リビジョン関節形成術後の周術期感染および長期死亡率のリスク層別化における免疫抑制状態の評価

The prognostic significance of immunosuppression in revision arthroplasty has not been well established: (1) Is preoperative immunosuppressive status associated with increased risk of periprosthetic joint infection (PJI) and long-term mortality after revision arthroplasty? (2) Does the severity of immunosuppression correlate with a dose-dependent increase in adverse outcomes?

A total of 1218 patients who underwent initial hip or knee revision arthroplasty between 2008 and 2024 were retrospectively analyzed. Immunosuppression was graded as none, mild, moderate, or severe based on clinical diagnosis and immunosuppressive therapy. The primary outcome was PJI requiring re-revision; the secondary outcome was all-cause mortality. Multivariable logistic and Cox regression models were used to evaluate independent associations, and 1:1 propensity score matching was performed to adjust for confounders.

Immunosuppressed patients (15.1%) exhibited significantly higher rates of PJI (8.70% vs. 2.61%) and mortality (10.87% vs. 5.80%) compared to non-immunosuppressed patients (both P < 0.01). Immunosuppression was independently associated with increased risk of PJI (adjusted OR = 3.27; 95% CI: 1.43-7.49; P = 0.005) and mortality (adjusted HR = 1.76; 95% CI: 1.02-3.01; P = 0.041). A stepwise increase in adverse outcomes was observed with advancing immunosuppression grade. Findings remained robust after propensity score adjustment.

Preoperative immunosuppression is a strong, independent predictor of periprosthetic joint infection and long-term mortality in revision arthroplasty patients. Graded immunosuppression assessment may serve as a valuable tool for perioperative risk stratification and individualized clinical decision-making.

Level III, prognostic study.