Enhanced cage insertion assembly

• US 9,833,334 B2
• Filed: 02/17/2015
• Issued: 12/05/2017
• 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): NEGRELLIRODRIGUEZ, CHRISTINA
• Application Number:
  US14/623,982
• Publication Number:
  US 20150157470A1
• Time in Patent Office: 1,022 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 assembly comprising:

a) an intervertebral fusion cage having a leading end, a trailing end, an upper face having teeth and a lower face having teeth, and

b) an inserter comprising a cannulated sheath having a plurality of flexible sheath portions extending distally therefrom,

wherein a first sheath portion has an inner portion bearing against the teeth of the lower face of the cage,

wherein a second sheath portion has an inner portion bearing against the teeth of the upper face of the cage,

and

wherein the sheath contains bone graft, at least a first portion of the bone graft is located within the cage, and at least a second portion of the bone graft is located outside of the cage but is contained by the first and second sheath portions.

2. The assembly of claim 1 wherein the sheath is located at a distal end of the inserter.

3. The assembly of claim 1 wherein the inserter further comprises a docking port having a bore therethrough, wherein the cannulated sheath is slidingly received in the docking port.

4. The assembly of claim 3 wherein the docking port has a proximal handle.

5. The assembly of claim 3 wherein the docking port has teeth for seating into or unto the vertebral bodies.

6. The assembly of claim 1 wherein the cage comprises PEEK.

7. The assembly of claim 1 wherein the cage comprises carbon fiber.

8. The assembly of claim 1 wherein the cage comprises PEEK and carbon fiber.

9. The assembly of claim 1 wherein the upper and lower faces of the cage comprise a plurality of teeth.

10. The assembly of claim 1 wherein the cage has a substantially rectangular cross-section and the sheath has a substantially corresponding substantially rectangular cross-section.

11. The assembly of claim 1 wherein the sheath comprises distal sheath leaves.

12. The assembly of claim 1 wherein the sheath comprises distal sheath quarter leaves.

13. The assembly of claim 1 wherein the sheath portions form a substantially conical sheath shape distally.

14. The assembly of claim 1 wherein the sheath portions form a distal bullet tip.

15. The assembly of claim 1 wherein the sheath portions form a substantially tubular sheath shape proximally.

16. The assembly of claim 1 wherein the sheath is curved.

17. The assembly of claim 1 wherein the sheath comprises a superelastic shape memory material.

18. The assembly of claim 1 wherein the sheath has a tensioning cable attached thereto.

19. The assembly of claim 1 wherein the sheath is modular.

20. The assembly of claim 1 wherein the cage comprises a plurality of components.

21. The assembly of claim 1 wherein the sheath leaves do not contact each other.

22. A method of inserting a fusion cage into a disc space bounded by a pair of vertebral endplates, comprising the steps of:

a) selecting the assembly of claim 1;

b) inserting the distal sheath portions of the assembly into the disc space so that the cage is within the disc space,

c) retracting the sheath from the disc space, thereby engaging the cage with the vertebral endplates.