Artificial disc replacement (ADR) systems with intradiscal components feature non anterior-posterior (A-P) or oblique-oriented keels such that the great vessels do not require as much retraction during insertion. The system may further include guides for aligning the ADR prior to insertion, and for cutting an oblique slot into a vertebral endplate to receive the keel. A screw adapted to penetrate a vertebral body may be used in conjunction with the keel. The screw and keel may converge, diverge or intersect. The screw may further include a mechanism providing a locking relationship with the keel. The system may further including a guide to direct drill bits and screws through holes in the keel. ADRs according to the invention may additionally, independently include a non-symmetrical endplate shaped so as to decrease the risk of injuring the great vessels. By virtue of the invention, a second ADR may be installed at a second level having a keel oriented differently from that of the ADR having an orientation other than anterior-to-posterior.

An artificial disc includes a top vertebra-attachment portion and a lower spacer support connected to the top vertebra-attachment portion; a bottom vertebra-attachment portion and an upper spacer support connected to the bottom vertebra-attachment portion. The spacer supports are disposed between the vertebra-attachment portions, and the lower spacer support is disposed between the bottom vertebra-attachment portion and the upper spacer support. The disc further includes a first elastic spacer positioned between the spacer supports for compressively resisting tensile loading of the disc; and a second spacer disposed between the bottom vertebra-attachment portion and the lower spacer support or between the top vertebra-attachment portion and the upper spacer support for compressively resisting compressive loading of the disc.

A spinal disc prosthesis (10) to replace a damaged spinal disc in a spinal column (16) of a human, includes an elastomeric core (200) having upper and lower surfaces (202, 212) which are parallel to each other. An upper rigid plate (20) has opposed first and second surfaces (42, 52). The first surface (42) is affixed to the upper surface (202) of the elastomeric core. The second surface (52) is inclined relative to the first surface (42). A lower rigid plate (120) has opposed third and fourth surfaces (142, 152). The third surface (142) is affixed to the lower surface (212) of the elastomeric core (200) and extends parallel to the first surface (42). The fourth surface (152) is inclined relative to the third surface (142). The second and fourth surfaces (52, 152) are inclined relative to each other.

Intervertebral disc prostheses are provided. More particularly, the invention provides disc prostheses that have adjustable disc heights, that are readily converted into fusion prostheses and that provide a range of motions that effectively mimic the natural range of motions of a spinal disc.

Intervertebral disc prostheses are provided. More particularly, the invention provides disc prostheses that have adjustable disc heights, that are readily converted into fusion prostheses and that provide a range of motions that effectively mimic the natural range of motions of a spinal disc.