Culture-Negative Infection After Operative Fixation of Fractures

OBJECTIVES: (1) Compare the outcomes of patients with orthopaedic trauma with culture-negative infection with those with pathogens identified; (2) identify the incidence of culture-negative infection and describe the common characteristics. DESIGN: Retrospective study. SETTING: Two level 1 trauma centers. PATIENTS: A total of 391 patients 16 years of age or older who underwent irrigation and debridement for surgical site infection after having undergone fracture fixation were included. INTERVENTION: Patients underwent irrigation and debridement with cultures, and antibiotic therapy was initiated. MAIN OUTCOME MEASUREMENT: Treatment failure due to unsuccessful eradication of infection and time to union. RESULTS: We found 9% incidence of culture-negative infection. Approximately one-third of patients in both groups went on to have treatment failure (25% of pathogen-specific infections, 38% of culture-negative infections, P = 0.15), and there was no difference between the 2 groups with regard to time to union (22 vs. 24 weeks, P = 0.55). More than one-third of patients required subsequent reconstructive procedure and 5% of patients in each group required amputation to control their infection. There was no difference between the groups with respect to the use of antibiotics before intervention and culture. CONCLUSION: This study confirms the devastating effect that postoperative infections can have and suggests that, with clinical sign of infection, negative cultures do not portend a better prognosis. These entities should be treated in a similar manner to infections with positive cultures. Furthermore, we believe that future studies should not strictly rely on the presence of positive intraoperative cultures. Consensus as to what constitutes a clinical infection, in the absence of positive cultures, is needed. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.