A randomized, prospective study of primary total knee components designed for increased flexion.

Abstract

This prospective, randomized study reports early results for range of motion (ROM) after primary total knee arthroplasty. Group A received standard posterior-stabilized (PS) implants. Group B had PS implants designed for increased flexion. Average preoperative ROM was 2 degrees to 121 degrees for group A and 1.8 degrees to 122 degrees for group B. At 12-month follow-up, average ROM for group A was 0.6 degrees to 120 degrees as compared with 0.6 degrees to 133 degrees for group B (P < .05). Significantly more patients in group B flexed more than 135 degrees (P < .05). Furthermore, 12 patients (48%) in group A failed to return to preoperative ROM versus 2 patients (8%) in group B (P < .05). Although long-term follow-up is desirable, these early results support the use of PS implants designed for increased flexion.