Evidence map for treatment outcomes and prognostic determinants in periprosthetic joint infection: an umbrella review

Background The reporting of outcomes following treatment for periprosthetic joint infection (PJI) suffers from inconsistent terminology and methodological constraints, complicating the interpretation of prognostic factors and treatment efficacy. This umbrella review synthesized systematic reviews and meta-analyses to evaluate the burden, comparative effectiveness, and prognostic factors associated with adverse PJI outcomes. Methods Following PRISMA guidelines, a comprehensive search of Cochrane Library, Embase, PubMed, and Web of Science was conducted from inception to April 20, 2026. We included meta-analyses reporting quantitative post-treatment outcomes for PJI. Methodological quality, risk of bias, and evidence certainty were assessed using AMSTAR-2, ROBIS, and GRADE, respectively. Evidence signals were stratified to separate comparative and prognostic associations from descriptive outcome-burden estimates. Results 53 reviews were included, predominantly assessing hip (THA) and knee (TKA) PJI. The overall certainty of evidence was generally low. PJI demonstrated a high descriptive outcome burden: across variable follow-up periods, overall pooled mortality was 11.0% after THA PJI and 13.3% after TKA PJI. The pooled failure rate for debridement, antibiotics, and implant retention (DAIR) was 35.9%, escalating to 73.6% in late chronic cases. Following one-stage revision, all-cause revision rates were 11.1% (THA) and 11.8% (TKA). These pooled burden estimates should be interpreted descriptively when follow-up durations differed across source reviews. Prognostically, several adverse associations were identified, including positive culture at two-stage reimplantation (OR = 1.92), obesity (OR up to 3.63 in TKA), and smoking (RR = 1.84), although the certainty and replication of these associations varied across evidence sources. Conclusion PJI carries a substantial burden of mortality and treatment failure. Available evidence identifies associations between adverse outcomes and host vulnerabilities, microbiological factors, treatment context, and surgical timing, although these relationships remain largely based on observational evidence rather than demonstrated causal mechanisms. Future research must prioritize standardized outcome definitions and prospective designs to clarify comparative treatment effects and improve individualized risk stratification.