Six degree of freedom calculation based on principal component analysis for the knee joint in MDCT image

The anterior cruciate ligament (ACL) injury can cause a reason of instability along anterior posterior translation at extension. Thus, it is important to examine the knee joint quantitatively for understanding clinical outcome. However, an quantitative calculation method of the knee joint has not been reported. Therefore, we have developed six degree of freedom (6 DOF) calculation based on principal component analysis (PCA) for the knee joint in multi-detecter row computer tomography (MDCT) image. The proposal method was applied to six ACL injured knees obtained at two periods. As a result, the proposed methods could calculated 6 DOF of the knee joint quantitatively.