Abstract: Superior and/or inferior facets of one or more facet joints may be replaced by superior and/or inferior facet joint prostheses. In one embodiment, a kit of superior or inferior prostheses is provided, in which the prostheses have at least two dimensions that vary among members of the kit independently of each other. Each prosthesis may have a bone engaging surface having a surface that is polyaxially rotatable against a corresponding resection of a vertebra. Each prosthesis may also have an articulating surface shaped such that, after attachment to the spine, the replaced or partially replaced facet joints provide a larger medial-lateral range of motion when the spine is flexed than when the spine is extended. Crosslinks may be used to connect left and right prosthesis together in such a manner that they are stabilized in a position in which they are seated directly against the vertebra.

Abstract: A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: an articulating surface that articulates with another facet; a bone contacting surface that contacts a surface of the vertebra, the articulating surface being connected to the bone contacting surface; and a fixation element that attaches the bone contacting surface to the vertebra, the fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra; wherein the prosthesis is configured so that no portion of the prosthesis contacts the posterior arch of the vertebra.

Abstract: A dilating system for dilating bodily tissue includes a elongate tubular first dilator and a elongate tubular second dilator. The second dilator has an outer diameter greater than the outer diameter of the first dilator, the first dilator being configured to be received within the second dilator. In one embodiment, a first mating member is formed on the exterior surface of the first dilator while a second mating member is formed on the interior surface of the second dilator. The first mating member engages with the second mating member when the second dilator is passed over the first dilator so as to cause the second dilator to travel along a fixed path relative to the first dilator.