A femoral prosthesis has a stem part and a head part, in which the stem part has a body section for location in the femur of a patient and a neck section including a trunion or spigot. The head part has a bearing surface formed as part of a sphere and a reverse side. The bearing surface has a polar axis extending through a center of the sphere formed thereby. A bore is provided in the reverse side adapted to receive the spigot wherein the bore comprise a bore axis, and in which the bore axis is oblique to the polar axis.
