successful in 13 patients
after the initial procedure (76%). Four patients had recurrent infections. One of these patients was successfully
reimplanted after a one-stage procedure, two had a second two-stage procedure and have retained their
spacers, and one had an amputation. Successful limb salvage in regards to infection control occurred in 14/17
patients (82%). One additional patient required an amputation for an oncologic complication (local
recurrence), so the overall limb salvage rate was 13/17 (76%).
Conclusions
Patients with megaprosthetic infections following limb salvage treatment for musculoskeletal tumors do not
have to be uniformly subject to amputation. Radical debridement and appropriate antibiotics in conjunction
with custom spacers followed by selective one- and two-stage reimplantation results in successful limb salvage
in 82% of patients. This result is similar to other reports despite the large size average defects.
36
FP32 – (#109) - Free Paper
THE BONE DEFECT IN SEPTIC SURGERY TREATED WITH MEGAPHROSTHESIS
J. Baeza, T. Mut, M. Angulo, J. Amaya, F. Baixauli, M. Fuertes
1
Hospital Universitario la Fe de Valencia, Valencia, Spain
E-mail: [email protected]
Keywords: Bone Defect, Megaprosthesis
References
1 Calori GM, et al. Megaprosthesis in large bone defects: Opportunity or chimaera? Injury (2013), http://
dx.doi.org/10.1016/j.injury.2013.09.015
2 Fujii R, Ueda T, Tamai N, Myoui A, Yoshikawa H. Salvage surgery for persistent femoral non-union after total
knee arthroplasty using a megaprosthesis. J Orthop Sci 2006;11:401–4.
3 Giannoudis PV, Einhorn TA, Marsh D. Fracture healing: the diamond concept.Injury 2007;38(Suppl. 4):S3–6.
Aim
The use of new megaprosthesis for massive bone loss is an option for the replacement of skeletal segments.
There are several clinical scenarios that can be associated with this situation including severe trauma with
multiple failed osteosynthesis with a non union or with a previous prosthetic replacement of a neighbouring
joint; multiple revision of arthroplasty with or without infections or large resections of tumours.The aim of this
work is to evaluate retrospectively both clinical and radiological outcomes and any complications in patients
treated with megaprosthesis in SEPTIC BONE DEFECTS in our Hospital from February 2012 to January 2015.
Methods
From February 2012 to January 2014 a total of 20 patients were treated with mono-and bi-articular
megaprosthesis subdivided as follows: 4 proximal femur, 11 distal femur, 3 total femur,1 total humerus and 1
proximal humerus. Clinical and serial radiographic evaluations were performed at 6 weeks, 3, 6, 12, 18 and 24
months. Blood parameters with CRP and ESR were monitored for at least 2 months. The mean follow-up of
patients was about 24.4 months (range 5 months to 31 months). The mean age of the patients was 53 years
(range 37–80years). Of the patients 20 , 9 were female and 11 were male. The aetiology was: 11 septic non
unions, 3 infected TKA, 4 infected THR and 2 infected tumor prostheses.
20101
Results
We have evaluated retrospectively both clinical and radiological outcomes of 20 patients. They had large bone
defects that threatened the viability of the limb. They were treated with megaprosthesis. Although the mean
length of follow-up was only 24.4 months they showed encouraging clinical results, with good articulation of
the segments, no somato-sensory or motor deficit and acceptable functional recovery. There were three cases
of dislocation , one case with rifampicin toxicity, one case with acute prosthetic infection (case that needed
debridement and one case with chronic oral antimicrobial.
Conclusions
Megaprosthesis provides a valuable opportunity to restore functionality to patients with highly disabling
diseases. The number of complications is not depreciable.
Acknowledgements
Thanks to the collaboration of our patients
37
FP33 – (#189) - Free Paper
MANAGING LARGE BONE DEFECTS WITH CUSTOM SPACERS IN PATIENTS WITH MUSCULOSKELETAL
INFECTIONS
1
2
1
2
J. Benevenia , F. Patterson , K. Beebe , S. Rivero
1
Rutgers New Jersey Medical School, Newark, United States
2
Rutgers New Jersey Medical School, New Jersey, United States
E-mail: [email protected]
Keywords: Musculoskeletal Oncology, Infection, Two-Stage Reimplantation, PMMA Spacer
Aim
In patients requiring two-stage procedures, stabilization of large skeletal defects after radical debridement
must be attained in order to successfully treat the infection. With the use of standard rod plus antibiotic
impregnated PMMA spacers limb salvage may be attempted with satisfactory results.
Methods
Between 1992 and 2014, 23 patients were treated for hip, knee, or shoulder musculoskeletal infections
resulting in an average skeletal defect of 22 cm. There were 13 males and 10 females. Twelve patients had
infected tumor prostheses, seven patients had an infected total joint arthroplasty, and four patients had a
primary infection involving a large skeletal defect. The mean time from the index procedure until infection was
22 months. Following debridement, the defect was stabilized with Tobramycin and Vancomycin impregnated
PMMA and intramedullary nails. Patients were treated with IV and oral antibiotics for six weeks each. In 18
patients who had resection about the knee stabilization was achieved with a single femoral or tibial nail in nine
patients and with two nails joined by a screw or cerclage wire in the other nine. In four patients a
cephalomedullary femoral nail was used for stabilization after resection of the proximal or total femur. One
patient had a custom total humeral prostalac using threaded Steinmann pins and 16-gauge wire.
Results
The organisms cultured were gram positive in 19 cases, mixed gram positive and fungal in one, mixed gram
negative and mycobacterium in one, and two patients had no growth on cultures but histologic evidence of
acute infection. Of the 23 patients, 16 were successfully reimplanted following the initial procedure (70%) and
seven had recurrent infections. Three patients with recurrent infections were successfully reimplanted after an
additional one-stage procedure and four patients were not reimplanted. Two of these four had amputations
and the other two had a second two-stage procedure and have retained their spacers. There were seven
complications including a broken spacer, three periprosthetic fractures, two contractures, and one case of
aseptic loosening. Successful limb salvage with infection control was 19/23 (83%). One patient required an
amputation for local recurrence of their tumor. The overall limb salvage rate was 18/23 (78%).
Conclusions
Stable temporary antibiotic laden cement spacers, made in conjunction with standard intramedullary nails, can
provide the necessary limb stability to treat musculoskeletal infections and allow for reimplanation of tumor
prostheses for limb salvage.
38
FP34 – (#282) - Free Paper
KNEE INFECTION WITH COMPLICATED CLINICAL COURSE - PRESERVATION OF THE LOWER EXTREMITY BY
KNEE ARTHRODESIS
A. Tiemann
1
Clinic for Orthopedic and Trauma Surgery; SRH Zentralklinikum, Suhl, Germany
E-mail: [email protected]
Keywords: Knee Infection, Arthrodesis
References
The primary treatment goal of arthrodesis is the sedation or better eradication of the infection and
maintenance of a weight bearing lower extremity with a reasonable function. Generally a limb with a knee
fusion is more efficient and functional than is one with an above–the–knee amputation.
Aim
The purpose of the following study was to present the general strategy for preserving the lower extremity by
knee arthrodesis and to analyze the outcome of knee arthrodeses performed by a special modular system.
Methods
Between 2009 and 2014 35 knee arthrodeses were performed. 23 patients were male, 12 female. The average
age was 66 years (42 to 83 years). The patients underwent an average of 6 operations because of infected
knee arthroplasties previous to the knee arthrodesis. The main pathogen was S. epidermidis followed by
MRSA. The arthrodeses system included a non cemented femoral and tibial stem (press fit application plus two
static locking screws). These were connected by a special stem to stem clamp.
Results
Immediate postoperative full weight-bearing was possible in 32 of 35 patients. We saw 4 recurrent infections
(all connected to the patients, who did not show a full weight bearing after knee arthrodesis). In two cases rerevision surgery was successful and lead to a sufficient re-arthrodesis. In two cases above-knee-amputation
was necessary. Peri-implant fractures were detected in 3 cases. All of them could be cured by changing the
arthrodesis stem and to a longer one bridging the fracture. In one case a stem loosening was seen. This was as
well addressed by the use of a longer stem.
Conclusions
Knee arthrodesis by a modular non cemented system is a god alternative in order to preserve the weightbearing lower extremity. The complication rate is rather high due to the fact, that this procedure presents the
final alternative to do so in patients, who are in extremis in terms of a long lasting aggressive peri-arthroplasty
infection the lead to massive destruction of the soft tissue around the knee and a significant loss of function.
39
Septic non-union
40
FP35 – (#160) - Free Paper
PATIENT AND SURGICAL PREDISPOSING FACTORS FOR SURGICAL ACETABULAR FRACTURES INFECTION
M. Salles, W. Junior, F. Santos, C. Cavalheiro, R. Guimarães, N. Ono, M. Queiroz, E. Honda, G. Plosello
1
Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
E-mail: [email protected]
Keywords: Acetabular Fractures, Surgical Treatments, Risk Factores, Deep Infection
Aim
Deep infection after acetabular fracture surgery is a serious complication, ranging between 1.2% and 2.5% and
has been a challenge for patients and surgeons. It increases length of hospital stay by three to four times due
to the need of extra surgeries for debridement, impairs future patient’s mobility, and increases the overall
costs of care. Aim: We aim to identify pre- and intra-operative risk factors associated with deep infections in
surgically treated acetabular fractures.
Methods
Methods: In a single-center retrospective case-control study, 447 consecutive patients who underwent open
reduction and internal fixation of acetabular fractures were included in the study. Diagnosis of surgical site
infections required a combination of clinical signs and positive tissue culture or histological signs of tissue
infection according to Lipsky et al (2010) and Fleischer et al (2009). To evaluate risk factors from SSI we
performed uni- and multivariate analysis by multiple logistic regression.
Results
Results: Among 447 patients studied, 23 (5.1%) presented diagnosis of postoperative infection. 349 (78.1%)
were male with a mean age of 33.3 years old. Posterior wall fractures accounted for 119 cases (26.6%)
followed by 102 (22.8%) double column fractures and 57 (12.8%) T fractures. Factors associated with a
significantly risk of infection were patient-related: older age and alcoholism (OR = 5.15, 95% CI = 1.06 to 21.98;
p=0.036); trauma-related: fractures of the lower limb (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.8
to 6.78; p=0.017), comminution (OR = 3.6, 95% CI = 1.19 to 8.09; p=0.009), pelvic ring injuries (OR = 2.89, 95%
CI = 1.07 to 7.63; p=0.037); and surgical-related: peri- operative complications (OR = 5.12, 95% CI = 1.85 to
13.8; p=0.001), and dislocation (OR = 0.21, 95% CI = 0.03 to 0.96; p=0.023). Duration of surgery longer than
300 min (p=0.002), and type of surgical approach (p<0.001) were also associated with infection.
Conclusions
Conclusion: Deep infections after acetabular fracture surgery were mainly associated with prolonged duration
of surgery and the interrelation with the complexity of the fracture such as double column fractures, combined
surgical approach, comminution and intra operative complications. Pelvic ring injuries, lower limb fractures,
mean age, no dislocations at the time of accident and alcoholism is others associations.
41
FP36 – (#74) - Free Paper
USE OF BONE SUBSTITUTES WITH GENTAMYCIN IN THE TREATMENT OF BONE INFECTIONS: PRELIMINARY
EXPERIENCE OF 8 CASES
P. Neves, L. Costa, A. Encernação, F. Guitian, A. Pereira, P. Barreira, P. Serrano, M. Silva, P. Leite, R. Sousa
1
Centro Hospitalar do Porto, Porto, Portugal
E-mail: [email protected]
Keywords: Infection, Antibiotics, Bone
References
Treatment of bone infections, especially those in which there is already loss of bone substance, is one of the
most challenging situations to an orthopedic surgeon.
