Expandable intervertebral spacers

• US 6,193,757 B1
• Filed: 10/29/1998
• Issued: 02/27/2001
• Est. Priority Date: 10/29/1998
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Foley, Kevin, Liu, Mingyan, Boyd, Lawrence M., Ebner, Harald, Branch, Charles
• Primary Examiner(s): Willse, David H.
• Assistant Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US09/182,560
• Time in Patent Office: 852 Days
• Field of Search: 623/17.11, 623/17.13, 623/17.15, 623/17.16
• US Class Current: 623/17.16
• 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 a space between two adjacent vertebrae, the device comprising:

a spacer having a longitudinal axis and opposite bone engaging surfaces adapted to contact each of the adjacent vertebrae, said spacer further including a first arm and a second arm movably coupled to said first arm to permit lateral movement transverse to said longitudinal axis,

wherein said first arm and second arm are coupled in a first lateral position for insertion through a portal in a disc annulus into the intradiscal space, said first arm being laterally movable with respect to said second arm to a second expanded lateral position in which said first arm is spaced a distance from said second arm, and

wherein each of said first and second arms include opposing first and second ends, said first arm is movably coupled to said second arm by a pair of laterally extending portions at each of said first and second ends.

2. The device of claim 1, wherein said laterally extending portions define a catch mechanism for maintaining said pair of arms in spaced relation.

3. The device of claim 2, wherein said laterally extending portion of said first arm includes a projection and said laterally extending portion of said second arm defines a receptacle, said projection being movably received within said receptacle.

4. The device of claim 3, wherein a plurality of interdigiting serrations are defined by said projections and said receptacles.

5. The device of claim 2, wherein said first arm is pivotably coupled to said second arm at said first ends, said laterally extending portions being included only at said second ends.

6. The device of claim 5, wherein said pivotable connection is a resilient hinge.

7. The device of claim 1, wherein said catch mechanism includes a plurality of interdigiting serrations formed on each of said laterally extending portions.

8. The device of claim 1, wherein said pair of arms define a cavity when in said second lateral position.

9. The device of claim 8, further including bone-growth material placed within said cavity.

10. The device of claim 1, wherein said device is made of a bio-compatible metal material.

11. The device of claim 1, wherein said device is made of a fiber reinforced polymer composite.

12. The device of claim 1, wherein said device is made of bone material.

13. The device of claim 1, wherein said opposite end-face plates of said pair of arms define an angle for enhancing lordosis of the spine.

14. The device of claim 1, wherein said bone engaging surfaces of said pair of arms defines an area that is substantially smaller than the area of the intradiscal space.

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

a body portion including a first end and an opposite second end; and

a laterally expandable portion attached to said body to form a spacer, said laterally expandable portion movably coupled to said body portion at said first end, said laterally expandable portion being moveable to a first position whereby said spacer defines a first lateral width,

wherein said laterally expandable portion is movable to a second position whereby said spacer defines a second lateral width, said second width greater than said first lateral width, and

wherein said second end includes a notch and said laterally expandable portion includes an integrally formed catch proximate said second end, said catch engaging said notch when said laterally expandable portion is in said second position.

16. The device of claim 15, wherein said catch is positioned adjacent said notch when said laterally expandable portion is in said first position, said catch being pivotably biased away from said first end to engage said notch when said laterally expandable portion is in said second position.

17. The device of claim 15, wherein said laterally expandable portion is coupled to said spacer via a resilient hinge.

18. The device of claim 15, wherein said spacer has a maximum height, the maximum height substantially identical in said first position and said second position.