SUPPLEMENTATION OR REPLACEMENT OF A NUCLEUS PULPOSUS OF AN INTERVERTEBRAL DISC

• US 20080312744A1
• Filed: 06/27/2008
• Published: 12/18/2008
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Keane, Michael F., Vresilovic, Edward, Schaer, Thomas P.
• Granted Patent: US 8,147,553 B2
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4445 Means for culturing intervertebral disc tissue
• 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 2002/4631 the prosthesis being specially adapted for being cemented
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2230/0071 spherical

Abstract

A degenerated nucleus pulposus located in a central core region of an intervertebral disc within the annulus fibrosus is supplemented or replaced by a method wherein an amount of a biocompatible material is introduced into the central core region by a process including the steps of 1) forming a channel through a vertebral body adjacent to said intervertebral disc, extending from an exterior surface of the vertebral body to the central core region of the annulus fibrosus; 2) introducing an amount of a biocompatible material through the channel into the central core region of the annulus fibrosus; 3) pressurizing the biocompatible material through the channel to a postsurgical pressure sufficient to alleviate symptoms caused by the degenerated nucleus pulposus; and 4) sealing the channel while maintaining the sufficient postsurgical pressure. After sealing the channel, a vertebroplasty may optionally be performed in the vertebra.

Claims

1-28. -28. (canceled)

29. A method for replacing or supplementing an intervertebral disc located between endplates of adjacent superior and inferior vertebral bodies, the endplates of the vertebral bodies each defining a longitudinal axis, the method comprising the steps of:

(a) forming a channel through one of the superior and inferior vertebral bodies adjacent to the intervertebral disc, the channel extending from an exterior surface of the vertebral body to the intervertebral disc, the channel having a longitudinal axis defining a vertical approach angle with respect to the longitudinal axis of the endplate of the vertebral body through which the channel is formed, the vertical approach angle being in a range from about 10°

to about 70°

;

(b) introducing a biocompatible material through the channel into the intervertebral disc; and

(c) sealing the channel with a plug.

30. The method of claim 29, wherein the vertical approach angle being in a range from about 35°

to about 45°

.

31. The method of claim 29, wherein the vertical approach angle is about 40°

.

32. The method of claim 29, wherein the longitudinal axis of the channel forms a lateral approach angle with respect to a spinous process plane of the adjacent superior and inferior vertebral bodies, the lateral approach angle being in a range from about 20°

to about 70°

.

33. The method of claim 32, wherein the lateral approach angle is about 50°

.

34. The method of claim 29, wherein the plug is constructed of a biocompatible sealing material.

35. The method of claim 34, wherein the biocompatible sealing material is selected from the group consisting of a bone cement, an autograft, an allograft, and a xenograft.

36. The method of claim 35, wherein the bone cement is selected from the group consisting of poly(methylmethacrylate), calcium phosphate, calcium sulfate, calcium carbonate, and hydroxyapatite.

37. The method of claim 29, wherein the plug is comprised of a biocompatible sealing material and a mechanical plug.

38. The method of claim 37, wherein the mechanical plug is selected from the group consisting of a bone screw and a barbed plug.

39. The method of claim 29, further comprising the step of:

(d) inserting a predetermined quantity of a generally incompressible material in the channel between the biocompatible material and the plug.

40. The method of claim 39, wherein the generally incompressible material is selected from the group consisting of a bone cement, an autograft, an allograft, and a xenograft.

41. The method of claim 29, further comprising the step of:

(d) exerting pressure on the biocompatible material through the channel before sealing the channel.

42. The method of claim 41, wherein the biocompatible material in step (d) is pressurized by inserting a bone screw or a barbed plug into the channel.

43. The method of claim 29, wherein the biocompatible material has a compressional modulus not greater than about 4 Mpa.

44. The method of claim 29, wherein the biocompatible material has a Poisson ratio in a range of from about 0.30 to 0.50.

45. The method of claim 29, wherein the biocompatible material is a hydrogel.

46. The method of claim 45, wherein the hydrogel is a thin string.

47. The method of claim 29, wherein the biocompatible material is selected from the group consisting of a polyurethane and a silicone.

48. A method for replacing or supplementing a nucleus pulposus in an intervertebral disc having an annulus fibrosus surrounding a nucleus pulposus, the intervertebral disc being located between endplates of adjacent superior and inferior vertebral bodies, the endplates of the vertebral bodies each defining a longitudinal axis, the method comprising the steps of:

(a) forming a channel through one of the superior and inferior vertebral bodies adjacent to the intervertebral disc, the channel extending from an exterior surface of the vertebral body to the nucleus pulposus, the channel having a longitudinal axis defining a vertical approach angle with respect to the longitudinal axis of the endplate of the vertebra through which the channel is formed, the vertical approach angle being about 40°

, the longitudinal axis of the channel forms a lateral approach angle with respect to a spinous process plane of the adjacent vertebral bodies, the lateral approach angle being about 50°

;

(b) introducing an amount of a biocompatible material through the channel into the annulus fibrosus; and

(c) sealing the channel with a plug.