Expandable implant for partial disc replacement and reinforcement of a disc partially removed in a discectomy and for reduction and maintenance of alignment of cancellous bone fractures and methods and apparatuses for same

• US 20030074075A1
• Filed: 08/27/2002
• Published: 04/17/2003
• Est. Priority Date: 08/27/2001
• Status: Abandoned Application

• Current Assignee: James C. Thomas Jr
• Original Assignee: James C. Thomas Jr
• Inventors: Rowe, Travis, Thomas, James C. Jr., Forster, David C. Jr., Mast, Gregory M.
• Application Number:
  US10/229,949
• Publication Number:
  US 20030074075A1
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7095 the filler comprising unlinked macroscopic particles
• CPC Class Codes: A61B 17/7266 with fingers moving radially outwardly
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• 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 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30166 H-shaped or I-shaped
• CPC Class Codes: A61F 2002/30233 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2002/30299 umbrella-shaped or mushroom-shaped
• CPC Class Codes: A61F 2002/30566 Helical springs
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30581 having a pocket filled with fluid, e.g. liquid
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/3093 : for promoting ingrowth of bone tissue
• CPC Class Codes: A61F 2002/4435 : Support means or repair of the natural disc wall, i.e. annulus, e.g. using plates, membranes or meshes
• CPC Class Codes: A61F 2002/444 : for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4622 : having the shape of a forceps or a clamp
• 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 2002/4658 : for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2210/0019 : operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2210/0033 : electrically, e.g. heated by resistor
• CPC Class Codes: A61F 2230/0028 : Shapes in the form of latin or greek characters
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0071 : spherical
• CPC Class Codes: A61F 2230/0093 : Umbrella-shaped, e.g. mushroom-shaped
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00616 : Coating made of titanium oxide or hydroxides
• CPC Class Codes: A61F 2310/00982 : Coating made of collagen

Abstract

Expandable implants for intervertebral disc repair, and methods and apparatuses for delivering the same into the disc. The present implants can also be used for repair of bone fractures. The implants generally comprise a compressed form having a size adapted for insertion into a defect in the intervertebral disc, and a composition that allows the implant to expand from the compressed form into an expanded form after the implant is inserted into the defect. The expanded form of the implant has a configuration that fills the defect in the disc. The defect in the disc can be an annular defect that resulted from repair of a herniation of the disc, or a nucleus that needs to be repaired. The composition used to make the implant can comprise a shape memory alloy (SMA) or any other suitable material.

Claims

1. An expandable implant for intervertebral disc repair comprising:

a compressed form having a size adapted for insertion into a defect in the intervertebral disc;

a composition that allows the implant to expand from the compressed form into an expanded form after the implant is inserted into the defect; and

the expanded form having a configuration that fills the defect in the disc.

2. The expandable implant of claim 1 wherein the composition of the expandable implant comprises a shape memory alloy, wherein the expandable implant restores flexibility and provides support to residual intervertebral disc structure, and does not result in a fusion of intervertebral disc segments.

3. The expandable implant of claim 1 wherein the defect is an annular defect in an annular portion of the disc.

4. The expandable implant of claim 2 wherein the compressed form is a non-memory shape that is retained until the implant is activated by temperature or electrical current, such that activation transforms the expandable implant to a predetermined memory shape that defines the expanded form.

5. The expandable implant of claim 4 wherein the shape memory alloy is nitinol.

6. The expandable implant of claim 3 wherein the composition of the expandable implant is a superelastic shape memory alloy that changes from the compressed form to the expanded form automatically after the expandable implant is inserted into the annular defect.

7. The expandable implant of claim 1 wherein the defect is a nucleus of the disc, wherein a portion of the nucleus has ruptured through an annulus of the disc and has been surgically removed.

8. The expandable implant of claim 7 wherein the expandable implant is inserted into the nucleus in the compressed state and after the expandable implant has expanded to the expanded form the defect in the nucleus is filled.

9. The expandable implant of claim 8 wherein the composition of the expandable implant comprises a shape memory alloy.

10. The expandable implant of claim 9 wherein the compressed form is a non-memory shape that is retained until the implant is activated by temperature or electrical current, such that activation transforms the expandable implant to a predetermined memory shape that defines the expanded form.

11. The expandable implant of claim 10 wherein the shape memory alloy is nitinol.

12. The expandable implant of claim 8 wherein the composition of the expandable implant is a superelastic shape memory alloy that changes from the compressed form to the expanded form automatically after the expandable implant is inserted into the annular defect.

13. The expandable implant of claim 7 wherein the expandable implant is a shape memory alloy that enters the nucleus in the compressed form having a straight wire construction, and after insertion of the expandable implant is complete the straight wire construction transforms to a coil construction that defines the expanded form.

