Tibiofemoral movement 3: Full flexion in the living knee studied by MRI

Abstract

We studied active flexion from 90°to 133°and passive flexion to 162°using MRI in 20 unloaded knees in Japanese subjects. Flexion over this arc is accompanied by backward movement of the medial femoral condyle of 4.0 mm and by backward movement laterally of 15 mm, i.e., by internal rotation of the tibia. At 162°the lateral femoral condyle lies posterior to the tibia.