Minimally-invasive retroperitoneal lateral approach for spinal surgery

Abstract

A method is disclosed for introducing a spinal disc implant into an intervertebral space of a subject. The subject is placed in a lateral position, and the anterior face of the spinal disc intervertebral space is accessed, between the L5 and S1 vertebrae, from an anterior and lateral retroperitoneal approach. An operative corridor to the anterior face of the spinal disc space is established by introducing a retractor instrument anterolaterally to the spinal disc space between the anterior superior iliac spine and the anterior inferior iliac spine. The damaged spinal disc contents are removed from the intervertebral space through the operative corridor, and the implant is advanced into the intervertebral space at an oblique angle and pivoted to position the implant substantially laterally within the intervertebral space. Elongated retractor and insertion instruments, as well as a modified disc implant, are also disclosed for carrying out the method.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and the benefit of U.S. Provisional Application No. 61 / 140,926, filed Dec. 26, 2008, and U.S. Provisional Application No. 61 / 178,315, filed May 14, 2009, both of which are hereby incorporated by reference in their entireties.FIELD[0002]Spinal surgery methods and devices are disclosed for repairing damaged or deteriorated vertebrae at the lower lumbar levels, such as in the L5-S1 intervertebral space.BACKGROUND[0003]The vertebral column is the central pillar of the body. It is a generally flexible column that bears tensile and compressive loads, permits bending motions, and provides an attachment site for ribs, muscles and other structures. The vertebral column includes irregular bones called vertebrae that are separated by fibrocartilaginous structures known as intervertebral discs. There are seven vertebral, twelve thoracic, five lumbar, five sacral, and four coccygeal vertebrae. A typical vertebra con...

AI Technical Summary

Benefits of technology

"The patent describes a new method for accessing the intervertebral space in a minimally-invasive way. The method involves inserting a disc implant into the space and then pivoting it within the space to achieve a medial-lateral position. This allows for better distribution of the mechanical load on the implant. The method also allows for the removal of native disc contents through a lateral approach, which is advantageous for accessing the L5-S1 intervertebral space. The invention provides a device for positioning the implant and retracting the native disc contents, as well as an elongated implant that can be pivoted within the space. The technical effects of this new method include improved access to the intervertebral space, reduced trauma to the patient, and better distribution of the mechanical load on the implant."

Problems solved by technology

The intervertebral discs can be damaged or undergo degeneration, which often results in painful and sometimes debilitating nerve impingement syndromes.

Procedures such as total disc arthroplasty (disc replacement) have used a direct anterior approach orthogonal to the midline of the vertebral body, but such procedures require unfettered anterior spinal exposure for precise midline placement of the prosthetic disc.

The procedure also causes significant surgical disruption of the anterior annular element around the disc.

Injury to the left iliac vessel is an unfortunate complication of such procedures.

The direct lateral retroperitoneal approach to the L5-S1 space has not been possible because the anterior superior iliac spine obstructs a direct lateral approach to the L5-S1 intervertebral space.

Minimally invasive surgical approaches to the intervertebral spaces in the past have also been limited by the need to insert the prosthetic disc implant either into the front portion, posterior portion, or the side of the disc space to achieve stable placement of the prosthetic implant.

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