Facet joint stabilization

• US 20060235391A1
• Filed: 03/07/2006
• Published: 10/19/2006
• Est. Priority Date: 03/08/2005
• Status: Active Grant

• Current Assignee: Xtant Medical Holdings, Inc. (OrbiMed Advisors LLC (China))
• Original Assignee: Zyga Technology, Inc. (Surgalign Holdings, Inc.)
• Inventors: Sutterlin, Chester III
• Granted Patent: US 8,696,707 B2
• Time in Patent Office: Days
• US Class Current: 606/86.A
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062

Abstract

Various implementations for therapy to facet joints connecting vertebrae are disclosed including: A) Facet joint stabilization that may be implemented using stabilization band that maintains tension between two anchors. The stabilization band may be retained in any one of a number of ways including the use of an anti-slip device such as a mechanically deformed crimp that abuts one of the anchors. B) Facet joint augmentation may be implemented by dilating the facet joint and inserting a facet joint spacer before adding a facet joint stabilization assembly. The facet joint augmentation may include connecting a tail section of the facet joint spacer to the first anchor used in the facet joint stabilization assembly. C) Facet joint immobilization may be implemented by inserting a fastener across the facet joint and into the vertebra so that the assembled fastener expands inside the vertebra.

Claims

1. A facet joint stabilization assembly for use across a facet joint, the facet joint located between two adjacent vertebrae in a spine, the facet joint stabilization assembly comprising:

a stabilization band including a first end and a second end;

a first anchoring means for anchoring the first end of the stabilization band into a first vertebra;

a second anchoring means anchored into a second vertebra on the opposite side of the facet joint; and

a retaining means adapted to prevent a tensioned stabilization band to move relative to the second anchor, the prevention of movement maintaining a tensile force on the stabilization band between the first anchoring means and the second anchoring means.

2. The facet joint stabilization assembly of claim 1 wherein:

the facet joint includes;

an inferior articular process from a cephalad vertebra; and

a superior articular process from a caudal vertebra which is caudal relative to the cephalad vertebra and adjacent to the cephalad vertebra; and

the stabilization band is positioned so that;

a portion of the stabilization band in a completed facet joint stabilization assembly is in contact with the inferior articular process; and

a portion of the stabilization band in the completed facet joint stabilization assembly is in contact with the superior articular process.

3. The facet joint stabilization assembly of claim 1 including a pre-formed opening in the stabilization band running transverse to the long axis of the stabilization band located near the first end of the stabilization band, the pre-formed opening engaged with the first anchoring means such that the stabilization band is anchored to a first vertebra.

4. The facet joint stabilization assembly of claim 1 wherein the first anchoring means is adapted to be driven through the stabilization band to form an opening in the stabilization band running transverse to the long axis of the stabilization band located near the first end of the stabilization band, the pre-formed opening engaged with the first anchoring means such that the stabilization band is anchored to a first vertebra.

5. The facet joint stabilization assembly of claim 1 wherein the first anchoring means is adapted to grip the stabilization band without the need for an opening in the stabilization band running transverse to the long axis of the stabilization band.

6. The facet joint stabilization assembly of claim 1 wherein the first anchoring means includes a staple that engages the first end of the stabilization band.

7. The facet joint stabilization assembly of claim 1 wherein the first anchoring means includes a foraminal hook.

8. The facet joint stabilization assembly of claim 1 wherein the first anchoring means includes a laminar hook.

9. The facet joint stabilization assembly of claim 1 wherein the first anchoring means engages the cortex of vertebra.

10. The facet joint stabilization assembly of claim 1 wherein the first anchoring means expands within the vertebra.

11. The facet joint stabilization assembly of claim 1 wherein the first anchoring means includes a bone screw.

12. The facet joint stabilization assembly of claim 1 wherein the first anchoring means includes:

a base configured to receive a snap lock pin; and

a snap lock pin that connects the stabilization band to the base implanted in the first vertebra.

