Systems and methods for fixation of adjacent vertebrae

Abstract

A method for internal fixation of vertebra of the spine to facilitate graft fusion includes steps for excising the nucleus of an affected disc, preparing a bone graft, instrumenting the vertebrae for fixation, and introducing the bone graft into the resected nuclear space. Disc resection is conducted through two portals through the annulus, with one portal supporting resection instruments and the other supporting a viewing device. The fixation hardware is inserted through small incisions aligned with each pedicle to be instrumented. The hardware includes bone screws, fixation plates, engagement nuts, and linking members. In an important aspect of the method, the fixation plates, engagement nuts and linking members are supported suprafascially but subcutaneously so that the fascia and muscle tissue are not damaged. The bone screw is configured to support the fixation hardware above the fascia. In a further aspect of the invention, a three component dilator system is provided for use during the bone screw implantation steps of the method.

Description

BACKGROUND OF THE INVENTION [0001] The present invention concerns a method for internal fixation of vertebra of the spine. [0002] It has long been known that internal fixation is an adjunct to fusion, such as a transverse process fusion. In early prior art techniques, a surgeon made an incision in the patient's back and separated tissue and muscle in order to expose a wide area of the spine in which the procedure was to take place. The fusion and fixation in one prior art process is by grafting bone segments between opposing transverse processes of adjacent vertebrae. However, this technique resulted in gross destruction of normal anatomy as well as high blood loss. Moreover, this surgical technique did not completely stabilize the vertebra since there was no direct connection between the vertebral bodies. [0003] In more recent times, a surgical technique known as dowel interbody fusion has been developed. In this technique, bores are formed in disc tissue through either open surger...

AI Technical Summary

Benefits of technology

[0007] The present invention contemplates a percutaneous fusion technique using subcutaneous suprafascial internal fixation. More particularly, the minimally invasive technique of the present invention permits anterior fusion of the disc space of the lumbar spine following appropriate disc resection and bone grafting. The fixation process is suprafascial, that is above the muscle fascia, but subcutaneous, that is beneath the surface of the skin. Thus, none of the muscle tissue is destroyed and the subcutaneous nature of the procedure greatly decreases the risk of pin tract secretions or infections, or the potential of osteomyelitis.

[0013] It is one object of the present invention to provide a method for internal fixation of the spinal column which is minimally invasive and which poses a minimal health risk to the patient. Another object is to provide such a technique which further permits subcutaneous removal of the temporarily implanted hardware in an out-patient procedure.

Problems solved by technology

Thus, none of the muscle tissue is destroyed and the subcutaneous nature of the procedure greatly decreases the risk of pin tract secretions or infections, or the potential of osteomyelitis.

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