The combination of multiple debridement and intravenous antibiotics may be insufficient in several cases.
It is described in the literature the use of a bone substitute consisting of calcium sulfate, calcium carbonate
and gentamicin that, in addition to the control of bone infection, allows the stimulation of osteogenesis while
complete resorption of the bone substitute occurs.
Aim
Evaluation of the effectiveness of biodegradable bone substitute with high doses of antibiotics in cavitary
osteomyelitis and infected nonunions.
Methods
The authors evaluated 8 cases, 5 of them related to osteomyelitis with bone sequestration and other 3
regarding infected nonunions. All of them had in common the persistence of infection after antibiotic therapy.
All infections were confirmed by microbiological studies. In all cases the surgeons conducted a thorough
surgical debridement and filling of bone defects with Herafill®. Later a tight clinical, analytical and imagiological
control was performed.
Results
Five of the cases were a success with simultaneous healing of the bone loss and treatment of the infection.
These corresponded to the cases of cavitary osteomyelitis. In the remaining 3 cases, despite infection
eradication, union was not achieved and additional surgical procedures were required for definitive treatment
of nonunion.
Conclusions
In the treatment of bone infection, use of high doses of antibiotics at the site is a consensus as it allows
eradication of the infection with lower systemic effects. With the emergence of biodegradable bone
substitutes, the need for a new surgical intervention for their removal can be avoided. Properties of calcium
sulfate and calcium carbonate stimulate osteogenesis at the site, allowing their absorption and replacement by
bone matrix. These properties make them ideal to usage in cases of cavitary bone defects.
Our experience supports the idea that the use of high doses of antibiotics locally permits remission of the
infection. However, when this is implemented through a bone substitute, it is possible to achieve osteogenesis
in bony cavities. Nevertheless, when applied to infected nonunions, their role seems to be limited to the
eradication of the infection.
42
FP37 – (#213) - Free Paper
THE IMPACT OF ANTIBIOTIC THERAPY TOWARDS RESISTANT COMMUNITITY-ACQUIRED MICROOGANISM
IDENTIFIED IN LOWER EXTREMITITES OPEN FRACTURES
M. Salles, J. Gomes, P. Toniolo, J. Melardi, I. De Paula, G. Klautau, M. Mercadante, R. Christian
1
Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
E-mail: [email protected]
Keywords: Community-Acquired Microorganism, Antibiotic Resistance, Infection Rate, Open Fractures
Aim
There have been a worldwide change in the susceptibility patterns of antibiotics by many community-acquired
microorganisms including those associated to wound infection after open fractures. However, the current
antibiotic prophylaxis practice adopted by orthopedic surgeons to prevent infectious complications following
open fractures has not changed, since Gustilo and Andersen classification was published several decades ago.
Few studies have addressed the current pattern of infectious organisms identified in open fracture wounds
and its susceptibility to antibiotics that have been empirically used. We aim to study the incidence of
community-acquired resistant organisms isolated in lower extremities open fracture and analyze if antibiotic
therapy based upon identified resistant pathogens, would decrease surgical site infection (SSI) rates.
Methods
In a prospective, single center cohort study, from August 2013 to March 2015 at a tertiary public university
institution, 136 subjects presenting Gustilo type II or III lower extremities open fractures were randomly
assigned in two arms. Both arms were submitted to surgical debridement, fracture stabilization, and empirical
antibiotic therapy, but subjects on Group II had at least three samples of tissue cultures collected during
debridement. Patients previously treated at an emergency department other them ours were excluded. When
resistant bacteria was identified, antibiotic therapy was modified according to antibiogram tests. The primary
outcome was to compare the infection rates between these two groups, after early 60-days follow up.
Results
We included 136 patients with Gustilo-II (43.4%), –III, (34.5%) open fractures, of which 86% were male, with
median age of 33.7 years, and 69.1% presented no comorbidities. Group II (collection of tissue cultures)
accounted 36.7% of patients, and among them bacterial growth were detected in 36% (16/50). Microorganism
resistant to empirical antibiotic therapy was identified in 18% (9/50), including Staphylococcus aureus,
coagulase-negative Staphylococci, Enterococcus sp, Pseudomonas aeruginosa, Klebsiella sp, Serratia sp,
Escherichia coli, and Enterobacter sp. Median duration of antibiotic treatment was eleven days. During 60-days
of follow up, 71 patients (52.2%) were evaluated for signs of infection using the Centers for Disease Control
and Prevention criteria, of which 63.4% (45/71) and 36.6% (26/71) were on Group I and II, respectively. No
significant difference in the rates of SSI was observed between the study arms (19.2% vs 22.2%, respectively, P
= 0.95).
Conclusions
We detected higher rates of bacterial resistance on Gustilo type II and III open fracture wounds, but adjusting
antibiotic therapy towards these contaminants did not affected the rates of infection afterwards.
43
FP38 – (#232) - Free Paper
UTILITY OF RIA TECHNIQUE WITH INTRAMEDULLARY CEMENT IMPREGNATED NAILING IN TREATMENT OF
SEPTIC LONG BONE NON-UNION
M. Drózdz, A. Brychcy, J. Bialecki, S. Rak, W. Marczynski
1
Orthopedic Clinic of Centre of Postgraduate Medical Education; Professor Gruca Teaching Hospital, Otwock,
Poland
E-mail: [email protected]
Keywords: Osteomyelitis, Non-Union, Nail, RIA
Aim
Septic complications of long bone fracture are still a significant clinical problem. Although inflammatory
process after intramedullary nailing is a rare complication, its treatment is complex. The aim of this study is to
analyze the effectiveness of the treatment of septic complications of the long bone union with use of Reamer–
Irrigator–Aspirator (RIA) technique and intramedullary antibiotic-coated PMMA nailing.
Methods
An analysis of the effectiveness of treatment of 49 patients with septic non-union of long bones (12 femur, 37
tibia), in which the RIA method was applied with antibiotic cement impregnated intramedullary nailing.
Treatment consisted of reaming of long bone canal using the RIA technique and the intramedullary cement
coated nail with the targeted antibiotic. Treatment required second stage with nail exchange and PMMA
removal after 6 weeks to prevent the resitant strains selection.
Results
In a group of patients treated with use of above-mentioned method the remission of inflammatory process
was achieved in all cases. 32 (67%) patients developed bone union, 24 patients with tibial and 8 patients with
femoral septic bone union disorders. The average duration of bone union obtainment with intramedullary
nailing was 37 weeks. The most common inconveniences that occurred during treatment was prolonged
wound discharge and pain.
Conclusions
1. Inflammatory complications of fractures in our material involved extensive injuries, usually high-energetic.
2. Stabilization with intramedullary locked nail coated with antibiotic cement after debridement with RIA
method is a convincing treatment.
3. An essential element of biological bone union is to provide a good cover of the bone tissue with a soft tissue
envelope and sequestrectomy.
4. The success of the treatment of infected pseudoarthrosis may be obtained under condition of:
radical removal of inflammation tissue, convincing biomechanical dynamized stabilization and antibiotic
therapy.
44
FP39 – (#182) - Free Paper
CUSTOM-MADE ANTIBIOTIC-IMPREGNATEDCEMENT INTRAMEDULLARY LOCKED NAILS IN INFECTED NONUNION OF LOWER EXTREMITY
O. Bondarev, A. Sitnik, P. Volotovski
1
BELARUS REPUBLIC SCIENTIFIC AND PRACTICAL CENTRE OF TRAUMATOLOGY AND ORTHOPAEDICS, Minsk,
Belarus
E-mail: [email protected]
Keywords: Infected Non-Union, Antibiotic-Impregnated Cement Locked Nails
Aim
Problems of infected non-unions include not only infection and impossibility of weight-bearing, but also
restricted ROM and compromised soft-tissues as result of trauma and previous surgeries. In such cases,
treatment is long and difficult both for patient and treating surgeon. This study was performed to evaluate the
efficacy of using antibiotic-impregnated cement locked nails for management of this condition.
Methods
The study included 28 patients with infected non-unions of femur (18) and tibia (10) treated from 01.2009 to
11.2013. Mean time from the injury to AB-cement nailing was 16.5(9-27) months. 4/18 femoral and 5/10 tibial
fractures were open. Other fractures were closed and infected non-union developed as complication of
previous surgeries: IM-nailing, ORIF or Ilizarov external fixation. Fistulas were revealed in all patients, but have
closed by the time of AB-cement nailing in 18 cases. Pre- and intraoperative cultures revealed S.aureus in 18,
S.epidermidis in 5, no grows in 5 cases. Solid stainless-steel locked nails (SIGN) were coated with AB-cement
intraoperatively. Full weight-bearing was allowed 3 months after surgery. Follow-upwas performed in 6, 12, 24
and 52 weeks.
Results
One year after surgery, X-ray revealed bone union in 25 (89.3%) patients and all 28 (100%) patients were full
weight-bearing. In 3 (10.7%) cases, X-ray has revealed evident fracture line. Open fistulas were found in
4(14.3%) patients and required hardware removal and debridment.
Conclusions
AB-cement locked nailing achieved elimination of infection and fracture healing in the majority of patients.
This method can be considered as effective and requires further studies.
45
Revision surgery in infected joint replacement
46
FP40 – (#47) - Free Paper
VALIDATION OF THE PROSTHETIC JOINT INFECTION DIAGNOSIS IN THE DANISH HIP ARTHROPLASTY
REGISTER
1
2
3
4
P. Gundtoft , A. Pedersen , H. Schoenheyder , S. Overgaard
1
Orthopaedic, Kolding Sygehus, Kolding, Denmark, Odense, Denmark
2
Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
3
Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark
4
Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense, Denmark
E-mail: [email protected]
Keywords: Validation, Danish Hip Arthroplasty Register'
Aim
The Danish Hip Arthroplasty Register (DHR) is a national database on total hip arthroplasties (THAs) with a high
completeness and validity of registration for primary procedures. The aim was to validate the registration in
DHR for revisions due to Prosthetic Joint Infection (PJI).
Methods
We identified a cohort of patients in the DHR who underwent primary THA from January 1, 2005 to December
31, 2012 and we followed these patients until first-time revision, death, emigration or December 31, 2012. The
PJI diagnosis registered was tested against a gold standard encompassing information from microbiology,
prescription, and clinical biochemistry registries in combination with clinical findings retrieved from medical
records. We estimated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value
(NPV) with 95% confidence interval (CI) for PJI in DHR alone and in DHR combined with microbiology registries.
Results
Out of 37,828 primary THAs, 1,382 were registered with any revision, 232 of which were due to PJI. For PJI
revisions in DHR, the sensitivity was 67.0% (CI: 61.0 - 72.6), specificity 95.2% (CI: 93.8 - 96.4), PPV 77.2% (CI:
71.2 - 82.4), and NPV 92.3% (CI 90.7 - 93.8).
Combining DHR with microbiology registries led to a notable increased in the sensitivity for PJI revision to
90.3% (CI: 86.1 - 93.5) and likewise for specificity 99.6% (CI: 99.1 - 99.9), PPV 98.4% (CI: 95.9 - 99.6) and NPV
98.5% (CI: 97.6 - 99.1).
Conclusions
Only two thirds of PJI revisions were captured in DHR and the PPV was moderate. However, combining DHR
with microbiology registries improved the accuracy remarkably.
Acknowledgements
The study was supported by Region of Southern Denmark and Lillebaelt Hospitals.
47
FP41 – (#19) - Free Paper
CAN WE TRUST STUDIES BASED ON PROSTHESIS RELATED INFECTION CODES FROM ADMINISTRATIVE
DISCHARGE REGISTERS?
