Facet arthroplasty devices and methods
Devices and surgical methods treat various types of adult spinal pathologies, such as degenerative spondylolisthesis, spinal stenosis, degenerative lumbar scoliosis, and kypho-scoliosis. Various types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments are used to perform the surgical procedures.
1 - 7 . (canceled)
8 . A prosthesis to replace a cephalad portion of a left natural facet joint on a vertebral body and a cephalad portion of a right natural facet joint on the vertebral body, the prosthesis comprising:
left and right prosthesis bodies accommodating fixation to the vertebral body at or near respective left and right pedicles without support of a lamina;
an artificial left facet joint structure on the left prosthesis body adapted and configured to replace a cephalad portion of the left natural facet joint; and
an artificial right facet joint structure on the right side region prosthesis body adapted; and configured to replace a cephalad portion of the right natural facet joint,
the prosthesis further including a third artificial facet joint structure on one of the left and right prosthesis bodies superior to the respective one of the artificial left or right facet joint structures adapted and configured to replace a caudal portion of a natural facet joint formed by a vertebral body.
9 . A prosthesis according to claim 8 wherein the third artificial facet joint structure includes means for replacing a caudal portion of a natural facet joint after removal of the caudal portion of the natural facet joint from the vertebral body.
10 - 11 . (canceled)
12 . A prosthesis according to claim 8 wherein the third artificial facet joint structure includes means for replacing a caudal portion of a natural facet joint after removal of at least a portion of a mamillary process, or an accessory process, or part of a transverse process, or part of a pedicle from the vertebral body.
13 - 31 . (canceled)