13. The facet joint stabilization assembly of claim 1 wherein the first anchoring means is a facet screw.

14. The facet joint stabilization assembly of claim 1 wherein the retaining means includes an anti-slip device adapted to prevent a tensioned stabilization band to move relative to the anti-slip device in order to maintain a tensile force on the stabilization band between the first anchoring means and the second anchoring means.

15. The facet joint stabilization assembly of claim 14 wherein the anti-slip device includes a mechanical crimp which is deformed after a portion of the stabilization band moves relative to the mechanical crimp.

16. The facet joint stabilization assembly of claim 14 wherein the anti-slip device includes a channel that allow relative motion of the stabilization band in a first direction to increase the tension in the stabilization band but does not allow the stabilization band to freely move in the direction opposite to the first direction so that at least a portion of the tension applied to the stabilization band is maintained within the stabilization band between the anti-slip device and the first anchor after completion of the facet joint stabilization assembly.

17. The facet joint stabilization assembly of claim 14 wherein the anti-slip device includes a channel with a cam that allow relative motion of the stabilization band in a first direction but does not allow the stabilization band to freely move in the direction opposite to the first direction so that at least a portion of the tension applied to the stabilization band is maintained within the stabilization band between the anti-slip device and the first anchor after completion of the facet joint stabilization assembly.

18. The facet joint stabilization assembly of claim 14 wherein the anti-slip device is integral to the second anchoring means.

19. The facet joint stabilization assembly of claim 1 wherein the retaining means includes a knot tied in the stabilization band so that the knot cannot pass through a channel in the second anchor means.

20. The facet joint stabilization assembly of claim 1 wherein the retaining means includes an engagement between the second end of the stabilization band and the second anchoring means so that the second end of the stabilization band is not free to move towards the first anchoring means to release the tensile force on the stabilization band.

21. The facet joint stabilization assembly of claim 1 wherein:

the facet joint includes;

an inferior articular process from a cephalad vertebra; and

a superior articular process from a caudal vertebra which is caudal relative to the cephalad vertebra and adjacent to the cephalad vertebra; and

the first anchoring means is placed in the first vertebra that is also the cephalad vertebra.

22. The facet joint stabilization assembly of claim 21 wherein the second anchoring means is placed in the second vertebra that is also the caudal vertebra.

23. The facet joint stabilization assembly of claim 21 wherein the second anchoring means is placed in a vertebra more caudal than the caudal vertebra.

24. The facet joint stabilization assembly of claim 1 wherein:

the facet joint includes;

an inferior articular process from a cephalad vertebra; and

a superior articular process from a caudal vertebra which is caudal relative to the cephalad vertebra and adjacent to the cephalad vertebra; and

the first anchoring means is placed in the first vertebra that is also the caudal vertebra.

25. The facet joint stabilization assembly of claim 24 wherein the second anchoring means is placed in the second vertebra-that is also the cephalad vertebra.

26. The facet joint stabilization assembly of claim 24 wherein the second anchoring means is placed in a vertebra more cephalad than the cephalad vertebra.

27. The facet joint stabilization assembly of claim 1 wherein:

the facet joint includes;

an inferior articular process from a cephalad vertebra; and

a superior articular process from a caudal vertebra which is caudal relative to the cephalad vertebra and adjacent to the cephalad vertebra; and

neither the first vertebra or the second vertebra is either the cephalad vertebra or the caudal vertebra.

28. The facet joint stabilization assembly of claim 1 wherein the stabilization band is adapted to become progressively more resistant to flexion of the spine as the stabilization band is stretched along the long axis of the stabilization band.

29. An installed stabilization band assembly for use across a facet joint between two adjacent vertebrae, the installed stabilization band assembly comprising:

a stabilization band having a first end and a second end;

a first anchoring means for anchoring the first end of the stabilization band into a first vertebra on a first side of the facet joint;

a crimp; and

a second anchoring means anchored into an second vertebra on a second installed stabilization band assembly, the second anchoring means adapted to allow the stabilization band to be tensioned to impose tension on the stabilization band between the first anchoring means, the crimp abutting the second anchoring means, the crimp having been deformed so that the stabilization band that previously moved relative to the crimp and away from the first anchoring means is prevented from moving relative to the crimp towards the first anchoring means.

