Patent ID: 7569056

Claim:
Apparatus for providing access to a series of adjacent vertebrae located within a human lumbar and sacral spine having an anterior aspect, a posterior aspect and an axial aspect from an anterior or posterior sacral target point of a sacral vertebra in alignment with a visualized, axial instrumentation/fusion line extending in the axial aspect through the series of adjacent vertebral bodies, wherein the axial aspect is curved in the posterior-anterior plane due to curvature of the spinal column, the vertebrae separated by intact or damaged spinal discs, the apparatus comprising: a controllable boring device configured for boring a curved trans-sacral axial bore from the accessed sacral target point in alignment with the axial instrumentation/fusion line cephalad and axially through the vertebral bodies of the series of adjacent vertebrae and any intervertebral spinal discs; and a bore enlarging tool sized to fit within the curved axial bore, the tool adapted to be inserted from the accessed sacral target point to a selected location along the curved axial bore, the tool operable to enlarge a section of the curved axial bore to form at least one recess therein; wherein the controllable boring device comprises an elongated drill shaft assembly comprising: a drill bit attached to a flexible drive shaft; a sheath with an inner lumen for receiving the flexible drive shaft, the sheath comprising a distal segment and one or more radially offset tip deflection wire lumens; and one or more tip deflection wires disposed in the one or more radially offset tip deflection wire lumens for imparting a desired curvature in the distal segment of the sheath; wherein the bore enlarging tool comprises a counterboring tool assembly comprising: an elongate drive shaft extending between a shaft proximal end and a shaft distal end, the shaft having a shaft lumen; a cutting head mounted to the shaft distal end, the cutting head comprising deployment/retraction means for deploying the cutting head from a retracted locked position to a deployed locked position and for retracting the cutting head from the deployed locked position to the retracted locked position, the cuffing head capable of cuffing away bone or intervertebral disc material while in the deployed locked position; and rotating means for rotating the cutting head from the shaft distal end to cut away vertebral bone or disc material.