1
2
3
4
J. Lange , A. Pedersen , A. Troelsen , K. Søballe
1
Lundbeckfoundation centre for fast-track hip and knee surgery, Aarhus, Denmark
2
Department of clinical epidemiology Aarhus University Hospital, Aarhus, Denmark
3
Department of orthopaedic surgery Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
4
Department of orthopaedic surgery Aarhus University Hospital, Aarhus, Denmark
E-mail: [email protected]
Keywords: Hip Joint Replacement, Prosthesis Related Infection, Register, Cross Sectional Study
References
1.Lange J. Clin Epidemiol 2012;4:57-73.
2.Bozic KJ. J Bone Joint Surg Am 2012;94:794-800.
3.Kurtz SM. J Arthroplasty 2012;27:61-65.
4.Ong KL. J Arthroplasty 2009;24:105-109.
5.Gundtoft PH. Acta Orthop 2015 epub ahead of print
Aim
There is an apparent need for easily accessible research data on Periprosthetic hip joint infections (PJI)(1).
Administrative discharge registers could be a valuable single-sources for this purpose, and studies originating
from such registers have been published(2-4). However, the quality of routinely collected data for
administrative purposes may be questionable for use in epidemiological research. The aim of this study was to
estimate the positive predictive value of the International Classification of Disease 10th revision (ICD-10)
periprosthetic hip joint infection diagnose code T84.5.
Methods
The study was performed as a cross-sectional study on data extracted from the Danish National Patient
Register. Patients with a registration of performed surgical treatment for hip PJI were identified via the ICD-10
code T84.5 (Infection and inflammatory reaction due to internal joint prosthesis) in association with hip-joint
associated surgical procedure codes. Medical records of the identified patients (n=283) were verified for the
existence of a periprosthetic hip joint infection. Positive predictive values with 95% confidence intervals (95%
CI) were calculated.
Results
A T84.5 diagnosis code irrespective of the associated surgical procedure code had a positive predictive value of
85 % (95% CI: 80-89). Stratified to T84.5 in combination with an infection-specific surgical procedure code the
positive predictive value increased to 86% (95% CI: 80-91), and in combination with a noninfection-specific
surgical procedure code decreased to 82% (95% CI: 72-89).
Conclusions
This study is the first to evaluate the only discharge diagnose code of prosthesis-related infection in an
administrative discharge register. It is apparent, that codes in administrative discharge registers are prone to
misclassification on an administrative level, either by wrongful coding by the physician or administrative
personal in the registration process. Misclassification must be expected and taken into consideration when
using single-source administrative discharge registers for epidemiological research on periprosthetic hip joint
infection. We believe that the periprosthetic hip joint infection diagnose code can be of use in single-source
register based studies, but preferably should be used in combination with alternate data sources to ensure
higher validity(5)
Acknowledgements
This study is funded in part by the Lundbeck foundation Centre for Fast-track Hip and Knee Surgery, Denmark.
48
FP42 – (#48) - Free Paper
ECONOMICAL ANALYSIS OF 4221 REVISIONS FOR PERIPROSTHETIC JOINT INFECTIONS FROM NATIONAL
REGISTER IN POLAND IN THE YEARS 2009-2013
I. Babiak, P. Pedzisz, J. Janowicz, M. Kulig, F. Dabrowski
1
Department of Orthopedics and Traumatology, Medical University of Warsaw, Warsaw, Poland
E-mail: [email protected]
Keywords: Periprosthetic Joint Infections, Economical Impact On Therapy
Aim
The aim of the study is to determine reimbursement cost of treating periprosthetic joint infection ( PJI) in
Poland, the rate of THR and TKA septisc revisions in the years 2009-2013, the type of revision, comparison of
the costs of septic and aseptic revisions.
Methods
Data published on the website of the National Health Fund (NHF) were analysed on revision arthroplasty for
aseptic and septic recisions in the years 2009-2013. To calculate the cost of revision NHF report for 2013 was
analysed giving the average cost of the group of septic and aseptic revision.
Results
According to NHF „point system”, in therapy of PJI three types of revisions can by choosen: partial revision
(305 points), one-stage revision (490 points), and two-stage revision with spacer (728 points for two stages). In
the years 2009-2013 a total of 260030 THR and TKA were performer, including 23027 revisions. There were
4221 septic revisions: 1677 hips and 1430 knees. In 2013 septic revisions stated 1.38% (556 of 40152) of all hip
and 2.56% (325 of 12654) of all knee replacements. Septic revisions constituted 14.67% of all hip revisions and
30.23% of all knee revisions. The average refund of the NHF for a minor revision for PJI in 2013 was 3889 Euro
and the average cost for hospital was 4127 Euro. The average refund of the NHF for a one-stege revision (for
any reason) in 2013 was 6124 Euro, and the average cost for hospital was 6339 Euro. The average refund of
the NHF for a two-stage revision (for two stages ) in 2013 was 10013 Euro, and the average cost for hospital
was 10466 Euro for two hospital stays. Data revealed that in 2013 all 921 revisions performed for PJI were
reimbursed as „minor revisions” for 3889 Euro. In 2013 the difference between the average cost incurred by
the hospital and the refund of the NHF for septic revision was at least 238 Euro and for the entire year
undervalued refund for treatment of 921 infected prostheses was at least 219198 Euros.
Conclusions
The reimbursement for revision due to infection encourages surgeons to perform two-stage septic revision
instead of debridement or one-step, because two-step treatment in the final bill is better paid.
49
FP43 – (#29) - Free Paper
A SYSTEMATIC REVIEW OF THE MANAGEMENT OF PERIPROSTHETIC SHOULDER INFECTIONS: WHAT
TREATMENT PROVIDES THE BEST ERADICATION RATE AND FUNCTIONAL OUTCOME?
1
1
2
2
1
D. George , A. Volpin , S. Scarponi , L. Drago , F. Haddad , C. Romano
1
University College London Hospitals, London, United Kingdom
2
Orthopaedic Research Institute Galeazzi, Milan, Italy
E-mail: [email protected]
2
Keywords: Eradication Rate, Functional Outcome, Periprosthetic Shoulder Infection, Resection Arthroplasty,
Permanent Spacer
Aim
The best surgical modality for treating chronic periprosthetic shoulder infections has not been established,
with a lack of randomised comparative studies. This systematic review compares the infection eradication rate
and functional outcomes after single- or two-stage shoulder exchange arthroplasty, to permanent spacer
implant or resection arthroplasty.
Methods
Full-text papers and those with an abstract in English published from January 2000 to June 2014, identified
through international databases, were reviewed. Those reporting the success rate of infection eradication
after a single-stage exchange, two-stage exchange, resection arthroplasty or permanent spacer implant were
included, with a minimum follow-up of 6 months and sample size of 5 patients.
Results
Eight original articles reporting the results after resection arthroplasty (n = 83), 6 on single-stage exchange (n =
75), 13 on two-stage exchange (n = 142) and 8 papers on permanent spacer (n = 68) were included.
The average infection eradication rate was 86.7% at a mean follow-up of 39.8 months (SD 20.8) after resection
arthroplasty, 94.7% at 46.8 months (SD 17.6) after a single-stage exchange, 90.8% at 37.9 months (SD 12.8)
after two-stage exchange, and 95.6% at 31.0 months (SD 9.8) following a permanent spacer implant. The
difference was not statistically significant.
Regarding functional outcome, patients treated with single-stage exchange had statistically significant better
postoperative Constant scores (mean 51, SD 13) than patients undergoing a two-stage exchange (mean 44, SD
9), resection arthroplasty (mean 32, SD 7) or a permanent spacer implant (mean 31, SD 9) (p=0.029). However,
when considering studies comparing pre- and post-operative Constant scores, the difference was not
statistically significant.
Conclusions
This systematic review failed to demonstrate a clear difference in infection eradication and functional
improvement between all four treatment modalities for established periprosthetic shoulder infection. The
relatively low number of patients and the methodological limitations of the studies available point out the
need for well designed multi-center trials to further assess the best treatment option of peri-prosthetic
shoulder infection.
50
FP44 – (#20) - FREE PAPER
POLYMICROBIAL ETIOLOGY OF PROSTHETIC JOINT INFECTIONS (PJI) AS A RISK FACTOR OF TREATMENT
FAILURE AFTER THE REVISION SURGERY
S. Bozhkova, R. Tikhilov, A. Denisov, D. Labutin, V. Artiukh
1
Vreden Russian Research Institute of Traumatology and Orthopedics, Saint-Petersburg, Russia
E-mail: [email protected]
Keywords: Prosthetic Joint Infections, Revision Surgery, Treatment Failure, Polymicrobial Etiology, MultidrugResistant Pathogens
Aim
to evaluate the proportion of microbial associations causing PJI, diversity of their strains and impact on
treatment failure after the removal of the hip implant and insertion of a spacer.
Methods
Spectrum of pathogens in 189 cases of PJI was studied retrospectively. Strains were isolated from the joint
aspirates, tissue samples and removed orthopedic devices. The cohort comprised 144 cases of PJI after
primary THA and 45 cases after the hip replacement revision surgery. All patients underwent first stage of twostage revision procedure which involves the removal of a hip implant, debridement of infected periprosthetic
tissues and subsequent insertion of a bone cement spacer. There were 92 males and 97 females (median age
of 57 yrs). Statistical analysis of the results was performed with GraphPad Prism 6.0 (California, USA).
Results
Microbial associations were detected in 28.6% (n=54) of PJI cases. Gram-positive bacteria prevailed in both
groups with mono- and polymicrobial etiology. There were 52.5% of S. aureus isolates in monomicrobial group
and 25% isolates in polymicrobial group (p=0.0002). This also included 8.4 and 20.6% isolates of MRSA,
respectively (p<0.0001). CNS were detected in 20.1% of mono- and 27.9% of polymicrobial infection isolates,
including about 40% of MRSE in both groups. Gram-negative pathogens accounted for 25.7% of isolates in
polymicrobial group and 14.1% in monomicrobial group (p=0.022). Non-fermenting bacteria prevailed among
Gram-negative strains presented in associations. Acinetobacter sp. and P. aeruginosa were identified in 7.4%
(p=0.043) and 5.1% (p=0.56) of polymicrobial isolates. The percentage of treatment failure after the removal of
the hip implant and insertion of a spacer was considerably higher (p<0.0001) in patients with polymicrobial
than monomicrobial infection: 72.2 vs 25.2%, respectively. The proportion of isolates in microbial associations
involving Gram-negative pathogens was 61.5% in patients with infection recurrence and 26.7% in patients with
a successful outcome of the surgery (p=0.033).
Conclusions
Microbial associations were found in 28.6% of PJI cases after hip arthroplasty. They posed a significant risk for
treatment failure after removal of the hip implant and insertion of a spacer. The multidrug-resistant strains
(MRSA, Acinetobacter sp. and P. aeruginosa) were often isolated in microbial associations. Our results suggest
that further study of the risk factors for polymicrobial infection is necessary in patients with PJI. Identification
of a patient group at high risk for developing polymicrobial PJI will allow prescription of empiric antimicrobial
therapy in time, taking into account possible multi-resistant pathogens.
51
FP45 – (#34) - Free Paper
MICROBIOLOGICAL AND CLINICAL EFFECTIVENESS OF VANCOMYCIN PLUS GENTAMICIN OR GENTAMICIN
LOADED SPACERS: A COMPARATIVE STUDY
1
2
1
1
1
1
J.C. Martínez Pastor , T. Frada , G. Bori , E. Tornero , J.M. Segur , J. Bosch , S. García
1
Hospital Clinic, Barcelona, Spain
2
Hospital de Braga, Braga, Portugal
E-mail: [email protected]
1
Keywords: Spacer, Vancomycin, Gentamycin
Aim
Two-stage revision surgery is the current gold standard for treating prosthetic joint infections (PJI). Between
the first and the second stage gentamicin-loaded (G) spacers are widely used but the rate of gentamicin
resistant staphylococci is increasing. The potential benefit of vancomycin + gentamicin-loaded (V/G) spacers
has not yet been evaluated. The aim of our study was to compare the microbiological eradication and infection
control rates in PJI treated with G- or V/G-spacers.