30. The installed stabilization band assembly of claim 29 including a pre-formed opening running transverse to the long axis of the stabilization band located near the first end of the stabilization band, the pre-formed opening engaged with the first anchoring means such that the stabilization band is anchored to the first vertebra.

31. The installed stabilization band assembly of claim 29 wherein the first anchoring means and the second anchoring means each include a bone screw.

32. The installed stabilization band assembly of claim 31 wherein each of the bone screws are configured to receive a snap lock pin and the first anchoring means includes a snap lock pin that connects the stabilization band to the bone screw implanted in the first vertebra.

33. The installed stabilization band assembly of claim 32 wherein the implanted bone screw is expanded by the insertion of the snap lock pin.

34. The installed stabilization band assembly of claim 29 wherein the first anchoring means is a hook.

35. The installed stabilization band assembly of claim 29 wherein the first anchoring means is a facet screw used as a stand alone anchor.

36. A facet joint dilator for use in increasing the distance between the superior articular process of a particular vertebra and an inferior articular process of an adjacent more cephalad vertebra, the facet joint dilator comprising:

an elongated shaft with a distal end for use at a facet joint and a proximal end that is manipulated by the user of the facet joint dilator; and

a dilator foot connected to the distal end of the elongated shaft and extending from the elongated shaft, the dilator foot having a leading edge that is smaller in cross section than the cross section of the dilator foot midway between the leading edge and the centerline of the elongated shaft.

37. The facet joint dilator for claim 36 wherein a first face of the dilator foot is substantially convex and a second face of the dilator foot being substantially concave.

38. The facet joint dilator of claim 36 wherein the cross sectional area measured in planes to the long axis of the dilator foot increase in size from the leading edge towards the shaft.

39. The joint dilator of claim 36 wherein the joint dilator is part of a set of joint dilators with an ascending set of foot thicknesses to impose increasing amounts of facet joint distraction.

40. The joint dilator of claim 36 where the dilator foot is tapered so that increasing the depth of insertion of the dilator foot into the gap between the superior articular process of the particular vertebra and the inferior articular process of the adjacent more cephalad vertebra increases the distance between the superior articular process and the inferior articular process.

53. The facet joint augmentation assembly of claim 40 wherein the first vertebra is cephalad to the first facet joint.

41. A facet joint spacer for insertion into a facet joint for use in maintaining a separation distance between a superior articular process on one vertebra and a corresponding inferior articular process on an adjacent more cephalad vertebra, the facet joint spacer comprising an implant section for insertion into the facet joint and a tail section with a pre-formed opening to engage with an anchoring means.

42. The facet joint spacer of claim 41 wherein the leading edge of the facet joint spacer is rounded to facilitate insertion into the facet joint.

43. The facet joint spacer of claim 41 wherein the implant section of the facet joint spacer is given a surface treatment to reduce resistance to the insertion of the implant section of the facet joint spacer into the facet joint.

44. The facet joint spacer of claim 41 wherein the implant section of the facet joint spacer is made of a material with a low coefficient of friction to reduce resistance to the insertion of the implant section of the facet joint spacer into the facet joint.

45. The facet joint spacer of claim 41 wherein the implant section of the facet joint spacer is made of a material adapted to conform,to the shape of the space between the superior articular process on one vertebra and the corresponding inferior articular process on the adjacent more cephalad vertebra.

46. The facet joint spacer of claim 41 wherein the facet joint spacer is wedge shaped so as to increase the relative angle of the superior articular process on one vertebra and the corresponding inferior articular process and the adjacent more cephalad vertebra.

47. The facet joint spacer of claim 41 wherein the implant section of the facet joint spacer includes a concave surface and a convex surface.

48. The facet joint spacer of claim 41 wherein the facet joint spacer includes a polytetrafluoroethylene polymer that facilitates inserting the facet joint spacer into the facet joint.

