Patent ID: 8403841

Claim:
A system for forming an operating corridor to a lumbar spine, comprising: an elongate member deliverable to a spinal disc along a lateral, trans-psoas path to the lumbar spine such that a distal tip region of the elongate member engages an annulus of the spinal disc, the distal tip region of the elongate member including a stimulation electrode to deliver electrical stimulation for nerve monitoring when the elongate member is positioned in the lateral, trans-psoas path; a dilator system to create a distraction corridor along the lateral, trans-psoas path to the lumbar spine, the dilator system comprising a dilator that slidably engages an exterior of the elongate member, the dilator being deliverable to the spinal disc along the lateral, trans-psoas path to the lumbar spine; a three-bladed retractor assembly slidable over the dilator system toward the spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including: a blade holder assembly and first, second, and third retractor blades that extend generally perpendicularly relative to arm portions of the blade holder assembly, the first, second, and third retractor blades each having a concave surface region along an inner facing distal end portion, wherein the three-bladed retractor assembly is adjustable from a first position in which the first, second, and third retractor blades are slidable over the dilator system to a second position in which the second and third retractor blades are positioned away from the first retractor blade to enlarge the distraction corridor and thereby form an operative corridor along the lateral, trans-psoas path to the lumbar spine, and wherein the second and third retractor blades are movable relative to the first blade in response to pivoting movement of two of the arm portions of the blade holder assembly, a posterior shim element to releasably engage with a posterior-most retractor blade of the first, second, and third retractor blades so that a portion of the posterior shim element extends distally from the posterior-most retractor blade to anchor into the spinal disc; and wherein when the three-bladed retractor assembly is adjusted to the second position to form the operative corridor along the lateral, trans-psoas path to the lumbar spine, the first retractor blade is the posterior-most retractor blade of the first, second, and third retractor blades and the operative corridor is dimensioned so as to pass an implant through the operative corridor along the lateral, trans-psoas path to the lumbar spine.