Systematic effects of femoral component rotation and tibial slope on the medial and lateral tibiofemoral flexion gaps in total knee endoprostheses

ConclusionFor established surgical methods, we recommend a neutral femur rotation for a 0° tibial slope and a 3° external femur rotation for a tibial slope of 9–10°. The translational potential of this research shows that while the rotation of the femoral component in extension has no effect on the gap size, owing to the axis of rotation being perpendicular to the gap, for a 90° flexion, we not only observe differences in the gap size between the medial and lateral ​but also unequal differences on either side depending on the inward or outward rotation. The main reason for this is the position of the axis of rotation, which is not precisely half way between the lateral and medial contact points. The results show that rotation of the femoral component always creates an unbalanced flexion gap.

Source: Journal of Orthopaedic Translation - October 23, 2019 Category: Orthopaedics Source Type: research