49. A facet joint spacer delivery device for delivery of a facet joint spacer, the facet joint spacer delivery device comprising:

an elongated shaft with a distal end for use at a facet joint and a proximal end that is manipulated by the user of the facet joint spacer delivery device;

a first arm extending from the distal end of the elongated shaft with a substantially concave face; and

a second arm extending from the distal end of the elongated shaft with a substantially concave face;

the facet joint spacer delivery device adapted to be pre-loaded with a facet joint spacer with a portion of the facet joint spacer located between the two arms, with a portion of the facet joint spacer within the concave face of the first arm and a portion of the facet joint spacer within the concave face of the second arm with a curved leading edge of the facet joint spacer extending beyond the first and second arms and away from the elongated shaft, and a tail section of the facet joint spacer extending beyond the first and second arms away from the curved leading edge of the facet joint spacer.

50. A facet joint augmentation assembly comprising:

a facet joint spacer inserted into a first facet joint between an superior articular process of one vertebra and a corresponding inferior articular process of an adjacent more cephalad vertebra;

a facet stabilization band with a first end;

a first anchoring means engaged with the first end of the facet stabilization band to anchor the first end of the facet stabilization band to a first vertebra;

a second anchoring means anchored to a vertebra the second anchoring means having an opening substantially surrounding a portion of the facet stabilization band; and

a retaining means engaged with a portion of the facet stabilization band to prevent movement of the facet stabilization band relative to the second anchoring means.

51. The facet joint augmentation assembly of claim 50 wherein the facet joint spacer includes a tail that extends beyond the facet joint and the first anchoring means anchors the facet joint tail to the first vertebra.

52. The facet joint augmentation assembly of claim 50 wherein the facet joint spacer tail has a pre-formed opening running transverse to the long axis of the facet joint spacer and the facet stabilization band has a pre-formed opening running transverse to the long axis of the facet stabilization band and at least a portion of the first anchoring means passes through the pre-formed opening in the facet stabilization band and the pre-formed opening in the tail of the facet joint spacer.

54. The facet joint augmentation assembly of claim 50 wherein the first vertebra is caudal to the first facet joint.

55. The facet joint augmentation assembly of claim 50 wherein the second anchoring means as anchored to a vertebra that is not adjacent to the first vertebra.

56. The facet joint augmentation assembly of claim 52 wherein the first anchoring means includes a cannulated split screw and a snap lock pin such that the cannulated split screw is adapted to be placed through the pre-formed opening in the facet stabilization band and through the pre-formed opening in the tail of the facet joint spacer and then into a bore hole in the vertebra before the snap lock pin is fully inserted into the cannulated split screw to expand portions of the cannulated split screw within the vertebra.

57. The facet joint augmentation assembly of claim 50 wherein the first anchoring means is a cannulated bone screw adapted to be passed over a guide wire.

58. The facet joint augmentation assembly of claim 50 wherein the second anchoring means incudes a cannulated split screw, and a snap lock pin with an eyelet plate with a portion of the facet stabilization band passing through an opening in the eyelet plate, the cannulated split screw adapted for placement into a bore hole in the vertebra before the snap lock pin with engaged eyelet plate is inserted into the cannulated split screw to expand portions of the cannulated split screw within the vertebra.

59. The facet joint augmentation assembly of claim 50 wherein the facet joint spacer is comprised of a lubricious material that facilitates inserting the facet joint spacer into the first facet joint.

60. The facet joint augmentation assembly of claim 59 wherein the facet joint spacer is comprised of a polytetrafluoroethylene polymer that facilitates inserting the facet joint spacer into the first facet joint.

