Is Routine Patellar Resurfacing During Primary Total Knee Arthroplasty Associated With Increased Rates of Postoperative Peripatellar Injury?

Background Routine patellar resurfacing during primary total knee arthroplasty (TKA) is common in the United States. Complications to the peripatellar area and extensor mechanism following TKA are rare but catastrophic. The purpose of this study was to investigate the association between routine patellar resurfacing during primary TKA and rates of postoperative peripatellar injury requiring operative treatment. Methods This was a retrospective, single, high-volume practice cohort study of 3383 consecutive primary TKAs between June 2023 and April 2025. Surgical data including surgeon, performance of routine patellar resurfacing, and type of peripatellar surgery performed were collected. Data analysis was analyzed using Fisher's exact test, and statistical significance was defined as a P value less than 0.05. Results There were 2508 knees in the resurfaced patella group and 875 knees in the non-resurfaced patella group. All peripatellar injuries (22) occurred in the patellar resurfaced group (0.88%; 95% confidence interval (CI), 0.55% to 1.33%). No patients underwent surgical treatment of patellar fracture. In the routine non-resurfaced group, 0 patients underwent peripatellar repair surgery (0%; 95% CI, 0% to 0.42%), corresponding to an absolute risk difference of 0.88 percentage points ( P value=.002). Firth regression produced an odds ratio of 15.85 (profile 95% CI, 2.20 to 2013.54; P = .0015). Conclusion In this retrospective single-practice cohort, operatively treated peripatellar injuries were observed only among resurfaced knees. Although a statistically significant association was identified, the absolute event rate was low. Longer-term data are required to determine the rates of overall revision between the 2 groups.