Bone treatment systems and methods

• US 20060122622A1
• Filed: 06/24/2005
• Published: 06/08/2006
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Original Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Inventors: Shadduck, John H., Truckai, Csaba, Luzzi, Robert, Rappleye, C. Travis, Carlson, Grace A.
• Granted Patent: US 7,678,116 B2
• Time in Patent Office: Days
• US Class Current: 606/94
• CPC Class Codes: A61B 17/7095 the filler comprising unlinked macroscopic particles
• CPC Class Codes: A61B 17/7098 wherein the implant is permeable or has openings, e.g. fenestrated screw hollow surgical screws A61B17/864
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/8811 characterised by the introducer tip, i.e. the part inserted into or onto the bone
• CPC Class Codes: A61B 17/8836 for heating, cooling or curing of bone cement or fluid fillers
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs

Abstract

The present invention relates in certain embodiments to medical devices for treating osteoplasty procedures such as vertebral compression fractures. More particularly, embodiments of the invention relate to instruments and methods for controllably restoring vertebral body height by controlling the geometry of fill material introduced into cancellous bone. An exemplary system utilizes Rf energy in combination a conductive bone fill material for polymerizing the surface of the inflow plume to control the geometry of the fill material and the application of force caused by inflows of fill material. In another embodiment, method of treating bone includes injecting a volume of fill material into a bone and selectively modifying a viscosity of a selected portion of the bone filler to control the direction of flow of the fill material within the bone. A system for treating bone using this method includes an introducer for delivering fill material into the bone and an energy source selectively coupleable to the fill material to alter the viscosity of the fill material as it flows out of the introducer.

Claims

1. A method of treating bone, comprising:

introducing a volume of polymerizable bone fill material into a bone;

altering a property of at least a portion of the volume to create a differential in flowability wherein a first selected region is substantially non-flowable and a second selected region is flowable; and

introducing an additional volume of fill material wherein a direction of flow of the additional volume is controlled by said differential in flowability.

2. The method of claim 1, wherein the property altered is selected from the group consisting of viscosity, Young'"'"'s modulus, surface hardness and durometer.

3. The method of claim 2, wherein the altered property comprises a viscosity that is greater than about 100,000 cps.

4. The method of claim 2, wherein the altered property comprises a Young'"'"'s modulus that ranges between about 10 kPa and about 10 GPa.

5. The method of claim 1, wherein the non-flowable region is at least a portion of the surface of the volume.

6. The method of claim 1, wherein the non-flowable region comprises the entire surface of the volume.

7. The method of claim 5, wherein introducing the additional volume expands at least a portion of the surface.

8. The method of claim 1, wherein introducing the additional volume supports or moves cortical bone.

9. The method of claim 1, wherein introducing the additional volume reduces a vertebral fracture.

10. The method of claim 1, wherein altering a property of at least a portion of the volume includes applying energy from a remote energy source.

11. A method of controlling the direction of flow of a bone fill material in a vertebra, comprising:

injecting a volume of bone filler into a vertebra;

selectively modifying the viscosity of a selected portion of the fill material to control a direction of flow, said modification defining at least one higher viscosity portion and at least one lower viscosity portion of the fill material.

12. The method of claim 11, further comprising injecting an additional volume of fill material within a preceding volume of fill material.

13. The method of claim 12, wherein the additional volume applies asymmetric retraction forces to the vertebra and wherein the flow direction is toward deformation of the lower viscosity portions and away from the higher viscosity portions.

14. The method of claim 11, wherein selectively modifying the viscosity of the fill material includes applying energy from an energy source to the fill material.

15. The method of claim 14, wherein the energy source is at least one of a radiofrequency source, a resistive heat source, a laser source, a microwave source, a magnetic source, and an ultrasound source.

16. The method of claim 11, wherein the direction of flow is toward the lower viscosity portion and away from the higher viscosity portion.

17. The method of claim 11, wherein the volume of fill material flows within cancellous bone in the vertebra.

18. The method of claim 12, wherein injecting the additional volume of fill material expands cancellous bone.

19. The method of claim 18, wherein the expansion of cancellous bone at least partially restores a height of a fractured vertebra.

20. A method for treating a vertebral body, comprising:

introducing a bone fill material into an interior of the vertebral body, the bone fill material interdigitating with cancellous bone;

increasing the viscosity of the bone fill material at selected regions within the interior of the vertebral body to form substantially flow impermeable portions within the vertebral body; and

applying an expansion force within the bone fill material.

21. The method of claim 20, wherein the expansion force is applied by a continued introduction of a bone fill material.

22. The method of claim 20, wherein the viscosity of the bone fill material is increased about an outer periphery of the bone fill material.

23. The method of claim 20, wherein the viscosity of the bone fill material is increased by applying energy to the bone fill material.

24. The method of claim 23, wherein the energy is applied continuously while bone fill material is introduced into the vertebral body.

25. The method of claim 23, wherein the amount of energy applied increases as the bone fill material within the vertebral body increases in volume.

26. The method of claim 25, wherein the bone fill material includes an electrically conductive filler such that when the energy is applied, the bone fill material delivers energy to adjacent tissue to cause coagulation.

27. The method of claim 20, wherein the viscosity of the bone fill material is increased by about 20% or more.

28. The method of claim 20, wherein the viscosity of the bone fill material is increased by about 50% or more.

29. The method of claim 20, wherein the substantially flow impermeable portions are formed at least partially from bone fill material.

30. The method of claim 20, wherein the substantially flow impermeable portions are formed at least partially from coagulated tissue.

31. The method of claim 20, wherein applying an expansion force within the bone fill material expands cancellous bone.

32. The method of claim 20, wherein applying an expansion force within the bone fill material moves cortical bone.

33. The method of claim 20, wherein applying an expansion force within the bone fill material applies an asymmetric retraction force against cortical bone to restore vertebral height.

34. A method of moving a body structure, comprising:

introducing a flowable material into an interior of the body structure;

selectively transforming a selected portion of the flowable material in the interior of the body structure into an elastic portion, said elastic portion at least partially surrounded by body structure; and

applying an expansion force within said elastic portion thereby expanding the elastic portion to move the body structure.

35. The method of claim 34, wherein the flowable material is introduced into cancellous bone.

36. The method of claim 35, wherein the elastic portion is penetrated by cancellous bone.

37. The method of claim 35, wherein the elastic portion is expanded symmetrically.

38. The method of claim 35, wherein the elastic portion is expanded asymmetrically.

39. The method of claim 35, wherein expansion of the elastic portion seals a fracture in a bone.

40. The method of claim 35, wherein expansion of the elastic portion expands cancellous bone.

41. The method of claim 35, wherein expansion of the elastic portion at least partially restores a height of an abnormal vertebra.

42. The method of claim 34, wherein applying an expansion force comprises introducing additional flowable material within the elastic portion.