The Design of the Patellar Component Does Not Affect the Patient-Reported Outcome Measures in Primary Posterior-Stabilized Total Knee Arthroplasty: A Randomized Prospective Study

Abstract

This randomized comparative study was conducted to investigate the outcomes of patellar resurfacing with a medialized dome or an anatomical type in patients receiving primary unilateral posterior-stabilized TKA. Between March 2019 and January 2021, 98 knees were randomly assigned to receive patellar resurfacing by a medialized dome type (group D, 49 knees) or an anatomic type (group A, 49 knees). The primary outcome was the Knee Injury and Osteoarthritis Outcome Score. The secondary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index, Feller’s patella score, the Kujala anterior knee pain score, knee joint range of motion (ROM), and postoperative complications, including periprosthetic patellar fracture, patellar tilt angle, and lateral patellar shift. Patient-reported outcomes were not significantly different between the two groups. The ROM of the knee joint was significantly better in group A at six months after surgery (p = 0.021). No complications such as patellar fractures were observed. The anatomic type of patellar component showed a significant improvement of the patellar tilt angle after surgery compared with the medialized dome type of component. However, there were no significant differences in patient-reported clinical outcomes between the two groups during the follow-up period of 12 months.