Investigations into the mechanical reliability of ceramic femoral heads for hip joints

This paper reports the findings of a finite element analysis applied to the study of ceramic femoral ball heads. The objective of carrying out these analyses was to assess the shape design and loading conditions applied to specific femoral heads and to capture the stress fields developed when they are subjected to idealized test conditions. Two designs were considered, these being the existing Biolox keyhole shape, manufactured by Cerasiv, Medical Products Division and an alternative design with a flat top internal hole. For each of these designs, three load cases and two types of frictional contact were considered. It is shown that the key hole shape with full taper contact conditions together with the higher value of surface friction produce the lowest tensile stress fields in the ball head hence increasing mechanical reliability.