US Patent 9107754 Prosthetic joint assembly and prosthetic joint member

A prosthetic joint member includes: a generally concave cup with an outer surface that is bone-implantable, the cup including a first indexing feature; a concave insert disposed inside the cup, the insert comprising a rigid material and including a concave interior defining a nominal surface, the interior including a cantilevered flange defined by an undercut in the insert, the flange defining a wear-resistant first contact surface which protrudes inward relative to the nominal surface, the insert including a second indexing feature. The first and second indexing features engage each other so as to retain the insert in a fixed angular orientation relative to the cup.