Methods
147 PJIs treated in our institution were retrospectively reviewed. From 2003 to 2009 G-spacers (Tecres®) were
used (group G) and from 2010 to 2013 V/G-spacers (Group V/G). Gender, age, body mass index (BMI), comorbidities, ASA score, type of infection, microorganisms isolated in the first and second stages, time between
stages, infection outcome at last visit were collected. The 2 main outcome variables were microbiological
eradication in the second stage (≤1 positive culture out of 6) and infection control after the second stage.
Univariate and multivariate analysis were performed using SPSS®.
Results
There were 83 patients in group G and 63 in group V/G. The mean (SD) age was 71.5 (10.3) years and 54%
were female. Groups were similar in gender, age, BMI, ASA score, time with spacer, microorganism isolated in
the first stage, or type of infection (acute or chronic) (P>0.05). The presence of ≥2 positive cultures in the
second stage was significantly higher in group G (23.2%) than in group V/G (6.7%, P<0.05). Logistic regression
model identified polymicrobial infections (OR: 4.26, CI95%: 1.44-12.64) and the use of G-spacers (OR: 5.88,
CI95%: 1.60-21.74) as independent predictors of failure in microbiological eradication. The global rate of
infection control was 75% after a mean (SD) follow-up of 56 (32) months. Infection control was higher in
chronic than acute PJI (83.6% vs 59.6%, P<0.05), when cultures during second stage were negative (81.5%) vs
positive (61%, P<0.05), and there was a trend towards a higher control rate when V/G-spacers (82%) vs Gspacers (69.5%) were used (P=0.09). Multivariate analysis identified chronic PJI (OR: 5.43, CI95%: 2.20-13.51)
and, at the limit of significance, the use of V/G spacers (OR: 2.36, CI95%: 0.97-5.71) as predictors of infection
control.
Conclusions
Vancomycin loaded spacers were significantly associated with a higher microbiological eradication and there
was a trend towards a higher infection control than gentamicin loaded spacers.
52
FP46 – (#87) - Free Paper
OUTCOME FOLLOWING DEBRIDEMENT, ANTIBIOTICS AND IMPLANT RETENTION (DAIR) IN HIP PROSTHETIC
JOINT INFECTION – A 18-YEAR EXPERIENCE
G. Grammatopoulos, B. Kendrick, N. Athanasou, I. Byren, B. Atkins, M. Mcnally, P. Mclardy-Smith, R. Gundle, A.
Taylor
1
Nuffield Orthopaedic Centre, Oxford, United Kingdom
E-mail: [email protected]
Keywords: DAIR, Hip Arthroplasty PJI
Aim
Debridement, antibiotics and implant retention (DAIR) is a surgical option in the treatment of prosthetic joint
infection (PJI). It is thought to be most appropriate in the treatment of early (≤6 weeks post-op) PJI. Most
studies to-date reporting on DAIRs in hip PJI have been underpowered by reporting on small cohorts (n= <45),
or report on registry data with associated biases and limitations. In our, tertiary referral, bone infection unit
we consider DAIR to be a suitable option in all cases of PJI with a soundly fixed prosthesis, with early or late
presentation, especially in patients who are too elderly or infirm to undergo major surgery.
Aim: To define the 10-year outcome following DAIR in hip PJI and identify factors that influence it.
Methods
We retrospectively reviewed all DAIRs performed in our unit between 1997 and 2013 for hip PJI. Only infected
cases confirmed by histological and microbiological criteria were included. Data recorded included patient
demographics and medical history, type of surgery performed (DAIR or DAIR + exchange of modular
components), organism identified and type/duration of antibiotic treatment. Outcome measures included
complications, mortality rate, implant survivorship and functional outcome.
Results
121 DAIRs were identified with mean age of 71 years (range: 33-97). 67% followed an index procedure of 1°
arthroplasty. 53% included exchange of modular components. 60% of DAIRs were for early onset PJI. Isolated
staphylococcus was present in 50% of cases and 25% had polymicrobial infection. At follow-up (mean:7 years,
range: 0.3 - 18) , 83 patients were alive; 5- and 10- year mortality rates were 15% and 35% respectively. 45%
had a complication (persistence of infection: 27%, dislocation: 10%) and 40% required further surgery. Twenty
hips have been revised to-date (17%). Performing a DAIR and not exchanging the modular components was
associated with an almost 3x risk (risk ratio: 2.9) of subsequent implant failure (p=0.04). 10-yr implant
survivorship was 80% (95%CI: 70 – 90%). Improved 10-year implant survivorship was associated with DAIR
performed for early PJI (85% Vs 68%, p=0.04). Functional outcome will be discussed.
Conclusions
DAIR is a particularly valuable option in the treatment of hip PJI, especially in the early post-operative period.
Whenever possible, exchange of modular implants should be undertaken, however DAIRs are associated with
increased morbidity even in early PJI. Factors that predict success of DAIR in late PJI need to be identified.
53
FP47 – (#65) - Free Paper
CHEMICAL DEBRIDEMENT USING ACETIC ACID DURING REVISION ARTHROPLASTY
1
1
1
1
1
2
1
R. Williams , W. Khan , H. Williams , A. Abbas , A. Mehta , W. Ayre , R. Morgan-Jones
1
University Hospital Llandough, Cardiff, United Kingdom
2
University Dental School, Cardiff, United Kingdom
E-mail: [email protected]
Keywords: Acetic Acid, Infection, Debridement, Revision
Aim
A common step to revision surgery for infected total knee replacement (TKR) is a thorough debridement.
Whilst surgical and mechanical debridement are established as the gold standard, we investigate a novel
adjuvant chemical debridement using an Acetic Acid (AA) soak that seeks to create a hostile environment for
organisms, further degradation of biofilm and death of the bacteria.
We report the first orthopaedic in vivo series using AA soak as an intra-operative chemical debridement agent
for treating infected TKR’s. We also investigate the in vitro efficacy of AA against bacteria isolated from
infected TKR’s.
Methods
A prospective single surgeon consecutive series of patients with infected TKR were treated according to a
standard debridement protocol. Patients in the series received sequential debridement of surgical, mechanical
and finally chemical debridement with a 10 minute 3% AA soak.
In parallel, we isolated, cultured and identified bacteria from infected TKR’s and assessed the in vitro efficacy
of AA. Susceptibility testing was performed with AA solutions of different concentrations as well as with a
control of a gentamicin sulphate disc. The effect of AA on the pH of tryptone soya was also monitored in an
attempt to understand its potential mechanism of action.
Results
Physiological responses during the AA soak were unremarkable. Intraoperatively, there were no tachycardic or
arrythmic responses, any increase in respiratory rate or changes in blood pressure. This was also the case
when the tourniquet was released. In addition, during the post-operative period no increase in analgesic
requirements or wound complications was noted. Wound and soft tissue healing was excellent and there have
not been any early recurrent infections at mean of 18 months follow up.
In vitro, zones of inhibition were formed on less than 40% of the organisms, demonstrating that AA was not
directly bactericidal against the majority of the clinical isolates. However, when cultured in a bacterial
suspension, AA completely inhibited the growth of the isolates at concentrations as low as 0.19%v/v.
Conclusions
This study has shown that the use of 3% AA soak, as part of a debridement protocol, is safe. Whilst the exact
mechanism of action of acetic acid is yet to be determined, we have demonstrated that concentrations as low
as 0.19%v/v in solution in vitro is sufficient to completely inhibit bacterial growth from infected TKR’s.
54
FP48 – (#79) - Free Paper
STAPHYLOCOCCUS CAPITIS ISOLATED FROM PROSTHETIC JOINT INFECTIONS
1
2
3
4
S. Tevell , B. Hellmark , Å. Nilsdotter-Augustinsson , B. Söderquist
1
Faculty of Medicine and Health, Örebro University, Örebro; Department of Infectious Diseases, Karlstad
Hospital, Karlstad, Sweden
2
Department of Laboratory Medicine, Clinical Microbiology, Örebro University Hospital, örebro, Sweden
3
Department of Infectious Diseases and Department of Clinical and Experimental Medicine, Linköping
University, Linköping, Sweden
4
Faculty of Medicine and Health, School of Medicine, Örebro University, örebro, Sweden
E-mail: [email protected]
Keywords: Staphylococcus Capitis, Prosthetic Joint Infections, Epidemiology
References
(1)Tevell et al, EJCMID 2014;33(6):911-917.
(2)Månsson et al, APMIS (in press, 2015)
Aim
Implementation of new diagnostic methods (i.e. MALDI-TOF MS) has made it possible to identify coagulasenegative staphylococci (CoNS) to species level in routine practice. Further knowledge about clinical and
microbiological characteristics of prosthetic joint infections (PJIs) caused by different CoNS may both facilitate
interpretation of microbiological findings and improve clinical algorithms.
The aim of this study was clinical and microbiological characterization of PJIs caused by Staphylococcus capitis.
Methods
Patients with PJIs caused by S. capitis (growth in ≥2 perioperative tissue samples, n=19, identified by MALDITOF MS) from three centres between 2005-2014 were included. Medical records were examined (n=16).
Further characterization of S. capitis was performed; rep-PCR (Diversilab, BioMerieux), standard antibiotic
susceptibility testing, GRD Etest and macromethod Etest for detection of heteroresistant subpopulations and
microtitre plate assay for detection of biofilm production.
Results
Multi-drug resistant (MDR) S. capitis (R≥3 antibiotic groups) was detected in 5/19(26%) of isolates, 1/19(5%)
were ciprofloxacin resistant and no isolates was rifampin resistant. Biofilm formation was present in
14/19(74%). The dendrograms created by rep-PCR showed two distinct clusters, including one that contained
isolates from all centres, as well as the reference isolates. Furthermore, three additional clusters were
identified, all of these mainly obtained from single centres. In two of these, MDR was highly prevalent. In one
of these clusters, 4 of the 8 strictly monomicrobial infections were found.
All of the PJIs were defined as either early postinterventional (10/16) or chronic (6/16). No late
haematogenous infection was found. The highest CRP values were reported in monomicrobial infections.
Wound healing disturbances was noted in 8/10 early postinterventional infections. Fever was absent in chronic
infections, sinus tracts rare (1/6), while pain was a common symptom (5/6).
Conclusions
S. capitis has the potential to cause PJIs, both by itself as well as part of a polymicrobial infection. The
antibiotic susceptibility patterns were more favourable than has previously been reported in S. epidermidis
isolated from PJIs(1). Clinical data suggests that PJIs caused by S. capitis were acquired perioperatively or in the
early postoperative phase. The clustering found by rep-PCR together with data showing high prevalence of S.
capitis in the air of operation rooms during prosthetic joint surgery(2) implicates that nosocomial spread might
be present. Epidemiological surveillance may be of value in order to ensure early detection of nosocomial
transmission.
Acknowledgements
Grants were received from the research committees of Värmland County Council and Örebro University,
Sweden.
55
FP49 – (#269) - Free Paper
CLINICAL RESULTS OF AN ANTI-BACTERIAL HYDROGEL COATING OF IMPLANTS. A MULTICENTER
PROSPECTIVE, COMPARATIVE STUDY
1
2
3
3
2
K. Malizos , S. Scarponi , K. Simon , M. Blauth , C. Romanò
1
Orthopaedic Surgery & Trauma, Medical School, University of Thessaly, Larissa, Greece
2
Orthopaedic Institute IRCCS Galeazzi, Milano, Italy
3
Department for Trauma Surgery, Medical University Innsbruck, Innsbruck, Austria
E-mail: [email protected]
Keywords: Infection, Hydrogel, DAC, Coating, Prosthesis
References
Drago et al.. (2014) Does implant coating with antibacterial-loaded hydrogel reduce bacterial colonization and
biofilm formation in vitro ? CORR 472; 3311-3323.
