Tools and implants for lateral disc replacement
In accordance with at least one aspect of this disclosure, a disc replacement implant includes, a first endplate configured to engage a vertebral endplate of a first vertebra adjacent an intervertebral space, a second endplate configured to engage a vertebral endplate of a second vertebra opposite the first end plate in the intervertebral space, a core between the first and second endplates, and an annulus surrounding the core and connecting a perimeter of the first endplate to a perimeter of the second end plate. In embodiments, the annulus can include a portion that extends inwardly between the first and second core plates to the spacer.
1 . A disc replacement implant comprising:
a first endplate configured to engage a vertebral endplate of a first vertebra adjacent an intervertebral space;
a second endplate configured to engage a vertebral endplate of a second vertebra opposite the first end plate in the intervertebral space;
a core between the first and second endplates, wherein the core includes a first core plate that engages an inner surface of the first endplate and a second core plate that engages an inner surface of the second endplate, wherein a first pocket is defined between the first endplate and the first core plate, wherein there are a plurality of holes through the first end plate from an external surface of the first endplate into the first pocket for osseointegration; and
an annulus surrounding the core and connecting a perimeter of the first endplate to a perimeter of the second end plate.
2 . The implant as recited in claim 1 , wherein the first endplate and second end plate are metallic.
3 . The implant as recited in claim 1 , wherein the core is of a material more flexible than that of the first and second endplates.
4 . The implant as recited in claim 3 , wherein the core is of a polymer material.
5 . The implant as recited in claim 3 , wherein the annulus is of a material more flexible than that of the core.
6 . The implant as recited in claim 5 , wherein the annulus is of viscoelastic material.
7 . The implant as recited in claim 1 , wherein the core includes:
a spacer between the first and second core plates, wherein the spacer is connected to each of the first and second core plates and is configured to allow bending and twisting motion of the first and second core plates relative to one another.
8 . The implant as recited in claim 7 , wherein the spacer includes a spherical section and connects a center portion of the first core plate to a center portion of the second core plate, and has a neutral position that maintains a wedge angle and spacing between the first and second core plates.
9 . The implant as recited in claim 7 , wherein a second pocket is defined between the second endplate and the second core plate, and wherein there are a plurality of holes through the second endplate from an external surface of the second endplate into the second pocket for osseointegration.
10 . The implant as recited in claim 1 , further comprising,
a spacer between the first and second core plates, wherein the spacer is connected to each of the first and second core plates and is configured to allow bending and twisting motion of the first and second core plates relative to one another; and
wherein the annulus includes a portion that extends inwardly between the first and second core plates to the spacer.
11 . The implant as recited in claim 1 , wherein the first endplate has an external surface defining a plurality of pyramidal teeth, and wherein the second endplate has an external surface defining a plurality of pyramidal teeth.
12 . The implant as recited in claim 11 , wherein a plurality of the pyramidal teeth of the first endplate have osseointegration holes defined through each pyramidal face thereof, and wherein a plurality of the pyramidal teeth of the second endplate have osseointegration holes defined through each pyramidal face thereof.
13 . The implant as recited in claim 12 , wherein the first endplate has a biologics aperture therethrough from the external surface of the first endplate into a pocket, wherein the biologics aperture is larger in diameter than the osseointegration holes, for introduction of osseointegration biologics into the first pocket.
14 . The implant as recited in claim 1 , wherein an inserter pocket is defined on a first end of the first endplate, second endplate, and annulus, wherein the inserter pocket includes a first recess defined on an inward facing surface of the first end plate, and wherein the inserter pocket includes a second recess defined on an inward facing surface of the second end plate.
15 . The implant as recited in claim 14 , wherein the inserter pocket is defined on a first lateral end of the first endplate, the second endplate, and the annulus, wherein the first endplate, second end plate, and annulus have a length from the first lateral end to an opposite second lateral end thereof that is greater than a width measured from a front side of the first and second endplates and annulus to a back side thereof to facilitate implantation through a lateral approach.