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Etiologies and outcomes in patients with open fractures and osteomyelitis.
Retrospective Analysis of the Bone And Joint Infection Organization (BAJIO) Group
Britto Johnson MD1, Mariko Cheick CRC1, Harting Julie PharmD1,2, Kelley Robert PhD1, Seligson, David MD1, Christensen Diana MD1, Ramirez, Julio MD1.
1. Division of Infectious Diseases, University of Louisville 2. Sullivan College of Pharmacy
ABSTRACT
MATERIALS AND METHODS
.
Background: One of the most devastating complications of an
open fracture is infection, which has an incidence of 3% to
40%. The objectives of this study were to describe the
etiologies of osteomyelitis in patients with open fractures, and
to evaluate the outcomes at 4-6 weeks, 6 months and 1 year
after treatment.
Methods: Retrospective study of patients at the University of
Louisville (UofL) Hospital. Inclusion criteria were the diagnosis
of open fractures and osteomyelitis. Outcomes were evaluated
at the end of initial IV therapy, 6 months and 1 year posttherapy. Clinical success was defined as clinical improvement;
decrease ESR and CRP.
Results: Forty one patients were reviewed. Mean patient age
was 48 years and 28 (68%) were male. The etiology was GPC
49% and GNR in 45%.The average length of antibiotics was 31
days. Surgical debridement was performed in 40/41 cases
(98%). The initial outcomes were: success 30/31 (97%), failure
1/31 (3%), and loss of follow-up (FU) 10/41 (24%). At 4-6
months 27/41 (66%) of patients were lost from FU, success was
11/14 (79%) and failure in 3/14 (21%). At 12 months success
was documented in 3/4 (75%), and failure 1/4(25%).
Conclusion: This study revealed that patients admitted at the
UofL hospital with open fractures and osteomyelitis the most
common etiologies were Staphylococcus aureus, Enterococcus,
Serratia, Enterobacter, E.coli and Pseudomonas. Clinical success
at the end of initial therapy and 4-6 months follow up was seen
in majority of patients (97-79%) with a high percentage of loss
of follow up.
INTRODUCTION
• Posttraumatic osteomyelitis can occur in up to 40 percent of open
fractures;
• The risk depends upon the severity of fracture, severity of soft
tissue injury, degree of bacterial contamination, and presence of
underlying vascular insufficiency.
• The incidence of osteomyelitis after open fractures is reported to
be 3% to 40%, depending significantly on the grade of trauma
and the type of treatment administered.
• Prompt and thorough treatment helps to reduce the risk of
infection, decreasing the probability of developing osteomyelitis.
• The tibia is the most frequent site of posttraumatic osteomyelitis,
since it is the most vulnerable bone with the least vigorous blood
supply in the body.
• The presence of bacteria alone in an open fracture is not
sufficient to cause osteomyelitis. In most cases, the body's
immune system is capable of preventing the colonization of
pathogens.
• The micro-environment determines whether infection occurs.
• The timing and extent of treatment are critical in determining
whether infection develops.
Study Population and Setting: This was a retrospective study of
adult patients at the University of Louisville Hospital in Louisville,
KY. All patients from November 2010 to July 2013 from the
University of Louisville Bone and Joint Infection Service were
evaluated.
• Demographics, site of infection, infection type, microbiologic,
treatment data, including surgical intervention, choice and
duration of antibiotic therapy were abstracted from medical
records and entered into electronic database for analysis.
• Outcomes were evaluated at the end of initial IV therapy, 6
months and 1 year post-therapy.
Inclusion criteria:
• >18 years of age
• Confirmed osteomyelitis:
• By xrays, computed tomography, magnetic resonance imaging,
and/or nuclear medicine studies.
• Suggestive radiologic indices augmented by histologic
evaluation of bone and/or positive cultures for bacteria in
bone biopsy specimens
Study definition:
• Clinical success was defined as clinical improvement; decrease
in ESR and CRP.
Statistical Analysis: Percentages, averages, and standard deviations
were calculated using Microsoft Excel 2010
RESULTS
•Forty one patients were reviewed.
•Demographic data, site and type of osteomyelitis in open fractures
is represented in Table 1.
•Etiology of open fractures and osteomyelitis is represented in
Table 2.
•The average length of antibiotics was 31 days.
•Surgical debridement was performed in 40/41 cases (98%).
•Outcomes in open fractures and osteomyelitis is represented in
Table 3
RESULTS (con’t)
Variable
RESULTS (con’t)
Number (%)
n=41
Demographics
Age, mean (SD)
Male Gender
48 (14.8)
28 (68%)
Risk Factors
Smoking
Hypertension
Hyperlipidemia
Coronary Artery Disease
Diabetes
IV Drugs
Alcohol
Peripheral Vascular Disease
Site of infection
Tibia/Fibula
Radius/Ulna
Femur
Others
Type of osteomyelitis
Acute
Chronic
23 (56)
18 (43)
11 (27)
11 (27)
10 (24)
8 (19)
6 (15)
3 (7)
17
13
6
21
Table 3: Outcomes in open fractures and osteomyelitis. Success and
Failure rates calculated from number of patients in each follow up
period.
CONCLUSIONS
• This study revealed that patients admitted at the UofL
hospital with open fractures and osteomyelitis, the most
common etiologies were Staphylococcus aureus, Enterococcus
species, Serratia, Enterobacter, E.coli and Pseudomonas.
• Clinical success at the end of initial therapy and 6 months
follow-up was seen in the majority of patients (79%) with a high
percentage of loss of follow up.
•Knowing the local microbiology of osteomyelitis due to open
fractures will allow us to optimize our initial empiric therapy for
these patients.
REFERENCES
24 (58)
16 (39.0)
Table 1. Baseline characteristics, site and type of osteomyelitis
in open fractures
Number (%)
Organisms
(n=50)
Gram Positive Cocci (GPC)
Staphylococcus aureus
Methicillin Resistant
8 (16%)
Methicillin Senitive
7 (14%)
Enterococus species
6 (12%)
Gram Negative Rods (GNR)
Serratia marcescens
5 (10%)
Enterobacter cloacae
4 (8%)
Escherichia coli
3 (6%)
Pseudomonas aeruginosa
3 (6%)
Table 2: Etiology of open fractures and osteomyelitis
6 weeks 6 months 12 months
Outcome
No.(%) No. (%) No. (%)
30 (97%) 11 (79%)
3 (75%)
Success
Failure
1(3%)
3 (21%)
1 (25%)
Loss to follow up 10 (24%) 27 (66%)
37 (90%)
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