Patent Application
20120209339
The present invention relates generally to intervertebral defect devices, and more particularly, to an intervertebral defect device for insertion into an intervertebral space using minimally invasive techniques.
Referring to prior art
In
The natural aging process can cause a deterioration of the intervertebral disks, and therefore, their intrinsic support strength and stability is diminished. Sudden movements may cause a disk to rupture or herniate. A herniation of the disk is primarily a problem when the nucleus pulposus protrudes or ruptures into the spinal canal 108 placing pressure on nerves which in turn causes spasms, tingling, numbness, and/or pain in one or more parts of the body, depending on the nerves involved. Further deterioration of the disk can cause the damaged disk to lose height and as bone spurs develop on the vertebrae 100, result in a narrowing of the spinal canal 108 and foramen 111, and thereby causes pressure on the nerves emanating from the spinal cord 128.
Presently, there are several techniques, in addition to non-surgical treatments, for relieving the symptoms related to intervertebral disk deterioration. Surgical options include chemonucleolysis, laminectomy, diskectomy, microdiskectomy, and spinal fusion.
A laminectomy, or hemi-laminectomy, is performed to decompress the spinal canal by open surgical techniques under general anesthesia. In this procedure, the lamina 110, (the bone that curves around and covers the spinal canal 108 as shown in
What is needed, but not provided in the prior art, is a stand alone vertebral defect device that can be inserted into the void created during a hemi-laminectomy to provide stability of the spine, promote bone growth and protect the protect the patient's nerves during and after recovery.
An improved device for filling a void created in the lamina during spinal surgery including a top layer, a bottom layer and a body portion. The body portion is attached to the top layer and the bottom layer and includes a compliant mesh portion. The compliant mesh portion includes a bone material with bone morphogenetic protein (BMP) growth factor entrained thereon. The body portion is adapted to be conformable to a void left in a vertebral space after a surgeon has performed a laminectomy or hemi-laminectomy procedure. The flexible top layer has a periphery larger than that of the bottom layer such that the body portion has a section that is oblique or perpendicular to another section of the body portion or the top layer to define a flange. A method of using the device is also disclosed.
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
The present invention comprises an improved device for filling a void created by a laminectomy or hemi-laminectomy surgical procedure. The device comprises a flexible top and bottom layer and a gel-suspended bone portion between the top and bottom layer to conform to the laminectomy void.
In that regard and referring to
The top layer 12 and bottom layer 14 are flexible to conform to the anatomy of the patient. The top layer further has an anti-adhesion coating to prevent the posterior tissue and muscle from adhere to the top layer 12. Likewise, the bottom layer 14 further includes a coating with anti-adhesion properties to prevent the spinal cord and spinal tissue from adhering to the bottom layer 14.
Attaching the top layer 12 and bottom layer 14 is a body portion 16. The body portion 16 comprises a first, void filler section 18 attached to a second, transition section 20 further attached to a third, flange section 22.
The first section 18 has an outer circumference that general corresponds to the outer circumference of the bottom layer 14 and adheres the bottom layer 14 to the body portion 16. It is preferably a compliant mesh portion having bone material with bone morphogenetic protein (BMP) growth factor and generally conforms to the void left in a vertebrae after a surgeon has performed a laminectomy or hemi-laminectomy procedure. As mentioned, the compliant mesh will deform to conform to the void and contact the remaining bone from the vertebrae to promote bone regrowth in the void. In that regard, the mesh having BMPs create an osteinductive environment and the mesh construction create an osteoconductive mold upon which new bone may grow.
The third section 22 is generally perpendicular to the first section 18 and is compliant to the void over which it is placed. The third section 22 expands outwardly from the first section 18 and forms a flange having a coating that adheres to bone. The third section 22 contacts the remaining bone surrounding void made in the vertebra and with the bone-adhering coating adheres the entire device 10 to the vertebra and within the void. The flange of the third section 22 is also compliant to match the shape of the patient's vertebra to provide better adherence thereto. The third section 22 further attaches the top layer 12 to the device 10.
The second section 20 is preferably arcuate and attached the first section 18 to the third section 22. The second section 20 may be either mesh, as in the first section 18, or non-mesh as in the third section 22, but most preferably transitions from a mesh to a non-mesh construction.
The device 10 of the present invention is utilized by a surgeon who has removed a portion 54 of a vertebra 50 of a patient's spine 52, as shown in
Exemplary embodiments of the present invention are described above in detail. The device is not limited to the specific embodiment described herein. While the invention has been described in terms of a specific embodiment, those skilled in the art will recognize that the invention can be practical with modification within the spirit and scope of the claims. In view of the above, it will be seen that the advantages of the present invention have been achieved and other advantageous results have been obtained.
