Finite Element Analysis and Mechanical Assessment for the Constraint of Total Knee Replacement

The constraint level of TKR is essential for ensuring product performance to prevent knee joint dislocation. Computer modeling and simulation (CM&S) technology is widely used in the medical device industry due to its advantages such as reducing testing time and costs. However, there is a lack of research on the constraint level of TKR according to the size and flexion angle of the femoral component. In this study, the constraint levels of AP draw, ML shear, and rotary laxity were tested according to the size and flexion angle of TKR products using finite element analysis. A TKR model was constructed using a 3D scanner, and a finite element model with mechanical testing and error rates of 2.49% and 3.00% was developed through AP draw testing. In AP draw, as the size of TKR decreases, the constraint level increases by about 3.6%, and rotary laxity also increases by about 1.3%. In all tests, the constraint level increased as the bending angle of the femoral component increased. We found that the curvature and contact area of a TKR influenced the constraint level. Through this study, it is believed that CM&S technolaogy can be widely used in evaluating the unique performance of medical devices.