Method and apparatus for correcting spinal deformity

• US 20020055740A1
• Filed: 07/05/2001
• Published: 05/09/2002
• Est. Priority Date: 11/08/2000
• Status: Active Grant

• Current Assignee: Cleveland Clinic Foundation
• Original Assignee: Cleveland Clinic Foundation
• Inventors: Lieberman, Isador H.
• Granted Patent: US 6,551,320 B2
• Time in Patent Office: Days
• US Class Current: 606/61
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/701 Longitudinal elements with a non-circular, e.g. rectangular, cross-section A61B17/7005, A61B17/7007 take precedence
• CPC Class Codes: A61B 17/7022 Tethers, i.e. longitudinal elements capable of transmitting tension only, e.g. straps, sutures or cables A61B17/702 takes precedence
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7044 also having plates, staples or washers bearing on the vertebrae
• CPC Class Codes: A61B 17/7055 connected to sacrum, pelvis or skull
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/8665 Nuts
• CPC Class Codes: A61B 17/869 characterised by an open form, e.g. wire helix
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30092 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30224 : cylindrical
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30289 : helically-coiled
• CPC Class Codes: A61F 2002/30324 : differing in thickness
• CPC Class Codes: A61F 2002/30326 : differing in height or in length
• CPC Class Codes: A61F 2002/30383 : made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30401 : with additional means for preventing or locking said sliding
• CPC Class Codes: A61F 2002/30405 : made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30428 : made by inserting a protrusion into a slot
• CPC Class Codes: A61F 2002/30451 : soldered or brazed or welded
• CPC Class Codes: A61F 2002/30507 : using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30568 : Multiple spring systems including two or more helical springs
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30738 : Sleeves
• CPC Class Codes: A61F 2002/30769 : madreporic
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30851 : Multiple threadings
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0036 : differing in thickness
• CPC Class Codes: A61F 2250/0037 : differing in height or in length
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

An apparatus (10) for correcting spinal deformity comprises at least one anchor (20) for implantation into a vertebral body (90). The anchor (20) includes a platform (24) having a first surface (38) for facing the vertebral body (90). The anchor (20) further includes screw means (50 and 52) for embedding into the vertebral body (90) upon rotation of the platform (24). The platform (24) includes at least one passage (44) extending transversely through the platform. The passage (44) receives a cable (120) connected with another anchor (20) in another vertebral body (92). The cable (120) is tensioned to cause relative movement between the vertebral bodies (90 and 92) and thereby correct the spinal deformity. Additional cables (150, 170) may be connected to the anchors (20) and tensioned to achieve correction in multiple planes.

Claims

1. An apparatus for correcting spinal deformity, said apparatus comprising:

at least one anchor for implantation into a vertebral body, said at least one anchor, when implanted, being resistant to toggling in the vertebral body and to being pulled from the vertebral body;

said at least one anchor including a platform having a first surface for facing the vertebral body, said platform including at least one passage extending transversely through said platform, said at least one passage for receiving a cable connected with another vertebral body;

said at least one anchor further including at least one helical spike for embedding into the vertebral body upon rotation of said platform, said at least one helical spike projecting from said first surface on said platform and extending around a longitudinal axis, said at least one helical spike having a tip portion at a distal end which penetrates into the vertebral body as said platform is rotated.

2. The apparatus of claim 1 wherein said platform includes a plurality of parallel passages extending transversely through said platform.

3. The apparatus of claim 2 wherein said platform includes an oppositely disposed pair of radially extending wing sections, one of said plurality of parallel passages extending through each of said pair of wing sections.

4. The apparatus of claim 3 further comprising at least one cable extending through one of said plurality of parallel passages in said platform.

5. The apparatus of claim 4 wherein said at least one anchor comprises first and second anchors for implanting in first and second vertebral bodies, respectively, said at least one cable extending through a respective one of said plurality of parallel passages in said platform of each of said first and second anchors, said at least one cable being tensionable to cause relative movement between the first and second vertebral bodies.

6. The apparatus of claim 5 wherein said platform on each of said first and second anchors includes structure for connecting a spinal fixation implant.

