Evaluation of time to reimplantation as a risk factor in two-stage revision with static spacers for periprosthetic knee joint infection

We investigated the time to reimplantation (TTR) during two-stage revision using static spacers with regard to treatment success and function in patients with chronic periprosthetic joint infection (PJI) of the knee. 163 patients (median age 72 years, 72 women) who underwent two-stage exchange for chronic knee PJI between 2012 and 2020 were retrospectively analyzed (based on the 2011 Musculoskeletal Infection Society criteria). A cutoff TTR for increased risk of reinfection was identified using the maximally selected log-rank statistic. Infection control, aseptic revisions and overall survival were analyzed using Kaplan–Meier survival estimates. Adjustment for confounding factors—the Charlson Comorbidity Index (CCI) and C-reactive protein (CRP)—was done with a Cox proportional hazards model. When TTR exceeded 94 days, the adjusted hazard of reinfection was increased 2.8-fold (95