Porous Implant For Spinal Disc Nucleus Replacement

• US 20080306595A1
• Filed: 03/24/2005
• Published: 12/11/2008
• Est. Priority Date: 03/26/2004
• Status: Abandoned Application

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Pearsalls Limited (Nuvasive Incorporated)
• Inventors: Reah, Christopher, McLeod, Alan Rory Mor
• Application Number:
  US10/594,377
• Publication Number:
  US 20080306595A1
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/0086 for preferentially controlling or promoting the growth of specific types of cells or tissues
• CPC Class Codes: A61F 2002/30009 differing in fibre orientations
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• 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 2002/30242 spherical
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30588 filled with solid particles
• CPC Class Codes: A61F 2002/30601 telescopic
• CPC Class Codes: A61F 2002/3093 for promoting ingrowth of bone tissue
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0061 swellable
• 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 2230/0071 spherical
• CPC Class Codes: A61F 2250/0028 differing in fibre orientations
• CPC Class Codes: A61F 2250/003 : differing in adsorbability or resorbability, i.e. in adsorption or resorption time
• CPC Class Codes: A61F 2250/0036 : differing in thickness
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00329 : Glasses, e.g. bioglass

Abstract

A spinal implant is provided in which the implant includes a porous component (7) and one or more filling elements (22) provided within the porous component. Tissue in-growth is promoted.

Claims

1. A spinal implant, the implant including a porous component and one or more filling elements provided within the porous component.

2. The implant of claim 1 in which the implant is a partial nucleus pulposus replacement or a total nucleus replacement.

3. The implant of claim 1 or claim 2 in which the porous component is a bag or other form of container having an opening to permit the insertion of the one or more filling elements.

4. The implant of any preceding claim in which the porous container is made of fabric, particularly a woven fabric.

5. The implant of any preceding claim in which the pores in the porous component have at least one cross-sectional dimension that is less than the smallest cross-sectional dimension of the filling elements.

6. The implant of any preceding claim in which the porous component is configured and/or formed of and/or provided with one or more materials intended to promote tissue growth, particularly tissue ingrowth through the porous component and/or between the porous component and one or more of the filling elements and/or between two or more of the filling elements.

7. The implant of any preceding claim in which one or more materials used in the porous component is bio-absorbable.

8. The implant of any preceding claim in which the bio-absorbable material is used to decrease the amount of porous component present and/or positions at which the porous component is present and/or density at which the porous component is present overtime.

9. The implant of any preceding claim in which the bio-absorbable material restrains the porous component in a first state, the bio-absorption of the material allowing the porous component to assume a second state.

10. The implant of any preceding claim in which the one or more filling elements is fibrous.

11. The implant of any preceding claim in which one or more filling elements that are porous and/or define voids within themselves and/or between parts of a filling element are provided.

12. The implant of any preceding claim in which one or more filling elements are formed of unconstrained fibres and/or unbraided fibres and/or interlaced fibres.

13. The implant of any preceding claim in which one or more filling elements are provided with aligned fibres.

14. The implant of any preceding claim in which one or more filling elements are provided, for instance wavy and/or curved and/or zig zag fibres.

15. The implant of any preceding claim in which one or more filling elements with fibres which act to space each other from one another are provided.

16. The implant of any preceding claim in which one or more filling elements with fibres of two or more different cross sections are provided.

17. The implant of any preceding claim in which one or more filling elements with fibres provided in a first direction are provided, with one or more restraining fibres or material which surround and/or enclose and/or be wrapped around and/or contact a plurality of fibres.

18. The implant of any preceding claim in which one or more filling elements are provided with peripheral fibres or material provided around the filling element, the peripheral fibres or material being wrapped around the filling elements in a spiral manner and/or criss-cross manner.

19. The implant of any preceding claim in which one or more filling elements are provided with pieces provided therein, the pieces being intermixed with one or more fibres.

20. The implant of any preceding claim in which the pieces are spheres, beads, blocks or the like.

21. The implant of any preceding claim in which the pores and/or voids and/or apertures and/or gaps occurring in the filling elements and/or there between are due to the manner of manufacture of the material from which it is formed or are supplemented with further pores and/or voids and/or apertures or gaps.

22. The implant of any preceding claim in which the one or more filling elements are configured and/or formed of one or more materials intended to promote tissue growth, particularly tissue ingrowth through one or more filling elements and/or between the porous component and one or more filling elements and/or between two or more of filling elements.

23. The implant of any preceding claim in which one or more materials used in one or more of the filling elements are bio-absorbable and the bio-absorbable material is used to decrease the amount of one or more filling elements present and/or positions at which one or more filling elements is present and/or density at which one or more filling elements is present overtime.

24. The implant of any preceding claim in which the bio-absorbable material restrains one or more of the filling elements, or a part thereof, in a first state, the bio-absorption of the material allowing one or more filling elements, or a part thereof, to assume a second state, the second state providing a greater internal volume for one or more filling elements and/or greater porosity for one or more filling elements and/or reduction in mass of one or more filling elements and/or provide more space for tissue ingrowth.

25. A surgical technique in which, at least part of a spinal disc is removed and an implant is provided, the implant having a porous component and one or more filling elements provided within the porous component.

26. A technique according to claim 25 in which the porous component is inserted through the same incision as is used to remove the nucleus material and the incision is only as large as needed for the nucleus material removal stage and the one or more filling elements are provided through the incision used to remove the nucleus material, the incision used for introducing the one or more filling elements being no larger than the incision necessary for the removal of the nucleus material.

27. A technique according to claim 25 or claim 26 in which the one or more filling elements are introduced into the porous component, with the porous component already within the intervertebral disc space.

28. A technique according to any of claims 25 to 27 in which the technique includes a first time in which the implant provides one or more characteristics of a naturally occurring disc by virtue of a non-biological mechanism, and a second time at which the implant provides one or more characteristics of a naturally occurring disc by a combination of a non-biological mechanism and biological mechanism.

29. A technique according to claim 28 in which the technique includes a third time with substantially all of the one or more characteristics of a naturally occurring disc are provided by a biological mechanism.

30. A technique according to claim 28 or claim 29 in which the transition from the mechanism at the first time to the second time and/or third time is due to bio-absorption of one or more of the materials forming the implant and particularly forming one or more filling elements thereon.