Prosthetic joints with contained compressible resilient members
In a total knee replacement (TKR), the use of a cushion element provides better wear characteristics than polyethylene (“poly”) alone. Since a metal-on-metal, metal-on-ceramic, or ceramic-on-ceramic articulating surface has better wear characteristics than metal on poly, the invention essentially provides cushioning for metal/ceramic-on-metal/ceramic joint replacements. It also allows the use of elastomers for their cushioning properties rather than their surface wear and tensile strength characteristics. The contained compressible elements could also be used as a cushion below polyethylene components, polyethylene over metal components, unicondylar knee replacements, patellar components, and prosthetic components for other parts of the body, including the hip, elbow, shoulder, wrist, and ankle.
1 - 8 . (canceled)
9 . A prosthetic joint, comprising:
a first member adapted for fixation to a first bone surface;
a second member adapted for fixation to a second bone surface opposing the first bone surface;
a joint articulation mechanism disposed between the first and second members, the mechanism including a piston arrangement and a compressible/resilient member.
10 . The prosthetic joint of claim 9 , wherein the compressible/resilient member is constructed of a natural or synthetic rubber, elastomer, viscoelastic polymer, foam polyurethane, or
11 . The prosthetic joint of claim 9 , wherein at least one of the members includes a bearing surface composed of polyethylene, metal, or ceramic.
12 . The prosthetic joint of claim 9 , wherein the piston arrangement is circular or oval in cross-section.
13 . The prosthetic joint of claim 9 , wherein the compressible/resilient member is surrounded by an elastic hoop or band.
14 . The prosthetic joint of claim 9 , wherein the articulation mechanism is configured for a total knee replacement, unicondylar replacement, patella replacement, or hip.
15 . the prosthetic joint of claim 9 , wherein the joint articulation joint mechanism is surrounded by a seal, or surrounded by a seal containing a lubricating fluid.