Patellar resurfacing in primary total knee arthroplasty is associated with fewer reoperations but comparable clinical and functional outcomes: an umbrella review of meta-analyses.

Abstract

Background: Patellar management in primary total knee arthroplasty (TKA) remains controversial despite numerous clinical trials and meta-analyses. While patellar resurfacing has been advocated to reduce anterior knee pain (AKP) and reoperation rates, reported effects on functional outcomes are inconsistent. This umbrella review synthesised and critically appraised published meta-analyses comparing patellar resurfacing and patellar retention in primary TKA, with a focus on anterior knee pain, reoperation rates, and patient-reported outcome measures (PROMs).

Methods: An umbrella review of meta-analyses was conducted in accordance with 2020 PRISMA guidelines. Meta-analyses comparing patellar resurfacing with patellar retention in primary TKA were eligible. Outcomes of interest were AKP, reoperation rates, knee range of motion, and PROMs. Quantitative synthesis was performed at the meta-analysis level using random-effects models, with heterogeneity assessed using the I² statistic and robustness evaluated through prediction intervals.

Results: Fourteen meta-analyses published between 2011 and 2025 were included. When AKP was analysed using odds ratios (OR), no significant association with patellar resurfacing was observed (OR 1.13, 95% CI 0.71-1.82; I² 88%). In contrast, relative risk (RR)-based analyses demonstrated a significantly reduced risk of AKP with resurfacing (RR 0.75, 95% CI 0.65-0.86; I² 0%). OR-based analyses showed no significant difference (OR 1.44, 95% CI 0.54-3.84; I² 94%), whereas relative risk-based analyses indicated a significantly lower reoperation risk with patellar resurfacing (RR 0.59, 95% CI 0.52-0.67; I² 51%). Functional outcomes showed no clinically relevant differences. Knee Function Score did not differ between groups (MD 0.63, 95% CI -0.42 to 1.68), while Knee Society Score showed a small statistically significant difference (MD 0.92, 95% CI 0.34-1.50) that was not consistently reproducible. No significant differences in postoperative ROM were observed.

Conclusions: Patellar resurfacing in primary TKA reduces the risk of reoperation but does not confer clinically meaningful benefits in PROMs and shows only limited and inconsistent effects on AKP.