An intervertebral disc is provided having an upper plate, a lower plate, and a core. The upper and lower plates include outer vertebral body contacting surfaces which are provided with attachment enhancing features to ensure bone integration. The attachment enhancing features shown include one or more fins, serrations and teeth. An opposite surface of the plates from the vertebral body contacting surfaces is formed with a recess which serves as a bearing surface for the core. In order to form an intervertebral disc with a lower disc height, at least one of the recesses is provided opposite a corresponding dome shaped portion on the vertebral body contacting surfaces. This allows the plates to be formed with a thinner profile for a smaller overall disc height. In addition to providing a lower overall height to the artificial disc, the dome shaped portion of the plates also provides a more anatomically shaped outer vertebral body contacting surface.

The disclosure provides an intervertebral disc and related methods. An upper plate includes an upper vertebra contacting portion and a lower bearing surface portion. The upper vertebra contacting portion includes a convex central portion, and a fin or anchoring element with a transverse hole therethrough. A lower plate has a lower vertebra contacting surface and an upper bearing surface. The lower vertebra contacting surface of the lower plate has a convex central portion. The upper bearing surface has a concavity disposed opposite the convex central portion and wherein the convex central portion and the concavity have nesting curvatures. A core positioned between the upper and lower plates has rigid upper and lower convex surfaces configured to slide and translate over the bearing surfaces of the upper and lower plates.

Surgically installed prostheses replace either the caudal portion of a natural facet joint, the cephalad portion of a natural facet joint, or both. The prostheses are readily attached to the pedicles of a vertebral body and support at least one element that defines an artificial facet joint structure. The caudal facet joint structure is sized and located to articulate with the cephalad facet joint structure. Together, the prostheses form a total facet replacement system. The system is suitable for use in virtually all levels of the spine.

An intervertebral spacer is designed particularly for patients who are not candidates for total disc replacement. The spacer maintains disc height and prevents subsidence with a large vertebral body contacting surface area while substantially reducing recovery time by eliminating the need for bridging bone. The intervertebral spacer or fusion spacer includes a rigid spacer body sized and shaped to fit within an intervertebral space between two vertebral bodies. In one embodiment, the spacer body has two opposed metallic vertebral contacting surfaces, at least one fin extending from each of the vertebral contacting surfaces and configured to be positioned within slots cut into the two vertebral bodies. Holes, if present, cover less than 40 percent of the entire vertebral body contacting surfaces to provide increased bone ongrowth surfaces and to prevent subsidence.

Surgically installed prostheses replace either the caudal portion of a natural facet joint, the cephalad portion of a natural facet joint, or both. The prostheses are readily attached to the pedicles of a vertebral body and support at least one element that defines an artificial facet joint structure. The caudal facet joint structure is sized and located to articulate with the cephalad facet joint structure. Together, the prostheses form a total facet replacement system. The system is suitable for use in virtually all levels of the spine.

An intervertebral disc includes a superior endplate having an upper vertebral contacting surface and a lower bearing surface, wherein the upper vertebral contacting surface of the superior endplate has a central portion that is raised relative to a peripheral portion of the superior endplate, and wherein the lower bearing surface has a concavity disposed opposite the raised central portion. The disc includes an inferior endplate having a lower vertebral contacting surface and an upper surface, wherein the lower vertebral contacting surface of the inferior endplate has a central portion and wherein the upper bearing surface has a concavity disposed opposite the central portion. A core is positioned between the upper and inferior endplates, the core having upper and lower core bearing surfaces configured to mate with the bearing surfaces of the upper and inferior endplates. The upper vertebral contacting surface of the superior end plate has a different shape than the lower vertebral contacting surface of the inferior end plate.