EXPANDABLE IMPLANT

• US 20110160870A1
• Filed: 11/30/2010
• Published: 06/30/2011
• Est. Priority Date: 11/30/2009
• Status: Active Grant

• Current Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Original Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Inventors: Frigg, Robert, Voisard, Cyril, Baumgartner, Adrian, Saladin, Stefan, Brunner, Christian, Nardini, Reto, Schmidli, Dieter
• Granted Patent: US 8,608,743 B2
• Time in Patent Office: Days
• US Class Current: 623/23.61
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone
• CPC Class Codes: A61B 17/7266 with fingers moving radially outwardly
• CPC Class Codes: A61B 17/7275 with expanding cylindrical parts
• CPC Class Codes: A61B 17/742 having one or more longitudinal elements oriented along or parallel to the axis of the neck
• CPC Class Codes: A61B 17/744 the longitudinal elements coupled to an intramedullary nail
• CPC Class Codes: A61B 17/746 the longitudinal elements coupled to a plate opposite the femoral head
• CPC Class Codes: A61B 17/848 Kirschner wires, i.e. thin, long nails
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 17/8635 Tips of screws
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/866 Material or manufacture
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61B 17/8858 laterally or radially expansible inflatable A61B17/8855
• CPC Class Codes: A61B 2017/0409 Instruments for applying suture anchors
• CPC Class Codes: A61B 2017/044 with a threaded shaft, e.g. screws
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30062 : (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30065 : thermoplastic, i.e. softening or fusing when heated, and hardening and becoming rigid again when cooled
• CPC Class Codes: A61F 2002/30075 : swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30092 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/465 : using heating means
• CPC Class Codes: A61F 2310/00185 : based on metal oxides

Abstract

An implant system includes a fixation device that, in turn can include an expandable implant alone or in combination with an auxiliary implant. The expandable implant includes an expandable implant body that is made from an expandable material. The expandable material includes a polymer matrix and an expandable gas source contained within at least a portion of the polymer matrix. The implant system can further include an energy source configured to heat the polymer matrix to a temperature above its glass transition temperature, thereby causing the gas source to expand inside the polymer matrix. The fixation device can further include an insertion instrument configured to implant the fixation device into an anatomical cavity.

Claims

1. An implant system, comprising:

an expandable implant including an expandable implant body that is made from an expandable material, the expandable material including a polymer matrix and an expandable gas source contained within at least a portion of the polymer matrix;

wherein the polymer matrix transitions when heated from a first state in which the polymer matrix resists expansion to a second state in which the polymer matrix can be expanded thereby allowing the expandable gas source to expand inside the polymer matrix causing the implant body to expand from a first stable volume to a second expanded volume that is greater than the first stable volume.

2. The implant system of claim 1, wherein the polymer matrix transitions from the first state to the second state when heated from a first temperature to a second temperature at which the polymer matrix softens and allows the expandable gas source to increase the volume of the expandable implant.

3. The implant system of claim 1, wherein the implant body remains in the second expanded volume when the expandable material is cooled.

4. The implant system of claim 1, wherein the polymer matrix is biodegradable.

5. The implant system of claim 1, wherein the expandable gas source comprises at least one gas bubble that is held under compression in the first state.

6. The implant system of claim 1, wherein the expandable gas source comprises a stable chemical mixture at a first temperature, and wherein the chemical mixture is capable of reacting to produce a pressurized gas at an activation temperature greater than the first temperature.

7. The implant system of claim 6, wherein the chemical mixture comprises sodium bicarbonate and an acid salt.

8. The implant system of claim 1, wherein the implant body comprises a plurality of particles, at least one of which is made from the expandable material.

9. The implant system of claim 1, wherein at least a portion of the implant body comprises a sensitizer at the expandable implant material.

10. The implant system of claim 1, wherein the expandable implant comprises a bone anchor including a head and a shaft that extends from the head, the shaft configured to be inserted into bone.

11. The implant system of claim 1, wherein the expandable implant is shaped as an intramedullary fixation member.

12. The implant system of claim 1, wherein the expandable material contains at least one region that includes an expandable gas source, and at least one region that is devoid of expandable gas sources.

13. The implant system of claim 1, further comprising a bone fixation device that comprises the expandable implant and further comprises an auxiliary implant, such that the expandable implant is configured to fix the auxiliary implant to the bone.

14. The implant system of claim 13, wherein the bone fixation device defines an intramedullary fixation member.

15. The implant system of claim 13, wherein the bone fixation device defines a Kirschner wire.

16. The implant system of claim 13, wherein the expandable material is coated on at least a portion of an outer surface of the auxiliary implant.

17. The implant system of claim 13, wherein the auxiliary implant defines an interior passage, and at least a portion of the expandable material is disposed within the interior passage prior to expansion.

18. The implant system of claim 17, wherein the auxiliary implant further defines at least one perforation that extends from the interior passage to an outer surface of the auxiliary implant, such that the expandable implant is configured to travel through the at least one perforation.

19. The implant system of claim 17, wherein the expandable implant travels through the at least one perforation during expansion.

20. The implant system of claim 1, further comprising an insertion instrument that delivers the expandable material to a targeted anatomical cavity.

21. The implant system of claim 20, further comprising an energy source that transmits energy to the expandable implant sufficient to heat the expandable material and raise the temperature of the polymer matrix from the first temperature to the second temperature.

22. The implant system of claim 21, wherein the energy source is coupled to the insertion instrument.

23. The implant system of claim 21, wherein the energy source is a laser beam adapted to heat the expandable material.

24. The implant system according to claim 1, wherein the polymer matrix is made from at least one thermoplastic polymer.

25. A method of manufacturing an expandable material comprising the steps of:

heating a polymer matrix to a temperature sufficient to soften the polymer matrix;

introducing an expandable gas source into the polymer matrix;

cooling the polymer matrix while under an elevated external pressure to a temperature that hardens the material and entraps the expandable gas source within the polymer matrix.

26. The method according to claim 25, wherein the expandable gas source is pressurized.

27. The method according to claim 25, wherein the expandable gas source comprises a chemical mixture capable of generating gas at an activation temperature into the polymer matrix.

28. The method according to claim 25, further comprising the step of manufacturing a plurality of particles made from the expandable material.

29. A method of manufacturing an expandable implant, comprising the steps of:

compressing a plurality of expandable particles having a polymer matrix and an expandable gas source from an initial volume to a compressed volume that is less than the initial volume;

surrounding the compressed particles with a polymerizable material; and

polymerizing the polymerizable material such that the particles are retained by the polymerizable material at the compressed volume and the expandable gas source is in a compressed state.

30. A method of filling an anatomical cavity comprising:

inserting an expandable implant into an anatomical cavity, the implant including a polymer matrix and an expandable gas source disposed within at least a portion of the polymer matrix, the implant defining a first volume at a first temperature; and

transmitting energy from an energy source to the polymer matrix so as to heat the polymer matrix from the first temperature to a second temperature to soften the polymer matrix and allow the expandable gas source to expand the expandable implant to a second expanded volume greater than the first volume.

31. The method according to claim 30, wherein the heating step is performed after the expandable implant is inserted into the anatomical cavity.

32. The method according to claim 30, wherein the heating step is performed before the expandable implant is inserted into the anatomical cavity.

33. The method according to claim 30, wherein the expandable material is configured to adapt to the contour of the anatomical cavity after the heating step.

34. The method according to claim 30, further comprising the step of coating the expandable implant onto at least a portion of an outer surface of an insertion instrument.