Facet arthroplasty devices and methods

Abstract

Devices and surgical methods treat various types of adult spinal pathologies, such as degenerative spondylolisthesis, spinal stenosis, degenerative lumbar scoliosis, and kypho-scoliosis. Various types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments are used to perform the surgical procedures.

Description

RELATED APPLICATIONS [0001] This application is a divisional of co-pending application Ser. No. 09 / 693,272 filed Oct. 20, 2000, which is a continuation-in-part of U.S. Provisional Patent Application Ser. No. 60 / 160,891, filed Oct. 22, 1999, and entitled “Facet Arthroplasty Devices and Methods,” which is incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention generally relates to devices and surgical methods for the treatment of various types of spinal pathologies. More specifically, the present invention -is directed to several different types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments which may be used to perform the surgical procedures. BACKGROUND OF THE INVENTION [0003] Back pain is a common human ailment. In fact, approximately 50% of persons who are over 60 years old suffer from lower back pain. Although many incidences of back pain are due to sprains or muscle strai...

AI Technical Summary

Benefits of technology

[0012] The present invention overcomes the problems and disadvantages associated with current strategies and designs in various treatments for adult spine diseases. The present inventive spinal arthroplastic systems avoid the problems of spine stiffness, increased loads on unfused levels, and predictable failure rates associated with spinal arthrodesis.

[0017] Another aspect of the invention provides surgical procedures for performing replacements of various facets and lamina in the spine, as well as surgical instruments for facilitating performance of the disclosed surgical procedures, including spinal fusion.

Problems solved by technology

Furthermore, although patients with one or two levels of spinal stenosis tend to do reasonably well with just a one to two level wide decompressive laminectomy, patients whose spinal stenosis is associated with degenerative spondylolisthesis have not seen good results.

Although patients who undergo concomitant arthrodesis do demonstrate a significantly better outcome with less chance of further vertebral slippage after laminectomy, arthrodesis poses problems of its own.

Aside from the occurrence of further spondylolisthesis in some patients, additional effects include non-unions, slow rate of fusion even with autografts, and significant morbidity at the graft donor site.

Furthermore, even if the fusion is successful, joint motion is totally eliminated at the fusion site, creating additional stress on healthy segments of the spine which can lead to disc degeneration, herniation, instability spondylolysis, and facet joint arthritis in the healthy segments.

Although different designs achieve different levels of success with patients, disc replacement mainly helps patients with injured or diseased discs; disc replacement does not address spine pathologies such as spondylolisthesis and spinal stenosis caused by facet joint degeneration or disease.

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