APPARATUS AND METHODS FOR FRACTURE REPAIR

• US 20090182336A1
• Filed: 01/14/2009
• Published: 07/16/2009
• Est. Priority Date: 01/14/2008
• Status: Active Grant

• Current Assignee: Conventus Orthopaedics, Inc.
• Original Assignee: Conventus Orthopaedics, Inc.
• Inventors: Brenzel, Michael P., Hindrichs, Paul
• Granted Patent: US 8,287,538 B2
• Time in Patent Office: Days
• US Class Current: 606/62
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7097 Stabilisers comprising fluid filler in an implant, e.g. balloon; devices for inserting or filling such implants disc prostheses made of inflatable chambers or pockets filled with fluid A61F2/441; replacing the nucleus pulposus A61F2002/444
• CPC Class Codes: A61B 17/7225 for bone compression
• CPC Class Codes: A61B 17/7233 with special means of locking the nail to the bone
• CPC Class Codes: A61B 17/725 with locking pins or screws of special form
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone
• CPC Class Codes: A61B 17/7275 with expanding cylindrical parts
• CPC Class Codes: A61B 17/863 with thread interrupted or changing its form along shank, other than constant taper
• CPC Class Codes: A61B 17/869 characterised by an open form, e.g. wire helix
• CPC Class Codes: A61B 17/8858 laterally or radially expansible inflatable A61B17/8855
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone

Abstract

Apparatus and methods for bone fracture repair. The apparatus may include a structural support for positioning a first bone segment relative to a second bone segment. The apparatus may include an anchoring substrate. The anchoring substrate may be configured to compress the first bone segment to the second bone segment. The anchoring substrate may transmit tension from a distal bone segment anchor in the first bone segment to a proximal bone segment anchor in the second bone segment. The apparatus may be configured to be deployed percutaneously in an inner cavity of a bone. The apparatus may be installed in an open fracture. The apparatus may be expanded, self-expanding or configured for mechanically actuation. Some embodiments of the apparatus may include a central axis member that may be used in conjunction with expansion of one or both of the structural support and the anchoring substrate to configure the apparatus.

Claims

1. An apparatus for treating a fracture of a bone, the fracture including segments, the bone having an inner cavity, the apparatus comprising:

a structural support for positioning a first of the bone segments relative to a second of the bone segments, the structural support being configured to be deployed in the inner cavity; and

an anchoring substrate configured to compress the first bone segment to the second bone segment, the anchoring substrate being configured to be deployed in the inner cavity.

2. The apparatus of claim 1 wherein the anchoring substrate is fixed to the structural support.

3. The apparatus of claim 1 wherein the anchoring substrate is configured to be disposed within the structural support.

4. The apparatus of claim 1 wherein the anchoring substrate is configured to at least partially surround the structural support.

5. The apparatus of claim 4 further comprising, when the anchoring substrate is a first anchoring substrate, a second anchoring substrate that is configured to be disposed within the structural support.

6. The apparatus of claim 1 wherein the anchoring substrate is configured to be fixed to the structural support.

7. The apparatus of claim 1 wherein the structural support is configured to expand from a contracted state to an expanded state after release from a percutaneous delivery instrument.

8. The apparatus of claim 7 wherein the expanded state is based on a thermally preset shape.

9. The apparatus of claim 7 wherein the expanded state is based on plastic deformation.

10. The apparatus of claim 1 wherein the anchoring substrate is configured to expand from a contracted state to an expanded state after release from a percutaneous delivery instrument.

11. The apparatus of claim 10 wherein the expanded state is based on a thermally preset shape.

12. The apparatus of claim 10 wherein the expanded state is based on plastic deformation.

13. The apparatus of claim 1 wherein:

the structural support includes a first relative displacement member;

the anchoring substrate includes a second relative displacement member; and

the first and second relative displacement members are configured to displace a portion of the anchoring substrate relative to a portion of the structural support.

14. The apparatus of claim 13 wherein the first and second relative displacement members are configured to move substantially linearly with respect to each other.

15. The apparatus of claim 14 wherein the first and second relative displacement members are substantially coaxial with each other.

16. The apparatus of claim 15 wherein the first and second relative displacement members are configured to be detachably engaged, respectfully, by first and second manipulators.

17. The apparatus of claim 13 wherein the first and second relative displacement members are configured to rotate with respect to each other.

