Prosthetic Intervertebral Discs Having Folding End Plates That Are Implantable By Minimally Invasive Surgical Techniques

• US 20090069895A1
• Filed: 03/31/2008
• Published: 03/12/2009
• Est. Priority Date: 03/31/2007
• Status: Abandoned Application

• Current Assignee: Spinal Kinetics Incorporated (Orthofix Medical Inc.)
• Original Assignee: Spinal Kinetics Incorporated (Orthofix Medical Inc.)
• Inventors: Gittings, Darin C., Wistrom, Elizabeth V.
• Application Number:
  US12/060,212
• Publication Number:
  US 20090069895A1
• Time in Patent Office: Days
• US Class Current: 623/17.160
• 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 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30075 swellable, e.g. when wetted
• 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 2002/30492 using a locking pin
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• 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 2210/0004 bioabsorbable
• 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 2220/0075 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 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

Abstract

The described devices are spinal implants that may be surgically implanted into the spine to replace damaged or diseased discs using a posterior approach. The discs are prosthetic devices that approach or mimic the physiological motion and reaction of the natural disc.

Claims

1. A prosthetic intervertebral disc, comprising:

a.) a first end plate and a second end plate;

at least one of the first and second end plates including at least one hinge and configured to bend at the at least one hinge towards the other end plate, the hinged end plate further configured with at least one slot configured to accept a stiffening bar and to straighten the hinged end plate,

b.) at least one stiffening bar, corresponding in number to the number of the at least one slot,

c.) at least one compressible core member positioned between said first and second end plates;

d.) at least one fiber extending between and engaged with said first and second end plates; and

wherein said end plates and said core member are held together by said at least one fiber.

2. The prosthetic intervertebral disc of claim 1 wherein each of the first and second end plates is hinged.

3. The prosthetic intervertebral disc of claim 1 wherein each one of the at least one first and second end plates configured with at least one slot configured to accept a stiffening bar, contains one such slot.

4. The prosthetic intervertebral disc of claim 1 wherein each of the first and second end plates configured with at least one slot configured to accept a stiffening bar, contains two such slots.

5. The prosthetic intervertebral disc of claim 1 wherein each slot has a cross-sectional shape selected from the group of dovetail, “

T”

shape, and round.

6. The prosthetic intervertebral disc of claim 1 wherein each of the first and second end plates includes edges and faces, and wherein the at least one slot configured to accept a stiffening bar resides in the edges.

7. The prosthetic intervertebral disc of claim 1 wherein each of the first and second end plates includes edges and faces, and wherein the at least one slot configured to accept a stiffening bar resides in the faces.

8. The prosthetic intervertebral disc of claim 1 wherein the disc is bullet-shaped.

9. The prosthetic intervertebral disc of claim 1 wherein the disc is lozenge-shaped.

10. A kit for surgically replacing a discs in a spine with a posterior approach, comprising exactly two of the prosthetic discs of claim 1.

11. The kit of claim 10 further comprising at least one cannula suitable for a posterior approach configured to access a disc to be replaced and to bypass the spinal cord and local nerve roots and further sized for passage of at least one of the two prosthetic discs of claim 1.

12. The kit of claim 10 wherein the first and second end plates of each of the prosthetic discs have a length and a width, and wherein the length is greater than the width.

13. The kit of claim 12 wherein the first and second end plates of the prosthetic discs have a length:

width aspect ratio of the first and second end plates is in the range of about 1.5 to 5.0.