Prosthetic intervertebral discs

• US 20070050033A1
• Filed: 11/15/2005
• Published: 03/01/2007
• Est. Priority Date: 09/01/2005
• Status: Active Grant

• Current Assignee: Spinal Kinetics LLC (Orthofix Medical Inc.)
• Original Assignee: Spinal Kinetics Incorporated (Orthofix Medical Inc.)
• Inventors: Gittings, Darin, Reo, Michael
• Granted Patent: US 7,731,753 B2
• Time in Patent Office: Days
• US Class Current: 623/17.120
• CPC Class Codes: A61B 17/7062 Devices acting on, attached to, or simulating the effect of, vertebral processes, vertebral facets or ribs rib fixation devices A61B17/8076; Tools for such devices
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• 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 2/3094 Designing or manufacturing processes
• 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 2/4425 made of articulated components
• CPC Class Codes: A61F 2/484 Fluid means, i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2002/30009 differing in fibre orientations
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30075 swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30168 L-shaped
• CPC Class Codes: A61F 2002/30179 X-shaped
• CPC Class Codes: A61F 2002/30224 cylindrical
• 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 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• 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 2002/30563 : having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30566 : Helical springs
• CPC Class Codes: A61F 2002/30576 : with extending fixation tabs
• 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 2002/30586 : having two or more inflatable pockets or chambers
• CPC Class Codes: A61F 2002/30594 : slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30662 : with rotation-limiting means
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30889 : Arcuate pegs
• CPC Class Codes: A61F 2002/30897 : Stepped protrusions, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30899 : Protrusions pierced with apertures
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/4415 : elements of the prosthesis being arranged in a chain like manner
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/444 : for replacing the nucleus pulposus
• 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 2002/4495 : having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2002/4677 : using a guide wire
• CPC Class Codes: A61F 2210/0061 : swellable
• 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 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2220/0091 : connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0043 : L-shaped
• CPC Class Codes: A61F 2230/0058 : X-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0028 : differing in fibre orientations

Abstract

Prosthetic intervertebral discs, systems including such prosthetic intervertebral discs, and methods for using the same are described. The subject prosthetic discs include upper and lower endplates separated by a compressible core member. The subject prosthetic discs exhibit stiffness in the vertical direction, torsional stiffness, bending stiffness in the saggital plane, and bending stiffness in the front plane, where the degree of these features can be controlled independently by adjusting the components, construction, and other features of the discs.

Claims

1. A prosthetic intervertebral disc comprising:

a first endplate;

a second endplate attached either directly or indirectly to said first endplate in a substantially parallel relationship thereto; and

a core member positioned between said first and second endplates;

wherein said first endplate includes a fixation member that is selectively moveable from an undeployed state to a deployed state.

2. The prosthetic intervertebral disc of claim 1, wherein said fixation member comprises a keel that is slidably engageable with said first endplate.

3. The prosthetic intervertebral disc of claim 2, wherein said keel has a generally triangular cross-sectional shape and said first endplate includes a slot having a generally trapezoidal cross-sectional shape for engaging said keel.

4. The prosthetic intervertebral disc of claim 2, wherein said first endplate has a generally curved cross-sectional shape.

5. The prosthetic intervertebral disc of claim 2, wherein said keel includes a base portion, an anchoring fin extending outward from an outer surface of said base portion, and an attachment member on another surface of said base portion, said attachment member configured to engage said first endplate.

6. The prosthetic intervertebral disc of claim 5, wherein said base portion has a generally wedge shape to accommodate a lordosis angle upon implantation.

7. The prosthetic intervertebral disc of claim 1, wherein said fixation member in its deployed state extends outward from an outer surface of said first endplate.

8. The prosthetic intervertebral disc of claim 7, wherein said fixation member comprises a retractable anchoring fin.

9. The prosthetic intervertebral disc of claim 8, further comprising a fixed anchoring fin extending outward from an outer surface of said first endplate.

10. The prosthetic intervertebral disc of claim 9, wherein said fixed anchoring fin is oriented at a generally right angle relative to said retractable anchoring fin.

11. The prosthetic intervertebral disc of claim 7, wherein said fixation member is moved from its undeployed state to its deployed state by an expandable member located generally between said first endplate and said second endplate.

12. The prosthetic intervertebral disc of claim 7, wherein said fixation member is moved from its undeployed state to its deployed state by a screw mechanism located generally between said first endplate and said second endplate.

13. A prosthetic intervertebral disc comprising:

a first endplate comprising an inner member and an outer member, with said inner member and said outer member being capable of rotation relative to one another;

a second endplate attached either directly or indirectly to said first endplate in a substantially parallel relationship thereto; and

a core member positioned between said first and second endplates;

wherein rotation of said inner member relative to said outer member causes a fixation member to extend outward from said first endplate.

14. The prosthetic intervertebral disc of claim 13, wherein said fixation member comprises a threaded screw.

15. The prosthetic intervertebral disc of claim 14, further comprising a slot formed in one of said inner member or said outer member, said threaded screw being configured to travel within said slot.

16. The prosthetic intervertebral disc of claim 15, wherein said slot is formed in said inner member of said first endplate.

17. The prosthetic intervertebral disc of claim 16, wherein said outer member of said first endplate includes a threaded hole that is adapted to engage the threads of said threaded screw to facilitate extension of said threaded screw outward from said first endplate.

18. The prosthetic intervertebral disc of claim 17, further comprising a plurality of fixation members adapted to extend outward from said first endplate.

19. The prosthetic intervertebral disc of claim 18, further comprising a plurality of fixation members adapted to extend outward from said second endplate.

20. A prosthetic intervertebral disc comprising:

a first endplate;

a second endplate attached either directly or indirectly to said first endplate in a substantially parallel relationship thereto; and

a core member positioned between said first and second endplates;

wherein said first endplate includes a central portion and a first side portion, said first side portion having a first position in which it lies in substantially the same plane with the central portion, and a second position in which it lies in a substantially different plane than the central portion.

21. The prosthetic intervertebral disc of claim 20, wherein said first endplate has a first hinge connecting said central portion and said first side portion.

22. The prosthetic intervertebral disc of claim 21, wherein said first endplate has a second side portion attached to said central portion by a second hinge, said second side portion having a first position in which it lies in substantially the same plane with the central portion, and a second position in which it lies in a substantially different plane than the central portion..

23. The prosthetic intervertebral disc of claim 20, wherein said second endplate includes a central portion and a first side portion, said first side portion having a first position in which it lies in substantially the same plane with the central portion, and a second position in which it lies in a substantially different plane than the central portion.

24. The prosthetic intervertebral disc of claim 23, further comprising a spring extending between and attached to the first side portions of each of the first endplate and the second endplate.

25. The prosthetic intervertebral disc of claim 24, wherein the first side portions of said first endplate and said second endplate each has a slot formed therein, each of said slots being adapted to engage said spring.