Condylar Lift Off in Fixed and Mobile Bearing Total Knee Arthroplasty

ABSTRACT

PURPOSE: To compare the performance of a total knee arthroplasty with either a PFC Sigma fixed bearing or a rotating platform in the same patient. MATERIALS AND METHODS: 48 cases (24 patients) that received a PFC Sigma fixed bearing and a rotating platform in both knees, one in each knee. The knee score, functional score, activity level, radiologic analyses through fluoroscope , varus/valgus stress, and subjective satisfaction evaluation were performed at the last follow up in the same patient. RESULTS: There were no significant differences in the knee score, functional score, activity level, radiological findings through fluoroscope, and subjective satisfaction. In the varus/valgus stress views, 3 cases of lateral femoral condylar lift-off were observed in the fixed bearing type and 6 cases of lateral femoral condylar lift-off were observed in the rotating platform type. CONCLUSION: In cases of total knee arthroplasty with PFC Sigma fixed bearing and with rotating platform performed in the same patient, there were no significant differences in the clinical, radiological and subjective satisfaction. However, it is considered that the fixed bearing is more stable in terms of medial and lateral femoral condylar lift-off with varus and valgus stress than rotating platform. Therefore long term follow-up would be necessary.