18. The apparatus of claim 17 wherein the first and second relative displacement members are substantially coaxial with each other.

19. The apparatus of claim 18 wherein the first and second relative displacement members are configured to be detachably engaged, respectfully, by first and second manipulators.

20. The apparatus of claim 1 further comprising a central axis member that is at least partially disposed inside the structural support and at least partially disposed inside the anchoring substrate.

21. The apparatus of claim 20 wherein:

the central axis member defines a longitudinal direction; and

a distal portion of the central axis member is longitudinally fixed, at a distal portion of the structural support, to the distal portion of the structural support.

22. The apparatus of claim 21 wherein a proximal portion of the structural support is configured to be displaced distally along the central axis member such that when the proximal portion of the structural support displaces distally along the central axis member, the structural support expands radially away from the longitudinal axis.

23. The apparatus of claim 22 further comprising a rotational member configured to rotate with respect to the central axis member and linearly displace the proximal portion of the structural support.

24. The apparatus of claim 23 wherein the rotational member is threadedly engaged with the central axis member.

25. The apparatus of claim 20 wherein:

the central axis member defines a longitudinal direction; and

a proximal portion of the central axis member is longitudinally fixed, at a proximal portion of the anchoring substrate, to the proximal portion of the structural support.

26. The apparatus of claim 25 further comprising a one-way lock configured to substantially prevent displacement of the central axis member, relative to the proximal portion of the structural support, in a distal direction.

27. The apparatus of claim 26 wherein the one-way lock is a ratcheting mechanism.

28. The apparatus of claim 20 wherein:

the central axis member defines a longitudinal direction;

a distal portion of the central axis member is longitudinally fixed, at a distal portion of the structural support, to the distal portion of the structural support; and

a proximal portion of the central axis member is longitudinally fixed, at a proximal portion of the support structure, to the proximal portion of the structural support.

29. The apparatus of claim 20 wherein:

the central axis member defines a longitudinal direction; and

a distal portion of the central axis member is longitudinally fixed, at a distal portion of the anchoring substrate, to the distal portion of the anchoring substrate.

30. The apparatus of claim 29 wherein a proximal portion of the anchoring substrate is configured to be displaced distally along the central axis member such that when the proximal portion of the anchoring substrate displaces distally along the central axis member, the anchoring substrate expands radially away from the longitudinal axis.

31. The apparatus of claim 30 wherein the anchoring substrate comprises:

a first portion having expansion cells that have a first expansion ratio;

a second portion having expansion cells that have a second expansion ratio;

the first expansion ratio being different from the second expansion ratio; and

at least one of the first and second expansion ratios are selected to provide a desired contour when the anchoring substrate is expanded.

32. The apparatus of claim 30 further comprising a rotational member configured to rotate with respect to the central axis member and linearly displace the proximal portion of the anchoring substrate.

33. The apparatus of claim 32 wherein the rotational member is threadedly engaged with the central axis member.

34. The apparatus of claim 20 wherein:

the central axis member defines a longitudinal direction; and

a proximal portion of the central axis member is longitudinally fixed, at a proximal portion of the anchoring substrate, to the proximal portion of the anchoring substrate.

35. The apparatus of claim 34 further comprising a one-way lock configured to substantially prevent displacement of the central axis member, relative to the proximal portion of the anchoring substrate, in a distal direction.

36. The apparatus of claim 35 wherein the one-way lock is a ratcheting mechanism.

37. The apparatus of claim 20 wherein:

the central axis member defines a longitudinal direction;

a distal portion of the central axis member is longitudinally fixed, at a distal portion of the anchoring substrate, to the distal portion of the anchoring substrate; and

a proximal portion of the central axis member is longitudinally fixed, at a proximal portion of the anchoring substrate, to a proximal portion of the anchoring substrate.

38. The apparatus of claim 20 wherein:

the central axis member comprises a catch; and

the anchoring substrate comprises a stop;

wherein, when the central axis member is drawn away from the anchoring substrate in a proximal direction;

the catch engages the stop to draw a proximal portion of the anchoring substrate in the proximal direction relative to a proximal portion of the structural support.

