ASTM_F_2003_-_02_2015.pdf

Designation:F200302(Reapproved 2015)Standard Practice forAccelerated Aging of Ultra-High Molecular WeightPolyethylene after Gamma Irradiation in Air1This standard is issued under the fixed designation F2003;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 It is the intent of this practice to permit an investigatorto evaluate the oxidative stability of UHMWPE materials as afunction of processing and sterilization method.This practicedescribes a laboratory procedure for accelerated aging ofultra-high molecular weight polyethylene(UHMWPE)speci-mens and components for total joint prostheses.The UHM-WPE is aged at elevated temperature and at elevated oxygenpressure,to accelerate oxidation of the material and therebyallow for the evaluation of its long-term chemical and me-chanical stability.1.2 Although the accelerated-aging method described bythis practice will permit an investigator to compare theoxidative stability of different UHMWPE materials,it isrecognized that this method may not precisely simulate thedegradative mechanisms for an implant during real-time shelfaging and implantation.1.3 The accelerated aging method specified herein has beenvalidated based on oxidation levels exhibited by certain shelf-aged UHMWPE components packaged in air and sterilizedwith gamma radiation.The method has not been shown to berepresentative of shelf aging when the UHMWPE is packagedin an environment other than air.For example,this practice hasnot been directly correlated with the shelf life of componentsthat have been sealed in a low-oxygen package,such asnitrogen.This practice is not intended to simulate any changethat may occur in UHMWPE following implantation.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are for information onlyand are not considered standard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsF648 Specification for Ultra-High-Molecular-Weight Poly-ethylene Powder and Fabricated Form for Surgical Im-plantsF1714 Guide for Gravimetric WearAssessment of ProstheticHip Designs in Simulator DevicesF1715 Guide for Wear Assessment of Prosthetic Knee De-signs in Simulator Devices(Withdrawn 2006)32.2 ISO Standards:4ISO 5834 Implants for surgeryUltra-high molecularweight polyethyleneISO 14242 Implants for surgeryWear of total hip jointprosthesesISO 14243 Implants for surgeryWear of total knee jointprostheses3.Terminology3.1 DefinitionsFor definitions of terms in this practicerelating to plastics,refer to Terminology D883.For definitionsof terms in this practice relating to UHMWPE,refer toSpecification F648 and ISO 5834.3.2 Definitions of Terms Specific to This Standard:3.2.1 oxidation,nthe incorporation of oxygen into anothermolecule(for example,UHMWPE)by means of a chemicalreaction,resulting in the formation of a chemical covalentbond.3.2.2 oxygen bomb,na pressure vessel suitable for pre-conditioning of UHMWPE at an elevated temperature andpartial pressure of oxygen.1This practice is under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved May 1,2015.Published July 2015.Originally approvedin 2002.Last previous edition approved in 2008 as F2003 02(2008).DOI:10.1520/F2003-02R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Significance and Use4.1 This practice summarizes a method that may be used toaccelerate the oxidation of UHMWPE components usingelevated temperature and elevated oxygen pressure.Underreal-time conditions,such as shelf aging and implantation,oxidative changes to UHMWPE after sterilization using highenergy radiation may take months or years to produce changesthat may result in deleterious mechanical performance.Themethod outlined in this practice permits the evaluation ofoxidative stability in a relatively short p