Fixed-bearing Research Articles

Moderate to Severe Varus Deformity in Total Knee Arthroplasty: PFC Sigma Fixed Bearing Versus Rotating Platform

Purpose: To compare the performance of a fixed bearing with a PFC Sigma with that of a rotating platform in a total knee arthroplasty performed on patients with a moderate to severe varus deformity. Materials and Methods: Among the patients who had received a total knee arthroplasty with either a PFC sigma fixed bearing or a rotating platform between October 1998 to June 2002, 77 cases (53 patients) with a > varus deformity were examined. The surgery time and the clinical ratings and the radiographic images for each patient were investigated. Results: There were no significant differences in the knee score, functional score, activity level, or radiological findings. There were seven cases where friction sounds were produced from the insertions in the rotating platform whilst walking and there were three cases of lateral instability. Conclusion: The PFC sigma fixed bearing was more effective for stabilizing the knees with a moderate to severe varus deformity because the rotating platform had a friction sound from the insertions while walking and lateral instability.

Mobile- vs. fixed-bearing total knee arthroplasty: a clinical and radiologic study

A consecutive series of patients undergoing total knee arthroplasty (TKA) using either a mobile-bearing (MB) or a fixed-bearing (FB) implant were studied. Forty-four patients received 57 MB rotating platforms, and 40 patients received 45 FB posterior stabilized implants. At an average 41-month follow-up (range, 2–6 years), no significant differences were found between the groups with respect to Knee Society ratings or pain scores. Postoperative flexion was not different between the groups (116° for MB and 118° for FB). Three MB knees were revised for implant-related complications. There was no difference between these MB or FB knee implants clinically or radiographically at early follow-up. However, more patients with a MB knee required early revision for failure of rotating patellar or tibial polyethylene implants.