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.

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.