An artificial disc replacement (ADR) that pivots along multiple, independent axes to accommodate both flexion/extension and lateral bending. In the preferred embodiment, the mechanism is a cruciate-shaped axle that allows independent movement along orthogonal axes, much like a "universal joint." The...http://www.google.es/patents/US20040106998?utm_source=gb-gplus-sharePatente US20040106998 - Multiaxial artificial disc replacements
