Method for subcutaneous suprafascial pedicular internal fixation

• US 5,357,983 A
• Filed: 01/04/1993
• Issued: 10/25/1994
• Est. Priority Date: 03/17/1992
• Status: Expired due to Term

• Current Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Original Assignee: Danek Medical, Inc. (Medtronic Plc)
• Inventors: Mathews, Hallett H.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US08/000,391
• Time in Patent Office: 659 Days
• Field of Search: 623/66, 623/17, 128/897, 128/898, 606/54, 606/60, 606/61, 606/64
• US Class Current: 128/898
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7007 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• CPC Class Codes: A61B 17/7049 Connectors, not bearing on the vertebrae, for linking longitudinal elements together A61B17/7055, A61B17/7053, A61B17/7019 take precedence
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30329 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2002/448 comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/449 comprising multiple spinal implants located in different intervertebral spaces or in different vertebrae
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements

Abstract

A method for internal fixation of vertebra of the spine to facilitate graft fusion includes steps for excising the nucleus of an affected disc, preparing a bone graft, instrumenting the vertebrae for fixation, and introducing the bone graft into the resected nuclear space. Disc resection is conducted through two portals through the annulus, with one portal supporting resection instruments and the other supporting a viewing device. The fixation hardware is inserted through small incisions aligned with each pedicle to be instrumented. The hardware includes bone screws, fixation plates, engagement nuts, and linking members. In an important aspect of the method, the fixation plates, engagement nuts and linking members are supported suprafascially but subcutaneously so that the fascia and muscle tissue are not damaged. The bone screw is configured to support the fixation hardware above the fascia. In a further aspect of the invention, a three component dilator system is provided for use during the bone screw implantation steps of the method.

Claims

1. A method for percutaneously resecting the nucleus of a spinal disc in a disk space, comprising the steps of:

a) introducing a pair of cannulae bilaterally into the disc space of the disc;

b) perforating the disc annulus at the location of each cannula;

c) inserting a cutting instrument into one cannula and a viewing instrument into the other cannula;

d) resecting the disc nucleus through the one cannula under direct vision through the other cannula; and

e) transposing the cutting instrument and viewing instrument between cannulae and resecting the remaining disc nucleus through the other cannula.

2. The method for percutaneously resecting the nucleus of a spinal disc of claim 1, wherein in the step of introducing the pair of cannulae the cannulae are introduced nominally ten centimeters bilaterally from the midline of the spinous process and the cannulae are introduced below the transverse processes of the vertebra adjacent the disk.

3. The method of percutaneously resecting the nucleus of a spinal disc of claim 1, further comprising the step of verifying the spinal anatomy under each cannulae using a visualization scope prior to perforating the disc annulus.

4. The method for percutaneously resecting the nucleus of a spinal disc of claim 1, wherein the step of resecting the disc material includes terminating resection through the one cannula when the cutting instrument can be seen under direct vision through the other cannula.

5. The method for percutaneously resecting the nucleus of a spinal disc of claim 1, wherein the step of resecting the disc material includes ablating the disc end plates using an ablating instrument introduced through the cannula.