FINITE ELEMENT ANALYSIS OF CUSTOMIZED KNEE IMPLANTS BY VARYING LOADS DURING FLEXION-EXTENSION MOVEMENT

A customized knee implant numerical modeling using finite element analysis (FEA) during flexion extension has been investigated in this paper with varying loads with an objective of studying its kinematics. Computed tomography (CT) images of 15 osteoarthritis subjects' images were used in this work. Various morphological characteristics were extracted from clinical images using a commercial CAE software and biomechanical properties were studied on applying standard loads on customized implant and off-the-shelf (OTS) implants. Patient-specific knee implants have been designed according to the morphological characteristics and bone dimension of patient with compressive loads (1500, 1700 and 3000 N) during normal gait and were compared with the normal knee. Results showed that the stresses are distributed equally to the spacer and the tibial plate, unlike the standard femoral component where the stresses get concentrated on the cut edges. In compressive load, active stress and strain (similar to 5-20 MPa) are lesser (similar to 5%) and in flexion extension also lesser with a scaling factor of 0.785 and 1.0. The designed implant was found to produce similar biomechanical properties when compared to normal knee joint and thus it can be considered as a valuable implant and could replace the standard OTS knee implants.