Devices and methods for altering the spacing and motion at the facet joints ofthe vertebral column are provided. One embodiment of the invention comprises aprosthesis 34 with surfaces or faces 46, 48 configured to articulate with thefacets 20, 22 of the facet joint 28. A retaining member 72 for anchoring theprosthesis 34 within the facet joint 28 is optionally included. Methods forsurgically and less invasively implanting the prosthesis 34 and securing theprosthesis 34 to the articular processes or surrounding soft tissue are alsoprovided.
