Multipiece allograft implant

• US 20050113918A1
• Filed: 09/01/2004
• Published: 05/26/2005
• Est. Priority Date: 09/02/2003
• Status: Active Grant

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Angelucci, Christopher H., Boyer, Michael L. II, Messerli, Dominique, Myer, Jacqueline
• Granted Patent: US 7,226,482 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30057 made from both cortical and cancellous adjacent parts
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30492 using a locking pin
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30843 Pyramidally-shaped
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/003 differing in adsorbability or resorbability, i.e. in adsorption or resorption time

Abstract

An allogenic implant for use in intervertebral fusion is formed from two parts. The first part, composed of cortical bone, provides mechanical strength to the implant, allowing the proper distance between the vertebrae being treated to be maintained. The second part, composed of cancellous bone, is ductile and promotes the growth of new bone between the vertebrae being treated and the implant, thus fusing the vertebrae to the implant and to each other. The implant is sized and shaped to conform to the space between the vertebrae. Teeth formed on the superior and inferior surfaces of the implant prevent short-term slippage of the implant.

Claims

1. An intervertebral implant having superior and inferior surfaces comprising:

a first part composed of cortical bone; and

a second part composed of cancellous bone;

wherein

the first part and the second part are connected with a dovetail joint;

the superior and inferior surfaces are formed by the combination of the first and second part; and

substantially the entire superior and inferior surfaces of the first part further comprise a plurality of teeth.

2. The implant of claim 1, wherein the teeth are arranged in a two dimensional array, with the teeth being of a pyramid shape.

3. The implant of claim 1, wherein the implant has a wedge-shaped profile to help restore disc height and spine curvature.

4. The implant of claim 2, having an anterior height which is greater than a posterior height to produce the wedge-shaped profile.

5. The implant of claim 1, wherein the top and bottom surfaces are parallel and are spaced by a distance that approximates that of an intervertebral disc.

6. The implant of claim 1, wherein the top surface is a curved surface which is contoured to mimic the end plates of the adjacent vertebrae.

7. The implant of claim 1, further comprising an exterior surface formed by the combination of the first and second parts wherein the exterior surface has been processed to a predetermined shape.

8. The implant of claim 1, wherein the implant further comprises a pin, wherein the pin connects the first part and the second part.

9. The implant of claim 1, wherein the first part and the second part are connected by an adhesive.

10. A method of manufacturing an intervertebral implant having a superior surface, an inferior surface, and an exterior surface, comprising the steps of:

forming a first part from cortical bone;

forming a second part from cancellous bone;

connecting the first part with the second part using a dovetail joint; and

forming a plurality of teeth on the superior and inferior surfaces.

11. The method of claim 10, wherein the step of forming a first part further comprises forming a male portion of the dovetail joint, and wherein the step of forming a first part further comprises forming a female portion of the dovetail joint.

12. The method of claim 11, wherein the step of forming a first part further comprises forming a hole in the male portion, and wherein the step of forming a second part further comprises forming a hole in the second part, and wherein the method further comprises the steps of:

forming a pin; and

inserting the pin through the holes in the male portion and the female portion after the first part is connected to the second part.