Patent ID: 7618453

Claim:
A system for replacing at least a portion of a natural facet of a first vertebra, the system comprising: a first prosthesis comprising: a fixation element implantable in the first vertebra; a bone apposition surface shaped to abut the first vertebra, wherein the bone apposition surface is formed as a separate piece from the fixation element and surrounds an opening through which the fixation element is configured to extend to secure the first prosthesis to the first vertebra; and articulating structure shaped to replace a removed portion of a natural superior articular process of the first vertebra, the articulating structure comprising a first superior articular surface shaped to articulate with a first inferior articular surface on a second vertebra; wherein the first superior articular surface is not formed as a single piece with any other articular surface; wherein an end of the fixation element is exposed when the fixation element is fully implanted in the first vertebra through the opening, the bone apposition surface is positioned to abut the first vertebra, and the first superior articular surface is positioned to articulate with the first inferior articular surface.