Spinal implants with body and insert

• US 20050251257A1
• Filed: 05/04/2004
• Published: 11/10/2005
• Est. Priority Date: 05/04/2004
• Status: Active Grant

• Current Assignee: Zimmer Biomet Spine, Inc. (Zimvie Incorporated)
• Original Assignee: Zimmer Spine, Inc. (Zimmer Biomet Holdings, Inc.)
• Inventors: Freid, Jim, Mitchell, Margaret E.
• Granted Patent: US 7,833,271 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• 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 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30187 D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30266 wedge-shaped parallelepipeds
• 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 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30487 Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2002/30795 Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/3082 Grooves
• CPC Class Codes: A61F 2002/30909 Nets
• 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 2230/0034 D-shaped
• CPC Class Codes: A61F 2230/0065 toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0082 parallelepipedal
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite

Abstract

A spinal implant is provided which maintains intervertebral spacing and stability within the spine. The spinal implant may include a body and an insert. The body of the spinal implant may be formed of a ceramic material. In some embodiments, the body may be formed of beta tricalcium phosphate. The body may include an opening that is complementary to the insert. The insert may fit within the opening. The insert may include a number of passageways. Some of the passageways may intersect to form a scaffold for bone growth. Bone growth promoting material may be introduced into the insert before the insert is positioned in a body and inserted in a patient between two vertebrae.

Claims

1. A human intervertebral spacer, comprising:

a body comprising an opening;

an insert configured to be positioned in the opening in the body, wherein the insert is configured to facilitate bone ingrowth when the insert is positioned in the opening of the body and the insert and the body are placed between two human vertebrae; and

wherein the body is configured to inhibit the insert from passing through the opening.

2. The human intervertebral spacer of claim 1, wherein the body has a mechanical crush resistance that is greater than the mechanical crush resistance of the insert.

3. The human intervertebral spacer of claim 1, wherein the insert comprises a permeable and porous material.

4. The human intervertebral spacer of claim 1, wherein the spacer is configured such that bone ingrowth into the insert occurs at a faster rate than bone ingrowth into the body.

5. The human intervertebral spacer of claim 1, wherein the insert comprises passages.

6. The human intervertebral spacer of claim 1, wherein the insert comprises a first passage and a second passage, and wherein the first passage is nonparallel relative to the second passage.

7. The human intervertebral spacer of claim 1, wherein the insert comprises a first passage and a second passage, wherein the first passage is nonparallel relative to the second passage, and wherein the first passage intersects the second passage.

8. The human intervertebral spacer of claim 1, wherein an upper surface of the body is angled relative to a lower surface of the body to establish a desired amount of lordosis between the human vertebrae.

9. The human intervertebral spacer of claim 1, wherein the body is made of a ceramic material.

10. The human intervertebral spacer of claim 1, wherein the body comprises a guide configured to mate to a corresponding guide formed in a vertebra to guide the body during insertion.

11. The human intervertebral spacer of claim 1, wherein the body is sized to fit between cervical vertebrae.

12. The human intervertebral spacer of claim 1, wherein the body is sized to fit between lumbar vertebrae.

13. A method of forming a spinal implant to be positioned between human vertebrae, comprising:

forming an opening in a block of beta tricalcium phosphate; and

making an insert configured to fit in the opening such that the insert is inhibited from moving completely through the opening, and wherein a mechanical crush resistance of the insert is less than a mechanical crush resistance of the block.

14. The method of claim 13, further comprising machining the block to provide the block with a lordotic angle.

15. The method of claim 13, wherein the insert comprises a plurality of first passages from a top of the insert to a bottom of the insert, wherein the insert comprises a plurality of second passages, and wherein at least one second passage intersects with at least one first passage.

16. The method of claim 13, wherein the opening in the block is tapered.

17. A method of inserting an intervertebral spacer between two vertebrae in a human spine, comprising:

introducing bone growth promoting material in an insert;

placing the insert in an opening in a body to form the intervertebral spacer; and

positioning the spacer between two human vertebrae.

18. The method of claim 17, wherein the insert comprises a plurality of passages, and wherein at least two of the passages intersect within the insert.

19. The method of claim 17, wherein the body has a mechanical crush resistance that is greater than the mechanical crush resistance of the insert.

20. The method of claim 17, wherein introducing bone growth promoting material comprises soaking the insert in a solution.

21. The method of claim 17, wherein introducing bone growth promoting material comprises soaking the insert in blood.

22. The method of claim 17, wherein introducing bone growth promoting material comprises placing bone in passages in the insert.

23. The method of claim 17, wherein positioning the spacer comprises distracting the vertebrae, grasping the intervertebral spacer with an insertion instrument, positioning the intervertebral spacer between the vertebrae, and removing the distraction.