초록 ▼

A total wrist prosthesis which has a metacarpal component and a radial component having ellipsoidal articulating surfaces. The metacarpal component and the radial component each have a fixation stem for insertion into the third metacarpal and the radius respectively. The fixation stem of the metacar

A total wrist prosthesis which has a metacarpal component and a radial component having ellipsoidal articulating surfaces. The metacarpal component and the radial component each have a fixation stem for insertion into the third metacarpal and the radius respectively. The fixation stem of the metacarpal component is curved dorsally to volarly so as to approximate the natural curvature of the third metacarpal and capitate of the human hand. The fixation stem of the metacarpal component has a center line which attaches to the head of the metacarpal component which contains the articulating surface dorsally from the minor axis of the ellipsoidal articulating surface. The fixation stem and the head of the metacarpal component have a plurality of wings attached thereto and a spur to prevent rotation of the device once inserted into the metacarpal. Also, the surface area of the metacarpal component proximal to the ellipsoidal articulating surface is coated with porous coating to aid in cement fixation. The radial component of the wrist prosthesis also has a fixation stem which is fixedly attached to a holder which receives a bearing member that defines a concave ellipsoidal articulating surface which is complimentary to the convex articulating surface of the metacarpal component. The center line of the fixation stem of the radial component is displaced dorsally from the minor axis of the concave articulating surface and also radially from the minor axis. A porous coating is also present about the base of the holder and the fixation stem. The curvature of the metacarpal fixation stem and the displacement of the center lines of both fixation stems relative to the minor axis of the ellipsoidal surfaces to which they are attached cause the center of rotation and flexion-extension motion and radial-ulnar-deviation to approximate the natural centers of rotation of flexion-extension motion and radial-ulnar-deviation.

대표청구항 ▼

A total wrist prosthesis for implantation with the third metacarpal and the radius to provide an artificial wrist joint, comprising: a first component having a head portion defining an ellipsoidal, convex articulating surface and further including a first fixation stem fixedly attached to the head p

A total wrist prosthesis for implantation with the third metacarpal and the radius to provide an artificial wrist joint, comprising: a first component having a head portion defining an ellipsoidal, convex articulating surface and further including a first fixation stem fixedly attached to the head portion; a second component having a receptacle portion defining an ellipsoidal, concave articulating surface and further including a second fixation stem fixedly attached to the receptacle portion, said ellipsoidal, concave articulating surface being shaped complementary to the ellipsoidal, convex articulating surface of said first component; first fixation means for affixing the first fixation stem to one of the third metacarpal and the radius; and, second fixation means for affixing the second fixation stem to the other of the third metacarpal and the radius; the convex articulating surface of said first component being received adjacent the concave articulating surface of said second component when either said first fixation stem or said second fixation stem is received in the third metacarpal and the other of said first fixation stem or said second fixation stem is received in the radius.