Enhanced cage insertion assembly

• US 9,895,236 B2
• Filed: 05/05/2016
• Issued: 02/20/2018
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Voellmicke, John C., O'Neil, Michael J., Shaw, Derek, Grinberg, Alexander
• Primary Examiner(s): Hammond, Ellen C
• Assistant Examiner(s): Negrellirodrigue, Christina
• Application Number:
  US15/147,544
• Publication Number:
  US 20160242929A1
• Time in Patent Office: 656 Days
• Field of Search: 606 90, 606 96, 606 99, 606104, 606 86 A, 623 1711- 1716
• 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 2/4465 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 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• 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 2002/30593 hollow
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30731 Bone edge protectors
• 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 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 2310/00239 containing zirconia or zirconium oxide ZrO2

Abstract

A method of delivering a fusion cage to an intervertebral disc space bounded by adjacent vertebral endplates, comprising the step of delivering the fusion cage into the disc space without contacting its teeth to the vertebral endplates during delivery, wherein a sheath is interposed between a cage surface and the endplates to prevent contact therebetween during delivery.

Claims

1. An intervertebral assembly, comprising:

a fusion device having an upper surface, a lower surface disposed such that the upper and lower surfaces are spaced from each other along a vertical direction, an insertion nose, a proximal end portion that is spaced from the insertion nose in a proximal direction that is perpendicular to the vertical direction, and opposed sidewalls that are disposed between the insertion nose and the proximal end portion;

an upper leaf disposed at least partially above the upper surface of the fusion device, the upper leaf having a distal end, wherein the upper leaf is pivotable with respect to the upper surface about a hinge that is offset from the distal end of the upper leaf in the proximal direction;

a lower leaf disposed at least partially below the lower surface, the lower leaf having a distal end, wherein the lower leaf is pivotable with respect to the lower surface about a hinge that is offset from the distal end of the lower leaf in the proximal direction; and

a shaft having a proximal end portion and a distal end portion attached to the proximal end portion of the fusion device;

wherein the intervertebral assembly is movable between a closed arrangement whereby the distal ends of the upper and lower leaves are spaced apart a first distance along the vertical direction, and an open arrangement whereby the distal ends of the upper and lower leaves are spaced apart a second distance greater than the first distance along the vertical direction.

2. The assembly of claim 1, wherein respective inner surfaces of the upper and lower leaves rest against the upper and lower surfaces, respectively, of the fusion device when the intervertebral assembly is in the closed arrangement.

3. The assembly of claim 1, wherein the proximal direction is oriented along a longitudinal direction that further includes a distal direction opposite the proximal direction, the assembly further comprising a threaded member oriented along the longitudinal direction within the fusion device.

4. The assembly of claim 1, wherein the distal end portion of the shaft is threaded, and the fusion device has a threaded hole threadably attached to the shaft.

5. The assembly of claim 4, wherein the threaded hole extends into the proximal end portion of the fusion device.

6. The assembly of claim 1 wherein the proximal direction is oriented along a longitudinal direction that further includes a distal direction that is opposite the proximal direction, the upper and lower leaves each comprises a lateral edge running substantially along the longitudinal direction, and the lateral edges of the upper leaf are substantially parallel with the lateral edges of the lower leaf when the intervertebral assembly is in the closed arrangement.

7. The assembly of claim 1, wherein the distal ends of the upper and lower leaves comprise respective distal tips that tapers towards each other as they extend in a distal direction opposite the proximal direction.

8. The assembly of claim 1, wherein the insertion nose is tapered as it extends in a distal direction opposite the proximal direction.

9. The assembly of claim 1, wherein the fusion device defines a vertical throughhole that extends through the upper and lower surfaces at a location between the side walls.

10. The assembly of claim 1, wherein the hinges are offset from the insertion nose in the proximal direction.

11. The assembly of claim 1, wherein the upper surface defines a plurality of teeth adapted to grip an upper vertebral endplate, and the lower surface defines a plurality of teeth adapted to grip a lower vertebral endplate.

12. An intervertebral assembly, comprising:

a fusion device having an upper surface, a lower surface disposed such that the upper and lower surfaces are spaced from each other along a vertical direction, an insertion nose, a proximal end portion that is configured to attach to a shaft and is spaced from the insertion nose in a proximal direction that is perpendicular to the vertical direction, and opposed sidewalls that are disposed between the insertion nose and the proximal end portion;

a plurality of leaves each having a respective distal end, wherein each of the leaves is pivotable with respect to the fusion device about a hinge that is offset from the respective distal end in the proximal direction;

wherein the intervertebral assembly is movable between a closed arrangement whereby the respective distal ends of an opposed pair of the plurality of leaves are spaced apart a first distance along the vertical direction, and an open arrangement whereby the respective distal ends of the opposed pair of the plurality of leaves are spaced apart a second distance greater than the first distance along the vertical direction,

wherein when the intervertebral assembly is in the closed arrangement, the opposed pair of the leaves surround the upper and lower surfaces of the fusion device.

13. The assembly of claim 12, further comprising a shaft having a proximal end portion and a distal end portion spaced from the proximal end portion along a distal direction that is opposite the proximal direction, the distal end portion configured to attach to the proximal end portion of the fusion device.

14. The assembly of claim 13, wherein the distal end portion of the shaft is attached to the proximal end portion of the fusion device.

15. The assembly of claim 14, wherein the distal end portion of the shaft is threadably attached to the proximal end portion of the fusion device.

16. The assembly of claim 14, wherein the distal end portion of the shaft is configured to threadably attach to the proximal end portion of the fusion device.

17. The assembly of claim 12, wherein the fusion device defines a vertical throughhole that extends through the upper and lower surfaces at a location between the side walls.

18. The assembly of claim 12, wherein the upper surface defines a plurality of teeth adapted to grip an upper vertebral endplate, and the lower surface defines a plurality of teeth adapted to grip a lower vertebral endplate.

19. The assembly of claim 12, wherein respective surfaces of the opposed pair of the plurality of leaves are substantially parallel to each other when the intervertebral assembly is in the closed arrangement.

20. The assembly of claim 12, wherein respective inner surfaces of the upper and lower leaves rest against the upper and lower surfaces, respectively, of the fusion device when the intervertebral assembly is in the closed arrangement.