Femoral prosthesis head

A prosthetic head for a titanium femoral component comprising:

• a hollow titanium shell with a cavity, the shell having a part-spherical outer surface defining an inner hollow portion terminating in an open end;
• a polymeric material filling the inner hollow portion of the shell extending from an inner surface of the shell to the open end, the polymeric material including a conically tapered recess centered about the polar axis intermediate ends of the open end, the wider portion of the recess open to the open end of the shell;
• wherein the conically tapered recess having an inner conically tapered surface with an average surface roughness (Ra) of 1.3 μm;
• wherein the shell inner surface has at least one rib extending generally perpendicular to the inner surface of the hollow titanium shell;
• wherein the at least one rib includes an inner flange extending perpendicular to the rib;
• and
• wherein the at least one rib extends around the inner surface of the shell in a longitudinal or latitudinal direction.