61. A facet joint augmentation assembly comprising:

a facet joint spacer inserted into a first facet joint between an superior articular process of one vertebra and a corresponding inferior articular process of an adjacent more cephalad vertebra, the facet joint spacer having a tail that extends beyond the facet joint, the tail having a pre-formed opening running transverse to the long axis of the facet joint spacer;

a facet stabilization band with a first end having a pre-formed opening running transverse to the long axis of the facet stabilization band;

a first anchoring means with at least a portion of the first anchoring means passing through the pre-formed opening in the facet stabilization band and the pre-formed opening in the tail of the facet joint spacer to anchor both to a first vertebra;

a second anchoring means anchored to a vertebra the second anchoring means having an opening surrounding a portion of the facet stabilization band; and

a retaining means located adjacent to the second anchoring means with a portion of the facet stabilization band passing through the retaining means;

the retaining means adapted so that the facet stabilization band cannot move relative to the retaining means through the opening in the second anchoring means towards the first anchoring means;

the retaining means sized relative to the opening in the second anchoring means so that the retaining means cannot move through the opening in the second anchoring means.

62. A method of deploying a facet joint augmentation assembly to augment a facet joint between a superior articular process of one vertebra and a corresponding inferior articular process on an adjacent more cephalad vertebra, the method comprising the steps of:

accessing the spine through a posterior approach;

inserting a portion of facet joint dilator into the facet joint to increase the distance between the superior articular process and the inferior articular process;

removing the portion of the facet joint dilator from the facet joint to leave a created void;

inserting a facet joint spacer into the created void to maintain at a portion of the increased distance between the superior articular process and the inferior articular process;

using a first anchoring means to anchor a first end of a facet stabilization band to a first vertebra;

using a second anchoring means that surrounds a portion of the facet stabilization band to anchor the facet stabilization band to a vertebra;

moving a portion of the facet stabilization band relative to the second anchoring means; and

preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means.

63. The method of deploying a facet joint stabilization assembly of claim 62 including cutting the facet stabilization band near the second anchoring means leaving the facet stabilization band intact between the second anchoring means and the first anchoring means.

64. The method of deploying a facet joint stabilization assembly of claim 62 wherein the step of moving a portion of the facet stabilization band relative to the second anchoring means serves to reduce the distance between the first anchoring means and the second anchoring means such that the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means serves to substantially maintain the reduced relative distance between the positions of the first anchoring means relative to the second anchoring means.

65. The method of deploying a facet joint stabilization assembly of claim 62 wherein the step of moving a portion of the facet stabilization band relative to the second anchoring means follows the use of a tool to reduce the distance between the first anchoring means and the second anchoring means such that the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means serves to substantially maintain the reduced relative distance between the positions of the first anchoring means relative to the second anchoring means.

66. The method of deploying a facet joint augmentation assembly of claim 62 including the step of drilling a first bore hole through the cortical bone in the first vertebra.

67. The method of deploying a facet joint augmentation assembly of claim 62 including the step of punching a first bore hole through the cortical bone in the first vertebra.

68. The method of deploying a facet joint augmentation assembly of claim 62 wherein the step of using the first anchoring means includes engaging self-tapping threads into the first vertebra.

69. The method of deploying a facet joint augmentation assembly of claim 62 including the step of coating the facet joint spacer to increase lubricity.

70. The method of deploying a facet joint augmentation assembly of claim 62 wherein the first vertebra is cephalad to the facet joint.

71. The method of deploying a facet joint augmentation assembly of claim 62 wherein the first vertebra is caudal to the facet joint.

72. The ;

method of deploying a facet joint augmentation assembly of claim 62 wherein the facet joint spacer includes a tail portion that extends beyond facet joint after the facet joint spacer is inserted, and the method including anchoring the tail portion to the first vertebra.

73. The method of deploying a facet joint augmentation assembly of claim 72 wherein the tail portion is anchored to the first vertebra using the first anchoring means.

74. The method of deploying a facet joint augmentation assembly of claim 72 wherein the tail portion that extends beyond facet joint after the facet joint spacer is inserted includes a pre-formed opening that is engaged by the first anchoring means.

75. The method of claim 72 wherein the facet joint spacer is inserted into a facet joint spacer insertion tool between two arms extending from the distal end of the facet joint spacer insertion tool and the tail of the facet joint spacer has a pre-formed opening that is engaged by the first anchoring means before the facet joint spacer insertion tool is removed from the created void.

