Patent ID: 8002838

Claim:
A prosthesis assembly, comprising: a stem configured to be implanted in a bone, the stem including a first coupling portion; a head having a bearing surface configured to mate with at least one of a natural opposing joint component and a prosthetic opposing joint component, the head further having a second coupling portion; a coupler including a third coupling portion and a fourth coupling portion, the third coupling portion configured to couple with the second coupling portion; and an insert including (i) a fifth coupling portion configured to couple with the fourth coupling portion so that the insert may assume any one of a plurality of orientations with respect to the coupler, and (ii) a sixth coupling portion configured to couple with the first coupling portion only when the insert assumes a predetermined orientation with respect to the stem, wherein the first coupling portion comprises a stem receptacle extending inwardly from a proximal end which opens to a surface of the stem, to a closed distal end, the first coupling portion including a first key member and a tapered wall structure between the proximal end and the distal end; wherein the fourth coupling portion comprises a bulbous portion; wherein the fifth coupling portion comprises a first insert receptacle extending inwardly from a distal end which opens to a surface of the insert, to a closed proximal end, the first insert receptacle including a tapered wall structure between the proximal end and the distal end; wherein the sixth coupling portion comprises a tapered wall structure and a second key member configured to mate with the first key member, wherein (i) the stem receptacle is defined by a receptacle structure, (ii) a distal end portion of the receptacle structure includes a distal interior surface, and (i) the distal interior surface of the receptacle structure defines the first key member, and wherein (i) a distal end portion of the insert includes a distal exterior surface, and (ii) the distal exterior surface of the insert defines the second key member.