A prosthetic head for a femoral component has a metal shell with a tapered cavity. The shell has a part-spherical outer surface defining an inner portion terminating in an open end. A polymeric material completely fills the inner portion of the hollow shell extending from an inner surface of the shell to the open end. The polymeric material includes a conically tapered socket centered about the polar axis intermediate ends of the open end wherein the shell is a hollow titanium shell having an inner surface with a porous structure for receiving a portion of the polymeric material. The hollow titanium shell inner surface has at least one rib extending inwardly toward the conically tapered socket.