Expandable spinal fusion device and methods of promoting spinal fusion
AssigneeWarsaw Orthopedic, Inc.
InventorWilliam F. McKay
Life of this patent
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Abstract
An intervertebral disc space implant includes spaced-apart bone engagement portions that define an intermediate chamber that holds bone growth inducing material into contact with adjacent vertebral bodies. The implant is expandable to establish and maintain desired intervertebral spacing during fusion. The implant includes a first member and a second member arranged to move relative to each other by action of an expansion member, the first member being engageable with the vertebral body below the disc space.
Claims11
An expandable spinal implant positionable in an intervertebral disc space between adjacent vertebral bodies in a spine and comprising:
- a first member for contacting an endplate of one of the adjacent vertebral bodies, the first member defining a first bore, the first bore having a first threaded bore portion;
- a second member for contacting an endplate of the other of the adjacent vertebral bodies;
- a screw having a first threaded screw portion and a gear tooth screw portion, the first threaded screw portion being at least partially threaded into the first bore, the screw contacting the second member in a manner permitting the screw to rotate;
- an axle having a threaded axle portion, the threaded axle portion contacting the gear tooth screw portion such that rotation of the axle moves the first and second members from a first relative spacing to a second relative spacing, to simultaneously expand the implant in the intervertebral space and against the endplates;
- and
- a locking cap having a first protruding element capable of engaging the axle and a second protruding element configured for disposal in an aperture in one of the first member and the second member to prevent the axle from rotating.
A method of promoting osteogenic fusion of adjacent spinal vertebral bodies comprising:
- providing an implant that defines a chamber intermediate spaced portions of the implant and both of the adjacent vertebral bodies wherein the implant expands by adjusting a screw having a first threaded screw portion at least partially threaded into one of a first plurality of bores in the implant such that the screw contacts a spinal vertebral body in a manner permitting the screw to rotate, and a gear tooth portion which contacts a threaded axle region in an axle within the implant such that rotation of the axle expands the implant;
- providing the implant substantially intermediate the adjacent vertebral bodies;
- expanding the implant in a manner that substantially maintains communication of the adjacent vertebral bodies through the intermediate chamber;
- and
- connecting a locking cap having a first protruding element configured for engaging the axle and a second protruding element configured for disposal in an aperture in the implant to prevent the axle from rotating.
Dependencies are inferred from the claim text.