Expandable spacer and method for use thereof

• US 8,353,963 B2
• Filed: 01/12/2010
• Issued: 01/15/2013
• Est. Priority Date: 01/12/2010
• Status: Active Grant

• Current Assignee: Globus Medical, Inc.
• Original Assignee: Globus Medical, Inc.
• Inventors: Glerum, Chad
• Primary Examiner(s): Truong, Kevin T
• Assistant Examiner(s): BATES, DAVID W
• Application Number:
  US12/615,806
• Publication Number:
  US 20110172716A1
• Time in Patent Office: 1,099 Days
• Field of Search: 623/17.15, 623/17.16
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/0095 Packages or dispensers for prostheses or other implants for intraocular lenses A61F2/1691; for dental surgery A61C19/02
• CPC Class Codes: A61F 2/38 for elbows or knees
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• 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 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30354 Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30357 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30362 with possibility of relative movement between the protrusion and the recess
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/3041 having threaded portions of different pitches
• CPC Class Codes: A61F 2002/30411 having two threaded end parts connected by a threaded central part with opposite threads at its opposite ends, i.e. for adjusting the distance between both end parts by rotating the central part
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30523 by means of meshing gear teeth
• CPC Class Codes: A61F 2002/3055 : for adjusting length
• CPC Class Codes: A61F 2002/30553 : for adjusting a position by translation along an axis
• CPC Class Codes: A61F 2002/30579 : with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30586 : having two or more inflatable pockets or chambers
• CPC Class Codes: A61F 2002/30588 : filled with solid particles
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30601 : telescopic
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30622 : Implant for fusing a joint or bone material
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30843 : Pyramidally-shaped
• CPC Class Codes: A61F 2002/30858 : Threads interrupted by grooves or sidewalls, e.g. flat sidewalls
• CPC Class Codes: A61F 2002/30859 : having threaded portions of different pitches
• CPC Class Codes: A61F 2002/30957 : using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/3096 : trimmed or cut to a customised size
• CPC Class Codes: A61F 2002/3097 : using laser
• CPC Class Codes: A61F 2002/30976 : using hydrojet
• 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 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• 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: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00071 : Nickel or Ni-based alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

An expandable implant is disclosed having an adjustable height for insertion between two adjacent bony structures or joint surfaces, for example between two adjacent spinal vertebrae. The implant includes at least one gear associated with at least one threaded shaft. Rotation of the gear engages the threaded shaft to expand the implant. The implant can be inserted in a collapsed configuration and expanded in situ. The invention also provides methods for using the implant to facilitate arthrodesis or fusion of adjacent joint surfaces or spinal vertebrae.

Claims

1. An expandable implant for insertion in a space between adjacent bony structures, comprising:

a first threaded shaft and a second threaded shaft;

a base plate coupled to the first threaded shaft and the second threaded shaft; and

a first gear and a second gear operably coupled with said first threaded shaft and said second threaded shaft, respectively, and operably coupled with said base plate, said first gear and said second gear having respective interior surfaces including threads matably engaged with respective said first threaded shaft and said second threaded shaft, whereby rotation of said first gear and said second gear initiates displacement of said first threaded shaft and said second threaded shaft within said base plate, whereby said first threaded shaft and said second threaded shaft are extendable in a direction away from said base plate;

wherein the first threaded shaft and the second threaded shaft are coupled to a top plate;

wherein the first gear and the second gear are positioned with an axis parallel to the interior surface extending substantially perpendicular to a longitudinal axis of the base plate and adjacent to one another;

wherein the first gear and the second gear are operably coupled to one another whereby rotation of the first gear in a first direction initiates rotation of the second gear in the first direction.

2. The expandable implant according to claim 1, wherein the expandable implant has a first, collapsed height prior to extension of said first threaded shaft and said second threaded shaft and a second, expanded height after extension of said first threaded shaft and said second threaded shaft.

3. The expandable implant according to claim 2, wherein the second, expanded height is adjustable.

4. The expandable implant according to claim 1, wherein the implant is operable to distract the adjacent bony structures.

5. The expandable implant according to claim 1, wherein the space is the intervertebral space between two adjacent spinal vertebrae.

6. The expandable implant according to claim 1, wherein said first threaded shaft and said second threaded shaft each have a hollow interior.

7. The expandable implant according to claim 6, wherein a top end of said first threaded shaft and a top end of said second threaded shaft each include an opening, the opening operable for insertion of material into said hollow interiors.

8. The expandable implant according to claim 7, wherein the material is a bone graft material selected from a group consisting of autograft material, allograft material, xenograft material, artificial mixtures, synthetic mixtures, demineralized bone matrix, hydroxyapatite mixtures, and combinations thereof.

9. The expandable implant according to claim 8, wherein the bone graft material further includes an effective amount of a growth factor or differentiation factor.

10. The expandable implant according to claim 9, wherein the growth factor or differentiation factor is selected from a group consisting of bone morphogenic protein (BMP), transforming growth factor 131 (TGF131), insulin-like growth factor 1 (IGF-1), platelet-derived growth factor (PDGF), activin, parathyroid hormone, fibroblast growth factor (FGF), LIM mineralization protein (LMP), and combinations thereof.

11. The expandable implant according to claim 1, wherein the implant is formed from a material selected from a group consisting of titanium, titanium alloys, stainless steel, chrome cobalt, nickel, ceramics, plastics, shape-memory alloys, bioactive glass, composites, bone, bone substitutes, and combinations thereof.

12. An expandable implant for insertion in a space between adjacent bony structures comprising:

a first threaded shaft;

a second threaded shaft;

a bottom plate having an exterior surface and an interior surface, the interior surface including a base receiving the first threaded shaft and the second threaded shaft; and

a pair of coupled actuation gears comprising a first gear of the pair having a first interior gear surface operably coupled to the first threaded shaft, further comprising a second gear of the pair having a second interior gear surface operably coupled to the second threaded shaft;

whereby rotation of the first gear in a first direction initiates rotation of the second gear in a second direction, opposite the first direction, initiating rotation of the first threaded shaft and then the second threaded shaft such that the shafts extend to engage adjacent bony structures;

wherein the first gear and the second gear are directly coupled to each other and are positioned with a longitudinal axis of the first interior gear surface and a longitudinal axis of the second interior gear surface extending perpendicular to a longitudinal axis of the base plate.

13. The expandable implant according to claim 12, wherein the first threaded shaft and the second threaded shaft are in a substantially parallel configuration.

14. The expandable implant according to claim 12, wherein the base holds the first threaded shaft and the second threaded shaft in an angled configuration.