Giavaresi G et al.. (2014) Efficacy of antibacterial-loaded coating in an in vivo model of acutely highly
contaminated implant. Int Orthop 38:1505-12.
Aim
Infection is among the first reasons for failure of orthopedic implants. Various antibacterial coatings for
implanted biomaterials are under study, but only few technologies are currently available in the clinical
setting. Previous studies showed the in vitro and in vivo efficacy and safety of a fast resorbable (<96 h)
hyaluronic and polylactic acid based hydrogel, loaded with antibiotic or antibiofilm agents (DAC®, Novagenit
Srl, Mezzolombardo, TN). Aim of this study is to report the results of the largest clinical trial in trauma and
orthopedic patients.
Methods
In this prospective, controlled, study, a total of 184 patients (86 treated with internal osteosinthesis for closed
fractures and 98 undergoing cementless total hip or knee joint prosthesis) were randomly assigned in three
European orthopaedic centers to receive antibiotic-loaded DAC coating or to a control group, without coating.
Pre- and post-operative assessment of laboratory tests, wound healing (ASEPSIS score), clinical score (SF-12
score) and x-rays were performed at fixed time intervals. Statistical analysis was performed with Fisher exact
test or Student's t test. Significance level was set at p<0.05.
The study was approved by the local Ethical Committee and all patients provided a written informed consent.
Results
On average, wound healing, clinical scores, laboratory tests and radiographic findings did not show any
significant difference between the two-groups at a mean 12 months follow-up (min: 6, max: 18 months).
Four surgical site infections and two delayed union were observed in the control group compared to none in
the treated group.
No local or systemic side effects, that could be related to DAC hydrogel coating, were noted and no detectable
interference with bone healing or osteointegration could be found
Conclusions
This is the largest study, with the longest follow-up, reporting on clinical results after the use of a fastresosrbable anti-bacterial hydrogel coating for orthopaedic and trauma implants. Our results show the safety
of the tested coating in different indications; although not statistically significant, the data also show a trend
towards surgical site infection reduction, as previously demonstrated in the animal models.
Acknowledgements
Study performed under the European 7th Framework Programme (collaborative research project IDAC, grant
no. 277988).
56
Quality management for septic surgery - Is there a
european approach?
57
FP50 – (#231) - Free Paper
PREOPERATIVE ANTIBIOTIC PROPHYLAXIS: SHOULD WE LEAVE THE PROSTHESIS UNPROTECTED?
1
1
2
1
1
1
1
C. Gamba , D. Prieto , E. Bordonabe , A. Fabrego , S. Diaz , P. Castellnou , J.P. Gallego , L. Verdie
1
Hospital del Mar, Barcelona, Spain
2
Hospital del Mar - IMIM, Barcelona, Spain
E-mail: [email protected]
1
Keywords: Antibiotic Prophylaxis, Negative Cultures
Aim
Culture negative prosthetic joint infections (PJI) still remain an issue even the advantages in PJI diagnosis. This
is the reason why some orthopedic surgeons fear to use preoperative antibiotic prophylaxis when a PJI is
suspected. The purpose of the present study was to evaluate the influence of preoperative antibiotic
prophylaxis in intraoperative cultures
Methods
An enhanced diagnostic protocol for PJI (Zimmerli criteria) was used for the inclusion criteria in order to collect
all PJI accounted in a University Hospital. Patients were prospectively randomized in two groups.
The control group received the classical preoperative antibiotic prophylaxis. The study group did not receive
prophylaxis prior to surgery
Results
There were 14 patients in each group. They correspond to 13 infections of total hip arthroplasty (THA), 12
infections of total knee arthroplasty (TKA) and 3 reverse shoulder prosthesis (RSA) infections. There were 10
patients in the study group and 10 patients in the control group with at least one positive microbiological
criterion. There were 8 patients in each group with culture negative PJI (p>0.05)
Conclusions
Preoperative antibiotic prophylaxis does not affect intraoperative cultures in suspected or confirmed PJI.
Therefore it is essential to deliver antibiotic prophylaxis in any patient in which prosthesis is to be implanted in
order to protect the prosthesis from infection
58
FP51 – (#267) - Free Paper
ACL PLASTY PRESERVATION IN ARTHROSCOPIC LAVAGE TREATMENT OF SEPTIC ARTHRITIS SECONDARY TO
ACL ARTHROSCOPIC RECONSTRUCTION
A. Costa, D. Saraiva, A. Sarmento, P. Carvalho, F. Lebre, R. Freitas, P. Canela, A. Dias, T. Torres, F. Santos, R.
Pereira, M. Frias, M. Oliveira
1
CHVNGE, Vn Gaia / Espinho, Portugal
E-mail: [email protected]
Keywords: ACL Plasty Preservation, Arthroscopic Lavage, Septic Arthritis
Aim
Knee joint infection after an ACL reconstruction procedure is infrequently but might be a devastating clinical
problem, if not diagnosed promptly and treated wisely.
The results of functional outcomes in these patients are not well known because there aren’t large patient
series in the literature.
The objective of this study was to evaluate the prevalence and determine the adequate management of septic
arthritis following ACL reconstruction and to assess the patient functional outcomes.
Methods
The authors conducted a retrospective multicentric analysis of septic arthritis cases occurring after
arthroscopically assisted ACL reconstructions (hamstrings and BTB), in patients submitted to surgery between
2010 to 2014. The study reviewed patients submitted do ACL reconstruction, that presented objective clinical
suspicion of joint infection, in post-operative acute and sub-acute phases, associated with high inflammatory
seric parameters (CRP >=10,0, ESR>=30,0) and synovial effusion laboratory parameters highly suggestive (PMN
>=80, leucocytes >=3000).
All this patients were treated with antibiotic empiric suppressive therapy and then directed antibiotherapy
according to antibiotic sensitivity profile, then the patients were submitted to arthroscopic lavage procedure,
without arthropump, but with debris and fibrotic tissue removal preserving always the ACL plasty. The
functional outcomes analyzed were the Lysholm and the IKDC score.
Results
Eleven (2.2 %) out of 490 patients analyzed in the sudy were diagnosed with a post-operative septic arthritis.
The microbiologic exams showed coagulase-negative Staphylococcus was present in 5 patients (S. lugdunensis
in 4 cases and S. capitis in 1 case), Staphylococcus Aureus in 2 patients (1 MSSA and 1 MRSA). In four patients,
the micro-organism was not identified.
The studied patients had a mean follow-up of 28 ± 16 months, the Lysholm score was 74.8 ± 12.2, the IKDC
score was 66.4 ± 20.5.
Functional outcomes in the control group were better than those obtained in the infected group.
(Lysholm score 88.2 ± 9.4 (NS); IKDC score 86.6 ± 6.8 (NS). All patients retained their reconstructed ACL. None
of the patients relapsed or need other intervention because of ACL failure and chronic instability.
Conclusions
The prevalence of septic arthritis after an ACL reconstruction in this series was 2.2 %, slightly higher than other
international series (0.14 to 1.7 %). Arthroscopic lavages along with antibiotic treatment showed to be a
secure procedure and allowed the preservation of the ACL plasties, without infection relapse. But the
functional outcomes after active intra-articular infection were largely inferior to those obtained in patients
without infection, probably to uncontrolled and intense inflammatory local response.
59
FP52 – (#133) - Free Paper
A BONE AND JOINT INFECTION REGISTRY – EXPERIENCE OF OUR FIRST 200 PATIENTS PROSPECTIVELY
EVALUATED USING A CUSTOM-DESIGNED, MODULAR DATABASE.
1
2
1
1
1
1
1
1
1
H.K. Li , J. Finney , J. Kendall , R. Shaw , M. Scarborough , B. Atkins , A. Ramsden , D. Stubbs , M. Mcnally
1
The Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, United Kingdom
2
Modernising Medical Microbiology, University of Oxford, Oxford, United Kingdom
E-mail: [email protected]
Keywords: Bone, Joint, Infection, Database, Registry
References
[1] Kallala RF, Vanhegan IS, Ibrahim MS, Sarmah S, Haddad FS. Financial analysis of revision knee surgery based
on NHS tariffs and hospital costs: does it pay to provide a revision service? Bone Joint J. 2015 Feb;97-B(2):197201.
[2] Bejon P, Berendt A, Atkins BL, Green N, Parry H, Masters S, McLardy-Smith P, Gundle R, Byren I. Two-stage
revision for prosthetic joint infection: predictors of outcome and the role of reimplantation microbiology. J
Antimicrob Chemother. 2010 Mar;65(3):569-75.
[3] Ziran BH, Rao N, Hall RA. A dedicated team approach enhances outcomes of osteomyelitis treatment. Clin
Orthop Relat Res. 2003 Sep;(414):31-6.
[4] Salvana J, Rodner C, Browner BD, Livingston K, Schreiber J, Pesanti E. Chronic osteomyelitis: results
obtained by an integrated team approach to management. Conn Med. 2005 Apr;69(4):195-202.
Aim
Bone and joint infections are not only common but their management can be technically complex. They carry
significant healthcare costs and are a daunting experience for patients [1]. Frequently, multiple operations are
required in order to treat the infection. Each surgical intervention usually results in greater bone loss,
worsening skin and soft tissue scarring and increasingly diverse and resistant micro- organisms [2].
Specialist bone infection units involving highly integrated orthopaedic and plastic surgery, as well as infection
physicians, may improve patient outcomes [3-4]. However, it is difficult to determine the hierarchy of factors
contributing to outcome of treatment. This problem is confounded by a lack of structured, prospective data
collection in many units around the world.
Methods
In 2014, we designed a modular database which allows collection of patients’ details, components of the
disease, the treatment, microbiology, histology, clinical outcome and patient-reported outcome measures
(PROMS). The registry was implemented in November 2014 and has already demonstrated its function as a
Hospital-wide service evaluation tool.
Results
Over 200 patients have been referred to the unit and their baseline demographic information registered. Their
progress through the bone infection unit patient pathway is prospectively monitored with use of the registry
and data collection ongoing. We aim to present the preliminary clinical outcomes of these 200 patients
including surgical procedures performed, key microbiology results, antibiotic treatment regimens and patient
reported outcomes.
Conclusions
Our goal is to demonstrate that a bone infection registry is an integral part of infection management clinical
practice. It can be used for designing service provision, assist in allocating healthcare resources and expand the
evidence base for specialist bone infection units in managing complex orthopaedic infections.
Acknowledgements
Mustapha Ward (PROMS Administrator)
60
FP53 – (#264) - Free Paper
HIP ARTHOPLASTY INFECTION: RATES, DEMOGRAPHY, AND RISK FACTORES IN ONE CLINICAL CENTRE
1
2
1
1
1
N. Esteves , D. Azevedo , C. Santos , D. Pascoal , A. Carvalho , E. Salgado
1
Cova da Beira Hospitalar Centre, Covilhã, Portugal
2
Health Sciences Faculty - Beira Interior University, Covilhã, Portugal
E-mail: [email protected]
1
Keywords: Hip Arthroplasty, Infection
Aim
Infection is a complication in hip arthroplasty. It increases mortality and morbidity and is a cause for patient’s
dissatisfaction.
Previous Works report an infection rate between 0,4% e 1,5% in primary hip replacement and between 3,2% in
revision hip replacement.
The aim of this work was to access the infection rates in one hospital, compare them with the reported rates
and investigate possible risk factors for infection.
arthroplasty
Methods
Electronic clinical records were consulted. Patients who underwent total hip arthroplasty (primary or revision)
or hemiarthroplasty in one hospital, between the 1st February 2011 and 31st February 2013, were included.
Results
Two hundred and sixty one patients (267 surgeries) were included.
