Abstract
Single-radius (SR) prostheses and multiple-radii (MR) prostheses have different theoretical
advantages; however, few comparative studies have been reported. The aim of the study
was to compare mid-term clinical, radiological, and survival outcomes of SR and MR
posterior-stabilized prostheses in total knee arthroplasty (TKA). Two hundred consecutive
patients who underwent TKA between January 2012 and July 2013 were enrolled in the
SR group (100 patients) and an MR group (100 patients), with a minimum follow-up of
5 years. Functional, radiological, satisfaction, and survival rates were evaluated.
There was a significantly higher range of motion (ROM) in the SR group than in the
MR group (flexion, 123.65 ± 10.12 degrees vs. 115.52 ± 10.03 degrees, p < 0.001). Quadriceps strength (3.05 ± 0.43 vs. 2.68 ± 0.58 kg, p = 0.025) and chair test results (80 [93.02%] vs. 69 [83.13%], p = 0.027) were better in the SR group than in the MR group. The SR group also had
significantly less anterior knee pain (6 [6.98%] vs. 15 [18.07%], p < 0.05) and a better satisfaction rate than those in the MR group. No significant
differences were observed in clinical scale scores such as Hospital for Special Surgery
(HSS), Knee Society Score (KSS), and Short-Form 12 (SF-12), radiological results in
terms of component position and radiolucent lines. The Kaplan–Meier survival curve
estimates at 5 years were not significantly different (96.91% [95% confidence interval
[CI]: 93.5–99.5%] vs. 94.86% [95% CI: 90.6–98.6%], p = 0.4696). The SR prosthesis design was better than that of the MR in terms of ROM,
reduced anterior knee pain, contributions to better recovery of the extension mechanism,
and higher satisfaction rates. The SR had similar results in clinical scales such
as HSS, KSS, SF-12, radiological, or survival results to MR prostheses. More accurate
measurements and longer-term follow-up are required.
Keywords
total knee arthroplasty - single-radius - stability - anterior knee pain - mutiple-radii
