Spinal disc space distractor

Abstract

A distractor for separating adjacent elements, such as vertebrae. The distractor preferably has a scissors-type distracting mechanism, either in a simple scissors or double-acting scissors configuration. A set of blades is provided on each jaw such that an implant may be inserted between the spaced apart blades. The set of blades includes at least two blades.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of copending U.S. patent application Ser. No. 09 / 879,911, filed Jun. 14, 2001, which is a continuation of U.S. patent application Ser. No. 09 / 411,161, filed Oct. 1, 1999, now U.S. Pat. No. 6,261,296, which claims priority to U.S. Provisional Application No. 60 / 102,669, filed Oct. 2, 1998, which are incorporated by reference herein in their entirety.FIELD OF THE INVENTION [0002] The present invention relates to a device and method for spreading apart adjacent vertebrae of a vertebral column so that an implant may be inserted therebetween. More particularly, the present invention relates to a distractor device shaped and configured for minimally invasive insertion and use, such as for distraction of vertebrae using an anterior or anterolateral approach. BACKGROUND OF THE INVENTION [0003] Back pain can be caused by either one or a combination of the following: a loss of disc height, compression of nerve ro...

AI Technical Summary

Benefits of technology

[0013] The spinal disc distractor of the present invention is thus designed to distract disc space atraumatically with respect to both the vertebrae and the implant during endplate preparation, implant sizing, and implant insertion. The distractor may be used in a straight anterior, anterolateral, or lateral approach, and may be used in either an open or a laparoscopic procedure. Moreover, the distractor is designed to ensure the selection of an anatomically correct implant size by permitting the annulus to be fully stretched so that the largest possible implant may be inserted and compressed upon release of the vertebrae, thereby enhancing stability and assuring correct placement of the implant. Thus, the present invention permits disc height and lordosis to be restored. The jaws are shaped and configured to preserve the endplate and the vertebral body during distraction, as well as to permit insertion of an implant during distraction. The risk of breakage of allograft implants and other cages made from brittle materials during insertion is thereby reduced.

Problems solved by technology

However, the technique for the insertion of these implants generally does not achieve distraction because of their height limitations, thus making it difficult to restore the natural disc height.

The force necessary to insert these implants (such as by drilling and tapping) may cause damage to the vertebrae or vertebral endplates at the insertion site.

Moreover, allograft products and cages made out of other brittle materials (e.g., carbon fiber and ceramics) may break during insertion, particularly when distraction is not used and external force is necessary to insert the implant.

Threaded cages on the other hand do not restore lordosis, and do not allow for atraumatic distraction to restore disc height.

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