Spinal facet implants with mating articulating bearing surface and methods of use
First Claim
1. A prosthesis for replacing at least a portion of a facet of a vertebra of a spine, the prosthesis comprising:
- a fixation element implantable into the vertebra;
a coupling portion shaped to be coupled to the fixation element, the coupling portion having a bone engaging surface positioned to abut the vertebra; and
an articulating surface coupled to the coupling portion;
wherein, when the coupling portion is secured to the vertebra via the fixation element, the articulating surface is posterior to a vertebral body of the vertebra and is positioned and shaped to articulate against an articulating surface of an adjacent vertebra such that a medial-lateral range of relative motion between the vertebra and the adjacent vertebra decreases significantly with extension of the spine.
5 Assignments
0 Petitions
Accused Products
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.
-
Citations
19 Claims
-
1. A prosthesis for replacing at least a portion of a facet of a vertebra of a spine, the prosthesis comprising:
-
a fixation element implantable into the vertebra; a coupling portion shaped to be coupled to the fixation element, the coupling portion having a bone engaging surface positioned to abut the vertebra; and an articulating surface coupled to the coupling portion; wherein, when the coupling portion is secured to the vertebra via the fixation element, the articulating surface is posterior to a vertebral body of the vertebra and is positioned and shaped to articulate against an articulating surface of an adjacent vertebra such that a medial-lateral range of relative motion between the vertebra and the adjacent vertebra decreases significantly with extension of the spine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A prosthesis for replacing at least a portion of a facet of a vertebra of a spine, the prosthesis comprising:
-
a fixation element implantable into the vertebra; a coupling portion shaped to be coupled to the fixation element, the coupling portion having a bone engaging surface positioned to abut the vertebra; and an articulating surface coupled to the coupling portion to articulate against an articulating surface of an adjacent vertebra, the articulating surface of the prosthesis having a cephalad end and a caudal end, wherein the articulating surface has a radius of curvature about an axis extending generally from the cephalad end to the caudal end; wherein, when the coupling portion is secured to the vertebra via the fixation element, the articulating surface is posterior to a vertebral body of the vertebra, and the axis is significantly anteriorly inclined toward the cephalad end. - View Dependent Claims (12, 13, 14)
-
-
15. A superior prosthesis for replacing at least a portion of a superior facet of a vertebra of a spine, the prosthesis comprising:
-
a fixation element implantable into the vertebra; a coupling portion shaped to be coupled to the fixation element, the coupling portion having a bone engaging surface positioned to abut the vertebra; and an articulating surface coupled to the coupling portion to articulate against an articulating surface of an adjacent vertebra, the articulating surface of the prosthesis having a concave shape with a variable radius of curvature, wherein, when the coupling portion is secured to the vertebra via the fixation element, the articulating surface is posterior to a vertebral body of the vertebra and is positioned to articulate against an inferior facet of an adjacent vertebra. - View Dependent Claims (16, 17, 18, 19)
-
Specification