Demographically, 57,5% were female patients and 42,5% were male patients with an average age of 77,1 years
(± 12,3 years).
Infection rate for hemiarthroplasty 3,1%, for primary total hip arthroplasty was 1,4% and for revision
procedures 4,8%.
A statistically significant relation was found between arthroplasty infection and superficial wound infection
(p<0,001), wound dehiscence (p<0,001), and surgery performed during summer months (p<0,05)
No relation was found with duration of the surgery or the hospital stay or the patient’s comorbidities.
Conclusions
The infection rate is similar to the rate reported in other clinical centres.
Superficial wound complications are a good predictor for arthroplasty infection, so it is important to diagnose
and start prompt appropriate management and vigilance.
The increase in infection rates in summer months may be related to higher operating room temperature or
less routined personal.
We concluded, therefore, that infection is a complication in hip arthroplasty being
prevention is a key feature when arthroplasty is performed, as well as clinical vigilance for infection signs.
61
FP54 - (#122) - Free Paper
24 MONTHS FOLLOW-UP IN 70 CONSECUTIVE SURGICALLY TREATED PYOGENIC SPONDYLODISCITIS PATIENTS
B. Zillner, A. Stock
1
Schön Klinik München Harlaching, Munich, Germany
E-mail: [email protected]
Keywords: Spondylodiscitis, Spine, Epidural Abscess, Instrumentation
Aim
To investigate clinical outcome scores in surgically treated patients with either spontaneous or postoperative
pyogenic spondylodiscitis after 3, 12 and 24 month.
Methods
70 consecutive patients (mean age 64y; male n=33 female n=27) underwent surgical treatment due to
pyogenic spondylodiscitis with or without epidural abscess at our department from 2011 to 2013. We
performed either microsurgical debridement or debridement in combination with ventral support employing
dorsally instrumented spondylodesis followed by bracing and antibiotic therapy up to 12 weeks. European life
quality score (EQ-5D), Oswestry disability index (ODI) and visual analogue scale for pain (VAS) were recorded 3,
12 and 24 month after surgery. Length of hospital stay (LOS) was 25,3 days.
Results
The Mean time to presentation at our spine center and diagnosis was 3,8 weeks. Distribution of inflammation
was lumbar in 66 (94%) and thoracic in 4 (6%) patients. Thirtyfour patients (49%) had isolated spondylodiscitis
(SD). Epidural abscess (ED) was found in 26 patients (37%). Ten patients (14%) showed a combination of SD
and ED. SD or ED were predominantly found after previous surgery at the same or contiguous level 38 (54%).
Nine patients (13%) suffered from ED or SD after previous lumbar epidural steroid injections (LESI).
Spontaneous idiopathic inflammation was found only in 13 cases (19%).
Standardized follow-up (FU) protocol was scheduled at 3, 12, and 24 month. FU rate was 60%. Healing of the
inflammation was the rule.
In our study cumulative EQ-5D increased from 0.47 to 0,80. ODI decreased from 41.1 to 24.3 and VAS
concerning back pain decreased from 58.4 to 22.6 VAS according sciatica decreased from 46.8 to 20.5.
Conclusions
Due to an increasing number of spine surgeries and spinal interventions as well as the increasing age and
morbidity of patients, spinal surgeons have to deal more often with the diagnosis pyogenic spondylodiscitis.
Standardized conservative or radical surgical treatment strategies in order to achieve good results according to
patients life quality are gaining more importance.
62
FP55 – (#99) - Free Paper
IMPLEMENTATION OF A BUNDLE OF CARE TO REDUCE SURGICAL SITE INFECTIONS IN TOTAL HIP
ARTHROPLASTY; A RETROSPECTIVE COHORT STUDY
B. Leijtens, M. Tacken, J. Bruhn, J. Hopman, B. Schreurs
1
Radboud University Medical Centre, Nijmegen, The Netherlands
E-mail: [email protected]
Keywords: Post-Operative Wound Infection, Prevention, Total Hip Arthroplasty
Aim
Surgical site infections after total hip arthroplasty result in decreased quality of life, increased morbidity and
increased health care cost. We hypothesized that the implementation of a bundle of care for total hip
arthroplasty decreases the amount of surgical site infections.
Methods
In this retrospective cohort study we investigated the implementation of this bundle in a University Medical
Centre and its effect on perioperative surgical site infections after total hip arthroplasty and on incidence of
hypothermia.
In 2009 the bundle of care consisting of four elements was implemented in total hip arthroplasty in our
hospital; (I) perioperative normothermia, (II) hair removal before surgery, (III) the use of preoperative
antibiotic prophylaxis and (IV) discipline on the operation room measured by door movements. For this study
we used data from January 2010 - October 2013. We measured all parameters prospectively including surgical
site infections within 6 weeks postoperatively.
Results
In the study period a total of 585 patients received a primary total hip arthroplasty. Bundle compliance
improved significantly in 3.5 years from 71.7% in 2010 to 91.6% in 2013. Postoperative hypothermia decreased
from 10.5% to 8.4% (non-significant) and SSI rate from 0.9% to 0.0% (non-significant).
Conclusions
Implementation of this bundle of care is possible in an academic tertiary referral center. A relatively cheap
solution can increase patient safety in a surgical environment. Introduction of a bundle of care resulted in a
non-significant reduction of hypothermia and rate of surgical site infections in total hip arthroplasty.
63
10 Best Rated Free Papers 2015
64
FP56 – (#184) - Free Paper
LOCAL PROPHYLAXIS OF IMPLANT-RELATED INFECTIONS USING A HYDROGEL AS CARRIER
1
1
1
2
3
W. Boot , H. Vogely , P. Nikkels , W. Dhert , D. Gawlitta
1
Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands
2
Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
3
Department of Oral and Maxillofacial Surgery & Special Dental Care, University Medical Center Utrecht,
Utrecht, The Netherlands
E-mail: [email protected]
Keywords: Implant-Related Infection, Antimicrobial Prophylaxis, Hydrogel, Local Delivery
References
(1)Drago, Clin Orthop Relat Res (2014).
(2)Drago, BMC Infect Dis (2013).
(3)Valimaki, Scand J Surg (2006).
(4)Olofsson, Appl Environ Microbiol (2003).
Aim
Currently, no clinical options are available to prevent infections on uncemented orthopedic implants.
Therefore we investigated the efficacy of DAC-hydrogel (disposable antibacterial coating(1), Novagenit, Italy)
as carrier for various agents to prevent infections in an in vivo implant-model.
Methods
Titanium rods were implanted in the left tibiae in New Zealand White rabbits. Prior to implantation, the
implant bed was contaminated with 10^5 colony forming units S. aureus.
In the experimental groups, the hydrogel was loaded prior to be coated on the rods with: 2%(w/v) vancomycin
(Van2 group, N=6), 5%(w/v) vancomycin (Van5 group, N=6), 10%(w/v) bioactive glass (BonAlive, Finland) (BAG
group, N=6), which is antibacterial(2) and osteoconductive(3), or 0.5%(w/v) N-acetyl cysteine (NAC group,
N=6), which inhibits bacterial growth and decreases biofilm formation(4). In the control group, empty hydrogel
was applied (Gel group, N=12)
Blood values were measured weekly. Following explantation on day 28, the anterior tibia was processed for
bacterial culture. The posterior tibia and rod were used for measuring bone-implant contact using micro-CT
and for histopathology.
Results
Results of the experimental groups were compared to the Gel group results. The blood values in the Van2 and
Van5 groups were lower on day 7. Moreover, culture results demonstrated less animals with an infection in
both groups at day 28. In accordance, these groups showed lower grades for infection. Further, the Van2
group demonstrated more bone-implant contact. These results suggest that infection was reduced in the Van2
and Van5 groups. In contrast, blood values, histological grades, and bone-implant contact of the BAG and NAC
groups were comparable with the Gel group. These results suggest that infection was not prevented in the
BAG and NAC groups.
Conclusions
Local application of vancomycin-loaded DAC-hydrogel successfully reduced implant-related infections. Loading
of the hydrogel with BAG or NAC did not prevent infection. It is possible that BAG in powder form, as used in
the present study, dissolved before the antibacterial effect could take place. Instead, BAG granules may be a
viable alternative. Next, it is possible that the NAC concentration was too low to prevent infections in an in
vivo environment, although this concentration was proven effective in vitro for its antibacterial properties.
Acknowledgements
The study was performed under the multicenter Collaborative Project “I.D.A.C.”, funded by the EC, within the
7th Framework Programme, grant no. 277988.
65
FP57 – (#225) - Free Paper
PREVENTION OF IMPLANT-RELATED OSTEOMYELITIS DUE TO DOXYCYCLINE-RESISTANT METHICILLINRESISTANT STAPHYLOCOCCUS AUREUS USING A DOXYCYCLINE-LOADED POLYMER-LIPID ENCAPSULATION
MATRIX COATING.
1
2
2
2
1
2
1
3
W. Metsemakers , N. Emanuel , O. Cohen , M. Reichart , T. Schmid , D. Segal , R. Richards , S. Zaat , T.
1
Moriarty
1
AO Research Institute, Davos, Switzerland
2
PolyPid Ltd., Petach-Tikva, Israel
3
Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
E-mail: [email protected]
Keywords: Antibiotic Resistance, Doxycycline, Osteomyelitis, Orthopedic Implant, PLEX Technology
Aim
One of the most challenging complications in orthopedic trauma surgery is the development of infection.
Improved infection prophylaxis could be achieved by providing local delivery of antibiotics directly to the
tissue-implant interface. Especially implant-associated bone infections caused by antibiotic-resistant
pathogens pose significant clinical challenges to treating physicians. Prophylactic strategies that act against
resistant organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), are urgently required.
The objective of this experimental study was to determine the efficacy of a biodegradable Polymer-Lipid
Encapsulation MatriX (PLEX) loaded with the antibiotic doxycycline as a local prophylactic strategy against
implant-associated osteomyelitis in a humeral non-fracture rabbit model.
Methods
Activity of the PLEX-doxycycline-coating was tested against both a doxycycline susceptible (doxyS) methicillinsusceptible S. aureus (MSSA) as well as a doxycycline-resistant (doxyR) MRSA. In a rabbit intramedullary (IM)
nail-related infection model, twelve rabbits received an inoculum of a doxyS MSSA direct into the medullary
cavity of the humerus. After inoculation, animals received either a PLEX-doxycycline-coated nail, or an
uncoated nail. The animals were observed for four weeks. Upon euthanasia, quantitative bacteriology was
performed to determine bacterial load in tissues and biofilm formation on the implant. A second study was
performed with sixteen rabbits receiving a DoxyR MRSA inoculum, again in coated and uncoated groups.
Results
In vitro elution studies revealed that 25% of the doxycycline was released from the PLEX-coated implants
within the first day, followed by a 3% release per day up to day 28. Quantitative bacteriology revealed the
presence of osteomyelitis in all animals receiving an uncoated nail in both the MSSA and the DoxyR MRSA
studies (figure). All rabbits receiving a PLEX-doxycycline-coated nail were culture negative in the doxyS MSSAgroup and the surrounding bone displayed a normal physiological appearance in both histological sections and
radiographs. In the doxyR MRSA inoculated rabbits, a statistically significant reduction in the number of
culture-positive samples was observed for the PLEX-doxycycline-coated group when compared to the animals
that had received an uncoated nail, although the reduction in bacterial burden did not reach statistical
significance.
Conclusions
Improved prophylaxis against infection in trauma and orthopedic implant surgery is clearly required today. In
this study, we investigated a PLEX-doxycycline-coated IM nail in a humeral non-fracture rabbit model. The
PLEX-doxycycline coating on titanium alloy implants provided complete protection against implant-associated
MSSA osteomyelitis, and resulted in a significant reduction in the number of culture positive samples when
challenged with a doxycycline-resistant MRSA.
