Peanut spectacle multi discoid thoraco-lumbar disc prosthesis

• US 20030199982A1
• Filed: 05/22/2003
• Published: 10/23/2003
• Est. Priority Date: 09/04/1998
• Status: Abandoned Application

• Current Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Bryan, Vincent
• Application Number:
  US10/443,422
• Publication Number:
  US 20030199982A1
• 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 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• 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 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30016 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2002/30121 with lobes
• CPC Class Codes: A61F 2002/30123 with two diametrically opposed lobes
• CPC Class Codes: A61F 2002/3013 figure-"8"- or hourglass-shaped
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• CPC Class Codes: A61F 2002/30253 ellipsoidal or ovoid
• 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 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• 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 2002/30604 modular
• CPC Class Codes: A61F 2002/30673 Lubricating means, e.g. synovial pocket
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30822 : Circumferential grooves
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• 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 2230/001 : Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0076 : ellipsoidal or ovoid
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0019 : differing in hardness, e.g. Vickers, Shore, Brinell

Abstract

A small profile, peanut spectacle-shaped prosthetic disc device is provided. The device housing is comprised of two longitudinally split hollow halves, between which are contained multiple discoid shaped resilient bodies which may be of a polymeric type, or they may contain hydrogel. These bodies may lie in concave surfaces located on the interior of each side of the split cylindrical housing. The housing halves, even under maximum physiological loads, do not contact one another directly. The shell shape permits relatively easy introduction of the implant into inter-vertebral spaces in the thoracic or lumbar region of the human spine.

Claims

1. A disc prosthesis comprising, in combination, a housing, the housing including an upper half and a lower half, and a plurality of non-concentric, resilient, viscoelastic discs interposed between the upper half housing and the lower half housing to maintain the housing halves separate from one another.

2. A disc prosthesis according to claim 1 wherein said discs are ovoid in shape and the housing is peanut shaped.

3. A disc prosthesis according to claim 1 wherein each disc is partly surrounded by a concave surface formed within said housing.

4. A disc prosthesis according to claim 1 wherein the housing halves are maintained a consistent distance from one another.

5. A disc prosthesis for affixing within a human spine, the prosthesis comprising a peanut shaped upper half housing adapted to engage a cephalad vertebral bone inferior end plate and cancellous bone of a superior vertebral body;

a peanut shaped lower half housing adapted to engage a caudal vertebral bone superior end plate and cancellous bone of an inferior vertebral body; and

a plurality of separate, substantially solid and resilient discs interposed between the housing halves.

6. A disc prosthesis according to claim 5 wherein each disc is partly surrounded by a concave surface formed within one of said housings.

7. A plurality of disc prostheses for being located within a human spine, each prosthesis comprising an upper half housing adapted to engage a cephalad bone inferior end plate and cancellous bone of a superior vertebral body;

a lower half housing adapted to engage a caudal vertebral bone superior end plate and cancellous bone of an inferior vertebral body; and

at least two similarly sized resilient members interposed between the housing halves for maintaining a consistently spaced distance between the upper and lower half housings, the at least two similarly sized resilient members having a solid exterior surface.

8. A plurality of disc prostheses according to claim 7 wherein one or more of the prosthesis halves have recesses defined in its exterior surface to permit bone ingrowth.

9. A disc prosthesis comprising at least two resilient, viscoelastic discs interposed between an upper half housing adapted to engage a superior vertebral body and a lower half housing adapted to engage an inferior vertebral body, wherein the upper half housing and lower half housing are configured to maintain the at least two discs in a common plane and at a spaced distance from each other, and wherein the two discs are of sufficient thickness and resiliency to maintain a separation between the upper half housing and lower half housing.

10. A disc prosthesis according to claim 9 wherein the at least two discs are solid.

11. A disc prosthesis comprising, in combination, a housing, the housing including at least two rigid, confronting and complimentary parts, the prosthesis further comprising at least two resilient, viscoelastic discs interposed between the housing parts to maintain the housing parts at a spaced distance and to permit limited motion from between the housing parts.

12. A disc prosthesis according to claim 11 including a sheath attached to said housing halves.

13. A disc prosthesis according to claim 11 in which a sealable portal is defined in said housing, the portal defining a passageway through which a lubricant or irrigant can be introduced into space between the nucleus and the housing interior surface.

14. A disc prosthesis according to claim 11 wherein the housing has an exterior surface defining a spectacle-like formation.

15. A disc prosthesis comprising an oblong shell having first and second housing portions and first and second flexible members interposed between the first and second housing portions, respectively, the first and second flexible members including a relatively soft interior and a relatively hard exterior.

16. A disc prosthesis according to claim 15 wherein the first and second flexible members are positioned in a spaced relation to each other and are positioned an equal and opposite distance from a central point of the disc prosthesis.

17. A disc prosthesis according to claim 15 wherein the shell further comprises a spacing portion for maintaining a spaced relation between the first and second housing portions, the spacing portion having a width that is less than a corresponding width of either the first or second housing portions.