No difference in revision rate in patella-friendly total knee arthroplasty with or without patella resurfacing at 5 years' follow-up. A database analysis.

Abstract

Numerous studies have been published on the optimal management of the patella during total knee arthroplasty (TKA), but controversy remains. The aim of this study was to compare survivorship and functional outcomes with or without patella resurfacing, using a single TKA implant. This retrospective database analysis included 6078 TKA of the same cruciate-sacrificing, mobile-bearing, 'patella-friendly' model implanted between March 2002 and December 2018 for primary osteoarthritis. TKAs implanted for inflammatory arthritis or bone tumour were excluded. The implant's survivorship was estimated at 5 years' follow-up using the Kaplan-Meier method. Functional assessments consisted of the KSS score and knee flexion. The 1641 patients who had at least 5 years' follow-up were separated into two groups: patella resurfacing (PR) (<i>n</i> = 656) and no patella resurfacing (NPR) (<i>n</i> = 985). Mean age was 69.8 years [25-96] and mean follow-up time was 98.4 months [60-247]. There was no difference in survivorship without reoperation between the two groups (98.4% [95% confidence interval [CI] 97.8-99] vs. 98.4% [95% CI 97.6-99.1; <i>p</i> = 0.95), nor in the mean KSS score (181.7 [95% CI 158.35-205.0] vs. 179.9 [95% CI 156.5-203.2]; <i>p</i> = 0.51). Survival free of patella-related revisions was 99.3% [95% CI 98.9-99.7] in the NPR group versus 99.7% [99.3-100.0] in the PR group (<i>p</i> = 0.02). Mean knee flexion was significantly less in the NPR group than in the PR group (116.1° [95% CI 104.5-127.8] vs. 118.8° [95% CI 106.7-131.0]; <i>p</i> = 0.03). Systematic patella resurfacing when doing TKA using the SCORE™ implant does not reduce the overall revision rate and does not improve functional scores. When only the revisions for patella-related complications are considered, the revision rate is lower in the NPR group. Knee flexion is better in patients who underwent patellar resurfacing, but this difference did not reach the clinically relevant threshold. Level III, retrospective cohort study.