76. The method of deploying a facet joint augmentation assembly of claim 62 wherein the step of preventing the facet stabilization band from releasing all of the imposed tension includes use of an anti-slip device engaged with the facet stabilization band.

77. The method of deploying a facet joint augmentation assembly of claim 76 wherein the anti-slip device allows a portion of the facet stabilization band to move in a first direction through the anti-slip device but not in the second direction, opposite to the first direction to release all of the imposed tension.

78. The method of deploying a facet joint augmentation assembly of claim 62 wherein the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved includes~tying a knot in an end of the facet stabilization band.

79. The method of deploying a facet joint augmentation assembly of claim 62 wherein the step of preventing the facet stabilization band from returning to the position of the facet stabilization band I before it was moved includes mechanically deforming a crimp that surrounds a portion of the facet stabilization band such that the facet stabilization band with the mechanically deformed crimp cannot move through the second anchoring means towards the first anchoring means.

80. The method of deploying a facet joint augmentation assembly of claim 62 wherein the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved includes passing a portion of the facet stabilization band through a channel with teeth such that the facet stabilization band can move in a first direction away from the second anchor means but the facet stabilization band when engaged with the teeth cannot move through the second anchoring means towards the first anchoring means.

81. The method of deploying a facet joint augmentation assembly of claim 62 wherein the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved includes anchoring the facet stabilization band to both the first and second anchoring means and to a third anchor point different from the first anchor means and the second anchor means.

82. A method of deploying a facet joint stabilization assembly to stabilize a facet joint between a superior articular process of one vertebra and a corresponding inferior articular process on an adjacent more cephalad vertebra, the method comprising the steps of:

accessing the spine through a posterior approach;

using a first anchoring means to anchor a first end of a facet stabilization band to a first vertebra;

using a second anchoring means that surrounds a portion of the facet stabilization band to anchor the facet stabilization band to a vertebra;

moving a portion of the facet stabilization band relative to the second anchoring means; and

preventing the facet stabilization band from moving relevant to the second anchoring means to prevent the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means.

83. The method of deploying a facet joint stabilization assembly of claim 82 including the step of cutting the facet stabilization band near the second anchoring means leaving the facet stabilization band intact between the second anchoring means and the first anchoring means.

84. The method of deploying a facet joint stabilization assembly of claim 82 wherein the step of moving a portion of the facet stabilization band relative to the second anchoring means serves to reduce the distance between the first anchoring means and the second anchoring means such that the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means serves to substantially maintain the reduced relative distance between the positions of the first anchoring means relative to the second anchoring means.

85. The method of deploying a facet joint stabilization assembly of claim 82 wherein the step of moving a portion of the facet stabilization band relative to the second anchoring means follows the use of a tool to reduce the distance between the first anchoring means and the second anchoring means such that the step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means serves to substantially maintain the reduced relative distance between the positions of the first anchoring means relative to the second anchoring means.

86. The method of deploying a facet joint stabilization assembly of claim 82 wherein step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means includes placing a retaining means adjacent to the second anchoring and engaging the facet stabilization band with the retaining means before moving the facet stabilization band relative to the second anchoring means.

87. The method of deploying a facet joint stabilization assembly of claim 82 wherein step of preventing the facet stabilization band from returning to the position of the facet stabilization band before it was moved relative to the second anchoring means includes engaging the facet stabilization band with a retaining means and moving the retaining means adjacent to the second anchoring means after moving the facet stabilization band relative to the second anchoring means.

88. A method of rigid fixation of a facet joint to fixate a facet joint between a superior articular process of one vertebra and a corresponding inferior articular process on an adjacent more cephalad vertebra, the method comprising the steps of:

accessing the spine through a posterior approach;

drilling through the inferior articular process and into the corresponding superior articular process to create a channel;

inserting a cannulated base into the channel so one end of the cannulated base is placed in the superior articular process; and

inserting an expander into the cannulated base to expand the base within the channel in the superior articular process.