FINITE ELEMENT ANALYSIS of TOTAL KNEE REPLACEMENT with VARIOUS MISALIGNMENT ANGLES in the SAGITTAL PLANE

Custom-made prosthetic replacement is a common method of limb reconstruction after surgery of bone tumors. A custom-made tumor knee prosthesis was retrieved after fracture of the tibial stem. The fracture of stem was considered to be associated with some misalignment between the axis of femur and that of the femoral stem, which might cause stress concentration within the tibial component and eventually lead to fracture. To verify this hypothesis, finite element analysis was carried out to study the effect of various tilting degree (6° forward, 0° and 6° backward) of the stem in the sagittal plane on the stress distribution within the tibial component. The calculated maximum Von Mises stress in the tibial component was 225.8, 362.8 and 511.3MPa when the femoral component was tilted for 6° forward, 0° and 6° backward, respectively. The results demonstrated that the misalignment of femoral components in the sagittal plane has marked effect on the stress distribution of the tibial component.