Expandable intervertebral spacers

• US 7,993,403 B2
• Filed: 01/14/2010
• Issued: 08/09/2011
• Est. Priority Date: 10/29/1998
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Foley, Kevin, Liu, Mingyan, Branch, Charles, Boyd, Lawrence M., Ebner, Harald
• Primary Examiner(s): Isabella; David
• Assistant Examiner(s): SCHILLINGER, ANN M
• Application Number:
  US12/657,129
• Publication Number:
  US 20100161062A1
• Time in Patent Office: 572 Days
• Field of Search: 623 1711- 1716
• 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 device configured for introduction into an intradiscal space between two adjacent vertebrae, comprising:

a spacer having a height defined by opposite vertebral bearing surfaces adapted to contact each of the adjacent vertebrae, said spacer including a first arm movably coupled to a second arm to permit relative lateral movement therebetween; and

wherein said first and second arms are initially positioned in an insertion configuration defining a first lateral width sized for introduction through a portal in a disc annulus and into the intradiscal space; and

wherein said first and second arms are repositionable relative to one another to provide a laterally expanded configuration defining a second lateral width greater than said first lateral width, said first and second arms together defining a plurality of interdigitating elements that restrain lateral contraction of said first arm relative to said second arm to maintain said first and second arms in said laterally expanded configuration; and

wherein said first and second arms are pivotally connected to one another by a flexibly deformable hinge portion formed integral with said first and second arms to define a unitary, single-piece spacer body, and wherein said a flexibly deformable hinge portion is flexibly deformed to reposition said first and second arms relative to one another to said laterally expanded configuration.

2. The device of claim 1, wherein said interdigitating elements comprise a plurality of interdigiting serrations defined by said first and second arms.

3. The device of claim 1, wherein said first and second arms define a first pair of end portions positioned proximately adjacent one another and together defining opposing planar regions that each include at least a portion of said interdigitating elements.

4. The device of claim 3, wherein said first and second arms define a second pair of end portions positioned proximately adjacent one another and together defining a portion of said interdigitating elements.

5. The device of claim 1, wherein said first and second arms define an internal cavity therebetween;

and

wherein each of said first and second arms defines at least one opening extending therethrough in communication with said internal cavity; and

further comprising a bone-growth material positioned within said internal cavity.

6. The device of claim 1, wherein said height of said spacer remains constant as said first and second arms are repositioned from said insertion configuration to said laterally expanded configuration.

7. The device of claim 6, wherein said first arm includes a third laterally extending portion, said second arm including a fourth laterally extending portion positioned proximately adjacent said third laterally extending portion of said first arm, said third and fourth laterally extending portions together defining a portion of said interdigitating elements.

8. The device of claim 7, wherein said first and third laterally extending portions of said first arm are nested between said second and fourth laterally extending portions of said second arm.

9. The device of claim 7, wherein said first and third laterally extending portions of said first arm each define a receptacle, said second and fourth laterally extending portions of said second arm each defining a lateral projection movably received within respective ones of said receptacles of said first arm.

10. The device of claim 1, wherein said first arm includes a first laterally extending portion, said second arm including a second laterally extending portion positioned proximately adjacent said first laterally extending portion of said first arm, said first and second laterally extending portions together defining opposing planar regions that each include at least a portion of said interdigitating elements.

11. The device of claim 10, wherein said interdigitating elements comprise a first series of serrations defined by said first laterally extending portion and a second series of serrations defined by said second laterally extending portion, said first and second series of serrations cooperating in an interdigitating manner to provide said interdigitating elements.

12. The device of claim 1, wherein said first arm and said second arm cooperate to provide said spacer with a rectangular shape.

13. The device of claim 1, wherein said first arm includes a first receptacle, said second arm including a first lateral projection movably received within said first receptacle of said first arm, said first receptacle and said first lateral projection together defining a portion of said interdigitating elements.

14. The device of claim 13, wherein said interdigitating elements comprise a first series of serrations defined by said first receptacle and a second series of serrations defined by said first lateral projection, said first and second series of serrations cooperating in an interdigitating manner to provide said interdigitating elements.

