Patent ID: 8016767
Filing Date: 2011-09-13
Classification: A61B,A61N,Y10S

Abstract:
1. A method of accessing a surgical target site, comprising: forming an initial distraction corridor using an elongate stimulation instrument that is delivered to a lateral aspect of a targeted spinal disc along a lateral, trans-psoas path to the lumbar spine while a stimulation electrode of the elongate stimulation instrument outputs an electrical stimulation signal from a distal tip portion for nerve monitoring during delivery of the elongate stimulation instrument along the lateral, trans-psoas path to the lumbar spine; activating a nerve monitoring system that controls the electrical stimulation signal output from the stimulation electrode of the elongate stimulation instrument during delivery of the elongate stimulation instrument along the lateral, trans-psoas path to the lumbar spine, the nerve monitoring system detecting electromyographic (EMG) activity via a set of EMG sensor electrodes in communication with muscle myotomes associated with nerves in the vicinity of the targeted spinal disc; receiving nerve monitoring information from a video display device of the nerve monitoring system that contemporaneously displays: a numeric stimulation threshold required to obtain the EMG activity in at least one of said leg muscle myotomes, and a graphical representation of a patient, wherein the video display device is operable to alert a user to at least one of a presence and absence of a nerve near the elongate stimulation instrument; positioning an inner wire member in a disc annulus at the lateral aspect of the targeted spinal disc, the inner wire member being slidably disposed within a tubular distraction member of the elongate stimulation instrument such that a distal tip of the inner wire member is inserted along the lateral, trans-psoas path and penetrates into the disc annulus at the lateral aspect of the targeted spinal disc; after forming the initial distraction corridor using the elongate stimulation instrument, advancing a plurality of sequential dilators to further dilate tissue along the lateral, trans-psoas path to the lumbar spine while the inner wire member remains engaged with the disc annulus at the lateral aspect of the targeted spinal disc; slidably advancing a plurality of retractor blades of a retractor assembly simultaneously over an outer dilator of the plurality of sequential dilators and toward the targeted spinal disc along the lateral, trans-psoas path to the lumbar spine, the retractor assembly including the plurality of retractor blades and a handle assembly having pivotable arm portions that extend generally perpendicularly relative to the plurality of retractor blades, wherein the plurality of retractor blades are simultaneously advanced over the outer dilator while in a closed position, wherein the retractor blades are operable to adjust to an opened position by rotation of a rotatable knob element of the handle assembly that mates with teeth of a rack member so as to move a first retractor blade relative to a second retractor blade of the plurality of retractor blades, wherein each of the pivotable arm portions is arranged between the plurality of retractor blades and the rotatable knob element and is pivotable so as to reposition one arm portion relative to another; removing the plurality of sequential dilators away from the retractor assembly so that the plurality of retractor blades form a lateral operative corridor to the lateral aspect of the targeted spinal disc along the lateral, trans-psoas path to the lumbar spine, and removably engaging a fixation element with the first retractor blade of the plurality of retractor blades so that a distal portion of the fixation element extends from a distal end of the first retractor blade and secures into a portion of the lumbar spine; and inserting an implant through the lateral operative corridor formed by the plurality of retractor blades along the lateral, trans-psoas path to the lumbar spine.