Total prosthesis of the wrist

A total wrist prosthesis configured to replace the lunate and scaphoid bones and which is anchored between the radius bone and metacarpal bones of an individuals hand, the prosthesis having a radio-carpal articular level and a medio-carpal articular level, with said radio-carpal articular level having a first radio-ulnar center of rotation located in a frontal plane and said medio-carpal articular level having a second radio-ulnar center of rotation located also in said frontal plane, said second radio-ulnar center of rotation being distinct from said first radio-ulnar center of rotation, said prosthesis comprising:

• a radial element having an anchoring shank and a shoulder connected to said anchoring shank, said anchoring shank being configured to be inserted into a the radius bone with said shoulder resting against a distal face thereof;
• a plate of bio-compatible plastic material connected to said radial element, said plate having a concave bearing surface, said concave bearing surface having a radio-ulnar deviation radius of curvature in the frontal plane and a flexion-extension radius of curvature in a sagittal plane smaller than said radio-ulnar deviation radius of curvature;
• an intermediate element free to rotate in radio-ulnar deviation and in flexion-extension with respect to said concave bearing surface of the said plate according to the radio-carpal articular level of movement of the wrist, said intermediate element having a shape so as to cooperate with said concave bearing surface of said plate and including a recess, said recess being offset dorsally and in an ulnar direction;
• a metacarpal element having anchor means configured to anchor into the metacarpal bones, said metacarpal element being free to rotate in a radio-ulnar deviation movement with respect to said intermediate element according to the medio-carpal articular level of movement of the wrist.