Simulation of Three Dimentional Motion of the Knee Joint in Total Knee Arthroplasty

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty to yield adequate knee function. Ideally, the knee joint with total knee arthroplasy is expected to restore the characteristics of the normal joint kinematics, however, this is not necessarily true in the clinical cases. In this study, the motion of the intact knee joint and the knee joint after total knee arthroplasty (TKA) was investigated numerically using computer simulation. With the analysis of active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension and it showed only rotation at other flexion angle. Physiologic external rotation of the tibia near full extension known as screw home movement was also noted in the analytical model. Analysis with three different shapes of the tibial insert (flat type, semicurved type, curved type) demonstrated characteristic rotational and sliding motion as well as different contact forces.