Composites and methods for treating bone

• US 8,163,031 B2
• Filed: 11/09/2010
• Issued: 04/24/2012
• Est. Priority Date: 06/09/2004
• Status: Expired due to Fees

• Current Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Original Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Inventors: Truckai, Csaba, Shadduck, John H.
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): Ganesan, Suba
• Application Number:
  US12/942,936
• Publication Number:
  US 20110054482A1
• Time in Patent Office: 532 Days
• Field of Search: 606/94, 606 90- 93, 606/99, 623 2358- 2362, 623/23.19, 623/23.26, 623/23.48, 623/23.5, 623/23.51, 623/23.55, 623/23, 623/72, 623/23.73
• US Class Current: 623/23.51
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61B 17/686 Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw
• CPC Class Codes: A61B 17/7095 the filler comprising unlinked macroscopic particles
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30006 differing in density or specific weight
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30023 differing in viscosity
• CPC Class Codes: A61F 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30583 filled with hardenable fluid, e.g. curable in-situ
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/3085 with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0085 : hardenable in situ, e.g. epoxy resins
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0015 : differing in density or specific weight
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2250/0034 : differing in viscosity
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00353 : Bone cement, e.g. polymethylmethacrylate or PMMA
• CPC Class Codes: A61L 2430/02 : for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 27/50 : Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials

Abstract

A system and method for treating bone abnormalities including vertebral compression fractures and the like. In one method, an elastomeric composite implant body is inserted into bone. A rigid insert can be inserted into the elastomeric composite implant body. The elastomeric composite implant body can be deformed with the rigid insert to thereby form an interference fit between the bone and the implant.

Claims

1. A method of treating a bone with an implant comprising:

inserting an elastomeric composite implant body having a predetermined shape into an opening in a bone, the composite implant body defining an internal bore along a longitudinal axis of the composite implant body and comprising;

at least one first region and at least one second region, each region comprising;

an elastomeric polymer; and

reticulated elements dispersed within the elastomeric polymer;

wherein the at least one first region has a different elastic modulus from the at least one second region, the difference being a function of differences between the reticulated elements in the at least one first region as compared to the reticulated elements in the at least one second region;

inserting a rigid insert into the bore in the elastomeric composite implant body to secure the implant in the bone; and

deforming the elastomeric composite implant body with the rigid insert to thereby form an interference fit between the bone and the implant, the at least one first region deforming in a manner different from the at least one second region.

2. The method of claim 1, wherein the at least one first region comprises a plurality of first regions and the at least one second region comprises a plurality of second regions, respective first and second regions alternating sequentially in position as measured axially along the longitudinal axis of the composite implant body and the first regions of the composite implant body are deformable but more rigid than adjacent second regions.

3. The method of claim 2, wherein deforming further comprises forcing the higher modulus first regions farther into the bone than the second regions.

4. The method of claim 1, wherein inserting a rigid insert further comprises advancing a shaft of a hip implant into the bore.

5. The method of claim 1, wherein inserting a rigid insert further comprises inserting a threaded implant into the bore.

6. The method of claim 5, wherein inserting the threaded implant further comprises causing self-adjustment of the distribution, location and orientation of the reticulated elements in both the at least one first region and the at least one second region to self-distribute loads between the implant and the bone.

7. The method of claim 6, wherein inserting the threaded implant further comprises causing the engagement forces between the implant and the bone to be distributed about all surfaces of the threaded implant.

8. The method of claim 5, wherein a surface region of the threaded implant is reticulated, roughened or porous.

9. The method of claim 5, wherein the threaded implant comprises a bone screw.

10. The method of claim 1, wherein the at least one first region is adjacent the at least one second region as measured radially outward from the longitudinal axis of the composite implant body.

11. The method of claim 1, wherein the difference in elastic modulus between the at least one first region and the at least one second region as a function of differences between the reticulated elements comprises at least one of a difference in density;

cell dimensions;

density of ligaments of the reticulated elements dispersed in the elastomeric polymer;

the overall shape, dimensions and/or orientations of the reticulated elements;

the pore size of the reticulated elements;

the modulus, deformability and/or material of the reticulated elements;

the percentage volume of reticulated elements in the elastomeric polymer; and

the properties of media carried in pores of the reticulated elements.

12. The method of claim 1, wherein the implant body has a gradient modulus for transitioning from an interface with bone to an interface with the rigid insert.