Implants and methods for treating bone

• US 20060089715A1
• Filed: 06/07/2005
• Published: 04/27/2006
• Est. Priority Date: 06/07/2004
• Status: Active Grant

• Current Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Original Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Inventors: Truckai, Csaba, Shadduck, John H.
• Granted Patent: US 7,621,952 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/8858 laterally or radially expansible inflatable A61B17/8855
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30289 helically-coiled
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section

Abstract

An orthopedic implant comprising a deformable, expandable implant body configured for treating abnormalities in bones, such as compression fractures of vertebra, necrosis of femurs and the like. An exemplary implant body comprises a small cross-section threaded element that is introduced into a bone region and thereafter is expanded into a larger cross-section, monolithic assembly to provide a bone support. In one embodiment, the implant body is at least partly fabricated of a magnesium alloy that is biodegradable to allow for later tissue ingrowth.

Claims

1. An expandable implant comprising an elongated body extending along an axis, the body including a plurality of deformable helically-mated elements.

2. An expandable implant as in claim 1 wherein the helically-mated elements are at least partly of a metal.

3. An expandable implant as in claim 2 wherein the metal includes at least one of titanium, tantalum or a magnesium alloy.

4. An expandable implant as in claim 1 wherein the helically-mated elements are at least partly of a polymer.

5. An expandable implant as in claim 4 wherein the polymer is at least one of biodegradable, bioabsorbable or bioexcretable.

6. An expandable implant as in claim 1 wherein the body comprises a plurality of body segments configured for axial segment-to-segment insertion to thereby radially expand the body.

7. An expandable implant as in claim 6 wherein the body includes from 2 to 10 body segments.

8. An expandable implant as in claim 6 wherein the body segments are configured with a spiral thread surface.

9. An expandable implant as in claim 8 wherein the body segments have a common right-hand or left-hand spiral thread surface.

10. An expandable implant as in claim 8 wherein body segments have different right-hand and left-hand surface spiral thread surfaces.

11. An expandable implant as in claim 1 wherein the body has open cells.

12. A method of treating or prophylactically preventing a fracture of a bone comprising the steps of (a) helically introducing into bone a first body including a plurality of deformable helically-mated elements, and (b) helically introducing at least one additional body that include a plurality of deformable helically-mated elements into the interior of the first body thereby deformably radially expanding the assembly to support the bone.

13. The method of claim 12 wherein steps (a) and (b) displace cancellous bone.

15. The method of claim 12 wherein the bone is a vertebra.

14. The method of claim 14 wherein steps (a) and (b) move cortical bone.

16. The method of claim 14 wherein steps (a) and (b) at least partially restores vertebral height.

17. A method for treating an abnormality in a bone comprising (a) introducing an implant body into or proximate a bone wherein the implant body includes a biodegradable magnesium alloy, and (b) allowing the magnesium alloy to biodegrade thereby creating space for tissue ingrowth.

18. The method of claim 17 wherein the implant body is deformable and further including the step of radially expanding the deformable implant body.

19. The method of claim 17 wherein the implant body is configured for implantation in a vertebra.

20. The method of claim 17 wherein the implant body is configured for implantation in an intervertebral space.