Stand alone anterior cage

Abstract

The present invention teaches an improved spinal fusion implant and method of implanting same. The implant includes a shell and an insert, the insert capable of situating first and second plates of the shell with respect to each other and of preventing unwanted loosening of fasteners placed through the shell and into the adjacent vertebral bodies. The method includes implanting a shell, selecting an insert from a plurality of inserts, and placing an insert between first and second plates of the shell.

Description

BACKGROUND OF THE INVENTION[0001]The present invention is directed to spinal implants, and more particularly, spinal fusion implants.[0002]The deterioration of vertebral bodies and / or vertebral discs is a major cause of back and neck pain in many patients. Through the years, many different techniques for restoring the natural anatomical spacing in the spine and thereby alleviating this pain have been developed and practiced by surgeons. For instance, implants and techniques for implanting such implants have been designed to preserve motion between adjacent vertebral bodies. These motion preserving implants are adapted to emulate a removed spinal disc. Examples of such implants (and the methods of implanting same) are disclosed in U.S. Pat. Nos. 6,989,032 (“the '032 patent”) and 7,169,182 (“the '182 patent”), the disclosures of which are hereby incorporated by reference herein. Nonetheless, even given the success of such motion preserving devices, it is still sometimes necessary to f...

AI Technical Summary

Benefits of technology

[0010]The third aspect of the present invention is a method of fusing together first and second vertebral bodies. In accordance with one embodiment of the present invention, the method includes the steps of preparing a space between the first and second vertebral bodies to a spinal implant, implanting a shell, the shell including a first plate, a second plate, and a living hinge connecting the first and second plates, placing a first screw through the first plate and into the first vertebral body, placing a second screw through the second plate and into the second vertebral body, and inserting an insert between the first and second plates, wherein the insert prevents backout of the first and second screws.

[0011]In accordance with other embodiments of this third aspect, the inserting step may cause the first and second plates to move with respect to each other and such movement between the first and second plates is preferably translated to the first and second vertebral bodies. The method may also include the step of choosing an insert from a plurality of inserts. Moreover, the method may include the step of placing a third screw through the first plate and into the first vertebral body, and the step of placing a fourth screw through the second plate in the intervertebral body. Preferably, the insert prevents backout of the first, second, third, and fourth screws. The method may also include the step of retaining the insert between the first and second plates, where this retaining step may include engaging the insert with projections formed on the first and second plates. Finally, the method may also include the step of allowing bone growth through an aperture formed through the first plate, the insert, and the second plate.

Problems solved by technology

The deterioration of vertebral bodies and / or vertebral discs is a major cause of back and neck pain in many patients.

Nonetheless, even given the success of such motion preserving devices, it is still sometimes necessary to fuse adjacent vertebral bodies so that no movement is permitted therebetween.

However, even given this bone growth through the cage, it is sometimes necessary to at least initially mount the cage to the vertebral bodies through the use of fixation elements such as screws.

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