Long-term follow-up and survivorship of single-radius,posterior-stabilized total knee arthroplasty

Background

We sought to determine the 10-year survivorship of single-radius, posterior-stabilized total knee arthroplasty (TKA) in Asian patients. We also aimed to determine whether the long-term clinical and radiographic results differed between patients with and without patellar resurfacing.

Methods

This retrospective study included 148 (115 patients) consecutive single-radius, posterior-stabilized TKAs. Ten-year survivorship analysis was performed using the Kaplan–Meier method with additional surgery for any reason as the end-point. Furthermore, long-term clinical and radiographic results of 109 knees (74%; 84 patients) with more than 10-year follow-up were analyzed. Ten-year survivorship and long-term outcomes after surgery were determined, and outcomes were compared between patients with and without patellar resurfacing.

Results

The cumulative survival rate of the single-radius posterior-stabilized TKA of 148 knees was 97.7% (95% confidence interval, 93.1%–99.3%) at 10 years after surgery. Three knees required additional surgery during the 10-year follow-up because of one case of instability and two cases of periprosthetic infections. Mean postoperative Knee Society knee score and function score were 97 points and 75 points, respectively. There were no cases of aseptic loosening of the prosthesis, even though a non-progressive radiolucent line was found in 10 (9%) knees. There were no differences in postoperative scores and degree of patellar tilt and displacement between patients with and without patellar resurfacing.

Conclusions

Single-radius, posterior-stabilized TKA showed satisfactory long-term clinical and radiographic outcomes in Asian patients regardless of patellar resurfacing, with comparable survivorship to that reported in westerners.