66
FP58 – (#236) - Free Paper
IS PREOPERATIVE STAPHYLOCOCCUS AUREUS SCREENING AND DECOLONIZATION PROTOCOL REALLY
EFFECTIVE IN PREVENTING SURGICAL SITE INFECTION AFTER TOTAL JOINT ARTHROPLASTY?
P. Santos Leite, P. Barreira, P. Neves, P. Serrano, D. Esteves Soares, L. Leite, M. Silva, R. Sousa
1
Centro Hospitalar do Porto, Porto, Portugal
E-mail: [email protected]
Keywords: Carrier State, Staphylococcus Aureus, Prevention & Control, Risk Factors, Surgical Wound Infection;
Prosthesis-Related Infection
Aim
The goals of the present study are to describe the prevalence of both methicillin sensitive and resistant
S.aureus carriage among elective total hip and knee arthroplasty candidates and to evaluate the real impact of
preoperatively treating carriers in preventing prosthetic joint infection.
Methods
Patients undergoing elective primary THA or TKA at a single institution were enrolled in a prospective
randomized trial. S.aureus nasal carriage screening was performed in the outpatient setting and selected
carriers underwent a 5-day preoperative treatment of nasal mupirocin and chlorhexidine bathing. All patients
were followed regularly in the outpatient clinic. No patients were lost to follow-up at a minimum of one year
after surgery. The main outcome of the study was the diagnosis of prosthetic joint infection occurring in the
first year after surgery including all pathogens and a secondary outcome was defined as infections involving
S.aureus bacteria only.
Results
From January 2010 to December 2012, 1305 total joint arthroplasties were performed and 1028 of those were
screened. We observed a 22.2% (228/1028) S.aureus colonization rate and only eight patients colonized with
MRSA (0.8%). Twenty five cases of prosthetic joint infections were identified with an overall infection rate of
2.4%. S.aureus was involved in 14 cases. PJI rate in S.aureus carriers was 3.9% (9/228), which was not
significantly higher than the 2.0% (16/800) found among non carriers. Treated and untreated carriers infection
rate also showed no significant differences - 3.4% (3/89) vs. 4.3% (6/139). Multivariable analysis substantiates
ASA≥ 3 (OR=3.42, 95% CI=1.51 – 7.74) and duration of surgery above the 75th percentile (OR=2.74, 95%
CI=1.22 – 6.16) as independent predictors of PJI but not S.aureus carrier state. We obtained similar results
when considering infection involving S.aureus bacteria only.
Of the 14 cases where S.aureus was present in PJI, only five were carriers preoperatively. Of those five cases,
one was an untreated MSSA carrier that ultimately got an MRSA infection.
Conclusions
Our results show no clear benefit in screening and decolonizing S.aureus nasal carriers before total joint
arthroplasty. There seems to be a lack of causal relation between nasal S.aureus and PJI pathogen as most of
S.aureus PJI seems to have an exogenous source.
67
FP59 – (#194) - Free Paper
BACTERIA AGAINST BACTERIA: ANTI-BIOFILM ACTIVITY OF A SELECTED AND PATENTED BACTERIAL
COMPOUND AND ITS POTENTIAL ROLE ON BIOFILM-ASSOCIATED INFECTIONS.
M. Toscano, E. De Vecchi, L. Drago
1
IRCCS Galeazzi Orthopaedic Institute, Milan, Italy
E-mail: [email protected]
Keywords: Microbial Biofilm, Anti-Biofilm Activity, Lactobacilli
References
1. Parsek MR et al. Annu Rev Microbiol. 2003;57:677-701.
2. Stoodley P et al. Curr Orthop Pract. 2011;22:558-563.
Aim
The role of biofilm in pathogenesis of several chronic human infections is widely accepted, as this structure
leads pathogens to persist among the human body, being protected from the action of antibacterial molecules
and drugs (1). It has been estimated that up to 65% of bacterial infections are caused by microorganisms
growing in biofilms (2). Moreover, biofilm is involved in device-related orthopaedic bacterial infections, which
are unaffected by vaccines and antibiotic therapies, constituting a serious problem for the human health care.
The aim of the present work was to evaluate the anti-biofilm action of a selected and patented lactobacillus
strain (MD1) supernatant, both on the in-formation- biofilm and on mature biofilm produced by pathogenic
bacteria.
Methods
MD1 was grown in BHI for 48 h at 37°C. After incubation, the sample was centrifuged for 5’ for 14,000 x g and
the supernatant previously filtered and treated in order to obtain the anti-biofilm compounds (Special
Supernatant – SS) was collected. Staphylococcus aureus and Pseudomonas aeruginosa strains were grown in
BHI for 24h at 37°C. The anti-biofilm ability of the tested SS - lactobacillus strain was evaluated by a
spectrophotometric method according to Christensen at al., following the incubation of pathogens and the
“mature biofilm” with the lactobacillus supernatant. Confocal Laser Scanning Microscopy was used to confirm
the data obtained from Crystal Violet Assay.
Results
After the incubation of the SS with pathogens and mature biofilm, the formation of biofilm was inhibited and a
significant disruption of the mature biofilm was observed. Interestingly, the same properties were observed
also when the SS pH was neutralized to pH 6.5. In particular, the reduction of biofilm production and the
disruption of mature biofilm was about 50-70% for all microorganisms.
Conclusions
The SS lactobacillus strain MD1 exhibited a relevant antibiofilm action against mature and in-formation-biofilm
produced by S. aureus and P. aeruginosa strains tested in the study. Moreover, the antibiofilm action has been
observed to be pH-independent, as when the supernatant was neutralized to pH 6.5, the reduction of
pathogenic biofilm has been still observed. These promising results highlighted the possibility to use this SSlactobacillus anti-biofilm property to develop a cost-effective and safety treatment able to reduce the impact
of pathogenic biofilm on device-related orthopaedic bacterial infections.
68
FP60 – (#205) - Free Paper
USE OF AN INNOVATIVE SYSTEM FOR TRANSPORT AND TREATMENT OF IMPLANTS AND BIOPSIES FOR
DIAGNOSIS OF BONE AND JOINT INFECTIONS
E. De Vecchi, V. Signori, M. Bortolin, C. Romanò, L. Drago
1
IRCCS Galeazzi, Milano, Italy
E-mail: [email protected]
Keywords: Microbiological Diagnosis, Dithiothreitol, Prosthetic Joints Infections, Osteomyelitis
Aim
Prosthetic implants, periprosthetic and osteoarticular tissues are specimens of choice for diagnosis of bone
and joint infections including prosthetic joint infections (PJIs). However, it is widely known that cultures from
prostheses and tissues may fail to yield microbial growth in up to one third of patients. In the recent past,
treatment of prosthetic implants have been optimized in order to improve sensitivity of microbiological
cultures, while less attention has been addressed to tissue samples. For these latter homogenization is
considered the best procedure, but it is quite laborious, time-consuming and it is not always performed in all
laboratories. Dithiothreitol (DTT) has been proposed as an alternative treatment to sonication for
microbiological diagnosis of PJIs. In this study, we evaluated the applicability of MicroDTTect treatment, a
closed system developed for transport and treatment of tissues and prosthetic implants with DTT.
Methods
For evaluation of applicability of MicroDTTect to tissue specimens, samples (tissues and, in case of PJI,
prosthetic implants) from 40 patients (12 PJIs and 5 osteomyelitis and 23 not-infected) were evaluated.
MicroDTTect system consists of a sterile plastic bag containing a reservoir which allows for release of a 0.1%
(v:v) DTT solution, once the sample is placed into the bag. Comparison of MicroDTTect treatment of
prostheses with sonication included samples from 30 patients (14 with aseptic loosening of the prosthesis and
16 with PJIs). Of two tissue samples from the same region, one was placed into MicroDTTect bag and the other
was collected in a sterile container with addition of sterile saline. After agitation and centrifugation of the
eluate, aliquots of the pellets were plated on agar plates and inoculated into broths which were incubated for
48 hrs and 15 days, respectively.
Results
Treatment of prosthetic implants with MicroDTTect showed a higher specificity and sensitivity than sonication
(specificity 92.8% vs 85.7%; sensitivity: 87.5% vs 75.0 % DTT vs sonication). When used for tissue treatment,
MicroDTTect showed a sensitivity of 82.3% and a specificity of 97% which were higher than that observed
when saline was used (sensitivity: 64.7%; specificity 91% ).
Conclusions
Treatment of tissues and prosthetic implants with MicroDTTect may be a practicable strategy to improve
microbiological diagnosis of osteoarticular infections, reducing sample manipulation and therefore limiting
sample contamination. Moreover, use of MicroDTTect does not require dedicated instrumentation, and is time
and cost saving.
69
FP61 – (#36) - Free Paper
IMPORTANCE OF SELECTION AND DURATION OF ANTIBIOTIC REGIMEN IN PROSTHETIC JOINT INFECTIONS
TREATED WITH DEBRIDEMENT AND IMPLANT RETENTION
1
1
2
1
1
1
1
3
E. Tornero , S. Angulo , L. Morata , D.M. García-Velez , J.C. Martínez-Pastor , G. Bori , A. Combalia , J. Bosch ,
1
2
S. García-Ramiro , A. Soriano
1
Department of Traumatology and Orthopaedic Surgery, Hospital Clinic of Barcelona., Barcelona, Spain
2
Service of Infectious Diseases. Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
3
Service of Microbiology, Hospital Clinic of Barcelona, University of Barcelona, ISGlobal, Barcelona, Spain
E-mail: [email protected]
Keywords: Prosthetic Joint Infection, Debridement, Antibiotic Treatment
Aim
Early prosthetic joint infections (PJI) are managed with debridement, implant retention and antibiotics (DAIR).
Our aim was to evaluate risk factors for failure after stopping antibiotic treatment.
Methods
From 1999 to 2013 early PJIs managed with DAIR were prospectively collected and retrospectively reviewed.
The main variables potentially associated with outcome were gathered and the minimum follow-up was 2
years. Primary endpoint was implant removal or the need of reintroducing antibiotic treatment due to failure.
Results
A total of 143 patients met the inclusion criteria. The failure rate after a median (IQR) duration of oral
antibiotic treatment of 69 (45-95) days was 11.8%. In 92 cases PJI was due to gram-positive (GP)
microorganisms, in 21 due to gram-negatives (GN) and 30 had a polymicrobial infection. In GP infections,
combination of rifampin with linezolid, cotrimoxazole or clindamycin was associated with a higher failure rate
(27.8%, P=0.026) in comparison to patients receiving a combination of rifampin with levofloxacin, ciprofloxacin
or amoxicillin (8.3%) or monotherapy with linezolid or cotrimoxazole (0%) (Figure 1). Among patients with a
GN infection, the use of fluoroquinolones was associated with a lower failure rate (7.1% vs 37.5%, P=0.044).
Duration of antibiotic treatment was not associated with failure.
Conclusions
The only factor associated with failure was the oral antibiotic selection, but not the duration of treatment.
Linezolid, cotrimoxazole and clindamycin but not levofloxacin serum concentrations are reduced by rifampin; a
fact that could explain our findings. Further studies monitoring serum concentration could help to improve the
efficacy of these antibiotics when combining with rifampin.
70
FP62 – (#35) - Free Paper
KLIC-SCORE FOR PREDICTING EARLY FAILURE IN PROSTHETIC JOINT INFECTIONS TREATED WITH
DEBRIDEMENT, IMPLANT RETENTION AND ANTIBIOTICS
1
2
1
1
1
1
1
E. Tornero , L. Morata , S. Angulo , D.M. García-Velez , J.C. Martínez-Pastor , G. Bori , S. García-Ramiro , J.
3
4
Bosch , A. Soriano
1
Department of Traumatology and Orthopaedic Surgery, Hospital Clinic of Barcelona., Barcelona, Spain
2
Service of Infectious Diseases. Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS., Barcelona, Spain
3
Service of Microbiology, Hospital Clinic of Barcelona, University of Barcelona, ISGlobal., Barcelona, Spain
4
Service of Infectious Diseases. Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, Barcelona, Spain
E-mail: [email protected]
Keywords: Prosthetic Joint Infection, Debridement
Aim
Open debridement, irrigation with implant retention and antibiotic treatment (DAIR) is an accepted approach
for early prosthetic joint infections (PJI). Our aim was to design a score to predict patients with a higher risk of
failure.
