A prosthesis replaces all or a portion of a natural facet joint on a vertebral body. The prosthesis has a prosthesis body accommodating fixation to the vertebral body at or near a pedicle and without support by a lamina. The prosthesis body has a fastening element installed within the vertebral body at or near a pedicle. The prosthesis further has an artificial facet joint structure carried by the prosthesis body at a location spaced from the fastening element. The artificial facet joint structure is adapted and configured to replace all or a portion of a natural facet joint.
