Trapezial implant
AssigneeWright Medical Technology, Inc.
InventorsJoseph S. Clift, Jr., Kelly C. Richelsoph, James W. Strickland
Life of this patent
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Abstract
A trapezial implant is provided for attachment to the trapezium of a hand. The implant includes a base member fabricated from an inelastic material such a medical grade metal or ceramic. The base member includes a generally planar proximal attachment surface from which extend two pentihedral-shaped spikes. The base member also includes a distal articular surface having a non-symmetrical, complex curvature. The implant is retained in place on the trapezium under compression of the first metacarpal.
Claims2
In a prosthetic device adapted for presenting a prosthetic articular surface on a trapezium in a human hand, said prosthetic articular surface being adapted for engagement with a proximal end of a first metacarpal in said human hand, said prosthetic device including:
- (a) a base member defining distal and proximal ends;
- (b) said prosthetic articular surface being at said distal end;
- (c) an attachment surface at said proximal end;
- and
- (d) anchor means associated with said proximal attachment surface, the improvement comprising, in combination:
- (1) said prosthetic device being fabricated from a relatively inelastic, abrasion-resistant and biocompatible material selected from the group consisting of:
- medical grade metals including titanium, zirconium and alloys thereof;
- said ceramics including alumina, zirconia and silica;
- (2) said prosthetic articular surface having a saddle shaped configuration defined by a convex media portion, a convex lateral portion and a concave central portion therebetween;
- and an asymmetrical perimeter so as to substantially replicate the articular surface of a human trapezium;
- (3) said proximal attachment surface being generally planar;
- (4) said anchor means being in the form of a pair of spaced-apart posts extending perpendicularly from said proximal attachment surface and integrally formed with said base;
- (5) said posts being tapered and terminating in a point;
- and
- (6) said posts having sufficient rigidity to penetrate the cancellous interior of the trapezium without having pilot holes formed in said cancellous interior.
Dependencies are inferred from the claim text.