Methods
From 1999 to 2014 early (<90 days) PJIs without signs of loosening of the prosthesis were treated with DAIR
and were prospectively collected and retrospectively reviewed. The primary end-point was early failure
defined as: 1) the need of an unscheduled surgery, 2) death-related infection within the first 60 days after
debridement or 3) the need for suppressive antibiotic treatment. A score was built-up according to the logistic
regression coefficients of variables available before debridement.
Results
A total of 222 patients met the inclusion criteria. The most frequently isolated microorganisms were
coagulase-negative staphylococci (95 cases, 42.8%) and Staphylococcus aureus (81 cases, 36.5%). Fifty-two
(23.4%) cases failed. Independent predictors of failure were: chronic renal failure (OR:5.92, 95%CI:1.47-23.85),
liver cirrhosis (OR:4.46, 95%CI:1.15-17.24), revision surgery (OR:4.34, 95%CI:1.34-14.04) or femoral neck
fracture (OR:4.39, 95%CI:1.16-16.62) compared to primary arthroplasty, CRP >11.5 mg/dL (OR:12.308,
95%CI:4.56-33.19), cemented prosthesis (OR:8.71, 95%CI:1.95-38.97) and when all intraoperative cultures
were positive (OR:6.30, 95%CI:1.84-21.53). Furthermore, CRP showed a direct relationship with the
percentage of positive cultures (Linear equation, R2=0,046, P=0.002) and an inverse association with the time
between the debridement and failure (Logarithmic equation, R2=0.179, P=0.003). A score for predicting the
risk of failure was done using pre-operative factors (KLIC-score, figure 1) and it ranged between 0-9.5 points.
Patients with a score ≤2, >2-3.5, 4-5, >5-6.5 and ≥7 had a failure rate of 4.5%, 19.4%, 55%, 71.4% and 100%,
respectively.
Conclusions
The KLIC-score was highly predictive of early failure after debridement. In the future, it would be necessary to
validate our score using cohorts from other institutions.
71
FP63 – (#192) - Free Paper
A NOVEL SEROLOGICAL IMMUNOASSAY FOR THE GENUS LEVEL DIAGNOSIS OF PROSTHETIC JOINT
INFECTION: A PROSPECTIVE STUDY
1
1
2
2
3
3
3
3
2
2
S. Marmor , N. Desplaces , T. Bauer , B. Heym , O. Sol , J. Rogé , F. Mahé , L. Desire , I. Ghout , J. Ropers , J.
2
4
Gaillard , M. Rottman
1
Groupe Hospitalier Diaconesses Croix St Simon, Paris, France
2
Hopital Ambroise Paré, GHU Paris Ile de France Ouest (AP-HP), Boulogne Billancourt, France
3
Diaxonhit, Paris, France
4
Hopital Raymond Poincaré, GHU Paris Ile de France Ouest (AP-HP), Garches, France
E-mail: [email protected]
Keywords: Serology, Prosthetic Joint Infection, Diagnosis, Biomarker
Aim
The diagnosis of prosthetic joint infections (PJI) represents a critical challenge for orthopedic surgeons and
infectious disease specialists. The diagnosis of PJI is often delayed because non-invasive assays lack sensitivity
and specificity. A novel multiplex immunoassay detecting antibodies against Staphylococci, Propionibacteria
and Streptococcus agalactiae was developed and its performance evaluated in a prospective, multicenter, noninterventional study.
Methods
The Luminex-based assay measures serum IgG against a proprietary panel of recombinant purified antigens
from Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus lugdunensis, Streptococcus
agalactiae and Propionibacterium acnes. Patients undergoing revision arthroplasty were included over a 2-year
period (from 2012 up to 2014) in two French reference centers in compliance with IRB and French regulations.
PJI cases were defined microbiologically (≥2 intraoperative samples yielding the same microorganism) for
confrontation of microbiological and immunoassay data.
Results
455 patients were eligible for study analyses. 149 patients (32.7%) were found to be infected. Among the most
frequent infecting species recovered were S. aureus (30%), S. epidermidis (26%), P. acnes (9%), S. lugdunensis
(6%), and S. agalactiae (4%). The sensitivity and specificity values of the test were, respectively, 75.9% (63/83)
and 82.2% (180/219) for staphylococci (S. aureus, S. epidermidis, S. lugdunensis), 38.5% (5/13) and 81.9%
(190/232) for P. acnes, and 66.7% (4/6) and 92.4% (208/225) for S. agalactiae. Interestingly, all cases (9/9)
involving S. lugdunensis were detected by the test and the sensitivity for S. epidermidis reached 79.4% in
patients more than three months after joint replacement. In a similar fashion, 89.5% (17/19) in the
subpopulation with elevated inflammatory markers (ESR>30 and CRP>10).
The assay correctly identified 67% of the microbiologically positive patients that were negative by ESR or CRP
screening.
Conclusions
This novel multiplex serological test allows the rapid and non-invasive diagnosis of the most frequent PJI
pathogens, showing a good correlation with microbiological culture. and appears to be a new promising tool in
the management of PJI, adding sensitivity to the current serological assays and enhancing the management of
patients with pauci-inflammatory PJI.
Acknowledgements
We want to thank the patients for their participation to the study, and Mrs Layidé Méaude (Clinical Research
Unit, Hospital Ambroise Paré) and Mrs Laurence Raizonville (Clinical Research Unit, Hospital Ambroise Paré)
for their dedication to the study.
72
FP64 – (#152) - Free Paper
TISSUE CULTURE AND SONICATION FOR DIAGNOSIS OF PROSTHETIC JOINT AND ORTHOPAEDIC DEVICE
RELATED INFECTION.
1
2
2
3
2
2
2
2
2
A. Brent , L. Barrett , M. Dudareva , M. Figtree , R. Colledge , R. Newnham , P. Bejon , M. Mcnally , A. Taylor ,
2
B. Atkins
1
University of Oxford & Oxford University Hospitals NHS Trust, Oxford, United Kingdom
2
Oxford University Hospitals NHS Trust, Oxford, United Kingdom
3
Royal North Shore Hospital, Sydney, Australia
E-mail: [email protected]
Keywords: Prosthetic Joint Infection, Device Related Infection, Sonication, Diagnosis, Microbiology
Aim
Collection of 4-5 independent peri-prosthetic tissue samples is recommended for microbiological diagnosis of
prosthetic joint infections. Sonication of explanted prostheses has also been shown to increase microbiological
yield in some centres. We compared sonication with standard tissue sampling for diagnosis of prosthetic joint
and other orthopaedic device related infections.
Methods
We used standard protocols for sample collection, tissue culture and sonication. Positive tissue culture was
defined as isolation of a phenotypically indistinguishable organism from ≥2 samples; and positive sonication
culture as isolation of an organism at ≥50 cfu/ml. We compared the diagnostic performance of each method
against an established clinical definition of infection (Trampuz 2011), and against a composite clinical and
microbiological definition of infection based on international consensus (Gehrke & Parvizi 2013).
Results
350 specimens were received for sonication, including joint prostheses (160), exchangeable components (76),
other orthopaedic hardware and cement (104), and bone (10). A median of 5 peri-prosthetic tissue samples
were received from each procedure (IQR 4-5). Tissue culture was more sensitive than sonication for diagnosis
of prosthetic joint and orthopaedic device related infection using both the clinical definition (66% versus 57%,
McNemar’s Χ2 test p=0.016) and the composite definition of infection (87% vs 66%, p<0.001). The combination
of tissue culture and sonication provided optimum sensitivity: 73% (95% confidence interval 65-79%) against
the clinical definition and 92% (86-96%) against the composite definition.
Results were similar when analysis was confined to joint prostheses and exchangeable components; other
orthopaedic hardware; and patients who had received antibiotics within 14 days prior to surgery.
Conclusions
Tissue sampling appears to have higher sensitivity than sonication for diagnosis of prosthetic joint and
orthopaedic device infection at our centre. This may reflect rigorous collection of multiple peri-prosthetic
tissue samples. A combination of methods may offer optimal sensitivity, reflecting the anatomical and
biological spectrum of prosthetic joint and other device related infections.
73
FP65 – (#93) - Free Paper
IMPACT OF VIRULENCE GENETIC BACKGROUND AND PHYLOGENY OF PROPIONIBACTERIUM ACNES
INVOLVED IN SPINE-RELATED, PROSTHESIS-ASSOCIATED INFECTIONS AND ACNE LESIONS.
1
1
1
2
2
G. Aubin , F. Gouin , D. Lepelletier , C. Jacqueline , K. Ashenoune , S. Corvec
1
Nantes University Hospital, Nantes, France
2
Nantes Medicine school, EA3826, Nantes, France
E-mail: [email protected]
1
Keywords: Propionibacterium Acnes, Bone And Joint Infection, Virulence Factors, Hyaluronate Lyase, MLST
References
Aubin GG, Portillo ME, Trampuz A, Corvec S. Propionibacterium acnes, an emerging pathogen: from acne to
implant-infections, from phylotype to resistance. Med Mal Infect. 2014 Jun;44(6):241-50.
Aim
Propionibacterium acnes is an emerging pathogen especially in orthopedic implant infection. Aim of this study
was to investigate P. acnes phylogeny and to screen for virulence factors among a large collection of clinical
isolates involved in spine material infections, arthroplasty infections and acne lesions.
Methods
88 P. acnes clinical isolates were collected between January 2003 and December 2014 at Nantes University
Hospital (France). Fifty-eight isolates came from spine infections, 14 from prosthetic infections (knee, hip or
shoulder), 14 from acne lesions and two reference strains (ATCC11827 and ATCC6919). Implant associated
infections were confirmed using Infectious Diseases Society of America criteria for bone and joint infections.
Phylotypes and Multi-Locus Sequence Typing (MLST) was carried out on all isolates as described by Lomholt et
al. All isolates were tested by established PCR-based assays for 21 putative virulence factor genes
characteristic of P. acnes.
Results
MLST analysis revealed an association between clonal complexes (CCs) and origin of P. acnes isolates (p =
0,027). Regarding CCs distribution between different origins, CC36 and phylotype II P. acnes isolates are more
frequently observed in prosthetic joint infections. On the other hand, CC18 (IA) and CC28 (IB) P. acnes isolates
are more frequently involved in spine infections and acne lesions.
Among all virulence factors screened, hyaluronate lyase gene was only present in CC36 and phylotype II P
acnes isolates. Other virulence factors were present in all isolates, whatever their origin or CC.
Conclusions
Regarding molecular typing results, P. acnes involved in spine infections seem to have a skin origin (same CC as
isolates from acne lesion). Interestingly, the origin of prosthetic joint infection isolates seems different and
they all carry one more virulence factor.
Hyaluronate lyase (Hyl) is a major surface protein of P. acnes with potential antigenetically variable properties
that might be essential for P. acnes virulence. Increased tissue permeability caused by the action of
hyaluronidase on the extracellular matrix appears to play a role in wound infections, pneumonia, and other
sepsis such as bacteremia and meningitis. It could be also take a prominent part in P. acnes prosthetic joint
infection pathogenesis.
Acknowledgements
This study was supported by the French "Ministère de l’Enseignement Supérieur et de la Recherche".
Pr. Brigitte Dreno (Nantes Dermatology Unit) for providing acne lesion samples.
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