US Patent 7291171 Artificial disc replacement (ADR) using elastic tether member

Artificial disc (ADR) and joint replacement components, particularly those associated with the knee and hip, use compressible, resilient materials to approximate natural kinematics, often in conjunction with elastic or spring components to tether articulating components to avoid dislocation, excessive compression, flexion or other out-of-range movements. The preferred embodiments require only two or a few articulating components. The designs allow for normal flexion, extension, lateral bending, rotation, and translocation, depending upon the application.