CERAMIC DISC PROSTHESIS

• US 20060004453A1
• Filed: 05/25/2005
• Published: 01/05/2006
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Inventors: Bartish, Charles M. Jr., McCrea, Conor, Fatyol, Patrick, Brousseau, Jeffrey
• Granted Patent: US 8,021,428 B2
• Time in Patent Office: Days
• US Class Current: 623/17.150
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30179 X-shaped
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30561 breakable or frangible
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30649 Ball-and-socket joints
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/443 having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2210/0023 operated at different temperatures whilst inside or touching the human body, heated or cooled by external energy source or cold supply
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0058 X-shaped
• 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 2310/00203 containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00239 containing zirconia or zirconium oxide ZrO2
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A prosthetic is provided for replacing a vertebral disc. The prosthesis can comprise first and second endplates formed of a ceramic material, each including an articulating contact surface and a bone facing surface. The contact surface of the first endplate can have a shape complementary to the contact surface of the second endplate, thereby facilitating articulation of the first and second endplates while in contact with one another. The device can further include at least one non-ceramic bone attachment element mated with at least one of the bone facing surfaces, such that the bone attachment element covers less than a full area of the bone facing surface.

Claims

1. A disc prosthesis device comprising:

first and second endplates each having an articulating contact surface and a bone facing surface, at least one of the first and second endplates comprise a ceramic material; and

at least one non-ceramic bone attachment element formed on at least one of the bone facing surfaces, such that the bone attachment element covers less than a full area of the bone facing surface.

2. The device of claim 1, wherein the bone attachment element includes bone-penetrating teeth formed from a material selected from the group consisting of a metal, a plastic, and combinations thereof.

3. The device of claim 2, wherein the teeth are oriented at an angle of less then 90°

with respect to the bone facing surface.

4. The device of claim 2, wherein the teeth are oriented and adapted so as to be compressed during insertion.

5. The device of claim 1, wherein the bone attachment element includes bone-penetrating teeth formed from a shape memory material.

6. The device of claim 5, wherein the teeth are oriented in a non-bone penetrating position before activation and are orientated at an inclined angle, and effective to penetrate bone after activation.

7. The device of claim 1, wherein the bone attachment element comprises at least one strip of non-ceramic material that includes teeth formed thereon.

8. The device of claim 7, wherein the bone attachment element is mated to the endplate by a technique selected from the group consisting of bonding, mechanical interlock, brazing, overmolding, overcasting, thermal interference, and combinations thereof.

9. The device of claim 8, wherein the bone attachment element is seated within a recess in the bone facing surface.

10. The device of claim 1, wherein the bone attachment element includes a mating element adapted to mate with an insertion tool.

11. The device of claim 10, wherein the mating element is selected from the group consisting of a male mating element and a female mating element.

12. The device of claim 1, wherein the contact surface of the first endplate has a shape complementary to the contact surface of the second endplate such that the first and second endplates can articulate while in contact with one another.

13. The device of claim 1, wherein the first and second endplates include mating elements adapted to mate with a male or female insertion tool.

14. The device of claim 1, wherein a coating is positioned on at least one of the bone facing surfaces.

15. The device of claim 1, wherein a coating is positioned on the at least one bone attachment element.

16. A disc prosthesis comprising:

first and second endplates wherein the first and second endplates is formed of a ceramic material, the first and second endplates each having an articulating surface and an opposed bone contacting surface, wherein movement of the first and second endplates relative to one another is unconstrained by any portion of the prosthesis; and

bone engaging features positioned on at least one of the bone facing surfaces.

17. The device of claim 16, wherein at least one of the first and second endplates includes a mating element adapted to mate with an insertion tool.

18. The device of claim 16, wherein at least one of the bone contacting surfaces includes a coating.

19. The device of claim 16, wherein the articulating surfaces of the first and second endplates are complementary to each other such that the first and second endplates can articulate while in contact with one another.

20. A method of implanting a disc prosthesis, comprising:

providing a disc prosthesis having first and second endplates each having an articulating surface and an opposed bone facing surface, at least one of the bone facing surfaces including a bone attachment element with at least one bone penetrating feature formed from a heat-activated shape memory material;

inserting the disc prosthesis between two vertebral bodies wherein the bone penetrating feature is in a first, non-bone penetrating orientation; and

subjecting the bone attachment element to an activating force effective to orient the bone penetrating feature in a second, bone penetrating orientation.

21. The method of claim 20, wherein the activating force is body heat.

22. The method of claim 20, wherein the activating force is a supplemental heat source.

23. The method of claim 20, wherein the endplates comprise a ceramic material.

24. The method of claim 20, wherein the bone penetrating feature comprises bone penetrating teeth.