The simulation for study of von Mises stress sensitiveness to the change of coronal conformity in knee prosthesis

National Kaohsiung University of Applied Sciences, Mechanical Engineering Department, 80778 Kaohsiung, Taiwan, R.O.C.

Abstract

Two-dimensional finite element contact modelling is often conducted to simulate the contact mechanism in knee prosthesis. This is based on the assumption that the contact stresses are more sensitive to change in the coronal plane than in the sagittal plane. Therefore, the simulation is then can be simply conducted only in the coronal plane with neglecting the sagittal dimension. Thus, the model is only a two-dimensional model. Based on this issue, the investigation of the response of contact stress (von Mises) to the coronal and sagittal conformity variation was conducted. For the need of investigation, ten three-dimensional finite element models of knee prosthesis have been created. From the result, the gradient of von Mises stress when the conformity varied in the coronal plane was -12.015, and when the conformity was varied in the sagittal plane, the gradient was −9.774. This meant that the von Mises stress had high sensitiveness to the change of the coronal conformity variation of knee prosthesis than to the change of the sagittal conformity. Therefore, the contact modelling of knee prosthesis can be simply carried out in the coronal plane.