Stress Analyses of the Hip Joint Endoprosthesis Ceramic Head with Different Shapes of the Cone Opening

Abstract

During the analysis of the fracture surfaces of the destructed hip joint endoprosthesis ceramics heads it was detected that the shape (size and the position) of the cone end in the bottom of the cone opening were very different. The paper presents the influence of five typical shapes of the cone end on the stress in the ceramic head. The computational modelling is realized for two outer diameters of the ceramic head - 28 mm and 32 mm and three depths of it's cone. The system FEM - ANSYS was used for computational modelling of the stress and deformation of analyzed system (testing stem and ceramic head). Loading of the analyzed system is according to norm ISO 7206-5. There are assumed shape deviations of the cone surfaces-interaction of the ovality and different degree of taper of the stem and the head cone. © 2009 International Federation of Medical and Biological Engineering.