Total trispherical wrist prosthesis

Claim 1

A total trispherical prosthetic wrist device comprising a ball-headed radial component of a biocompatible metal, a radial stem on the ball-headed radial component for affixing it to the intramedullary canal of the distal radius, a radial flange separating the ball head of the radial component from its stem, a ball-headed metacarpel component of a biocompatible metal, a pair of metacarpel stems on the metacarpel component for affixing it to a pair of metacarpel bones of the hand, a metacarpel flange means separating the metacarpel ball from the metacarpel stems, a polygonal ball-capturing member having a pair of spherical sockets disposed substantially 180° from each other, the ball-capturing member comprising a pair of biocompatible cutout plastic hemipolygonal blocks sharing the sockets between them, clamping means joining the hemipolygonal bolcks together whereby the ball heads are rotatably trapped in the sockets to provide a substantially stable wrist prosthesis with substantially wide range of movement, the clamping means comprising a pair of metal elongated rectangular shells having longer sides and shorter ends with the ball heads extending through the shorter ends, the clamping means substantially surrounding the hemipolygonal blocks whereby the shells are spacially compatible within the wrist area and provide a range of motion in excess of normal, and fastening means joining the metal shells together.