Retrospective Analysis of Factors Influencing Clinical Outcomes of Revision Surgery for Periprosthetic Infection After Unicondylar Knee Arthroplasty.

Objective: To identify factors influencing clinical outcomes of revision surgery for periprosthetic joint infection (PJI) after unicondylar knee arthroplasty (UKA).

Methods: This retrospective study included 40 patients who underwent UKA revision for PJI (May 2009-May 2023). Patients were divided into responders (n=27, favorable outcomes: no infection, KSS ≥80, HSS ≥85 at 6 months) and non-responders (n=13, suboptimal outcomes: persistent infection or KSS <80/HSS <85). Inflammatory markers (CRP, WBC), Knee Society Score (KSS), and Hospital for Special Surgery (HSS) score were assessed. Multivariate logistic regression identified predictors of success.

Results: Non-responders had higher rates of diabetes (46.2% vs 14.8%), smoking (30.8% vs 18.5%), alcohol use (23.1% vs 14.8%), Gram-positive infections (30.8% vs 11.1%), and deep infections (84.6% vs 22.2%, all P<0.05). Key predictors of success included optimal antibiotic management (OR=1.33, 95% CI=1.02-1.74), patient compliance (OR=1.44, 95% CI=1.08-1.92), and absence of diabetes (OR=1.54, 95% CI=1.24-1.98), smoking (OR=1.60, 95% CI=1.08-2.37), or Gram-positive infections (OR=1.46, 95% CI=1.12-1.90, all P<0.05).

Conclusion: Diabetes, smoking, alcohol use, Gram-positive infections, deep infection, antibiotic management, and compliance significantly impact UKA revision outcomes. Smoking showed the strongest association (OR=1.60). Clinicians should prioritize preoperative optimization (glycemic control, smoking cessation) and protocol-driven antibiotic use. Findings are exploratory due to small sample size and require validation in larger cohorts.