# US 8,771,369 B2 · Surface modification of ultrahigh molecular weight polyethylene > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,369 B2 - Document ID: US8771369B2 - Status: Granted - Kind: B2 - Application number: 12/749,743 - Filed: 2010-03-30 - Published: 2010-09-30 - Granted: 2014-07-08 - Earliest claimed: 2009-03-31 - Assignees: Zimmer, Inc. - Applicants: Donald L. Yakimicki; Brian H. Thomas; Lynn A. Kirkpatrick - Inventors: Donald L. Yakimicki; Brian H. Thomas; Lynn A. Kirkpatrick - Web page: https://patentgrep.com/patent/US8771369B2 ## CPC - C08J 7/06: with compositions not containing macromolecular substances - A61L 27/16: obtained by reactions only involving carbon-to-carbon unsaturated bonds - C08J 7/043: Improving the adhesiveness of the coatings per se, e.g. forming primers (adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50) - C08J 7/056: Forming hydrophilic coatings - A61L 2400/18: Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment - C08J 2323/06: Polyethene - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) ## Abstract The present invention relates to polymers and, specifically, to surface modification of polymers. In one exemplary embodiment, the present invention increases the bond strength of UHMWPE components to PMMA bone cement by creating a chemical bond between the UHMWPE components and the PMMA bone cement. Specifically, in one exemplary embodiment, a surface of the UHMWPE component that is to be bonded to PMMA bone cement is treated with an oxidizing agent, such as an aqueous solution of hydrogen peroxide. In one exemplary embodiment, the UHMWPE component is treated with hydrogen peroxide by swabbing the surface of the UHMWPE component with the hydrogen peroxide solution. The surface of the UHMWPE component may then be dried and PMMA bone cement applied to the surface of the UHMWPE component. ## Claims ### Claim 1 An orthopedic assembly comprising: an orthopedic implant comprising antioxidant-stabilized ultra-high molecular weight polyethylene, the orthopedic implant having an oxidizing agent-modified surface formed by coating a surface of the orthopedic implant with a liquid comprising from about 0.5 wt % to about 10 wt % hydrogen peroxide; and a layer of bone cement that contacts the oxidizing agent-modified surface of the orthopedic implant. ### Claim 2 (depends on 1) The implant assembly of claim 1, wherein the polymer comprises at least one of ultrahigh molecular weight polyethylene, ethylene vinyl alcohol, polycarbonate, and polyetheretherketone. ### Claim 3 (depends on 1) The implant assembly of claim 1, wherein the bone cement comprises polymethylmethacrylate. ### Claim 4 (depends on 1) The implant assembly of claim 1, wherein the antioxidant comprises at least one of vitamin C, lycopene, honey, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, a disulfide, a phosphite, a hindered amine, a phenol, a cyclodextrin, a flavonoid, and a tocopherol. ### Claim 5 (depends on 1) The implant assembly of claim 1, wherein the antioxidant of the antioxidant stabilized polymer is present in an amount between 0.01 weight percent and 3 weight percent. ### Claim 6 (depends on 1) The implant assembly of claim 1, wherein the antioxidant of the antioxidant stabilized polymer is present in an amount between 0.1 weight percent and 0.6 weight percent. ### Claim 7 (depends on 1) The implant assembly of claim 1, wherein the liquid comprises a solution of hydrogen peroxide having a concentration of about 3 weight percent hydrogen peroxide. ### Claim 8 (depends on 1) The implant assembly of claim 1, wherein the orthopedic implant includes an articulating surface. ### Claim 9 (depends on 1) The implant assembly of claim 1, wherein a pull off strength between the treated surface and the layer of bone cement is at least 96 PSI. ### Claim 10 An orthopedic assembly comprising: an orthopedic implant comprising antioxidant-stabilized ultrahigh molecular weight polyethylene, the orthopedic implant having an oxidizing agent-modified surface formed by coating a surface of the orthopedic implant with a hydrogen peroxide solution comprising from about 0.5 wt % to about 10 wt % hydrogen peroxide; and a layer of bone cement that contacts the oxidizing agent-modified surface of the orthopedic implant wherein the bone cement comprises polymethylmethacrylate. ### Claim 11 (depends on 10) The implant assembly of claim 10, wherein the antioxidant comprises at least one of vitamin C, lycopene, honey, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, a disulfide, a phosphite, a hindered amine, a phenol, a cyclodextrin, a flavonoid, and a tocopherol. ### Claim 12 (depends on 10) The implant assembly of claim 10, wherein the antioxidant of the antioxidant stabilized ultrahigh molecular weight polyethylene is present in an amount between 0.01 weight percent and 3 weight percent. ### Claim 13 (depends on 10) The implant assembly of claim 10, wherein the antioxidant of the antioxidant stabilized ultrahigh molecular weight polyethylene is present in an amount between 0.1 weight percent and 0.6 weight percent. ### Claim 14 (depends on 10) The implant assembly of claim 10, wherein the hydrogen peroxide solution has a concentration of about 3 weight percent hydrogen peroxide. ### Claim 15 (depends on 10) The implant assembly of claim 10, wherein the orthopedic implant includes an articulating surface. ### Claim 16 (depends on 10) The implant assembly of claim 10, wherein a pull off strength between the treated surface and the layer of bone cement is at least 96 PSI.