Outcomes of Surgical Strategies for Prosthetic Joint Infection Following Unicompartmental Knee Arthroplasty: A 2-Year Follow-up.

BACKGROUND: There are limited guidelines on the standard surgical management of unicompartmental prosthetic joint infection (uPJI). The purpose of this study was to review the infection control and functional recovery of a standardized institutional treatment protocol, which included debridement, antibiotics, and implant retention (DAIR) and revision, to provide insights into the proper management of uPJI. METHODS: Twenty-seven patients (28 knees) diagnosed with uPJI according to the Musculoskeletal Infection Society (MSIS) criteria from 2017 to 2023 were analyzed. Patients with acute or hematogenous uPJI underwent DAIR, whereas chronic infections were managed with revision strategies according to an institutional protocol; these cohorts represent different infection chronicity categories and were not intended for direct comparative effectiveness analysis. The follow-up ranged from 24 to 102 months. Demographic information, infection types, clinical outcomes, functional assessments, and culture results were recorded. RESULTS: Infection control, defined according to MSIS outcome reporting criteria within 1 year after the index surgery, was achieved in 89.3% of cases (25 / 28): 80% after DAIR (12 / 15) and 100% after revision (13 / 13). Chronic uPJI cases received 2-stage revision with a unicompartmental spacer (n = 10), 2-stage revision with a bicompartmental spacer (n = 1), or 1-stage total knee arthroplasty (TKA) (n = 2). Three failures required reoperation (2 DAIR and 1 two-stage revision with a unicompartmental spacer). Unicompartmental spacers were retained in 4 two-stage cases. At 2-year follow-up, range of motion, Hospital for Special Surgery scores, visual analog scale, and 12-item Short Form Health Survey all improved significantly in both the DAIR and the revision patients. CONCLUSIONS: DAIR is suitable for acute or hematogenous uPJI, whereas revision is suitable for chronic uPJI. One-stage revision to TKA and 2-stage revision with unicompartmental spacers may be appropriate in carefully selected patients.