An implant for use on a joint- facing end of a bone includes a cap having convex outer surface overlying a concave inner surface and a stem protruding from the inner surface such that an edge of the cap surrounds the stem and overhangs a portion of the stem leading up to the inner surface. The stem may further include a plurality of raised ridges parallel to its length that begin near a tip of the stem and extend onto the portion of the stem overhung by the edge.
