Ceramic femur head for artificial joint

Abstract

A ceramic femur head is nearly spherical and has a planar end surface. The femur head has a diametric, tapered hole which extends from the planar surface in a way as to taper toward an inner end thereof and in which a correspondingly tapered stem portion of a metallic stem is fitted. The inner peripheral surface of the tapered hole of the ceramic femur head is ground so as to have the same degree of surface finish as that of an outer peripheral surface of the tapered stem portion. For example, in case the outer peripheral surface of the tapered stem portion of the metallic stem is finished to have a surface roughness in the range from 0.1 to 0.6 μm Ra, the surface roughness of the inner peripheral surface of the tapered hole of the ceramic femur head is set to be in the range from 0.1 to 0.6 μm Ra.

Dependencies are inferred from the claim text.