A 3-D NON-LINEAR FINITE ELEMENT ANALYSIS ON THE TIBIAL COMPONENT IN THE TRICON KNEE SYSTEM

摘要

A fully three-dimensional non-linear finite element analysis was performed on the Tricon(tm) knee system to investigate the differences in stress strain behavior between tibial inserts with and without a cruciate gap. The tibial inserts were loaded with a femoral component at 90-degree flexion with excessive roll back of the femur on the tibia plus 5-degree external rotation of the tibial component on the femur. The FE results revealed that contact stresses in the tibial insert with no cruciate gap were approximately 10 to 15 percent higher than those reported for the tibial insert with a cruciate gap. In contrast, the strains in the plane of the inserts were significantly greater in the tibial insert with a cruciate gap when compared to the tibial insert without the gap. Based on retrieval findings [1] there was more polyethylene wear in the tibial insert with a cruciate gap; despite lower contact, stresses. It is believed that the free boundaries created by the gap allow cold flow to take place near the free edges, thus generating significant damage close to or at the free boundary of the insert.