Expandable intervertebral spacers

• US 20020151976A1
• Filed: 05/23/2002
• Published: 10/17/2002
• Est. Priority Date: 10/29/1998
• Status: Active Grant

• Current Assignee: Charles Branch, Harald Ebner, Kevin Foley, Lawrence M. Boyd, Mingyan Liu
• Original Assignee: Charles Branch, Harald Ebner, Kevin Foley, Lawrence M. Boyd, Mingyan Liu
• Inventors: Liu, Mingyan, Foley, Kevin, Boyd, Lawrence M., Ebner, Harald, Branch, Charles
• Granted Patent: US 6,833,006 B2
• Time in Patent Office: Days
• US Class Current: 623/17.11
• CPC Class Codes: A61B 2017/2837 with a locking ratchet
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• 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 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30176 V-shaped
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30367 with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/30428 : made by inserting a protrusion into a slot
• CPC Class Codes: A61F 2002/30485 : plastically deformable
• CPC Class Codes: A61F 2002/30487 : Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/3052 : unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30522 : releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/30565 : having spring elements
• CPC Class Codes: A61F 2002/30571 : Leaf springs
• CPC Class Codes: A61F 2002/30579 : with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30624 : Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30836 : knurled
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/4619 : for extraction
• 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 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• 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 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0054 : V-shaped
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: Y10S 623/908 : Bone

Abstract

Laterally expanding vertebral spacer devices are provided for repairing damaged vertebral discs. The vertebral spacer devices maintain the height of a distracted vertebral disc space while providing stability to the spine. In one form of the invention, a vertebral spacer device is provided with a first arm movably coupled to a second arm. The first and second arms are laterally expandable from a first width for insertion into the disc space to a second width after insertion into the disc space. The first and second arms also define a cavity therebetween for placement of bone growth material.

Claims

1. A vertebral spacer, comprising:

a distal end portion;

a proximal end portion positioned opposite said distal end portion;

a pair of flexible lateral arms extending between said distal end portion and said proximal end portion;

wherein said pair of flexible lateral arms each have a pair of opposite vertebral bearing surfaces adapted to engage opposing vertebrae; and

wherein said pair of flexible lateral arms are adapted to laterally self-expand from a laterally contracted position to a laterally expanded position between the vertebrae.

2. The vertebral spacer of claim 1, wherein said pair of flexible lateral arms each define openings for increasing flexibility of said pair of flexible lateral arms.

3. The vertebral spacer of claim 2, wherein:

said pair of flexible lateral arms, said proximal end portion and said distal end portion define a central cavity adapted to receive bone growth material; and

said openings defined in said pair of flexible lateral arms are adapted permit communication into said central cavity.

4. The vertebral spacer of claim 1, wherein said proximal end portion defines at least one insertion tool opening adapted to receive an insertion tool.

5. The vertebral spacer of claim 1, wherein at least said pair of flexible lateral arms are made from a shape memory material.

6. The vertebral spacer of claim 5, wherein:

said pair of flexible lateral arms each define openings for increasing flexibility of said pair of flexible lateral arms;

said pair of flexible lateral arms, said proximal end portion and said distal end portion define a central cavity adapted to receive bone growth material;

said openings defined in said pair of flexible lateral arms are adapted permit communication into said central cavity; and

said proximal end portion defines a threaded insertion tool opening adapted to receive an insertion tool.

7. A spacer for spacing opposing vertebral bodies, comprising:

a spacer body having a pair of opposite vertebral bearing surfaces constructed and arranged to engage the opposing vertebral bodies;

wherein said spacer body encloses a central opening constructed and arranged to hold bone growth material;

wherein said spacer body has a height defined by said pair of opposite vertebral bearing surfaces; and

wherein said spacer body is formed from a shape memory material to self-expand said spacer body laterally between the vertebral bodies while said height of said spacer body is unchanged.

8. The spacer of claim 7, wherein said spacer body includes a pair of lateral members constructed and arrange to laterally expand said spacer body.

9. The spacer of claim 8, wherein said pair of lateral members define openings to allow communication of the bone growth material into said central opening.

10. The spacer of claim 7, wherein said spacer body defines openings constructed and arranged to increase flexibility of said body portion.

11. The spacer of claim 7, wherein said spacer body defines an insertion tool opening constructed and arranged to receive an insertion tool.

12. The spacer of claim 7, wherein said shape memory material includes nitinol.

13. The spacer of claim 7, wherein:

said spacer body includes a distal end portion and a proximal end portion; and

said spacer body further includes a pair of flexible lateral arms connected to and extending between said distal end portion and said proximal end portion.

15. The spacer body of claim 14, wherein said flexible lateral side walls are biased to urge said spacer to said expanded configuration.

16. The spacer body of claim 14, wherein said flexible lateral side walls each defines openings to increase flexibility of said flexible lateral side walls.

17. The spacer body of claim 16, wherein said flexible lateral side walls define a central cavity to contain bone growth material.

18. The spacer body of claim 14, wherein said spacer is made from a memory shape material.

19. The spacer body of claim 14, wherein said opposite ends include a distal end and a proximal end.

20. The spacer body of claim 19, wherein said distal end defines an insertion tool opening.

14. A spacer body, comprising:

a pair of flexible lateral side walls having opposite ends, said pair of flexible lateral side walls being connected at said opposite ends to form a spacer, said spacer having a reduced size configuration with a maximum height and a first maximum width and an expanded size configuration having said maximum height and a second maximum width, wherein said second width is greater than said first width; and

wherein said spacer is movable between said reduced size configuration and said expanded size configuration by movement of said flexible lateral side walls.