Improvements in or relating to ceramic femoral resurfacing head prosthesis

A ceramic femoral resurfacing head prosthesis 110 comprising a convex outer surface 112 engageable with an acetabulum of a patient or an acetabular cup prosthesis, and a concave inner surface 114, the outer surface 112 and inner surface 114 extending to interest each other at a rim 116 which is preferably at least substantially planar. A ceramic stem also 120 projects from the inner surface 114, with a free distal end of the stem 126 being located at, or spaced inwardly of, a plane defined by the prosthesis' rim 116. The stem may be provided with a base 122 comprising at least a two-part angular transition 138 in a longitudinal direction of the stem 120 (Fig 9). The inner surface 114 may additionally comprise at least one circumferentially elongate recesses (136, Fig 11). The rim 160 may define an asymmetrical profile between the prosthetics' inner 114 and outer 112 surfaces, the rim having two or more different arcs 148, 150 having a radius (R5, R6, Fig 14) of 0.2-1.5mm.