Wrist implants and methods
Wrists implants and methods are disclosed. A wrist implant can advantageously allow motion with respect to a reconstructed wrist to more closely resemble natural motion. For example, in one aspect, motion can include movement in more than one direction to allow for flexion/extension, rotational, and translational movement. The wrist implant can include a radial implant component and/or a carpal implant component with a bearing component or member disposed therebetween. The radial implant can have a radial articulation surface having at least one variable radius of curvature and/or a tray having a variable width.
1. A prosthetic wrist implant comprising:
a radial implant component comprising a tray having a distal bearing surface and a proximal surface having an elongated radial stem extending therefrom adapted for attachment to a radius bone, the tray comprising radial and ulnar sides and volar and dorsal sides; and
wherein the distal bearing surface of the radial implant component comprises a flexion/extension radius of curvature that increases along the radial/ulnar direction.
2. The prosthetic wrist implant of claim 1 , wherein the flexion/extension radius of curvature on the ulnar side is larger than the flexion/extension radius of curvature on the radial side.
3. The prosthetic wrist implant of claim 1 , wherein the flexion/extension radius of curvature increases from the radial side to the ulnar side.
4. The prosthetic wrist implant of claim 1 , wherein a radial/ulnar deviation radius of curvature is constant.
5. The prosthetic wrist implant of claim 1 , wherein the tray is wider on the ulnar side than the radial side.
6. The prosthetic wrist implant of claim 1 , wherein the width of the tray generally increases from the radial side to the ulnar side.
7. The prosthetic wrist implant of claim 1 , wherein the radial stem is non-circular and has a central plane that bisects the stem along an elongated length thereof, and wherein the radial tray comprises a central plane that bisects the radial tray between the volar and dorsal sides, and wherein the central plane of the radial tray is acutely angled with respect to the central plane of the radial stem.
8. The prosthetic wrist implant of claim 7 , wherein the central plane of the radial tray is acutely angled with respect to the central plane of the radial stem by about 3° to about 20°.
9. The prosthetic wrist implant of claim 1 , further comprising a carpal implant component comprising a carpal plate having a distal surface adapted for attachment to one or more carpal bones, and a proximal surface coupled with a bearing member, the bearing member having a proximal bearing surface for articulation with the distal bearing surface of the radial component.
10. A prosthetic wrist implant comprising:
a radial implant component comprising a radial tray and an elongated radial stem, the radial tray having a distal bearing surface and a proximal surface, wherein the elongated radial stem extends from the proximal surface for fixation to a radius bone, the radial tray having radial and ulnar sides and volar and dorsal sides; and
wherein the radial stem is non-circular and has a central plane that bisects the stem along an elongated length thereof, and wherein the radial tray comprises a central plane that bisects the radial tray between the volar and dorsal sides, and wherein the central plane of the radial tray is acutely angled with respect to the central axis plane of the radial stem.
11. The prosthetic wrist implant of claim 10 , wherein the central plane of the radial tray is acutely angled with respect to the central plane of the radial stem by about 3° to about 20°.
12. The prosthetic wrist implant of claim 10 , further comprising a carpal implant component comprising a carpal plate having a distal surface adapted for attachment to one or more carpal bones, and a proximal surface coupled with a bearing member, the bearing member having a proximal bearing surface for articulation with the distal bearing surface of the radial component.