Time to positivity of acute and chronic periprosthetic joint infection cultures

INTRODUCTION: A prolonged incubation time is generally recommended for diagnosing periprosthetic joint infections (PJI). However, in literature, no distinction is made between acute and chronic infections. METHODS: All patients with a PJI that underwent surgical debridement between November 2015 and February 2019 with or without revision of the prosthesis were retrospectively evaluated. Synovial fluid, 5 intraoperative periprosthetic tissue samples, and the sonicated prosthesis were cultured. RESULTS: Fifty-nine patients were analyzed, including 21 acute PJIs (33 isolates) and 38 chronic PJIs (46 isolates). In acute PJIs, all isolates grew within 5 days, while this took 11 days for chronic PJIs. Sonication fluid showed the shortest time to positivity (78% at day 2) for chronic PJIs, but no difference was observed for acute PJIs compared to tissue cultures. CONCLUSION: In contrast to cultures from chronic PJIs, acute PJIs do not need a prolonged incubation time and no clear benefit is observed for sonication.