Spinal facet joint implant
First Claim
1. A spinal implant kit for replacement of a superior facet and an inferior facet of one or more vertebrae, the spinal implant kit comprising:
- a plurality of superior facet prostheses, each of which is selectable to replace the superior facet, wherein each of the superior facet prostheses has an articulating component having an articulating surface with a generally concave shape, a coupling portion having a bone engaging surface with a generally convex shape, an angled flat extending between the articulating component and the coupling portion, and a first dimension, wherein the first dimension varies in magnitude among the superior facet prostheses; and
a plurality of inferior facet prostheses, each of which is selectable to replace the inferior facet, wherein each of the inferior facet prostheses has an articulating surface shaped to articulate against the articulating surface of any of the superior facet prostheses, and a second dimension,wherein the second dimension varies in magnitude among the inferior facet prostheses, wherein each of the plurality of superior facet prostheses are anteriorly inclined from a longitudinal axis of the spine, when attached thereto, to provide greater clearance between the articulating surfaces when the spine is under flexion, wherein each of the plurality of superior facet prostheses includes a hole defining an axis for receiving a fastener therethrough, wherein the axis does not intersect the articulating surface, andwherein the each articulating surface of the superior facet prosthesis comprises a uniform radius of curvature and the radius of curvature of each of the articulating surface of the inferior facet prosthesis is non-uniform.
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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.
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Citations
15 Claims
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1. A spinal implant kit for replacement of a superior facet and an inferior facet of one or more vertebrae, the spinal implant kit comprising:
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a plurality of superior facet prostheses, each of which is selectable to replace the superior facet, wherein each of the superior facet prostheses has an articulating component having an articulating surface with a generally concave shape, a coupling portion having a bone engaging surface with a generally convex shape, an angled flat extending between the articulating component and the coupling portion, and a first dimension, wherein the first dimension varies in magnitude among the superior facet prostheses; and a plurality of inferior facet prostheses, each of which is selectable to replace the inferior facet, wherein each of the inferior facet prostheses has an articulating surface shaped to articulate against the articulating surface of any of the superior facet prostheses, and a second dimension, wherein the second dimension varies in magnitude among the inferior facet prostheses, wherein each of the plurality of superior facet prostheses are anteriorly inclined from a longitudinal axis of the spine, when attached thereto, to provide greater clearance between the articulating surfaces when the spine is under flexion, wherein each of the plurality of superior facet prostheses includes a hole defining an axis for receiving a fastener therethrough, wherein the axis does not intersect the articulating surface, and wherein the each articulating surface of the superior facet prosthesis comprises a uniform radius of curvature and the radius of curvature of each of the articulating surface of the inferior facet prosthesis is non-uniform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification