Axial spinal implant and method and apparatus for implanting an axial spinal implant within the vertebrae of the spine

Abstract

Spinal implants for fusing and / or stabilizing spinal vertebrae and methods and apparatus for implanting one or more of such spinal implants axially within one or more axial bore within vertebral bodies in alignment with a visualized, trans-sacral axial instrumentation / fusion (TASIF) line in a minimally invasive, low trauma, manner are disclosed. Attachment mechanisms are provided that attach or affix or force the preformed spinal implants or rods to or against the vertebral bone along the full length of a TASIF axial bore or bores or pilot holes or at the cephalad end and / or caudal end of the TASIF axial bore or bores or pilot holes. The engagement of the vertebral body is either an active engagement upon implantation of the spinal implant into the TASIF axial bore or a passive engagement of the external surface configuration with the vertebral bone caused by bone growth about the external surface configuration. A plurality of such spinal implants can be inserted axially in the same TASIF axial bore or pilot hole or separately in a plurality of TASIF axial bores or pilot holes that extend axially and in a side-by-side relation through the vertebrae and discs, if present, between the vertebrae. Discectomies and / or vertebroblasty can be performed through the TASIF axial bore or bores or pilot holes prior to insertion of the spinal implants. Vertebroblasty is a procedure for augmentation of collapsed vertebral bodies by pumped-in materials, e.g., bone cement or bone growth materials. Materials or devices can also be delivered into the disc space to separate the adjoining vertebrae and / or into damaged vertebral bodies or to strengthen them.

Description

[0001] This application claims priority and benefits from U.S. patent application Ser. No. 09 / 684,820, filed Oct. 10, 2000, entitled AXIAL SPINAL IMPLANT AND METHOD AND APPARATUS FOR IMPLANTING AN AXIAL SPINAL IMPLANT WITHIN THE VERTEBRAE OF THE SPINE, which claims priority and benefits from Provisional Patent Application No. 60 / 182,748, filed Feb. 16, 2000, entitled METHOD AND APPARATUS FOR TRANS-SACRAL SPINAL FUSION.[0002] 1. Field of the Invention[0003] The present invention relates generally to spinal implants for fusing and / or stabilizing spinal vertebrae and methods and apparatus for implanting one or more of such spinal implants axially within one or more axial bore within vertebral bodies in alignment with a visualized, trans-sacral axial instrumentation / fusion (TASIF) line in a minimally invasive, low trauma, manner.[0004] 2. Description of the Related Art[0005] It has been estimated that 70% of adults have had a significant episode of back pain or chronic back pain emanati...

AI Technical Summary

Problems solved by technology

Patients who suffer from such conditions usually experience extreme and debilitating pain and often neurologic deficit in nerve function.

Although the initial proponents of this approach report 90% excellent to good results, subsequent studies have been unable to obtain acceptable outcomes and recommend adding internal fixation to improve fusion rates.

However, when generally used by practicing surgeons, the procedure was found to have a high failure rate of fusion.

Attempts to increase the fusion rate by performing a posterior stabilization procedure have been successful, but the second incision increases the morbidity and decreases the advantages of the technique.

Thus, the present surgical techniques available to remove and fuse painful lumbar discs are extensive operative procedures with potentially significant complications.

There is no single procedure which is universally accepted to surgically manage low back pain patients.

Although damaged discs and vertebral bodies can be identified with sophisticated diagnostic imaging, the surgical procedures are so extensive that clinical outcomes are not consistently satisfactory.

Furthermore, patients undergoing presently available fusion surgery experience uncomfortable, prolonged convalescence.

However, there are still disadvantages to the present fixation implants and surgical implantation techniques.

Since the pedicles of vertebrae above the second lumbar vertebra (L2) are very small, only small bone screws can be used which sometimes do not give the needed support to stabilize the spine.

These rods and screws and clamps or wires are surgically fixed to the spine from a posterior approach, and the procedure is difficult.

These approaches are criticized as failing to provide adequate medial-lateral and rotational support in the '899 patent.

These devices are difficult to place due to the length of the screws, and damage occurs when the screws are placed improperly.

The large hole or holes can compromise the integrity of the vertebral bodies, and if drilled too posteriorly, can injure the spinal cord.

The telescoping causes the length of the vertebral column to shorten and can cause damage to the spinal cord and nerves that pass between the two adjacent vertebrae.

While successful fusion of L5-S1 was reported in a number of cases, fusion of L4-S1 was unsuccessful or inadequate, and lateral surgical exposure and stripping of the vertebrae facets was still necessary.

The posterolateral or anterior lateral approach is necessitated to correct the severe spondylolisthesis displacement using the reduction tool and results in tissue injury.

As a result, the spinal column can be further weakened and / or result in surgery induced pain syndromes.

Only a limited access to and alignment of S1 and L5 can be achieved by this approach because the distal ends of the straight bore and shaft approach and threaten to perforate the anterior surface of the L5 vertebral body.

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