Does Patellar Resurfacing Impact Patient-Perceived Outcomes Following Primary Total Knee Arthroplasty? A Propensity-Matched Analysis.

BACKGROUND: Patellar resurfacing is performed in up to 87% of total knee arthroplasties (TKAs) in the United States. While reducing anterior knee pain is a theoretical benefit, there are no established best practices for resurfacing in primary TKA. Previous studies comparing resurfacing-related patient-reported outcome measures (PROMs) were limited by sample size and a lack of propensity matching. This study aimed to compare the impact of patellar resurfacing on complication rates and clinically meaningful PROMs in propensity-matched primary TKA patients using an institutional database.

METHODS: A total of 5,197 consecutive patients who underwent TKA were categorized based on patellar resurfacing. A 1:2 match by age, body mass index, sex, race, comorbidities, and implants was conducted. Commonly used PROMs were extracted. The mean PROM scores were recorded for each cohort. Differences between the mean preoperative and postoperative scores (delta scores) were calculated. The distribution-based minimal clinically important difference values were computed. Postoperative complication rates and proportions of clinical improvement, no change, and worsening were recorded. Of the eligible patients, 1,176 resurfaced patients were matched to 588 non-resurfaced patients. There were no demographic differences between matched groups (P > 0.05).

RESULTS: Preoperative Patient-Reported Outcomes Measurement Information System Global Health Physical (42.6 versus 41.8, P = 0.0414) and postoperative Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (73.2 versus 71.2, P = 0.0299) was significantly higher in the nonresurfaced group. All other absolute scores, delta scores, and proportions of clinically meaningful improvement were similar across PROMs (P > 0.05). Complication rates were also comparable between groups (P > 0.05).

CONCLUSIONS: This is one of the first studies to compare clinically meaningful PROMs in propensity-matched patellar resurfaced and non-resurfaced TKA patients. There were no differences in complication rates or PROMs, which suggests that patients achieve similar outcomes with modern implants regardless of patellar resurfacing.