Numerical three-dimensional contact model for total knee joint replacement
Résumé
A three dimensional linear elastic contact model for total knee joint replacements is developed. Metallic femoral and tibial parts are respectively represented as a contacting rigid ellipsoid and a UHMWPE layer on substrate. The coating finite thickness is similar or less than the contact half width. Different interfacial boundary conditions can be considered between layer and the underlying tibial tray substrate: a perfect bonding, an imperfect bonding or a slip condition. This model is based on linear elasticity theory, integral transforms, Fast Fourier techniques and unilateral contact analysis with friction. After solving for normal and tangential pressure distributions, contact area, stick and slip zone repartition within the former, UHMWPE stress field is calculated. The influences of the layer finite thickness and the boundary conditions between layer and substrate have been investigated on pressure distributions and stress field during a typical walk cycle.