The Knee · IF 1.6 · August 25, 2026 · LoE II
Functional outcomes of patient-specific instrumentation versus conventional instrumentation for unicompartmental knee replacement: A systematic review and meta-analysis
Valentin Rühle, Branavan Rudran, Brook Leung, Christian Merle, David Murray, Andrew Price, Abtin Alvand — Nuffield Orthopaedic Centre
This systematic review and meta-analysis compared patient-specific instrumentation (PSI) with conventional instrumentation (cUKA) in unicompartmental knee replacement, pooling 14 studies (1,680 knees, 1,670 patients: 5 RCTs and 9 retrospective comparisons). At 1-year follow-up, Oxford Knee Score was essentially the same between groups (mean difference 0.9, 95% CI -2.65 to 4.45, I2=0%), and secondary scores (KSS, KOOS) also showed no significant differences at 3 months or 1 year; revision rates were numerically higher with PSI (6% vs 2.3%) but too heterogeneous to pool statistically.
AI summary · from the full text · reviewed by Pukhraj Gaheer, Medical Student, Queen's University before publishing
Why it mattersPSI is being marketed as a way to improve component positioning and outcomes in UKA, so trainees should know the current pooled functional evidence does not support any advantage over standard instrumentation.
Conclusion strengthInconclusive
Two or more critical methodological failures for a review.
Presenting this at rounds? Start here
- ?If PSI does not improve patient-reported function at 1 year, should its added cost and preoperative imaging burden change how surgeons select instrumentation for UKA candidates?
- ?Given the higher (though unpooled) revision rate with PSI, particularly aseptic loosening, how should this influence counseling of patients considering UKA with custom guides versus conventional technique?