WITHDRAWN: Early Patellofemoral Function of Unilateral TKA with Medial Pivot Prostheses is Superior than with Conventional Posterior-Stabilized Prostheses

Abstract

PurposeThe purpose of this study was to provide a systematic evaluation of the patellofemoral joint design of Medial Pivot Prosthesis, which incorporates a variety of “Patella-friendly” design features, by comparing clinical and radiographic results with another prosthesis. MethodsEarly clinical and radiographic results of patients who underwent unilateral TKA with Medial Pivot Prosthesis (The study group, including 126 cases) and conventional Posterior-Stabilized Prosthesis (The control group) were retrospectively compared. Postoperative complications, including anterior knee pain, maltracking, patellar clunk or crepitus (PCC), were evaluated.ResultsThe postoperative Kujala score and its improvement from baseline in the study group (Group A) were significantly higher than those in the control group(Group B). The range of motion (ROM) in group A, including the improvement in ROM, was significantly inferior to group B. In the 90-degree Merchant view, the patellar tilt in group A was smaller than that in group B. Two cases of PCC and 3 cases of anterior knee pain were noted in group A, and 9 cases and 6 cases, respectively, were observed in group B. The incidence of PCC was significantly lower in group A. There were no significant between-group differences in the patella tilt angle at 30 or 60° or in the postoperative patellar translation at 30, 60 or 90°. No between-group difference in posterior condyles angle (PCA) was observed. The KSS scores and WOMAC scores between the two groups were similar.ConclusionThe medial pivot prosthesis could achieve satisfactory outcomes with superior patellofemoral performance attributed to its “patella-friendly” design characteristics compared to the conventional posterior-stabilized prosthesis.