1. Etiologies and outcomes in patients with open fractures and osteomyelitis. Retrospective Analysis of the Bone And Joint Infection Organization (BAJIO) Group Britto Johnson MD 1, Mariko Cheick CRC 1, Harting Julie PharmD 1,2, Kelley Robert PhD 1, Seligson, David MD 1, Christensen Diana MD 1, Ramirez, Julio MD 1. 1. Division of Infectious Diseases, University of Louisville 2. Sullivan College of Pharmacy 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 post- therapy. 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.. 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 Table 1. Baseline characteristics, site and type of osteomyelitis in open fractures 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. 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 Table 2: Etiology of open fractures and osteomyelitis Table 3: Outcomes in open fractures and osteomyelitis. Success and Failure rates calculated from number of patients in each follow up period. 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. 1.Merritt K. Factors increasing the risk of infection in patients with open fractures. J Trauma 1988; 28:823 2.DeLong WG Jr, Born CT, Wei SY, et al. Aggressive treatment of 119 open fracture wounds. J Trauma 1999; 46:1049 3.Gross T, Kaim AH, Regazzoni P, Widmer AF. Current concepts in posttraumatic osteomyelitis: a diagnostic challenge with new imaging options. J Trauma 2002; 52:1210 4.Patzakis MJ, Wilkins J. Factors influencing infection rate in open fracture wounds. Clin Orthop Relat Res 1989; :36. 5.Tsukayama DT. Pathophysiology of posttraumatic osteomyelitis. Clin Orthop Relat Res 1999; :22. 6.Lavery LA, Walker SC, Harkless LB, Felder-Johnson K. Infected puncture wounds in diabetic and nondiabetic adults. Diabetes Care 1995; 18:1588 7.Dirschl DR, Almekinders LC. Osteomyelitis. Drugs. 1993; 45: 29- 43. Ehara S. Complications of skeletal trauma. Radiol Clin North Am. 1997; 35: 767-781. 8.Sammak B, Abd El Bagi M, Al Shahed M, et al. Osteomyelitis: a review of currently used imaging techniques. Eur Radiol. 1999; 9: 894-900 ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS RESULTS (con’t) CONCLUSIONS REFERENCES RESULTS (con’t)