Patent ID: 7396360
Filing Date: 2008-07-08
Classification: A61B

Abstract:
1. A minimally invasive surgical method for fusing adjacent upper and lower vertebrae, said method comprising the steps of: providing an apparatus comprising first and second K-wires, first and second fixation blocks, a swivel block having relatively movable first and second block members, a rod member extending between the fixation blocks and the first block member, and a cannula extending from the second block member; inserting the first K-wire into the spinous process of the upper vertebrae; inserting the second K-wire into the transverse process on a first side of the lower vertebrae; securing the first fixation block to the first K-wire and the second fixation block to the second K-wire with the rod member extending across the K-wires; securing the second block member of the swivel block assembly relative to the first block member to achieve a desired angle for a first axis along which a first screw will be implanted into the facet joint on the first side; securing the swivel block assembly at a desired axial position on the rod member; obtaining percutaneous access along the first axis to a second side of the upper vertebrae via the cannula; providing a first one removable screw for insertion into the cannula, the first screw having a threaded section for implantation across the facet joint to promote fusion of the adjacent vertebrae and an elongated shank section that is shearable subcutaneously following implantation; inserting the first screw through the cannula; implanting the threaded section of the first screw along the first axis across the facet joint on the first side to attach the upper and lower vertebrae; percutaneously inserting a shearing tool over the elongated shank section of the first screw; and shearing the elongated shank section of the first screw with the shearing tool to form an accessible head portion of the shank section that lies above the surface of the lamina of the upper vertebrae.