Hi-Flexion and Gender-Specific Designs Fail to Provide Significant Increases in Range of Motion During Cruciate-Retaining Total Knee Arthroplasty

The effects of different femoral component designs on intraoperative range of motion were examined in 40 female patients during primary cruciate-retaining (CR) total knee arthroplasty. After complete bone resection and soft tissue balancing, standard CR, high-flexion, and gender-specific knee trials were sequentially inserted, and maximal flexion and extension under gravity were measured using a navigation system. Average maximal flexions were 134.3 degrees for standard CR knees, 136.2 degrees for high-flexion knees, and 136.4 degrees for gender-specific knees. No significant intergroup differences in intraoperative maximal flexion and extension were found (P > .05). High-flexion and gender-specific femoral designs were found to show subtle increases in intraoperative range of motion as compared with the standard design but no significant differences.