Lockable Spinal Implant

• US 20120245695A1
• Filed: 06/01/2012
• Published: 09/27/2012
• Est. Priority Date: 12/10/2008
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Coalign Innovations Inc. (Stryker Corporation)
• Inventors: Simpson, Philip J., Matsuura, David G., Gillespie, Walter Dean, Mansfield, George A. III, Ashley, John E.
• Granted Patent: US 8,894,710 B2
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/30742 Bellows or hose-like seals; Sealing membranes A61B17/8808 takes precedence; sealing membranes for retaining bone substitute A61F2/2846
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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 2/482 Electrical means
• CPC Class Codes: A61F 2/484 Fluid means, i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2002/30079 magnetic
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30365 with additional means for limiting said rotation
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30476 locked by an additional locking mechanism
• CPC Class Codes: A61F 2002/30484 Mechanically expandable devices located on the first prosthetic part for locking into or onto the second prosthetic part
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/30505 spring biased
• CPC Class Codes: A61F 2002/30514 using a locking washer
• CPC Class Codes: A61F 2002/30522 releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/30525 Worm gears
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30581 : having a pocket filled with fluid, e.g. liquid
• CPC Class Codes: A61F 2002/30589 : Sealing means
• CPC Class Codes: A61F 2002/30601 : telescopic
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2210/009 : magnetic
• 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 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2250/0007 : for adjusting length
• CPC Class Codes: A61F 2250/0069 : Sealing means
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• 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

Abstract

A spinal implant which is configured to be deployed between adjacent vertebral bodies. The implant has at least one extendable support element with a retracted configuration to facilitate deployment of the implant and an extended configuration so as to expand the implant and effectively distract the disc space, stabilize the motion segments and eliminate pathologic spine motion. Angular deformities can also be corrected, and natural curvatures restored. Preferably, the implant has a minimal dimension in its unexpanded state that is smaller than the dimensions of the neuroforamen through which it typically passes to be deployed within the intervertebral space. The implant is provided with a locking system preferably having a plurality of locking elements to lock the implant in an extended configuration.

Claims

1. A method of treating a patient'"'"'s vertebral structure, comprising:

a. providing a spinal implant having

i. a first member having a pressure applying surface for engaging an end of a first adjacent vertebral body,

ii. a second member having a pressure applying surface for engaging an end of a second adjacent vertebral body,

iii. at least one extendable support element having a contracted configuration within the implant to facilitate deployment of the implant between the first and second vertebral bodies and an extended configuration to extend the first pressure applying member to engage the end plate of the first adjacent vertebral body, and

iv. a locking system with a locking element for locking the implant in an extended configuration by engaging the extendable support element or the first member with the locking element;

b. inserting the spinal implant into a space between two vertebral bodies in the contracted configuration;

c. extending the support members so as to expand the implant until the first pressure applying surface engages an end of the first adjacent vertebral body and urges the vertebral body into a desired position; and

d. locking the implant in the extended configuration by moving the locking member into engagement with the extendable support element or the first member so as to fix the implant between the first and second vertebral bodies in an expanded configuration.

2. The method of claim 1, wherein said locking occurs automatically at the extended configuration

3. The method of claim 2, wherein said locking system comprises a rotatable locking member and a biasing element, the biasing element automatically rotating the locking member into a locked state upon the implant being extended to the extended configuration.

4. The method of claim 2, wherein said locking system comprises a ratchet.

5. The method of claim 2, wherein said locking system comprises a friction support.

6. The method of claim 1, further comprising delivering bone graft material into the space between the vertebrae through an opening in at least one of said first or second members.

7. The method of claim 6, further comprising filling an interior cavity of said implant with bone graft material.

8. The method of claim 6, further comprising transmitting bone graft material through passages in said implant to said opening.

9. The method of claim 7, wherein said implant includes at least first and second spaced apart extendable members extendable members defining said interior cavity therebetween.

10. The method of claim 1, wherein said extending comprises delivering a fluid under pressure to said at least one extendable support element.

11. The method of claim 10, wherein said extending further comprises expanding a piston outwardly within a cylinder.

12. The method of claim 1, wherein said extending comprises rotating a gear.

13. A method of treating a patient'"'"'s vertebral structure with an implant extendable between a contracted configuration and at least one extended configuration, comprising:

inserting the implant in the contracted configuration into a space between two vertebrae;

extending the implant to an extended configuration to apply a distracting force between said vertebrae; and

mechanically locking the implant in an extended configuration.

14. The method of claim 13, wherein said mechanically locking comprises automatically locking the implant in an extended configuration upon reaching said extended configuration.

15. The method of claim 14, further comprising automatically locking the implant in a series of sequentially greater extended positions as said implant is extended.

16. The method of claim 13, wherein said extending comprises delivering a fluid under pressure to said implant.

17. The method of claim 16, wherein said implant comprises at least one piston received in at least one cylinder and said delivering fluid under pressure expands the piston outwardly within the cylinder.

18. The method of claim 13, wherein said inserting comprises passing the implant in a contracted configuration through an opening that is smaller in at least one dimension than the implant in an extended configuration

19. A method of treating a patient'"'"'s vertebral structure with an implant extendable between a contracted configuration and at least one extended configuration, the implant comprising a body defining first and second spaced apart cylinders with an interior cavity defined therebetween, first and second pistons respectively received in said cylinders, a pressure applying plate acted on by said pistons, the pressure applying plate defining a central opening communicating with the interior cavity, and at least one locking member acting between said body and pistons, said method comprising:

inserting the implant in the contracted configuration into a space between two vertebrae;

delivering fluid under pressure to said cylinders to extend the implant to an extended configuration between said vertebrae; and

positioning the locking member to lock the implant in an extended configuration.

20. The method of claim 19, wherein said locking member comprises an arcuate member rotatable concentrically with respect to at least one said cylinder, said locking member being biased into a locking position by an actuator, and wherein said method further comprises automatically locking the implant at sequentially greater extended positions as fluid is delivered under pressure to said cylinders.