Method and apparatus for implanting a hydrogel prosthesis for a nucleus pulposus

• US 20060276802A1
• Filed: 03/29/2006
• Published: 12/07/2006
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: ReGelTec, Inc.
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Singhatat, Wamis, Keane, Michael, Vresilovic, Edward, Schaer, Thomas Peter, Arthur, Amy
• Granted Patent: US 7,850,730 B2
• Time in Patent Office: Days
• US Class Current: 606/102
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/30075 swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/3009 Transparent or translucent
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30581 having a pocket filled with fluid, e.g. liquid
• CPC Class Codes: A61F 2002/30617 Visible markings for adjusting, locating or measuring
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4663 for measuring volumes or other three-dimensional shapes
• CPC Class Codes: A61F 2002/4677 using a guide wire
• CPC Class Codes: A61F 2002/4693 hydraulic
• CPC Class Codes: A61F 2002/4694 pneumatic
• CPC Class Codes: A61F 2210/0061 swellable
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2250/0091 transparent or translucent
• CPC Class Codes: A61F 2250/0097 Visible markings, e.g. indicia

Abstract

An instrument for inserting an elongated hydrogel prosthesis into an intervertebral disc includes an insertion cannula that is inserted through the annulus fibrosus of an intervertebral disc to provide access to the nucleus region of the disc, an elongated hydrogel prosthesis packaged within a tubular container adapted to be coupled to a proximal end of the insertion cannula, and a source of fluid pressure adapted to be coupled to a proximal end of the tubular container. Auxiliary instruments for use in convenient insertion of the insertion cannula through the nucleus pulposus and providing for a complete and controlled passage of the hydrogel prosthesis through the insertion cannula are provided in a kit with the insertion cannula. A sizing apparatus for determining the volume of prosthesis to be inserted includes a catheter or cannula capable of being inserted through the insertion cannula into the nucleus region of the intervertebral disc and having at its distal end a balloon capable of being inflated within the intervertebral disc with a measurable volume of a fluid in order to determine the amount of hydrogel prosthesis to be injected.

Claims

1. An instrument for inserting a hydrogel prosthesis into an intervertebral disc, comprising:

a prosthesis delivery cannula having a distal end adapted to be inserted through an annulus fibrosus of said intervertebral disc, a proximal end, and a delivery lumen extending between said proximal end and said distal end;

a storage tube having a distal end, adapted to be coupled to said proximal end of said prosthesis delivery cannula, and a proximal end, said storage tube containing an elongated hydrogel prosthesis;

a fluid coupling adapted to couple said distal end of said storage tube to said proximal end of said prosthesis delivery cannula;

a source of fluid pressure adapted to be coupled to said proximal end of said storage tube;

a fluid coupling adapted to couple said proximal end of said storage tube to said source of fluid pressure; and

a pressure indicator adapted to indicate the pressure within said delivery lumen, said storage tube, or said source of fluid pressure.

2. The instrument of claim 1, wherein said prosthesis delivery cannula has an auxiliary lumen extending generally from said proximal end to said distal end.

3. The instrument of claim 1, wherein said source of fluid pressure is a pressurizing syringe.

4. A kit of instruments for inserting an elongated hydrogel prosthesis into an intervertebral disc, comprising

a prosthesis delivery cannula having a distal end adapted to be inserted through an annulus fibrosus of said intervertebral disc, a proximal end provided with a fluid coupling adapted to transmit said hydrogel prosthesis, and a delivery lumen extending between said proximal end and said distal end;

a first guidewire sized to have a sliding fit within said delivery lumen of said prosthesis insertion cannula and having a first end adapted for insertion through tissue surrounding said intervertebral disc; and

a second guidewire sized to be passed through said delivery lumen of said prosthesis insertion cannula and having a distal end adapted to pierce an annulus fibrosus of said intervertebral disc.

