Systems and methods for performing spine surgery

• US 8,790,406 B1
• Filed: 04/02/2012
• Issued: 07/29/2014
• Est. Priority Date: 04/01/2011
• Status: Active Grant

• Current Assignee: William D. Smith
• Original Assignee: William D. Smith
• Inventors: Smith, William D.
• Primary Examiner(s): Philogene, Pedro
• Application Number:
  US13/437,917
• Time in Patent Office: 848 Days
• Field of Search: 623/17.11, 623/17.16, 600/202, 600/210, 600/213, 600/215, 600/184, 600/214, 600/219, 600/235, 600/546, 600/554, 600/547, 606/90, 606/129, 606/190, 606/191, 606/198, 606/279, 606/32, 606/41, 607/43, 607/2, 607/131, 607/130
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/1662 for particular parts of the body
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• CPC Class Codes: A61B 17/3472 for bones, e.g. intraosseus injections
• CPC Class Codes: A61B 2017/564 Methods for bone or joint treatment
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30588 filled with solid particles
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/3093 for promoting ingrowth of bone tissue
• CPC Class Codes: A61N 1/18 Applying electric currents by contact electrodes

Abstract

Systems and methods are described for accessing and operating on an intervertebral disc at the lumbosacral junction via a trans-iliac approach. The instruments and methods described employ nerve monitoring to direct passage of the instruments through a safe zone between the L5 nerve root lying posterior to the trans-iliac path and the iliac vein (and iliac artery) lying anterior to the trans-iliac path.

Claims

1. A method for accessing the L5/S1 disc of the lumbosacral junction, comprising the steps of:

creating an access hole through the ilium;

advancing an initial dilator through the access hole and towards the L5/S1 disc while and electrical stimulation signal is delivered from a stimulation electrode on the distal end of the initial dilator;

assessing the neuromuscular response to the stimulation signal to indicate the proximity of the L5/S1 nerve root to the distal end of the initial dilator;

directing the distal end of the dilator closer to the L5/S1 nerve root until the neuromuscular response indicates that the distal end of the initial dilator is next to but not contacting the L5 nerve root;

advancing the distal end of the initial dilator through a safe zone between the L5 nerve root and the iliac vein to the L5/S1 disc; and

advancing at least one supplemental dilator over the initial dilator through the access hole and safe zone to the L5/S1 disc; and

removing all but the outermost dilator.

2. The method of claim 1, comprising the additional step of adjusting the position of the initial dilator anteriorly to the center of the safe zone.

3. The method of claim 2, comprising the additional step of docking the initial dilator to the spine by advancing a K-wire through the initial dilator and penetrating the annulus of the L5/S1 disc.

4. The method of claim 3, wherein three supplemental dilators are advanced over the initial dilator the access hole and safe zone to the L5/S1 disc.

5. The method of claim 1, wherein while advancing the at least one supplemental dilator an electrical stimulation signal is delivered from a stimulation electrode on the distal end of the at least one supplemental dilator to detect nerve proximity during advancement of the at least one supplemental dilator to the L5/S1 disc.

6. The method of claim 1, comprising the additional step of performing a procedure on the L5/S1 disc through a passageway in the outermost dilator.

7. The method of claim 6, wherein the procedure performed on the L5/S1 disc is a discectomy.

8. The method of claim 7, where the procedure performed on the L5/S1 disc further includes a fusion.

9. The method of claim 8, wherein the fusion procedure includes implanting a fusion implant in the L5/S1 disc space through the passageway in the outermost dilator.

10. The method of claim 9, wherein the fusion implant include an expandable textile bag that is inserted in a deflated stated and expanded within the L5/S1 disc space by introducing bone growth promoting materials into the bag.

11. The method of claim 10, wherein the textile bag includes integrated structural supports.

12. The method of claim 11, wherein the integrated structural supports are comprised of polymer blocks attached to the corners of the textile bag.

13. The method of claim 8, wherein the fusion implant is a single insert dimensioned to extend across the L5/S1 disc space.

14. The method of claim 13, wherein the single insert includes a fusion aperture extending from a top surface to a bottom surface that is packed with bone growth promoting materials prior to introduction of the implant.

15. The method of claim 1, wherein the step of creating the access hole through the ilium comprises:

advancing an instrument into the ilium and forming a pilot hole;

advancing an initial dilator into the pilot hole and impacting the dilator through the ilium to create an access hole; and

advancing at least one supplemental dilator over the initial dilator and impacting the dilator through the ilium to enlarge the access hole.

16. The method of claim 15, wherein the instrument advanced into the ilium to form the pilot hole is a jamshidi needle.

17. The method of claim 16, comprising the additional steps of:

removing an inner stylet from a cannula of the jamshidi needle;

introducing a K-wire through the cannula;

removing the cannula; and

introducing the initial dilator into the pilot hole over the K-wire.

18. The method of claim 15, wherein the instrument advanced to the ilium to form the pilot hole is a Steinman pin.

19. The method of claim 15, wherein three supplemental dilators are advanced over the initial dilator and impacted through the ilium to enlarge the access hole.

20. The method of claim 1, wherein the outermost dilator is anchored in position prior to removing the remaining dilators.