1.1 本规程旨在允许研究人员评估UHMWPE材料的氧化稳定性，作为加工和灭菌方法的函数。本规程描述了用于全关节假体的超高分子量聚乙烯（UHMWPE）样品和部件加速老化的实验室程序。UHMWPE在升高的温度和升高的氧气压力下老化，以加速材料的氧化，从而允许评估其长期化学和机械稳定性。 1.2 尽管本实践中描述的加速老化方法将允许研究人员比较不同UHMWPE材料的氧化稳定性，但人们认识到，该方法可能无法准确模拟植入物在实际使用过程中的降解机制- 时效和植入。 1.3 本文规定的加速老化方法已根据空气中包装并用γ射线灭菌的某些货架老化UHMWPE组件所表现出的氧化水平进行了验证。当UHMWPE包装在空气以外的环境中时，该方法不能代表货架老化。例如，这种做法与密封在低氧包装（如氮气）中的部件的保质期没有直接关系。本规程无意模拟植入后UHMWPE中可能发生的任何变化。 1.4 以国际单位制表示的值应视为标准值。 括号中给出的值是英寸-磅单位的数学转换，仅供参考，不被视为标准值。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 本实践总结了一种可用于使用升高的温度和升高的氧气压力加速UHMWPE组分氧化的方法。在实时条件下，如货架老化和植入，使用高能辐射灭菌后UHMWPE的氧化变化可能需要数月或数年才能产生可能导致有害机械性能的变化。本实践中概述的方法允许在相对短的时间（例如，几周）内评估氧化稳定性。 4.2 本规程也可用于在表征UHMWPE试样和接头更换部件的物理、化学和机械性能之前对其进行氧化。 特别是，如指南所述，在髋关节或膝关节磨损模拟器中进行评估之前，本规程可用于UHMWPE部件的加速老化 第714页 （臀部穿着），指南 第715页 （膝盖磨损），ISO 14242（臀部穿着），或ISO 14243（膝装）或其组合。

1.1 It is the intent of this practice to permit an investigator to evaluate the oxidative stability of UHMWPE materials as a function of processing and sterilization method. This practice describes a laboratory procedure for accelerated aging of ultra-high molecular weight polyethylene (UHMWPE) specimens and components for total joint prostheses. The UHMWPE is aged at elevated temperature and at elevated oxygen pressure, to accelerate oxidation of the material and thereby allow for the evaluation of its long-term chemical and mechanical stability. 1.2 Although the accelerated aging method described by this practice will permit an investigator to compare the oxidative stability of different UHMWPE materials, it is recognized that this method may not precisely simulate the degradative mechanisms for an implant during real-time shelf aging and implantation. 1.3 The accelerated aging method specified herein has been validated based on oxidation levels exhibited by certain shelf-aged UHMWPE components packaged in air and sterilized with gamma radiation. The method has not been shown to be representative of shelf aging when the UHMWPE is packaged in an environment other than air. For example, this practice has not been directly correlated with the shelf life of components that have been sealed in a low-oxygen package, such as nitrogen. This practice is not intended to simulate any change that may occur in UHMWPE following implantation. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 This practice summarizes a method that may be used to accelerate the oxidation of UHMWPE components using elevated temperature and elevated oxygen pressure. Under real-time conditions, such as shelf aging and implantation, oxidative changes to UHMWPE after sterilization using high-energy radiation may take months or years to produce changes that may result in deleterious mechanical performance. The method outlined in this practice permits the evaluation of oxidative stability in a relatively short period of time (for example, weeks). 4.2 This practice may also be used to oxidize UHMWPE test specimens and joint replacement components prior to characterization of their physical, chemical, and mechanical properties. In particular, this practice may be used for accelerated aging of UHMWPE components prior to evaluation in a hip or knee joint wear simulator as outlined in Guide F1714 (hip wear), Guide F1715 (knee wear), ISO 14242 (hip wear), or ISO 14243 (knee wear), or combination thereof.