THE WEAR EFFECT UPON THE STRESS FIELD OF UHMWPE ACETABULAR CUP

Andrei TUDOR¹

tudor@meca.omtr.pub.ro

Tiberiu LAURIAN¹

Felix PARVU¹

Mihai POPESCU²

¹ "Politehnica" University of Bucharest, Romania

² "Carol Davila" University of Medicine, Bucharest, Romania

Abstract. The longevity of total hip arthroplasties is significantly reduced by the wear of joint surfaces. Wear is proportional to contact pressure and sliding distance generated by the patient’s daily activity. While the sliding distance can be estimated using the variation of angles describing the hip kinematics, determining the pressure distribution proves to be difficult especially because the Hertz contact hypotheses are not valid in the case of ball-in-socket joints. By aid of a numerical method it was possible to find the behavior of hip joint prostheses having different radial clearances, in their turn caused by wear of acetabular cup.

Keywords: hip prosthesis, UHMWPE, pressure distribution, wear, friction torque