Apparatus for attaching fractured sections of bone

• US 6,527,774 B2
• Filed: 04/16/2001
• Issued: 03/04/2003
• Est. Priority Date: 11/08/2000
• Status: Expired due to Fees

• Current Assignee: Cleveland Clinic Foundation
• Original Assignee: Cleveland Clinic Foundation
• Inventors: Lieberman, Isador H.
• Primary Examiner(s): Wilson, John J.
• Application Number:
  US09/835,334
• Publication Number:
  US 20020055742A1
• Time in Patent Office: 687 Days
• Field of Search: 606/61, 606/69, 606/71, 606/72, 606/73
• US Class Current: 606/301
• 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 17/7032 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 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• 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
• CPC Class Codes: Y10S 606/911 : Memory material

Abstract

An apparatus (10) for attaching a first section (17) of a bone (12) to a second section (18) of the bone. The second section (18) is separated from the first section (17) by a fracture (14). The apparatus (10) comprises a bone screw (20) having a platform (24) and at least two helical spikes (50 and 52) for embedding into at least one of the first and second sections (17 and 18). The helical spikes (50 and 52) project tangentially from the platform (24). The helical spikes (50 and 58) have a tip portion (58) which penetrates into the bone (12) as the platform (24) is rotated. The bone screw (20) has a first condition in which a first portion (58) of the bone screw extends into one of the first and second sections (17 and 18) and a second condition in which a second portion (24) of the bone screw extends into the other of the first and second sections to compress the first and second sections together.

Claims

1. An apparatus for attaching a first section of a bone to a second section of the bone, the second section being separated from the first section by a fracture of the bone, said apparatus comprising:

a bone screw having a platform for drivingly rotating said bone screw and at least two helical spikes for embedding into at least one of the first and second sections of the bone upon rotation of said platform, said platform having a first surface that is solid and that extends generally transverse to a longitudinal axis of said bone screw;

said at least two helical spikes projecting tangentially from said first surface of said platform and extending around said longitudinal axis, said at least two helical spikes having a tip portion at a distal end which penetrates into the bone as said platform is rotated;

said bone screw having a first condition in which a first portion of said bone screw is extendable into one of the first and second sections of the bone, said bone screw further having a second condition in which a second portion of said bone screw is extendable into the other of the first and second sections of the bone to bring the first and second sections into engagement with one another so that the fracture of the bone can heal;

said at least two helical spikes, when embedded into at least one of the first and second sections of the bone, being resistant to toggling in the bone and to being pulled axially from the bone.

2. The apparatus of claim 1 wherein the fracture of the bone is defined by a first edge on the first section of the bone and a second edge on the second section of the bone, the first and second edges being pressed into contact with each other as said bone screw is moved into said second condition.

3. The apparatus of claim 1 wherein in said first condition of said bone screw, said at least two helical spikes are for embedding into one of the first and second sections of the bone and, in said second condition of said bone screw, said at least two helical spikes are for embedding into both of the first and second sections of the bone.

4. The apparatus of claim 1 wherein each of said at least two helical spikes, when implanted, has a conical shape that increases in diameter as said at least two helical spikes extend away from said platform.

5. The apparatus of claim 1 wherein at least a portion of each of said at least two helical spikes 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 two helical spikes being heated above said predetermined temperature transition range as said at least two helical spikes are being implanted into the bone.

6. The apparatus of claim 5 further comprising a tubular sleeve for receiving said bone screw, said bone screw being positionable inside said tubular sleeve when the temperature of said at least two helical spikes is below said predetermined transition temperature range.

7. The apparatus of claim 6 wherein said tubular sleeve includes internal threads for mating with said at least two helical spikes and helping to draw said at least two helical spikes into said tubular sleeve as said platform is rotated.

8. The apparatus of claim 1 wherein each of said at least two helical spikes 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.

9. The apparatus of claim 8 comprising a pair of helical spikes extending around said longitudinal axis, said proximal ends of said pair of helical spikes being spaced 180°

apart.

10. The apparatus of claim 8 comprising three helical spikes extending around said longitudinal axis, said proximal ends of said three helical spikes being spaced 120°

apart.

