Prosthetic intervertebral motion disc having dampening

• US 6,793,678 B2
• Filed: 03/27/2003
• Issued: 09/21/2004
• Est. Priority Date: 06/27/2002
• Status: Expired due to Term

• Current Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Inventors: Hawkins, John Riley
• Primary Examiner(s): Robert, Eduardo C.
• Assistant Examiner(s): Ramana, Anuradha
• Application Number:
  US10/400,969
• Publication Number:
  US 20040002762A1
• Time in Patent Office: 544 Days
• Field of Search: 623/11.11, 623/16.11, 623/17.11, 623/17.15, 623/17.16, 623/23.5, 606/60, 606/61
• US Class Current: 623/17.15
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• 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 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30232 Half-cylinders
• CPC Class Codes: A61F 2002/30245 Partial spheres
• CPC Class Codes: A61F 2002/30253 ellipsoidal or ovoid
• CPC Class Codes: A61F 2002/30327 differing in diameter
• CPC Class Codes: A61F 2002/30369 Limited lateral translation of the protrusion within a larger recess
• 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 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/304 with additional means for limiting said sliding
• CPC Class Codes: A61F 2002/30433 : using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30481 : using a locking clip
• CPC Class Codes: A61F 2002/30495 : using a locking ring
• CPC Class Codes: A61F 2002/305 : Snap connection
• CPC Class Codes: A61F 2002/30515 : using a locking wedge or block
• CPC Class Codes: A61F 2002/30528 : Means for limiting said movement
• 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 2002/30565 : having spring elements
• 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 2002/30604 : modular
• CPC Class Codes: A61F 2002/30649 : Ball-and-socket joints
• CPC Class Codes: A61F 2002/30662 : with rotation-limiting means
• CPC Class Codes: A61F 2002/30733 : Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30838 : Microstructures
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30843 : Pyramidally-shaped
• CPC Class Codes: A61F 2002/30878 : with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30883 : dovetail-shaped
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30939 : Means for modifying the geometry of articulating surfaces, e.g. for compensating excessive clearance caused by wear
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• 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 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0071 : spherical
• CPC Class Codes: A61F 2230/0076 : ellipsoidal or ovoid
• CPC Class Codes: A61F 2250/0039 : differing in diameter
• 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
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00203 : containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00239 : containing zirconia or zirconium oxide ZrO2
• CPC Class Codes: A61F 2310/0058 : Coating made of diamond or of diamond-like carbon DLC
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

An articulating motion disc having a core member that expands laterally in response to an axial load to mimic the shock absorbing function of a natural intervertebral disc.

Claims

1. An intervertebral motion disc comprising:

a) a first prosthetic vertebral endplate comprising;

i) an outer surface adapted to mate with a first vertebral body,

ii) an inner surface having a first articulation surface,

iii) a body portion connecting the inner and outer surfaces,

b) a second prosthetic vertebral endplate comprising;

i) an outer surface adapted to mate with a second vertebral body, and

ii) an inner surface comprising a first articulation surface, and

iii) a body portion connecting the inner and outer surfaces, and

c) a laterally expandable core member comprising;

a first articulation surface adapted for articulation with the first articulation surface of the first endplate,

a second articulation surface adapted for articulation with the first articulation surface of the second endplate,

wherein the core member is oriented therein to produce a first articulation interface between the first articulation surface of the first endplate and the first articulation surface of the core member, and a second articulation interface between the first articulation surface of the second endplate and the second articulation surface of the core member, and a height H between the outer surfaces of the prosthetic endplates, and

wherein the laterally expandable core member expands laterally when the disc is subjected to axial load of about 750 pounds force (3.4 kN) to reduce the height of the device between 0.5 and 2.0 mm; and

wherein the core member comprises;

i) an annulus having an inner diameter, and

ii) an inner articulation member comprising a plurality of articulation components, each articulation component comprising;

an outer radius adapted to sear upon the inner diameter of the expandable annulus,

a first articulation surface adapted for articulation with the first articulation surface of the first endplate,

a second articulation surface adapted for articulation with the first articulation surface of the second endplate.

2. The disc of claim 1 wherein the laterally expandable core member expands laterally when the disc is subjected to axial load of about 750 pounds force (3.4 kN) to reduce the height of the device between 0.5 and 1.5 mm.

3. The disc of claim 1 wherein the laterally expandable core member expands laterally when the disc is subjected to axial load of about 750 pounds force (3.4 kN) to reduce the height of the device between 0.8 and 1.2 mm.

4. The disc of claim 1 wherein the annulus is expandable.

5. The disc of claim 4 wherein the annulus is continuous.

6. The disc of claim 5 wherein the continuous annulus is a coil.

7. The disc of claim 5 wherein the continuous annulus has a first portion having a smaller outer radius and a second portion having a larger outer radius.

8. The disc of claim 4 wherein the annulus has a first end and a second end.

9. The disc of claim 8 wherein the annulus has a key ring shape.

10. The disc of claim 4 wherein the annulus is a split ring.

11. The disc of claim 1 wherein the inner articulation member comprises at least three articulation components.

12. The disc of claim 1 wherein the annulus has a groove and the outer radius of each articulation component has a lip adapted to seat in the groove.

13. The disc of claim 1 wherein each articulation component comprises an inner radius.

14. The disc of claim 1 wherein each articulation component has first and second side surfaces defining a width therebetween, wherein the width of each articulation component decreases inwardly.

15. The disc of claim 1 wherein the side surfaces of each articulation component form a frustoconcial cross-section.

16. The disc of claim 1 wherein the side surfaces of adjacent articulation components contact each other.

17. The disc of claim 1 wherein the core member is an integral body having a central hole.

18. An intervertebral motion disc comprising:

a) a first prosthetic vertebral endplate comprising;

i) an outer surface adapted to mate with a first vertebral body,

ii) an inner surface having a first articulation surface,

iii) a body portion connecting the inner and outer surfaces,

b) a second prosthetic vertebral endplate comprising;

i) an outer surface adapted to mate with a second vertebral body, and

ii) an inner surface comprising a first articulation surface, and

iii) a body portion connecting the inner and outer surfaces, and

c) a laterally expandable core member comprising;

i) an annulus having an inner diameter, and

ii) an inner articulation member comprising a plurality of articulation components, each articulation component comprising;

an outer radius adapted to seat upon the inner diameter of the expandable annulus,

a first articulation surface adapted for articulation with the first articulation surface of the first endplate,

a second articulation surface adapted for articulation with the first articulation surface of the second endplate,

wherein the core member is oriented therein to produce a first articulation interface between the first articulation surface of the first endplate and the first articulation surface of the core member, and a second articulation interface between the first articulation surface of the second endplate and the second articulation surface of the core member.