14. An expandable implant for treatment of an annular defect in an intervertebral disc comprising:

a body adapted for insertion into the annular defect;

the body adapted to radially expand to fill the annular defect; and

means for retaining the body within the annular defect.

15. The expandable implant of claim 14 wherein the means for retaining the expandable implant is selected from the group consisting of retention legs, barbs, and retention legs and barbs together.

16. The expandable implant of claim 15 wherein the retention legs and barbs are each adapted to at least partially penetrate annular tissue that defines the annular defect, such that the expandable implant is prevented from migration from its inserted location.

17. The expandable implant of claim 14 wherein the expandable implant is made of a shape memory alloy, wherein the expandable implant restores flexibility and provides support to residual annulus structure, and does not result in a fusion of intervertebral disc segments.

18. The expandable implant of claim 17 wherein the body is inserted into the annular defect in a compressed, non-memory shape.

19. The expandable implant of claim 18 wherein the compressed, non-memory shape transforms to an expanded, predetermined memory shape after the expandable implant has been inserted into the annular defect.

20. The expandable implant of claim 14 wherein the expandable implant is made of a superelastic shape memory alloy that changes from a compressed form to an expanded form automatically after the expandable implant is inserted into the annular defect.

21. An expandable implant for nuclear repair of an intervertebral disc comprising:

a pre-insertion shape adapted for insertion into a nucleus of the intervertebral disc;

a composition that allows the pre-insertion shape to be transformed to a post-insertion shape after the expandable implant is inserted into the nucleus; and

the post-insertion shape defining a larger volume than the pre-insertion shape, such that the expandable implant fills the nucleus.

22. The expandable implant of claim 21 wherein the composition comprises a shape memory alloy, wherein the expandable implant restores flexibility and provides support to residual nucleus structure, and does not result in a fusion of intervertebral disc segments.

23. The expandable implant of claim 22 wherein the expandable implant is inserted by a delivery device into the nucleus.

24. The expandable implant of claim 23 wherein the delivery device comprises a needle adapted to transport the expandable implant into the nucleus.

25. The expandable implant of claim 24 wherein the expandable implant is a nitinol wire that passes through the needle in a non-coiled shape.

26. The expandable implant of claim 25 wherein the delivery device further comprises means for controlling the amount of nitinol wire passing through the needle into the nucleus and for cutting the nitinol wire to separate the nitinol wire from the delivery device.

27. The expandable implant of claim 26 wherein the nitinol wire inserted within the nucleus transforms to a coiled shape that defines the post-insertion shape of the expandable implant.

28. The expandable implant of claim 27 wherein the expandable implant restores the height and elasticity of the nucleus.

29. A shape memory alloy implant for treatment of cancellous bone fractures comprising:

a compressed form adapted for insertion into areas of cancellous bone fractures; and

an expanded form that results from insertion of the compressed form into the cancellous bone fracture, wherein the expanded form fills in the cancellous bone fracture.

30. The shape memory alloy implant of claim 29 wherein the cancellous bone fractures comprises distal radius fractures, tibial plateau fractures, and calcaneous fractures.

31. A delivery device for inserting an implant into an intervertebral disc comprising:

means for retaining the implant within the device while the device is positioned into the intervertebral disc; and

means for controllably releasing the implant into the intervertebral disc.

32. The delivery device of claim 31 being adapted for inserting the implant into an annular defect in the intervertebral disc, and the means for retaining the implant comprises an inner rod to which the implant has been adjoined and an outer rod that is positioned over the inner rod until the implant is released.

33. The delivery device of claim 32 wherein the implant is retained in a compressed form by the inner rod until the implant is release from the device, at which point the implant transforms to an expanded form.

34. The delivery device of claim 32 wherein the means for controllably releasing the implant comprises one or more knobs that retract the inner rod and outer rod.

35. The delivery device of claim 31 being adapted for inserting an implant into a nucleus of the intervertebral disc, and the means for retaining the implant comprises a chamber and a needle, wherein the implant is passed through the chamber into the needle and into the intervertebral disc.

36. The delivery device of claim 36 wherein the chamber retains a predetermined amount of the implant.

37. The delivery device of claim 36 wherein the means for controllably releasing the implant comprises an activation trigger that feeds the implant through the chamber and needle.

38. The delivery device of claim 37 wherein the means for controllably releasing the implant further comprises a clasp that activates a cutting edge within the needle that severs the implant being fed therethrough.

39. The delivery device of claim 38 wherein the means for retaining the implant and the means for controllably releasing the implant are positioned into two separate portions of the delivery device that are designed to cooperatively engage.

40. A method of inserting an implant into an intervertebral disc comprising:

loading the implant into a delivery device adapted for insertion into the intervertebral disc, wherein the implant is in a compressed form;

inserting the delivery device into the intervertebral disc; and

releasing the implant from the delivery device into the intervertebral disc, wherein the implant transforms from the compressed form to an expanded form designed to repair the intervertebral disc.