Planning of prosthetic ligament insertion in the knee

Prosthetic anterior cruciate ligaments (ACL) for the knee often suffer from pre-mature failure due to fatigue. Deformations of these ligaments are calculated as a function of their insertion orientation via a computer model. To help physically interpret these deformation values, the average flexion axis of the knee is calculated using a least-squares algorithm on experimental kinematic data. The results indicate that deformations in prosthetic ACL can be explained in terms of their femoral insertion orientation with respect to this average knee flexion axis.