Isolated component revision increases all-cause failure risk in aseptic revision total knee arthroplastyIsolated Component Revision Linked to Higher Failure Rates in Knee Surgery

BACKGROUND: Aseptic loosening is a leading indication for revision total knee arthroplasty (rTKA). When one component remains well-fixed, surgeons may choose between isolated component revision (ICR) and full component revision (FCR), but the outcomes of these strategies remain uncertain. This systematic review and meta-analysis compared ICR with FCR in aseptic rTKA. METHODS: Comparative studies of adult patients undergoing aseptic rTKA with ICR vs. FCR were identified. Outcomes included all-cause and cause-specific revision failure, patient-reported outcome measures (PROMs), and range of motion (ROM). The risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions tool, and the certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation approach for statistically significant meta-analyses. Individual participant data (IPD) were reconstructed from Kaplan-Meier curves and pooled for time-to-event analyses to estimate hazard ratios (HRs). Aggregate data (AD) meta-analyses used random-effects models to calculate pooled odds ratios (ORs) and mean differences (MDs). RESULTS: Fifteen cohort studies (4,429 patients; 2,893 FCR, 1,536 ICR) were included. Reconstructed IPD from 5 studies (3,187 patients) showed a higher hazard of all cause revision failure after ICR compared with FCR (HR 1.51; 95% CI 1.28-1.78; p < 0.001). The AD meta-analysis of 13 studies showed a similar association (OR 1.58; 95% CI 1.21-2.07; p < 0.001; I2 = 33%). Cause-specific analyses were imprecise and crossed the null for aseptic loosening (OR 1.50; 95% CI 0.75-2.99), infection related failure (OR 0.90; 95% CI 0.41-1.96), and instability-related failure (OR 1.03; 95% CI 0.43-2.46). PROMs did not clearly differ between strategies. ICR was associated with greater postoperative ROM (MD 7.03°; 95% CI 0.21-13.85; p = 0.043). CONCLUSION: ICR in aseptic rTKA was associated with an increased overall all-cause revision failure rate compared with FCR. While ICR is associated with a higher all-cause revision failure rate, the choice between techniques remains subject to surgeon discretion and patient-specific factors. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.