Six-week antibiotic therapy after one-stage replacement arthroplasty for hip and knee periprosthetic joint infection

One-stage replacement arthroplasty for treatment of periprosthetic joint infection (PJI) results in similar cure rate than two-stage (around 85-92%), but antibiotic therapy duration is not well established. The aim of this study was to evaluate the efficacy of a short six-week antibiotic course in periprosthetic joint infections after onstage exchange.

Retrospective, observational study conducted at Orthopaedic Department of Cochin Hospital, Paris, between 1st January 2010 and 31 December 2015. Patients with a microbiologically proven PJI, treated with one-stage replacement and 6 weeks (+/1week) of antimicrobial therapy were included. Pearson's-χ² and Wilcoxon tests were used to compare categorical and continuous variables.

Fifty patients with periprosthetic joint infections (42 hip, 8 knee PJI) treated with one-stage replacement arthroplasty were included. Median age was 69.3 years (IQR 24.5-97.4). Infections occurred after a mean of 36 months (IQR 1-216). Bone biopsy cultures were positive for Staphylococcus spp. in 29 patients (58%), Cutibacterium acnes in 19 (38%), Gram-negative bacilli in 6 (12%). Polymicrobial infections occurred in 12 (24%). Intravenous antibiotics were administered for a median of 11 days (IQR 4-45) and 46 patients (92%) were switched to an oral therapy. Medium follow-up was of 32 months (IQR 12-101). Overall remission rate was 90%.

A six-week course of antibiotics in knee and hip PJIs treated with one-stage RA has a satisfactory remission rate in this open study.