초록 ▼

A prosthetic wrist joint for anchoring into the radius and the metacarpals includes a radial component, a metacarpal component and an intermediate component. The radial component has a part-cylindrical bearing surface and a stem portion for insertion into the end of the radius bone. The metacarpal c

A prosthetic wrist joint for anchoring into the radius and the metacarpals includes a radial component, a metacarpal component and an intermediate component. The radial component has a part-cylindrical bearing surface and a stem portion for insertion into the end of the radius bone. The metacarpal component has a ball-like hinge portion and a pair of outwardly protruding prongs for anchoring into the second metacarpal and the third metacarpal. The intermediate component includes a cylindrical bearing surface which cooperatively engages the part-cylindrical bearing surface of the radial component, and a socket-like recess for receiving the ball-like hinge portion of the metacarpal component for movement in the direction of radial-ulnar deviation. The modified ball and socket arrangement between the metacarpal component and the intermediate component permit limited rotational movement about the longitudinal axis of the arm. The three components are arranged such as to have a full range of motion wherein wrist motion is limited solely by the surrounding soft tissue rather than by the wrist prosthesis components. The calculated rotational motion has an axis which is coincident with the anatomical center of rotation of the wrist rather than being centered about the stem axis of the prosthesis. The intermediate component is arranged relative to the radial component such that when the prosthetic wrist joint is loaded beyond its capacity in one of the various motion planes, the intermediate component will dislocate rather than break or loosen.

대표청구항 ▼

A prosthetic wrist joint comprising: a radial component having a part-cylindrical bearing surface and means for anchoring into the end of a radius bone; a metacarpal component having a ball-like hinge member adjacent one end and means adjacent the other end for anchoring into metacarpals; and an int

A prosthetic wrist joint comprising: a radial component having a part-cylindrical bearing surface and means for anchoring into the end of a radius bone; a metacarpal component having a ball-like hinge member adjacent one end and means adjacent the other end for anchoring into metacarpals; and an intermediate component positioned between said radial component and said metacarpal component and having a part-cylindrical bearing surface cooperatively engaging the bearing surface of said radial component for solely flexion and extension hinged movement and a socket-like recess receiving said ball-like hinge member for movement in the direction of radial-ulnar deviation, said socket-like recess being suitably sized and arranged relative to said ball-like hinge member so as to permit limited rotational movement of said metacarpal component relative to said radial component about an axis substantially parallel with the longitudinal axis of the forearm, the angular rotational movement between extremes being less than 30 degrees, in which said intermediate component further includes a pair of oppositely disposed, part-circular end flanges and said radial component having a corresponding pair of oppositely disposed shoulder portions adjacent said bearing surface, said end flanges being received by said shoulder portions for preventing the prosthetic wrist joint from subluxing in the medial-lateral plane.