Functional Outcomes of a New Mobile-Bearing Ultra-Congruent TKA System: Comparison With the Posterior Stabilized System

Abstract We determined whether a new mobile-bearing ultra-congruent (UC) TKA system provides better functional outcomes than an established posterior-stabilized (PS) prosthesis. The functional outcomes (motion arc, AKS scores, WOMAC Index, and SForm-36 scores evaluated at 1 and 2 years postoperatively), satisfaction and incidences of adverse events were compared between the knees implanted with mobile-bearing UC prosthesis (n = 103) and the mobile-bearing PS prosthesis (n = 99). At 2 years, mobile-bearing UC TKAs showed similar functional outcomes and satisfaction, but smaller motion arc compared to mobile-bearing PS TKAs (126° vs. 131°). There were no differences in the incidence of adverse events. Mobile-bearing UC prosthesis can be considered a safe and viable alternative to the PS design, with an expectation of smaller postoperative maximum flexion.