Patent ID: 8034116

Claim:
A prosthetic implant for implantation into a resected bone, which implant comprises: a metal stem element which has a connector at one end that is shaped with a reentrant region of reduced dimension, an integral one-piece polymeric insert which has a central cavity that receives said connector, a head formed of brittle crystalline material having a central cavity being proportioned to receive said insert, said head having a concave articular surface which will interface with the patient's native bones said head cavity having an entrance of a size such that at least a portion of said polymeric insert must elastically deform inward to enter said cavity, said insert being formed with means for interengaging with said connector which requires radially outward deformation of at least a portion of said insert to lock said insert and said connector in engagement, and means providing a circumferential relief region into which said portion of said polymeric insert can elastically deform to facilitate final assembly, said integral polymeric insert being made of polymeric material having an elasticity, such that (a) it can deform radially inward sufficient to facilitate its entry into said head cavity and then return to shape, (b) it can deform radially outward to facilitate assembly with said connector and then return to shape, and (c) once assembled with both said head and said stem connector, disassembly cannot inadvertently occur.