One-Year Infection Eradication and Clinical Outcomes After Completed Two-Stage Revision for Hip and Knee Periprosthetic Joint Infection: A Retrospective Cohort Study

Background Two-stage revision is an established treatment for hip and knee periprosthetic joint infection (PJI). Infection eradication is the primary goal, but reconstruction should also provide acceptable pain relief and function. This study evaluated infection eradication and clinical outcomes approximately one year after completed two-stage revision arthroplasty. Methodology This retrospective, single-center cohort study included adults who completed two-stage revision for hip or knee PJI between January 2019 and December 2024. The index date was second-stage reimplantation. Successful eradication required no persistent or recurrent PJI, no further surgery for infection, and no suppressive antimicrobial therapy for persistent infection at one year. Secondary outcomes were pain score, ambulatory status, and joint-specific range of motion (ROM). Outcomes were compared by eradication status using the Mann-Whitney U test and the Fisher-Freeman-Halton exact test. These comparisons were exploratory. Results Of the 50 patients who underwent second-stage reimplantation, 46 survived and had sufficient follow-up for inclusion in the one-year analysis (24 hip, 22 knee). Successful infection eradication was observed in 41 of these 46 assessed patients (89.1%; 95% confidence interval (CI) = 76.4%-96.4%). The median pain score was 2 (interquartile range (IQR) = 1-2), and 37 (80.4%) patients were independently ambulant at one year. Patients with successful eradication had lower pain scores than those with persistent or recurrent infection (median = 2, IQR = 1-2 vs median = 3, IQR = 2-3; p = 0.012). Ambulatory status also differed between groups (p = 0.002), with independent ambulation in 36 of 41 (87.8%) patients and one of five (20.0%) patients, respectively. No significant differences in hip or knee ROM were detected, although only five patients had persistent or recurrent infection. Conclusions Among the 46 assessed survivors after reimplantation, 41 (89.1%) met the one-year infection-eradication criteria. Successful eradication was associated with less pain and greater independent mobility, while joint-specific ROM differences did not reach statistical significance in the small comparison groups. Assessment of pain and ambulation alongside infection status may provide a more clinically meaningful measure of early recovery after septic revision.