39. The apparatus of claim 38 wherein the stop is integral with the catch.

40. The apparatus of claim 38 wherein the stop is disposed inside the anchoring substrate.

41. The apparatus of claim 38 wherein the central axis member comprises a first threaded member;

and

the anchoring substrate comprises a second threaded member that is configured to threadedly engage the first threaded member;

wherein, when the first and second threaded members are engaged with each other, a proximal portion of the anchoring substrate is drawn in the proximal direction relative to a proximal portion of the structural support.

42. The apparatus of claim 41 further comprising a rotational coupling that rotatably secures a distal end of the central axis member to a distal portion of the anchoring substrate.

43. The apparatus of claim 1 further comprising a proximal anchor that is configured to secure a proximal portion of the anchoring substrate to the bone.

44. The apparatus of claim 43 wherein the proximal anchor is operationally substantially coaxial with the anchoring substrate.

45. The apparatus of claim 43 wherein the proximal anchor is operationally substantially coaxial with the structural support.

46. The apparatus of claim 43 wherein the proximal anchor is substantially cylindrical and comprises blades that extend radially outward.

47. The apparatus of claim 46 wherein the blades comprise circumferential portions of the proximal anchor.

48. The apparatus of claim 46 wherein the blades comprise helical portions of the proximal anchor.

49. The apparatus of claim 46 wherein:

the proximal anchor includes a proximal end and a distal end; and

the blades move radially outward when the proximal and distal ends are moved toward each other.

50. The apparatus of claim 49 further comprising, when the proximal anchor has a center axis, a detent configured to fix the distal end of the proximal anchor, with respect to the center axis, to the structural support;

wherein the proximal end of the proximal anchor is configured to be pushed distally to move the blades radially outward.

51. The apparatus of claim 48 further comprising, when the proximal anchor has a center axis, a detent configured to rotatably fix the distal end of the proximal anchor, with respect to the center axis, to the structural support;

wherein the proximal end of the proximal anchor is configured to be pushed distally and rotated about the center axis to move the blades radially outward while the proximal anchor rotates about the center axis.

52. The apparatus of claim 1 further comprising an anchor for transferring force from the anchoring substrate to the first and second bone segments.

53. The apparatus of claim 52 further comprising, when the anchoring substrate has a proximal opening:

a lumen configured to deliver the anchor distally through the opening; and

a steerable catheter configured to drive a portion of the anchor through the anchoring substrate, outside the structural support and into the bone segment.

54. The apparatus of claim 1 further comprising, when the structural support has a proximal opening:

a lumen configured to deliver an anchor distally through the opening;

a steerable catheter configured to drive a portion of the anchor outside the structural cage and into the first bone segment; and

a tether that is fixed to the anchor, the tether configured to transfer force from the anchor to the second bone segment.

55. An anchor for fastening bone to a substrate implanted in an inner cavity of a bone, the substrate including perforations, the anchor comprising:

a head;

a shaft; and

a plurality of locking surfaces that extend radially away from the shaft, each of the plurality of locking surfaces being configured to engage the substrate in the inner cavity after penetrating one of the perforations.

56. The anchor of claim 55 wherein each of the locking surfaces is present on an articulating tab that is configured to be moved radially away from the shaft after the locking surface penetrates the perforation.

57. The anchor of claim 55 further comprising a plurality of spiral thread segments;

wherein each of the locking surfaces is disposed on a corresponding spiral thread segment.

58. The anchor of claim 55 further comprising, when the shaft comprises a lumen and each of the plurality of locking surfaces is a first locking surface:

an articulated catch comprising a second locking surface;

an actuation rod that is present in the lumen and is configured to force the catch to extend radially outward away from the shaft; and

a second locking surface disposed on the catch to engage the substrate after penetrating one of the perforations.

59. The anchor of claim 55 wherein:

the shaft comprises a series of spiral turns; and

each of the locking surfaces is disposed on a corresponding spiral turn.

60. The anchor of claim 58 wherein the shaft comprises a penetration end that comprises spiral turns that do not have a corresponding locking surface, the penetration end configured to penetrate the perforation.

61. An anchor for fastening bone to a substrate implanted in an inner cavity of a bone, the substrate including perforations, the anchor comprising:

a head;

a shaft;

first and second locking surface disposed on a pivot that is pinned to the shaft; and

an actuator that is configured to move down a lumen in the shaft to pivot the surfaces into a locking position in the inner cavity after one or both of the surfaces penetrate one of the perforations.