11. The apparatus of claim 1 wherein said first surface has a shape that is complimentary to the shape of an outer surface of the bone for engaging the outer surface of the bone.

12. The apparatus of claim 1 wherein each of said at least two helical spikes has a solid cross-section.

13. The apparatus of claim 1 wherein each of said at least two helical spikes has a tubular cross-section.

14. The apparatus of claim 1 wherein a first portion of each of said at least two helical spikes has a solid cross-section and a second portion of each of said at least two helical spikes has a tubular cross-section.

15. The apparatus of claim 1 wherein said platform comprises a cylindrical body portion having oppositely disposed first and second ends, said at least two helical spikes projecting from said first end for embedding in the first section of the bone by rotation of said body portion, said first end of said body portion including a threaded section.

16. The apparatus of claim 15 further comprising a plate member having a sleeve section, said plate member for attaching to the second section of the bone, said sleeve section for extending through the second section of the bone and receiving said body portion of said bone screw.

17. The apparatus of claim 16 further comprising a fastener engaged with said threaded section of said body portion, wherein rotation of said fastener pulls said body portion of said bone screw farther into said sleeve section of said plate member to compress the first section of the bone against the second section of the bone.

18. The apparatus of claim 17 wherein said at least two helical spikes, when implanted, have a conical shape that increases in diameter as said at least two helical spikes extend away from said platform.

19. The apparatus of claim 18 wherein at least a portion of each of said at least two helical spikes 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 two helical spikes being heated above said predetermined temperature transition range as said at least two helical spikes are being implanted into the first section of the bone.

20. An apparatus for attaching a first section of a bone to a second section of the bone, the second section being separated from the first section by a fracture of the bone, said apparatus comprising:

a bone screw for extending between the first and second sections of the bone and for attaching the first section to the second section, said bone screw having a platform for drivingly rotating said bone screw, said platform including a first surface that is solid and that extends generally transverse to a longitudinal axis of said bone screw;

said bone screw further having at least two helical spikes for embedding into both of the first and second sections of the bone upon rotation of said platform, said at least two helical spikes projecting tangentially from said first surface of said platform and extending around said longitudinal axis, said at least two helical spikes having a tip portion at a distal end which penetrates into the bone as said platform is rotated;

said bone screw having a first condition in which said at least two helical spikes are embeddable into one of the first and second sections of the bone, said bone screw further having a second condition in which said at least two helical spikes are embeddable into both of the first and second sections of the bone to compress the first and second sections together so that the fracture of the bone can heal, said bone screw being movable from said first condition to said second condition by rotation of said platform;

said at least two helical spikes of said bone screw, when embedded into the first and second sections of the bone, being resistant to toggling in the bone and to being pulled axially from the bone.

21. The apparatus of claim 20 wherein each of said at least two helical spikes has a cylindrical shape with a generally constant overall diameter.

22. The apparatus of claim 20 wherein each of said at least two helical spikes, when implanted, has a conical shape that increases in diameter as said at least two helical spikes extend away from said platform.

23. The apparatus of claim 22 wherein at least a portion of each of said at least two helical spikes 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 two helical spikes being heated above said predetermined temperature transition range as said at least two helical spikes are being implanted into the bone.

24. The apparatus of claim 20 wherein each of said at least two helical spikes 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.

25. The apparatus of claim 24 comprising a pair of helical spikes extending around said longitudinal axis, said proximal ends of said pair of helical spikes being spaced 180°

apart.

26. The apparatus of claim 24 comprising three helical spikes extending around said longitudinal axis, said proximal ends of said three helical spikes being spaced 120°

apart.

27. The apparatus of claim 20 wherein said first surface has a shape that is complimentary to the shape of an outer surface of the bone for engaging the outer surface of the bone.

28. The apparatus of claim 27 wherein each of said at least two helical spikes has a solid cross-section.

29. The apparatus of claim 27 wherein each of said at least two helical spikes has a tubular cross-section.

30. The apparatus of claim 27 wherein a first portion of each of said at least two helical spikes has a solid cross-section and a second portion of each of said at least two helical spikes has a tubular cross-section.