7. The apparatus of claim 6 further comprising a spinal fixation implant extending between and connected to said platform on each of said first and second anchors after said at least one cable has been tensioned to effect relative movement between the first and second vertebral bodies.

8. The apparatus of claim 5 wherein said at least one cable includes a primary cable extending between a centrally located one of said plurality of parallel passages in each of said first and second anchors.

9. The apparatus of claim 8 wherein said at least one cable further includes a secondary cable extending between one of said plurality of parallel passages in one of said pair of wing sections on said platform of each of said first and second anchors, said secondary cable being tensionable to cause relative movement between the first and second vertebral bodies in one direction after said primary cable has been tensioned to effect relative movement between the first and second vertebral bodies in another direction.

10. The apparatus of claim 1 wherein said at least one anchor has a pair of helical spikes extending around said longitudinal axis, said proximal ends of said pair of helical spikes being spaced 180°

apart.

11. The apparatus of claim 1 wherein said at least one anchor has three helical spikes extending around said longitudinal axis, said proximal ends of said helical spikes being spaced 120°

apart.

12. The apparatus of claim 1 wherein said first surface on said platform of said at least one anchor has a shape that is complimentary to the shape of an outer surface of the vertebral body for engaging the outer surface of the vertebral body.

13. The apparatus of claim 1 wherein said at least one helical spike, when implanted, has a conical shape that increases in diameter as said at least one helical spike extends away from said platform.

14. The apparatus of claim 1 wherein at least a portion of said at least one helical spike is made of a shape memory alloy that is responsive to changes in temperature above and below a predetermined temperature transition range, said at least one helical spike being in said first condition when the temperature of said at least one helical spike is below said predetermined temperature transition range, said at least one helical spike being in said second condition when heated above said predetermined temperature transition range, said at least one helical spike being implanted into the vertebral body in said second condition.

15. The apparatus of claim 14 wherein said at least one helical spike further has a connecting portion at a proximal end connected to said platform and an intermediate portion extending between said connecting portion and said tip portion, at least one of said intermediate portion and said tip portion being made of said shape memory alloy.

16. The apparatus of claim 1 wherein said at least one helical spike has a solid cross-section.

17. The apparatus of claim 1 wherein said at least one helical spike has a tubular cross-section.

18. The apparatus of claim 1 wherein a first portion of said at least one helical spike has a solid cross-section and a second portion of said at least one helical spike has a tubular cross-section.

20. The apparatus of claim 19 wherein said platform on each of said first and second anchors includes a plurality of parallel passages extending transversely through said platform.

21. The apparatus of claim 20 wherein said platform on each of said first and second anchors includes an oppositely disposed pair of radially extending wing sections, one of said plurality of parallel passages extending through each of said pair of wing sections on each of said first and second anchors.

22. The apparatus of claim 21 wherein said platform on each of said first and second anchors includes structure for connecting a spinal fixation implant.

23. The apparatus of claim 22 further comprising a spinal fixation implant extending between to said platform on each of said first and second anchors, said spinal fixation implant being fixedly connected to each of said first and second anchors after said at least one cable has been tensioned to effect relative movement between the first and second vertebral bodies.

24. The apparatus of claim 23 wherein said at least one cable includes a primary cable extending between a centrally located one of said plurality of parallel passages in said platform of each of said first and second anchors.

25. The apparatus of claim 24 wherein said at least one cable further includes a secondary cable extending between one of said plurality of parallel passages in one of said pair of wing sections on said platform of each of said first and second anchors, said secondary cable being tensionable to cause relative movement between the first and second vertebral bodies in one direction after said primary cable has been tensioned to effect relative movement between the first and second vertebral bodies in a another direction.

26. The apparatus of claim 19 wherein said screw means on each of said first and second anchors comprises an externally threaded fastener.

27. The apparatus of claim 19 wherein said screw means on each of said first and second anchors comprises at least two helical spikes.

28. The apparatus of claim 27 wherein said at least two helical spikes on each of said first and second anchors, when implanted, have a conical shape that increases in diameter as said at least two helical spikes extend away from said platform on each of said first and second anchors.

30. The apparatus of claim 29 wherein said platform on each of said at least two anchors includes a plurality of parallel passages extending transversely through said platform.

