THUMB JOINT PROSTHESIS AND RELATED METHOD OF IMPLANTATION

摘要

A trapezium metacarpal thumb joint prosthesis (120) having a metacarpal component (122) for insertion into a metacarpal bone of a human thumb and a trapezium component (124) for insertion into a trapezium bone of a human thumb. The metacarpal component (122) has a forward end of generally truncated hemispherical shape with a convex surface (CS1) and a rear end having a base (B1) and a stem (S1). The trapezium component (124) has a forward end of a generally cylindrical shape with a concave surface (CS2) with a radially built up shoulder (SH) and a rear end having a base (B2) and a stem (S2). The concave surface is adapted for non captive rotational abutment with the convex surface. Also, a related method for implantation of the prosthesis into the metacarpal and trapezium bones of a human thumb, wherein the two components are respectively inserted into a pre-cut void in each of the respective bones from a direction above the radial side of the thumb substantially transverse to the longitudinal axis of each respective bones of the thumb.