BONE JOINT IMPLANTS

Abstract

A bone joint implant (1) has a proximal part (120) for translational motion over the trapezium in a first carpometacarpal joint and a distal part (110) for intramedullary engagement in the first metacarpal bone. An articulating coupling (103, 121, 123) is for multi-axial motion with translational movement over a bone in one part (120) and rotation in the other part (110) about the articulating coupling (121, 103). A flange (105) extends radially and around the coupling to limit relative rotational motion of the proximal and distal parts about the coupling, and to provide resilience for contact between the proximal and distal parts. The flange has a contoured surface (101) matching an abutting surface (125) of the proximal part (122) upon articulation of the parts in use to extreme positions. The flange (105) is included in an insert (100) in a stem (111) of the distal part (110), the flange extending proximally of the stem (111) and prohibiting contact between the proximal part (120) and the stem (111) during articulation.

IPC Classifications