Results of 331 Two-Stage Exchanges for PJI Following THA: Low Reinfection and Mechanical Failure Rates at 10 Years.

BACKGROUND The relative advantages and disadvantages of 2-stage versus 1-stage management of infection following total hip arthroplasty (THA) are the current subject of intense debate. To understand the merits of each approach, detailed information on the short and, importantly, longer-term outcomes of each must be known. The purpose of the present study was to assess the long-term results of 2-stage exchange arthroplasty following THA in one of the largest series to date. METHODS We identified 331 periprosthetic joint infections (PJIs) that had been treated with a 2-stage exchange arthroplasty between 1993 and 2021 at a single institution. Patients were excluded if they had had prior treatment for infection. The mean age at the time of reimplantation was 66 years, 38% of the patients were female, and the mean body mass index (BMI) was 30 kg/m2. The diagnosis of PJI was based on the 2011 Musculoskeletal Infection Society criteria. A competing-risk model accounting for death was utilized. The mean duration of follow-up was 8 years. RESULTS The cumulative incidence of reinfection was 7% at 1 year and 11% at 5 and 10 years. Factors predictive of reinfection included BMI ≥30 kg/m2 (hazard ratio [HR] = 2; p = 0.049) and the need for a spacer exchange (HR = 3.2; p = 0.006). The cumulative incidence of any revision was 13% at 5 and 10 years. The cumulative incidence of aseptic revision was 3% at 1 year, 7% at 5 years, and 8% at 10 years. Dislocation occurred in 33 hips (11% at 10 years); 15 (45%) required revision. Factors predictive of dislocation were female sex (HR = 2; p = 0.047) and BMI <30 kg/m2 (HR = 3; p = 0.02). The mean Harris hip score (HHS) improved from 54 to 75 at 10 years. CONCLUSIONS In this series of 331 two-stage exchange arthroplasties that were performed for the treatment of infection, we found a low rate of aseptic revision (8%) and a low rate of reinfection (11%) at 10 years. These long-term mechanical and infection data must be kept in mind when considering a paradigm shift to 1-stage exchanges. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.