The Incidence of and Clinical Approach to Positive Allograft Cultures in Anterior Cruciate Ligament Reconstruction

Objective: To define the incidence of positive allograft cultures in anterior cruciate ligament (ACL) reconstruction and to determine a clinical approach to a positive test. Design: Retrospective chart review, cohort series. Setting: Urban academic hospital. Patients: All patients who underwent anterior cruciate ligament reconstruction using allograft between January 2003 and December 2008. One hundred fifteen patients met the inclusion criteria. Interventions: Culture of allograft before surgical implantation. Main Outcome Measures: Positive allograft culture. Results: Positive allograft cultures were obtained in 3 of 115 grafts (2.6%). Two cultures grew coagulase-negative Staphylococcus and 1 grew Escherichia coli, both from the broth only. Conclusions: Positive cultures in ACL allografts have a reported incidence of 5.7% to 13.25%. Our current series shows an incidence of 2.6%. No patients who had a culture-positive allograft developed a clinical infection postoperatively. Routine preimplantation culture of soft tissue allografts cannot be recommended given the low incidence of positive culture and lack of correlation with clinical infection. In the presence of a positive preimplantation allograft culture without signs of clinical infection, our series and the 4 other published series in the literature demonstrate that antibiotic treatment is not indicated. In contrast, signs and symptoms of septic arthritis should be aggressively treated with irrigation, debridement, and intravenous antibiotics.