62. The anchor of claim 61 wherein the actuator is engaged in the shaft by threads.

63. Apparatus for repairing a fractured bone, the apparatus comprising:

a bone segment support configured to be deployed inside the bone;

an anchoring substrate configured to be deployed inside the bone; and

a relative displacement actuator configured to displace a portion of the anchoring substrate relative to a portion of the bone segment support.

64. The apparatus of claim 63 further comprising a central axis member having a longitudinal axis, the bone segment support having a first portion that is fixed with respect to the longitudinal axis and a second portion that is configured to translate with respect to the longitudinal axis when the bone segment support changes shape.

65. The apparatus of claim 63 further comprising a central axis member having a longitudinal axis, the anchoring substrate having a first portion that is fixed with respect to the longitudinal axis and a second portion that is configured to translate with respect to the longitudinal axis when the anchoring substrate changes shape.

66. The apparatus of claim 63 wherein the bone segment support is one of several bone segment supports that form a support cage.

67. The apparatus of claim 63 wherein:

the bone segment support is elongated and comprises along its length a first bone segment support portion and a second bone segment support portion;

the first bone segment support portion has a first bending resistance;

the second bone segment support portion has a second bending resistance; and

the first bending resistance is greater than the second bending resistance.

68. The apparatus of claim 63 wherein the relative displacement actuator has a central axis and comprises:

a first displacing member fixed, with respect to the central axis, to the bone segment support;

a second displacing member fixed, with respect to the central axis, to the anchoring substrate;

wherein the first displacing member is engaged with the second engaging member such that relative motion, along the central axis, of the first and second displacing members changes the distance, along the central axis, between a portion of the bone segment support and a portion of the anchoring substrate.

69. The apparatus of claim 68 wherein the first displacing member is threadedly engaged with the second displacing member.

70. The apparatus of claim 69 wherein rotation of the first displacing member relative to the second displacing member causes displacement, along the central axis, between the portion of the bone segment support and the portion of the anchoring substrate.

71. Apparatus for repairing a fractured bone, the apparatus comprising:

a bone segment support configured to be deployed inside the bone in a contracted state;

an anchoring substrate configured to be deployed inside the bone in a contracted state; and

a balloon configured to deform the bone segment support and the anchoring substrate.

72. The apparatus of claim 71 wherein:

the bone segment support is one of several bone segment supports that form a bone segment support cage; and

the balloon is further configured to expand the bone segment support cage.

73. A system for treating a fracture of a bone, the fracture including bone segments, the bone having an inner cavity, the system comprising:

a delivery assembly; and

a support for positioning one of the bone segments relative to another of the bone segments;

wherein the delivery assembly is configured to deliver the device to the inner cavity of the bone.

74. The system of claim 73 wherein the device is further configured to reduce the fracture.

75. The system of claim 73 wherein the device is further configured to align one of the bone portions relative to another of the bone portions.

76. The system of claim 73 wherein the device is further configured to compress the bone portions about the fracture.

77. The system of claim 73 wherein the device is further configured to stabilize the bone portions.

78. The system of claim 73 wherein the device comprises a structural cage configured to extend within the inner cavity.

79. The system of claim 78 further comprising an anchoring substrate that is supported in the inner cavity by the structural cage.

80. The system of claim 79 further comprising an anchor configured to engage the anchoring substrate with one of the portions of the bone.

81. The system of claim 78 further comprising a central member that extends from a first part of the structural cage to a second part of the structural cage and is configured to transmit a force from the first part to the second part.

82. A method for repairing a bone fracture, the fracture including a first bone segment and a second bone segment, the method comprising:

delivering through the fracture, into an inner cavity of a bone;

a structural support configured to position a first of the bone segments relative to a second of the bone segments; and

an anchoring substrate configured to compress the first bone segment to the second bone segment.

83. The method of claim 82 further comprising:

fastening the anchoring substrate to the first bone segment; and

fastening the anchoring substrate to the second bone segment.

84. A method for repairing a fractured bone, the fractured bone comprising a bone segment, the method comprising:

expanding in an intramedullary cavity a bone segment support cage; and

drawing the bone segment against the bone segment support cage using an anchoring substrate, the anchoring substrate in mechanical communication with the bone segment via an anchor.

85. The method of claim 84 further comprising, when the bone segment is a first bone segment and the fractured bone comprises a second bone segment, anchoring the bone segment support cage to the second bone segment.