Patent ID: 8303515

Claim:
A method of forming and using an operative corridor through a retroperitoneal space and a psoas muscle during a substantially lateral, retroperitoneal approach to a lumbar spine, the method comprising: while a user's finger is inserted through a skin incision, moving a tip portion of the user's finger through bodily tissue that is generally lateral from a lumbar spine for blunt finger dissection of the bodily tissue proximate to a retroperitoneal space; advancing the tip portion of the user's finger into the retroperitoneal space so as to palpate to a psoas muscle; advancing an elongate stimulation instrument along a lateral, trans-psoas path through the retroperitoneal space, through the psoas muscle, and to the lumbar spine such that a distal tip portion of the elongate stimulation instrument engages an annulus of a spinal disc of the lumbar spine, the distal tip portion of the elongate stimulation instrument including a stimulation electrode that outputs electrical stimulation for nerve monitoring during advancement of the elongate stimulation instrument through the psoas muscle; advancing a dilator system along the lateral, trans-psoas path to the lumbar spine to create a distraction corridor, the dilator system comprising at least one dilator that slidably engages an exterior of the elongate stimulation instrument, the at least one dilator being advanced to the spinal disc along the lateral, trans-psoas path to the lumbar spine; slidably advancing a three-bladed retractor assembly over the dilator system toward the spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including a posterior-most retractor blade, a caudal-most retractor blade, and a cephalad-most retractor blade that extend generally perpendicularly relative to arm members of a blade holder apparatus, wherein the three-bladed retractor assembly is slidably advanced over the dilator system when in a first position in which the posterior-most retractor blade, the caudal-most retractor blade, and the cephalad-most retractor blade are positioned to simultaneously advance over the dilator system; adjusting the blade holder apparatus to shift the three-bladed retractor assembly to a second position in which the caudal-most retractor blade and the cephalad-most retractor blade are spaced apart from the posterior-most retractor blade to enlarge the distraction corridor and form an operative corridor along the lateral, trans-psoas path to the lumbar spine; inserting an implant that is releasably secured to an inserter tool through the operative corridor formed by the three-bladed retractor assembly along the lateral, trans-psoas path to the lumbar spine; releasing the implant from the inserter tool when the implant is positioned in a disc space of the lumbar spine.