Prospective Comparison of Blood Culture Bottles and Conventional Swabs for Microbial Identification of Suspected Periprosthetic Joint Infection

Background Early, accurate detection of infection is vital to successful treatment of periprosthetic joint infection (PJI). Currently, no “gold standard” diagnostic testing exists. The goal of this prospective study was to compare the efficacy of a blood culture bottle system (BCBS) to commonly used culture swabs in confirming PJI in patients with high clinical suspicion. Methods Patients were selected for enrollment based on Musculoskeletal Infection Society guidelines for PJI. erythrocyte sedimentation rate and C-reactive protein were obtained before aspiration. Aspirated fluid was divided between BCBS, swab, and synovial fluid analysis. Forty-nine samples were analyzed. Results BCBS yielded 41 positive cultures vs 19 with swab (P <.0001), particularly with respect to Staphylococcus epidermidis. There were no false positive results in the BCBS group, using strict Musculoskeletal Infection Society guidelines. Conclusion BCBS increased identification of pathogens in lower extremity PJI, providing clinicians with a low-cost, broadly-applicable test.