Periprosthetic Joint Infection after Hip and Knee Arthroplasty: Pathogenesis, Diagnosis, Prevention and Treatment

Abstract

Periprosthetic joint infection (PJI) is an uncommon but disproportionately consequential complication of total hip and knee arthroplasty. Its clinical importance derives not only from the need for prolonged antimicrobial therapy and repeat surgery, but also from functional loss, healthcare expenditure, and excess mortality observed in registry cohorts. This critical narrative review evaluates contemporary evidence on PJI epidemiology, pathogenesis, diagnosis, treatment, and prevention, with emphasis on the methodological uncertainties that complicate translation into practice. Literature published principally from 2011 to 10 July 2026 was identified through multidisciplinary scholarly databases and citation searching, while earlier seminal studies were retained when necessary to explain biofilm biology, diagnostic methods, or antimicrobial strategy. Current evidence supports a model of PJI as a host-implant-microbe syndrome in which biofilm formation, microbial phenotype, tissue condition, implant stability, and host reserve interact. Diagnostic progress has been substantial, yet there remains no single reference standard. Weighted criteria, synovial biomarkers, optimised microbiology, molecular sequencing, and metal-artefact-reduction imaging improve discrimination in selected settings, but reported accuracy is strongly influenced by case definitions, spectrum effects, prior antimicrobial exposure, and threshold derivation. Treatment evidence is likewise heterogeneous. Debridement, antibiotics and implant retention can succeed in selected acute infections, whereas one-stage and two-stage exchange appear broadly comparable in appropriately selected cohorts; robust randomised comparisons remain scarce. Antibiotic duration and route should be integrated with surgical strategy rather than prescribed by habit, and suppressive therapy should be distinguished from curative treatment. Preventive evidence supports antimicrobial stewardship and targeted infection-control measures, while recent randomised data challenge routine expansion of vancomycin-based local or systemic prophylaxis in unselected settings. Future progress depends on harmonised definitions, prospective comparative trials, standardised patient-centred outcomes, validated molecular workflows, and clinically tested biofilm-directed or sensing technologies. PJI management is therefore best understood as multidisciplinary risk-stratified decision-making under persistent diagnostic and therapeutic uncertainty.