Distal component for wrist prosthesis

A distal wrist component for a wrist prosthesis comprising:

• a fixation plate having first and second side bores and a middle bore, said first and second side bores having a spheric inner surface;
• a boss extending from a surface of said fixation plate and about said middle bore;
• a bushing disposed in said first and second side bores, each said bushing having a spheric outer diameter matching said spheric inner surface of said first and second side bores such that said bushings are articulateable within said first and second side bores;
• and
• a head received on said boss,
• wherein said fixation plate is ovoid.

A distal wrist component for a wrist prosthesis comprising:

• a fixation plate having first and second peripheral bores and a middle bore;
• a boss extending from a surface of said fixation plate and about said middle bore;
• a bushing disposed in said first and second peripheral bores, each said bushing having internal tapered threads adapted to receive a bone screw having an end with matching tapered thread such that when the bone screw is engaged in said bushing, said bushing is radially loaded to lock a trajectory of the bone screw at moments consistent with an amount of friction between said bushing and said fixation plate;
• and
• a head received on said boss,
• wherein said fixation plate is ovoid.

A wrist prosthesis, comprising:

• a support member having a first side bore, a second side bore, and a middle bore interposed therebetween, said support member further having a tapered boss;
• a first bushing positioned within said first side bore, said first bushing having a first set of internal threads that defines a first passageway;
• a first bone screw having a first externally threaded head that is configured to mate with said first set of internal threads of said first bushing;
• a second bushing located within said second side bore, said second bushing having a second set of internal threads that defines a second passageway;
• a second bone screw having a second externally threaded head that is configured to mate with said second set of internal threads of said second bushing;
• a head component having (i) a bearing surface, and (ii) a tapered recess configured to mate in a friction fit manner with said tapered boss of said support member.

A wrist prosthesis, comprising:

• a support member having a fastener bore and an anchor bore, said support member further having a tapered boss;
• a bushing positioned within said fastener bore, said bushing having a set of internal threads that defines a passageway;
• a bone fastener having a threaded head that is configured to mate with said set of internal threads of said bushing;
• and
• a head component having (i) a bearing surface, and (ii) a tapered recess configured to mate in a friction fat manner with said tapered boss of said support member.