Current Diagnostic and Therapeutic Approaches to Periprosthetic Joint Infection: A Narrative Review

Background: Periprosthetic joint infection (PJI) remains one of the most serious complications after total hip and knee arthroplasty. Although its incidence after primary arthroplasty is relatively low, PJI causes major morbidity, repeated surgery, prolonged antimicrobial treatment, impaired function, and substantial healthcare costs. Diagnosis is difficult because clinical findings may be nonspecific, particularly in chronic low-grade infection, and no single test reliably confirms or excludes infection in all clinical settings. Objective: This narrative review summarizes contemporary diagnostic approaches to PJI and discusses current therapeutic strategies in relation to major definitions, guidelines, and recent evidence. Methodology: PubMed, Google Scholar, and the Cochrane Library were searched for English-language publications on hip and knee PJI, with emphasis on consensus definitions, diagnostic criteria, synovial biomarkers, microbiological and molecular diagnostics, imaging, surgical treatment, antimicrobial therapy, and suppressive treatment. The search was updated through March 2026. Results: Current diagnosis relies on multimodal assessment integrating clinical findings, serum inflammatory markers, synovial fluid analysis, microbiology, histopathology, and selected imaging studies. The 2018 ICM/MSIS criteria and the 2021 EBJIS definition remain the most influential frameworks. Treatment is primarily surgical and includes DAIR, one-stage revision, and two-stage revision supported by targeted antimicrobial therapy. Conclusion: Effective PJI management requires individualized multidisciplinary decision-making. Emerging biomarkers, molecular methods, artificial intelligence, and antibacterial implant technologies are promising but require further validation before routine implementation.