Intervertebral allograft spacer

• US 6,554,863 B2
• Filed: 07/06/2001
• Issued: 04/29/2003
• Est. Priority Date: 08/03/1998
• Status: Expired due to Term

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson), Musculoskeletal Transplant Foundation
• Inventors: Yaccarino, Joseph A. III, Paul, David C., Schenk, Beat, Emch, Hansjuerg W.
• Primary Examiner(s): Willse, David H.
• Assistant Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US09/899,086
• Publication Number:
  US 20020062153A1
• Time in Patent Office: 662 Days
• Field of Search: 623/17-1-
• US Class Current: 623/17.11
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4644 Preparation of bone graft, bone plugs or bone dowels, e.g. grinding or milling bone material bone material A61F2/28; disintegrating or milling devices B02C
• 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 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30057 made from both cortical and cancellous adjacent parts
• 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 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30126 oval-O-shaped
• CPC Class Codes: A61F 2002/30133 : kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30153 : rectangular
• CPC Class Codes: A61F 2002/30158 : trapezoidal
• CPC Class Codes: A61F 2002/302 : toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30228 : Cylinders of elliptical or oval basis
• CPC Class Codes: A61F 2002/30233 : Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30237 : partial tubes
• CPC Class Codes: A61F 2002/3028 : polyhedral different from parallelepipedal and pyramidal
• CPC Class Codes: A61F 2002/30324 : differing in thickness
• CPC Class Codes: A61F 2002/30327 : differing in diameter
• CPC Class Codes: A61F 2002/30329 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• 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 2002/30354 : Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30367 : with additional means for preventing said rotation
• 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 2002/30433 : using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30448 : using adhesives
• CPC Class Codes: A61F 2002/30459 : stapled
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30477 : using sharp protrusions, e.g. spikes, for anchoring into connecting prosthetic part
• CPC Class Codes: A61F 2002/30481 : using a locking clip
• CPC Class Codes: A61F 2002/30492 : using a locking pin
• CPC Class Codes: A61F 2002/30494 : Cooperating protrusions and recesses, e.g. radial serrations, located on abutting end surfaces of a longitudinal connection
• CPC Class Codes: A61F 2002/30507 : using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30515 : using a locking wedge or block
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30599 : stackable
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30617 : Visible markings for adjusting, locating or measuring
• CPC Class Codes: A61F 2002/3071 : Identification means; Administration of patients
• CPC Class Codes: A61F 2002/30733 : Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30782 : inclined obliquely
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/3082 : Grooves
• 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 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30894 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30909 : Nets
• CPC Class Codes: A61F 2002/30957 : using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2002/4649 : Bone graft or bone dowel harvest sites
• 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 2220/0033 : 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 2220/005 : using adhesives
• CPC Class Codes: A61F 2220/0066 : stapled
• 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 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2250/0036 : differing in thickness
• CPC Class Codes: A61F 2250/0039 : differing in diameter
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• CPC Class Codes: A61F 2250/0089 : coded with symbols, e.g. dots, numbers, letters, words
• CPC Class Codes: A61F 2250/0097 : Visible markings, e.g. indicia
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00353 : Bone cement, e.g. polymethylmethacrylate or PMMA
• CPC Class Codes: B29C 33/26 : by pivotal movement
• CPC Class Codes: B29C 43/006 : Pressing and sintering powders, granules or fibres
• CPC Class Codes: B29L 2031/3041 : Trim panels
• CPC Class Codes: Y10S 623/925 : Natural

Abstract

An allogenic intervertebral implant for fusing vertebrae is disclosed. The implant is a piece of allogenic bone conforming in size and shape with a portion of an end plate of a vertebra. The implant has a wedge-shaped profile to restore disc height and the natural curvature of the spine. The top and bottom surfaces of the implant have a plurality of teeth to resist expulsion and provide initial stability. The implant according to the present invention provides initial stability need for fusion without stress shielding.

Claims

1. An intervertebral implant comprising:

a piece of allogenic bone conforming in size and shape with a portion of an end plate of a vertebra and having a wedge-shaped profile, wherein top and bottom surfaces of the implant have a plurality of teeth, wherein the implant further comprises a top portion having a top connecting surface and a bottom portion having a bottom connecting surface, the top connecting surface mating with the bottom connecting surface when the top and bottom surfaces are joined.

2. The implant of claim 1, wherein a pin is inserted through a hole in the top portion and a hole in the bottom portion to secure the top and bottom portions together.

3. The implant of claim 2, wherein the pin is made of allogenic bone.

4. The implant of claim 2, wherein the pin intersects the top and bottom connecting surfaces at oblique angles.

5. The implant of claim 1, wherein the implant is made of a plurality of interconnecting sections with mating surfaces.

6. The implant of claim 1, wherein at least one side has a channel for receiving a surgical instrument.

7. The implant of claim 1, wherein the teeth have a pyramid shape.

8. The implant of claim 1, wherein the teeth have a saw tooth shape.

9. The implant of claim 1, wherein at least one side of the implant has at least one hole for attachment of an inserter.

10. The implant of claim 1, wherein the top and bottom surfaces are defined by flat planar surfaces.

11. The implant of claim 10, wherein a region between the top and bottom surfaces and an anterior side of the implant is a curved edge to facilitate implantation of the implant.

12. The implant of claim 1, wherein the top and bottom surfaces are defined by curved surfaces, said curved surfaces contoured to mimic surfaces of the end plates of the vertebrae.

13. A method for restoring disc height between adjacent vertebrae having facing endplates, the method comprising:

removing at least a portion of a disc located between the adjacent vertebrae;

distracting an inner space between the facing endplates; and

inserting the implant of claim 1 to the distracted inner space.

14. The method of claim 13 comprising measuring a distance between the adjacent vertebrae with a preoperative lateral radiograph to determine an implant height.

15. The method of claim 13 wherein a distractor is used to distract the inner space.

16. The method of claim 15 further comprising inserting a trial spacer implant to determine an implant height.

17. An allogenic intervertebral implant comprising top and bottom surfaces, each the top and bottom surfaces provided with a plurality of teeth;

a first portion having a first connecting surface;

a second portion having a second connecting surface; and

a core having a first mating surface that mates with the first connecting surface and a second mating surface that mates with the second connecting surface to thereby form the allogenic intervertebral implant.

18. The implant of claim 17, wherein the core is made of a single piece of allogenic bone.

19. The implant of claim 17, wherein a pin is inserted through a hole in the first portion, a hole in the core, and a hole in the second portion to secure the core and the first and second portions together.

20. The implant of claim 19, wherein the pin intersects the top and bottom connecting surfaces at oblique angles.