Prosthetic Intervertebral Discs

• US 20090018661A1
• Filed: 01/01/2008
• Published: 01/15/2009
• Est. Priority Date: 08/01/2003
• Status: Abandoned Application

• Current Assignee: Spinal Kinetics Incorporated (Orthofix Medical Inc.)
• Original Assignee: Spinal Kinetics Incorporated (Orthofix Medical Inc.)
• Inventors: Chee, Uriel Hiram, Frank, Curtis W., Ha, Sung Kyu, Reo, Michael L., Kim, Daniel H., Lee, Kunwoo, Cho, In Haeng, Afzal, Thomas A.
• Application Number:
  US11/968,185
• Publication Number:
  US 20090018661A1
• Time in Patent Office: Days
• US Class Current: 623/17.160
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• 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 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30523 by means of meshing gear teeth
• 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 2002/30578 having apertures, e.g. for receiving fixation screws
• 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 2002/30604 modular
• CPC Class Codes: A61F 2002/30733 Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• 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 2002/4622 : having the shape of a forceps or a clamp
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• 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 2230/0015 : Kidney-shaped, e.g. bean-shaped
• 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 2310/00161 : Carbon; Graphite
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61L 2430/38 : for reconstruction of the spine, vertebrae or intervertebral discs

Abstract

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 prosthetic discs described herein include one-piece, two-piece, three-piece, and four-piece structures. 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 of the discs. The interface mechanism between the endplates and the core members of several embodiments of the described prosthetic discs enables a very easy surgical operation for implantation.

Claims

1. A prosthetic intervertebral disc comprising:

a first endplate, a second endplate having a slot on its internal periphery, a core member fixedly attached on a first side to said first endplate and having a flange on a second side opposite said first side, said flange adapted to engage the slot on said second endplate to thereby attach said core member to said second endplate.

2. The prosthetic intervertebral disc of claim 1 further comprising a fixation member for securing said first endplate to a vertebral body.

3. The prosthetic intervertebral disc of claim 1 further comprising a fixation member for securing said second endplate to a vertebral body.

4. The prosthetic intervertebral disc of claim 2 wherein said fixation member comprises at least one anchoring fin.

5. The prosthetic intervertebral disc of claim 3 wherein said fixation member comprises at least one anchoring fin.

6. The prosthetic intervertebral disc of claim 2 wherein said fixation member comprises at least one anchoring spike.

7. The prosthetic intervertebral disc of claim 3 wherein said fixation member comprises at least one anchoring spike.

8. The prosthetic intervertebral disc of claim 2 wherein said fixation member comprises a plurality of serrations formed on an external surface of at least one of said first and said second endplates.

9. The prosthetic intervertebral disc of claim 3 wherein said fixation member comprises a plurality of serrations formed on an external surface of at least one of said first and said second endplates.

10. The prosthetic intervertebral disc of claim 1 wherein said flange of said core member and said slot of said second endplate cooperate to selectively attach said second endplate to said core member while allowing the flange to slide relatively freely within the confines of said slot.

11. The prosthetic intervertebral disc of claim 10 wherein said flange is formed on an inner second endplate attached to said core member.

12. The prosthetic intervertebral disc of claim 10 further comprising a retaining lip formed on said second endplate and adapted to retain said core member on said second endplate in a manner that allows the flange to slide relatively freely within the confines of the slot.

13. The prosthetic intervertebral disc of claim 11 further comprising a plurality of fibers connecting said first endplate to said inner second endplate.

14. The prosthetic intervertebral disc of claim 1 further comprising a center core retained within said core member, wherein said center core comprises one of either polyurethane or silicone.