Comparison of Midterm Clinical and Radiographic Results Between Total Knee Arthroplasties Using Medial Pivot and Posterior-Stabilized Prosthesis-A Matched Pair Analysis

Background: Despite the theoretical advantage of a knee design that can more reliably replicate the medial pivot (MP) of the natural knee, only a few clinical studies have compared the clinical results between the MP prosthesis and another design of prosthesis. We compared the midterm results of total knee arthroplasty (TKA) using an MP prosthesis vs a posterior-stabilized prosthesis via a matched-pair analysis; we included results related to patellofemoral joint symptoms. Methods: The midterm clinical and radiographic results of 125 consecutive patients (150 knees) who underwent a TKA with the ADVANCE MP prosthesis were compared with those of a control group who had undergone a primary TKA with a posterior-stabilized prosthesis. Results: Values of the Knee Society's Knee Scoring System, Western Ontario and McMaster Universities Osteoarthritis Index, and Kujala and Feller scoring systems, as well as the range of motion after TKA, did not significantly differ between the 2 groups. No differences in femorotibial angle and component position, including the patella component, were observed between the 2 groups. No significant differences in the change of patella tilt angle and the postoperative patellar translation were observed between the 2 groups. Conclusion: Patients with the MP prosthesis experienced satisfactory pain relief and a functional recovery, providing results similar to those of the posterior stabilized prosthesis, including the resolution of patellofemoral joint symptoms.