31. The apparatus of claim 30 wherein said platform on each of said at least two anchors includes an oppositely disposed pair of radially extending wing sections, one of said plurality of parallel passages extending through each of said pair of wing sections on each of said at least two anchors.

32. The apparatus of claim 31 wherein said at least one cable includes a primary cable extending between a centrally located one of said plurality of parallel passages in said platform of each of said at least two anchors.

33. The apparatus of claim 32 wherein said at least one cable further includes a secondary cable extending between one of said plurality of parallel passages in one of said pair of wing sections on said platform of each of said at least two anchors, said secondary cable being tensionable to cause relative movement between the vertebral bodies in one direction after said primary cable has been tensioned to effect relative movement between the vertebral bodies in a another direction.

34. The apparatus of claim 29 wherein each of said at least two anchors has three helical spikes.

35. The apparatus of claim 29 wherein said at least two helical spikes on each of said at least two anchors, when implanted, have a conical shape that increases in diameter as said at least two helical spikes extend away from said platform on each of said at least two anchors.

37. The method of claim 36 further comprising the step of:

connecting a spinal fixation implant to the platform on each of the at least two anchors.

38. The method of claim 36 wherein the platform on each of the at least two anchors includes a plurality of parallel passages extending transversely through the platform, the platform on each of the at least two anchors further including an oppositely disposed pair of radially extending wing sections, one of the plurality of parallel passages extending through each of the pair of wing sections on each of the at least two anchors.

39. The method of claim 38 further comprising the steps of:

extending a primary cable between a centrally located one of the plurality of parallel passages in the platform of each of the at least two anchors; and

tensioning the primary cable to cause relative movement between the vertebral bodies in one direction.

40. The method of claim 39 further comprising the steps of:

extending a secondary cable between one of the plurality of parallel passages in one of the pair of wing sections on the platform of each of the anchors; and

tensioning the secondary cable to cause relative movement between the vertebral bodies in another direction.

41. The method of claim 40 further comprising the step of:

connecting a spinal fixation implant to the platform on each of the at least two anchors.

19. An apparatus for correcting spinal deformity, said apparatus comprising:

first and second anchors for implantation into first and second vertebral bodies, respectively, said anchors, when implanted, being resistant to toggling in the vertebral bodies and to being pulled from the vertebral bodies;

each of said first and second anchors including a platform having at least one passage extending transversely through said platform;

each of said first and second anchors further including screw means for embedding into one of the vertebral bodies upon rotation of said platform, said screw means projecting from said platform on each of said first and second anchors and having a tip portion at a distal end which penetrates into a respective one of the vertebral bodies as said platform is rotated; and

at least one cable extending through said at least one passage in said platform on each of said first and second anchors, said at least one cable being tensionable to cause relative movement between the first and second vertebral bodies.

29. An apparatus for correcting spinal deformity, said apparatus comprising:

at least two anchors for implantation into separate vertebral bodies, said at least two anchors, when implanted, being resistant to toggling in the vertebral bodies and to being pulled from the vertebral bodies;

each of said at least two anchors including a platform having at least one passage extending transversely through said platform;

each of said at least two anchors further including at least two helical spikes for embedding into one of the vertebral bodies upon rotation of said platform, said at least two helical spikes projecting from said platform on each of said at least two anchors and having tip portions at a distal end which penetrate into a respective one of the vertebral bodies as said platform is rotated;

at least one cable extending through said at least one passage in said platform on each of said at least two anchors, said at least one cable being tensionable to cause relative movement between the vertebral bodies; and

a spinal fixation implant extending between and is connectable with said platform on each of said at least two anchors.

36. A method for correcting spinal deformity, said method comprising the steps of:

providing at least two anchors for implantation into separate vertebral bodies, each of the at least two anchors including a platform having at least one passage extending transversely through the platform, each of the at least two anchors further including screw means for embedding into one of the vertebral bodies upon rotation of the platform;

implanting the at least two anchors in the separate vertebral bodies;

connecting the at least two anchors with at least one cable that extends through the at least one passage in the platform on each of the at least two anchors; and

tensioning the at least one cable to cause relative movement between the vertebral bodies.