Method for subcutaneous suprafascial internal fixation

• US 5,728,097 A
• Filed: 07/09/1996
• Issued: 03/17/1998
• Est. Priority Date: 03/17/1992
• Status: Expired due to Term

• Current Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Mathews, Hallett H.
• Primary Examiner(s): Buiz, Micheal
• Assistant Examiner(s): Woo, Julian W.
• Application Number:
  US08/677,135
• Time in Patent Office: 616 Days
• Field of Search: 606/61, 606/72, 606/73
• US Class Current: 606/279
• 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 internal fixation of the spine comprising the steps of:

a) making an incision in the skin at an entry site adjacent at least two vertebrae to be instrumented for internal fixation;

b) introducing a bone screw into each of the at least two vertebrae to position the proximal end of the bone screw within a subcutaneous suprafascial space;

c) inserting an elongated fixation member into the subcutaneous suprafascial space adjacent the proximal ends of the bone screws; and

d) engaging the fixation member to the proximal ends of the bone screws.

2. The method for internal fixation of the spine of claim 1, wherein the step of introducing a bone screw includes:

inserting a guide pin into each of the at least two vertebrae; and

advancing a cannulated bone screw over the guide pin into the at least two vertebrae.

3. The method for internal fixation of the spine of claim 1, wherein the step of introducing a bone screw includes introducing a bone screw into the pedicle of each of the at least two vertebrae.

4. The method for internal fixation of the spine of claim 1, wherein:

the bone screws include an intermediate hub; and

the step of inserting an elongated fixation member includes supporting the fixation member on the hub of each of the bone screws.

5. The method for internal fixation of the spine of claim 4, comprising the additional step of further advancing the bone screw into a vertebra with the fixation member supported on the hub of the bone screw.

6. The method for internal fixation of the spine of claim 1, comprising the additional steps of:

resecting disc tissue from the disc space between at least two adjacent vertebrae; and

subsequently introducing fusion promoting material into the disc space.