Intervertebral disk prosthesis

• US 20040220669A1
• Filed: 12/16/2003
• Published: 11/04/2004
• Est. Priority Date: 06/27/2001
• Status: Abandoned Application

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Studer, Armin
• Application Number:
  US10/481,079
• Publication Number:
  US 20040220669A1
• Time in Patent Office: Days
• US Class Current: 623/17.12
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30291 spirally-coiled, i.e. having a 2D spiral cross-section
• CPC Class Codes: A61F 2002/30581 having a pocket filled with fluid, e.g. liquid
• CPC Class Codes: A61F 2002/30738 Sleeves
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• CPC Class Codes: A61F 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers

Abstract

An intervertebral disk prosthesis or a nucleus replacement prosthesis having an at least partially flexible jacket (3, 4, 5) that encloses a cavity (2) having a variable shape. The jacket (3, 4, 5) is at least partially configured as a semi-permeable membrane (3) for a solvent so that a solution of a substance contained in the cavity (2) can adapt its concentration and its volume to the external load conditions according to the principle of reverse osmosis.

Claims

1. An intervertebral disk prosthesis (1, 10, 20) or a nucleus replacement prosthesis with an at least partly flexible jacket (3, 4, 5) that encloses a cavity (2) with a varying shape, the jacket constructed at least partially as a semi-permeable membrane (3) for a solvent, wherein the jacket (3, 4, 5) is a longitudinal receptacle having a shape selected from the group consisting of spiral, serpentine and coil.

9. The intervertebral disk prosthesis according to claim 1, wherein the prothesis'"'"'s shape is selected from the group consisting of lens-shaped and balloon-shaped.

10. The intervertebral disk prosthesis according to claim 1, wherein the jacket (3, 4, 5) is a coil-shaped longitudinal receptacle in which individual coil windings have an intermediate space (19).

11. The intervertebral disk prosthesis according to claim 1, wherein the jacket (3, 4, 5) is a material having a memory effect of the shape.

12. The intervertebral disk prosthesis according to claim 1, wherein the cavity (2) is filled with a solution of a material in water or in another solvent, while the dissolved material is selected from the group consisting of organic salts and sugar.

13. The intervertebral disk prosthesis according to claim 12, wherein the solution is a hydrogel.

14. The intervertebral disk prosthesis according to claim 12, wherein the solution contains polymer or copolymer materials.

15. The intervertebral disk prosthesis according to claim 12, wherein the inorganic salt is natrium chloride.

16. The intervertebral disk prosthesis according to claim 1, wherein the semi-permeable membrane (3) is made from a material selected from the group consisting of parchment paper, pig'"'"'s bladder, and a polymer.

17. The intervertebral disk prosthesis according to claim 1, wherein said prosthesis has a laminate structure.

19. The intervertebral disk prosthesis according to claim 1, wherein a height of the prosthesis is between 4-5 mm.

20. The intervertebral disk prosthesis according to claim 1, wherein a maximum height of the prosthesis is between 12-15 mm.

21. The intervertebral disk prosthesis according to claim 1, wherein a minimum volume of the cavity (2) is between 0.5-0.8 cm³.

22. The intervertebral disk prosthesis according to claim 1, wherein a maximum volume of the cavity (2) is between 4-5 cm³.

23. The intervertebral disk prosthesis according to claim 1, wherein a maximum height increase due to water absorption is between 5-8 mm.

24. The intervertebral disk prosthesis according to claim 1. wherein the jacket (3, 4, 5) is fitted with a valve so that the jacket (3, 4, 5) can be implanted into the intervertebral space in the collapsed state by a laparoscope and then filled through the valve with an aqueous saline or sugar solution.

25. The intervertebral disk prosthesis according to claim 24, wherein the valve is provided on a periphery of the intervertebral disk prosthesis.

27. The intervertebral disk prosthesis according to claim 1, wherein the concentration of the solution of a material is between about 0.9% to 2.0%.

28. The intervertebral disk prosthesis according to claim 12, wherein a molarity of the solution of a material is between about 0.155-0.3 mol/L.

29. The intervertebral disk prosthesis according to claim 12, wherein a maximum molarity of the solution of a material is between about 3-53 mol/L.

30. The intervertebral disk prosthesis according to claim 12, wherein the solution additionally contains a contrasting agent for X-rays.

31. The intervertebral disk prosthesis according to claim 1, wherein said prosthesis'"'"' shape simulates a natural intervertebral disk.

32. The intervertebral disk prosthesis according to claim 1, wherein the casing (4, 5) contains a material that is opaque for X-rays.

2. The intervertebral disk prosthesis according to claim 2, wherein the jacket (3, 4, 5) comprises the semi-permeable membrane (3) and has a casing (4, 5) made from a biocompatible material that encloses the membrane (3).

3. The intervertebral disk prosthesis according to claim 2, wherein the casing (4, 5) is made from a polymer.

4. The intervertebral disk prosthesis according to claim 2, wherein the casing (4, 5) is made from a homogeneous material.

5. The intervertebral disk prosthesis according to claim 2, wherein the casing (4, 5) is made from at least two different materials.

6. The intervertebral disk prosthesis according to claim 2, wherein the material of the casing (4, 5), that encloses the semi-permeable membrane (3), is welded together by an injection molding process, whereby a first partial casing (5) obtained by a first injection extrusion molding step is completed by injection molding with a second partial casing to produce a compact intervertebral disk prosthesis.

7. The intervertebral disk prosthesis according to claim 2, wherein the casing (4, 5) has perforations so that it forms an outwardly open system.

8. The intervertebral disk prosthesis according to claim 2, wherein the casing (4, 5) forms an outwardly closed system.

18. The intervertebral disk prosthesis according to claim 2, wherein the semi-permeable membrane (3) is constructed as a virtually watertight pouch that is filled with a solution of salt or sugar and is enveloped by a casing (4, 5).

26. The intervertebral disk prosthesis according to claim 2, wherein, between the semi-permeable membrane (3) enveloping the cavity (2) and the casing (4, 5), a reservoir for pure solvent is provided.