15. The device of claim 13, wherein said first arm includes a first laterally extending portion defining said first receptacle, said second arm including a second laterally extending portion positioned proximately adjacent said first laterally extending portion of said first arm and defining said first lateral projection.

16. The device of claim 13, wherein said first arm includes a third laterally extending portion defining a second receptacle, said second arm including a fourth laterally extending portion positioned proximately adjacent said third laterally extending portion of said first arm and defining a second lateral projection movably received within said second receptacle, said second receptacle and said second lateral projection together defining a portion of said interdigitating elements.

17. The device of claim 16, wherein said first arm and said second arm cooperate to provide said spacer with a rectangular shape.

18. The device of claim 13, wherein said first arm includes a second receptacle, said second arm including a second lateral projection positioned within said second receptacle of said first arm, said second receptacle and said second lateral projection together defining a portion of said interdigitating elements.

19. A vertebral spacer device configured for introduction into an intradiscal space between two adjacent vertebrae, comprising:

a spacer having a height defined by opposite vertebral bearing surfaces adapted to contact each of the adjacent vertebrae, said spacer including a first arm movably coupled to a second arm to permit relative lateral movement therebetween; and

wherein said first and second arms are initially positioned in an insertion configuration defining a first lateral width sized for introduction through a portal in a disc annulus and into the intradiscal space; and

wherein said first and second arms arc repositionable relative to one another to provide a laterally expanded configuration defining a second lateral width greater than said first lateral width, said first and second arms together defining a plurality of interdigitating elements that restrain lateral contraction of said first arm relative to said second arm to maintain said first and second arms in said laterally expanded configuration, and wherein said interdigitating elements comprise a plurality of interdigiting ratchets defined by said first and second arms; and

wherein said first and second arms are pivotally connected to one another by a flexibly deformable hinge portion formed integral with said first and second arms to define a unitary, single-piece spacer body.

20. A vertebral spacer device configured for introduction into an intradiscal space between two adjacent vertebrae, comprising:

a spacer having a height defined by opposite vertebral bearing surfaces adapted to contact each of the adjacent vertebrae, said spacer including a first arm movably coupled to a second arm to permit relative lateral movement therebetween; and

wherein said first and second arms are initially positioned in an insertion configuration defining a first lateral width sized for introduction through a portal in a disc annulus and into the intradiscal space;

wherein said first and second arms are repositionable relative to one another to provide a laterally expanded configuration defining a second lateral width greater than said first lateral width, said first and second arms together defining a plurality of interdigitating elements that restrain lateral contraction of said first arm relative to said second arm to maintain said first and second arms in said laterally expanded configuration; and

wherein said first and second arms define a first pair of end portions positioned proximately adjacent one another and together defining at least a portion of said interdigitating elements, wherein said first and second arms define a second pair of end portions that are pivotally connected to one another by a flexibly deformable hinge portion formed integral with said first and second arms to define a unitary, single-piece spacer body.

21. A vertebral spacer device configured for introduction into an intradiscal space between two adjacent vertebrae, comprising:

a spacer having a height defined by opposite vertebral bearing surfaces adapted to contact each of the adjacent vertebrae, said spacer including a first arm movably coupled to a second arm to permit relative lateral movement therebetween; and

wherein said first and second arms are initially positioned in an insertion configuration defining a first lateral width sized for introduction through a portal in a disc annulus and into the intradiscal space;

wherein said first and second arms are repositionable relative to one another to provide a laterally expanded configuration defining a second lateral width greater than said first lateral width, said first and second arms together defining a plurality of interdigitating elements that restrain lateral contraction of said first arm relative to said second arm to maintain said first and second arms in said laterally expanded configuration;

wherein said first arm includes a first laterally extending portion, said second arm including a second laterally extending portion positioned proximately adjacent said first laterally extending portion of said first arm, said first and second laterally extending portions together defining at least a portion of said interdigitating element; and

wherein said first and second arms are pivotally connected to one another by a flexibly deformable hinge portion at an end of said spacer opposite said first and second laterally extending portions, and wherein said flexibly deformable hinge portion is formed integral with said first and second arms to define a unitary, single-piece spacer body.

22. The device of claim 21, wherein said flexibly deformable hinge portion is plastically deformable.