Patent ID: 7763075

Claim:
A spinal disc prosthesis, comprising: a first endplate and a second endplate, each of said first endplate and said second endplate having a respective bone-contacting surface for attaching to respective vertebrae and a respective non-bone-contacting surface opposite said respective bone-contacting surface; a polymeric member interposed between and adhered to said non-bone-contacting surfaces of said respective endplates; a compression stop having a first substantially planar uninterrupted contact surface on a surface facing said second endplate, and a second substantially uninterrupted contact surface on a surface facing said first endplate; wherein in a first position, said first substantially planar uninterrupted contact surface does not contact said second substantially uninterrupted contact surface, and said first endplate and said second endplate are substantially unconstrained to relative movement about six degrees of freedom; and wherein in a second position, said first substantially planar uninterrupted contact surface contacts said second substantially uninterrupted contact surface, and said first endplate and said second endplate are substantially constrained against relative translation in one direction along the cephalad-caudal axis, but are substantially unconstrained in relative translation and rotation about all other axes; and electronics contained within said compression stop.