5. A method for implanting a hydrogel prosthesis within an intervertebral disc, comprising the steps of:

a) advancing a first guidewire through tissue surrounding an intervertebral disk until an end portion of said first guidewire contacts an outer wall of an annulus fibrosus of said intervertebral disc;

b) advancing over said first guidewire a prosthesis insertion cannula, said prosthesis insertion cannula having distal end adapted to be inserted through said annulus fibrosus of said intervertebral disc, a proximal end, and a delivery lumen extending between said proximal end and said distal end, said delivery lumen sized to slide over said first guidewire, said prosthesis insertion cannula being advanced until said distal end thereof contacts said outer wall of said annulus fibrosus;

c) removing said first guidewire from said delivery lumen;

d) advancing through said delivery lumen a second guidewire sized to be passed through said delivery lumen of said prosthesis insertion cannula and having a distal end adapted to pierce an annulus fibrosus of an intervertebral disc, until said distal end has pierced said annulus fibrosus and extends into a nucleus pulposus region of said intervertebral disc;

e) advancing said prosthesis insertion cannula over said second guidewire until said distal end of said prosthesis insertion cannula extends into said nucleus pulpous region of said intervertebral disc;

f) removing said second guidewire from said delivery lumen, thereby leaving an open channel into said nucleus pulposus region of said intervertebral disc;

g) optionally, removing nucleus pulposus tissue from said nucleus pulposus through said open channel;

h) coupling to said proximal end of said prosthesis delivery cannula distal end of a storage tube, said storage tube containing an elongated hydrogel prosthesis;

i) coupling a proximal end of said storage tube to a source of source of fluid pressure;

j) applying said fluid pressure to said proximal end of said storage tube thereby to force said hydrogel prosthesis through said delivery lumen of said prosthesis delivery cannula and into said nucleus pulposus region;

k) removing said prosthesis delivery cannula from said intervertebral disc.

6. The method of claim 5, wherein prior to step h), volume within said intervertebral disc to be filled by said hydrogel prosthesis is determined.

7. The method of claim 6, wherein said volume is determined by inserting an inflatable balloon through said delivery lumen of said prosthesis insertion cannula, inflating said balloon with a fluid to a predetermined pressure, and determining the volume of said fluid required to inflate said balloon to said predetermined pressure.

8. An instrument for determining volume within an intervertebral disc to be filled with a hydrogel prosthesis, comprising:

an inflation catheter, at least a first portion thereof sized for insertion through a delivery lumen of a prosthesis insertion cannula, having a distal end and a proximal end adapted to be coupled to a source of pressurizing fluid; and

an inflatable balloon fastened to said distal end of said inflation catheter and adapted to be inflated by said pressurizing fluid,

wherein said inflatable balloon exhibits a compliance sufficient, when said balloon is inflated with a pressurized fluid, to substantially conformably fill a fillable region within said intervertebral disc.

9. The instrument of claim 8, further comprising a source of pressurizing fluid capable of determining pressure of said pressurizing fluid and volume of said pressurizing fluid supplied to inflate said balloon.

10. The instrument of claim 8, wherein a second portion of said inflation catheter adjacent to said distal end has a diameter less than said first portion.

11. The instrument of claim 10, wherein said balloon is fastened to said second portion of said inflation catheter.

12. The instrument of claim 8, additionally including at least one radiopaque marker positioned near said distal end of said inflation catheter.

13. The instrument of claim 8, wherein said balloon is sized such that upon filling with said pressurized fluid within said fillable region said balloon does not reach its fully distended condition.

14. A method of determining the volume of a fillable region within an intervertebral disc, comprising:

inserting into said fillable region a balloon in a collapsed state,

expanding said balloon within said fillable region by introducing into said balloon a quantity of a pressurized fluid until a pressure within said balloon reaches a predetermined pressure, and

measuring said quantity of said pressurized fluid.

15. The method of claim 14, wherein said predetermined pressure is in a range of from about 5 psi to about 50 psi.

16. The method of claim 14, wherein said predetermined pressure is in a range of from about 15 psi to about 45 psi.

17. The method of claim 14, wherein said predetermined pressure is in a range of from about 20 psi to about 40 psi.

18. The method of claim 14, wherein said predetermined pressure is in a range of from about 30 psi to about 40 psi.

19. The method of claim 14, wherein said predetermined pressure is about 35 psi.

20. The method of claim 14, wherein said balloon is sized such that when expanded within said fillable region, said balloon never attains a fully distended state.