Spinal facet joint implant
First Claim
1. A spinal implant kit for replacing at least one removed facet of a resected vertebra, wherein the resected vertebra has a pedicle saddle point (S1) defining an intersection between a posterior pedicle bone surface and a longitudinal axis of the pedicle wherein the at least one removed facet is a natural right superior facet, a natural left superior facet, a natural right inferior facet, or a natural left inferior facet, wherein the at least one removed facet has an articulating surface that, prior to removal of the at least one removed facet has a most medial and anterior point (P1), the spinal implant kit comprising:
- a plurality of fixation elements; and
a plurality of components for replacing a first facet of the at least one removed facet, wherein the components have the same parametric features characterized by a first dimension and a second dimension;
wherein each of the components is of monolithic construction and comprises a generally convex semispherical surface, wherein the first and second dimensions vary in magnitude disproportionately relative to each other among the components such that a subset of the components is selectable to provide a selected prosthesis dimensioned to match a morphology of the resected vertebra;
wherein a subset of the fixation elements is selectable to attach the selected prosthesis to the resected vertebra,wherein the selected prosthesis comprises;
an articulating surface positioned to approximate an original position of the first facet when the selected prosthesis is attached to the resected vertebra; and
a bone apposition surface to abut a resection surface of the vertebra;
wherein the first and second dimensions define at least one of the bone apposition surface and the articulating surface;
wherein the semispherical surface is incorporated in a ball and socket joint when the selected prosthesis is attached to the resected vertebra,wherein the articulating surface is concave and comprises one or more planar portions,wherein each of the components is configured with an aperture that extends completely there through.
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.
351 Citations
31 Claims
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1. A spinal implant kit for replacing at least one removed facet of a resected vertebra, wherein the resected vertebra has a pedicle saddle point (S1) defining an intersection between a posterior pedicle bone surface and a longitudinal axis of the pedicle wherein the at least one removed facet is a natural right superior facet, a natural left superior facet, a natural right inferior facet, or a natural left inferior facet, wherein the at least one removed facet has an articulating surface that, prior to removal of the at least one removed facet has a most medial and anterior point (P1), the spinal implant kit comprising:
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a plurality of fixation elements; and a plurality of components for replacing a first facet of the at least one removed facet, wherein the components have the same parametric features characterized by a first dimension and a second dimension; wherein each of the components is of monolithic construction and comprises a generally convex semispherical surface, wherein the first and second dimensions vary in magnitude disproportionately relative to each other among the components such that a subset of the components is selectable to provide a selected prosthesis dimensioned to match a morphology of the resected vertebra; wherein a subset of the fixation elements is selectable to attach the selected prosthesis to the resected vertebra, wherein the selected prosthesis comprises; an articulating surface positioned to approximate an original position of the first facet when the selected prosthesis is attached to the resected vertebra; and a bone apposition surface to abut a resection surface of the vertebra;
wherein the first and second dimensions define at least one of the bone apposition surface and the articulating surface;wherein the semispherical surface is incorporated in a ball and socket joint when the selected prosthesis is attached to the resected vertebra, wherein the articulating surface is concave and comprises one or more planar portions, wherein each of the components is configured with an aperture that extends completely there through. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 23, 24, 25, 26, 27, 28, 29, 30)
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15. A spinal implant kit for replacing at least one removed facet of a resected vertebra, wherein the resected vertebra has a pedicle saddle point (Sl) defining an intersection between a posterior pedicle bone surface and a longitudinal axis of a pedicle, wherein the at least one removed facet is a natural right superior facet, a natural left superior facet, a natural right inferior facet, or a natural left inferior facet, wherein the at least one removed facet has an articulating surface that, prior to removal of the at least one removed facet has a most medial and anterior point (P1), the spinal implant kit comprising:
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a plurality of fixation elements; and a plurality of components for replacing a first facet of the at least one removed facet, wherein the components are of a single parametric design characterized by a first dimension and a second dimension; wherein each of the components is of monolithic construction and comprises a generally convex semispherical surface, wherein the first and second dimensions vary in magnitude disproportionately relative to each other among the components such that a subset of the components is selectable to provide a selected prosthesis dimensioned to match a morphology of the resected vertebra.; wherein a subset of the fixation elements is selectable to attach the selected prosthesis to the resected vertebra; wherein, when the selected prosthesis is attached to the resected vertebra, the semispherical surface encircles at least one of the subset of the fixation elements and the selected prosthesis comprises an articulating surface positioned to approximate an original position of the first facet, wherein the plurality of components comprises a first prosthesis and a second prosthesis, each of which is independently selectable to provide the selected prosthesis, wherein the first dimension of the second prosthesis has a magnitude different from a magnitude of the first dimension of the first prosthesis, wherein either of the first and second prostheses is selectable to provide the selected prosthesis, wherein the articulating surface is concave and comprises one or more planar portions, wherein each of the components is configured with an aperture that extends completely therethrough. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 31)
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Specification