Patent ID: 8287597

Claim:
A method for correcting saggital imbalance of a lumbar spine, comprising the steps of: inserting an access system along a lateral, trans-psoas path to a target site on the lumbar spine to create an operative corridor to the target site, wherein the access system comprises a stimulation electrode and is inserted under conditions wherein an electrical stimulation signal is delivered through said stimulation electrode for nerve monitoring when the stimulation electrode is positioned in the lateral, trans-psoas path; preparing the intervertebral space between first and second vertebra of the lumbar spine for receipt of an intervertebral implant, the intervertebral space being at least partially defined by an anterior aspect, a posterior aspect, and opposing first and second lateral aspects; inserting a cutting device through the operative corridor along the lateral, trans-psoas path and severing the Anterior Longitudinal Ligament (ALL); and advancing the intervertebral implant through the operative corridor along the lateral, trans-psoas path into the intervertebral disc space between the first and second vertebra, the intervertebral implant having an upper surface to contact said first vertebra when the implant is positioned in the intervertebral space, a lower surface to contact the second vertebra when the implant is positioned in the intervertebral space, a first lateral wall and second lateral wall defining a longitudinal length therebetween, the longitudinal length being such that the implant extends from the apophyseal ring at the first lateral aspect to the apophyseal ring at the second lateral aspect when the implant is positioned in the intervertebral disc space, an anterior sidewall to face the anterior aspect of the intervertebral disc space when the implant is positioned in the intervertebral disc space, and a posterior sidewall to face the posterior aspect of the intervertebral disc space when the implant is positioned in the intervertebral disc space, the anterior sidewall and posterior sidewall defining a width therebetween, the anterior sidewall having a first height and the posterior sidewall having a second height smaller than the first height such that the upper and lower surfaces increase in slope from the posterior sidewall to the anterior sidewall forming an angle ranging from 20 degrees to 40 degrees.