Hydrogel arthroplasty device

• US 8,679,190 B2
• Filed: 03/12/2012
• Issued: 03/25/2014
• Est. Priority Date: 10/05/2004
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: US Department of Veterans Affairs (Government of the United States of America), Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Myung, David, Kourtis, Lampros, Hartmann, Laura, Frank, Curtis W., Goodman, Stuart B., Carter, Dennis R.
• Primary Examiner(s): Heincer, Liam
• Assistant Examiner(s): Salvitti, Michael A
• Application Number:
  US13/418,294
• Publication Number:
  US 20120232657A1
• Time in Patent Office: 743 Days
• Field of Search: 623 1111- 2376
• US Class Current: 623/23.58
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3603 implanted without ablation of the whole natural femoral head endoprosthetic cartilage A61F2/30756
• CPC Class Codes: A61F 2/3872 Meniscus for implantation between the natural bone surfaces
• CPC Class Codes: A61F 2/4202 for ankles
• CPC Class Codes: A61F 2/4225 for feet, e.g. toes
• CPC Class Codes: A61F 2/4241 for hands, e.g. fingers
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2002/30075 swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30754 Implants for interposition between two natural articular surfaces
• CPC Class Codes: A61F 2210/0061 swellable
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2310/00293 containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61L 2430/24 for joint reconstruction
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/3843 Connective tissue
• 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
• CPC Class Codes: A61L 27/52 : Hydrogels or hydrocolloids

Abstract

An arthroplasty device is provided having an interpenetrating polymer network (IPN) hydrogel that is strain-hardened by swelling and adapted to be held in place in a joint by conforming to a bone geometry. The strain-hardened IPN hydrogel is based on two different networks: (1) a non-silicone network of preformed hydrophilic non-ionic telechelic macromonomers chemically cross-linked by polymerization of its end-groups, and (2) a non-silicone network of ionizable monomers. The second network was polymerized and chemically cross-linked in the presence of the first network and has formed physical cross-links with the first network. Within the IPN, the degree of chemical cross-linking in the second network is less than in the first network. An aqueous salt solution (neutral pH) is used to ionize and swell the second network. The swelling of the second network is constrained by the first network resulting in an increase in effective physical cross-links within the IPN.

Claims

1. An arthroplasty device comprising a bearing region adapted to articulate with another bearing surface and a bone-interfacing region adapted to interact with underlying bone, the bearing region comprising a hydrogel having a first interpenetrating polymer network, the bone-interfacing region comprising another polymer integrated with the first interpenetrating polymer network to form a second interpenetrating polymer network between the hydrogel in the bearing region and the other polymer in the bone-interfacing region, wherein the interpenetrating polymer network hydrogel of the bearing region comprises a first network and a second network, the other polymer in the bone-interfacing region is partially interpenetrated within the first and second networks to form a triple network in the bone-interfacing region.

2. The arthroplasty device of claim 1 wherein the interpenetrating polymer network comprises preformed non-ionic telechelic macromonomers.

3. The arthroplasty device of claim 2 wherein the macromonomer has at least one end group selected from diacrylates, dimethacrylates, diallyl ethers, divinyls, diacrylamides, dimethacrylamides.

4. The arthroplasty device of claim 2 wherein the preformed non-ionic telechelic macromonomers are polyurethane macromonomers.

5. The arthroplasty device of claim 1 wherein the interpenetrating polymer network hydrogel comprises an ionic polymer.

6. The arthroplasty device of claim 5 wherein said ionic polymer comprises carboxylic acid groups.

7. The arthroplasty device of claim 5 wherein said ionic polymer comprises sulfonic acid groups.

8. The arthroplasty device of claim 5 wherein said ionic polymer comprises both carboxylic acid and sulfonic acid functional groups.

9. The arthroplasty device of claim 5 wherein said ionic polymer comprises poly(acrylic acid).

10. The arthroplasty device of claim 1 wherein the interpenetrating polymer network comprises a network of preformed non-ionic telechelic macromonomers physically entangled with the ionic polymer network.

11. The arthroplasty device of claim 1 wherein the bone-interfacing region comprises polyurethane, silicone rubber, or derivatives or combinations thereof.