1.1 本实践旨在允许研究人员将滑膜环境中发现的脂质纳入聚合物样本中。这可以作为预处理步骤来评估超高分子量聚乙烯（UHMWPE）材料的氧化稳定性。本规程描述了超高分子量聚乙烯试样预处理的实验室程序。 1.2 预处理的超高分子量聚乙烯可以按照实践中描述的加速老化方法在高温和高压氧下老化 F2003 ，以加速材料的氧化，从而评估其长期稳定性- 术语化学稳定性。 1.3 预处理的UHMWPE可以使用测试方法中描述的评估氧化稳定性的方法（例如氧化诱导时间）进行测试，而无需进一步老化 D3895 . 1.4 本实施规程的方法可用于任何类型的UHMWPE材料，用于滑膜关节的全关节置换术（例如，常规、交联、抗氧化剂稳定等）。看见 附录X1 . 1.5 虽然本规程中描述的加速老化后的预处理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，该方法无法模拟植入物在实际使用过程中的降解机制- 货架老化或 体内 . 尚未对所述方法进行循环荷载下的机械试验评估。 1.6 本文规定的预处理和加速老化方法旨在根据植入后UHMWPE中可能发生的脂质吸收对材料的抗氧化性进行排序，并确定对氧化变化的敏感性。尚未评估这些方法是否用于UHMWPE部件的预处理，以用于随后的机械或磨损性能测试。程序A不应用于UHMWPE组件的预处理，以进行后续的机械或磨损性能测试。 1.7 以国际单位制表示的数值应视为标准值。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。 1.8 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 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《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 本实践总结了两种可用于通过吸收脂质来预处理超高分子量聚乙烯的方法，以区分模拟的 体外 脂质暴露后超高分子量聚乙烯的氧化稳定性。 4.1.1 程序A，高角鲨烯吸收- 这种脂质预处理方法可用于比较氧化稳定性测试，以筛选侵蚀性条件下的不同材料。 4.1.2 程序B，混合脂质吸收- 这种预处理方法可用于在更接近模拟的温和条件下进行比较氧化稳定性测试 体内 条件 4.2 根据实践方法，当使用高温和高压氧时，本实践可用于加速超高分子量聚乙烯组件的氧化 F2003 . 在植入等实时条件下，UHMWPE配方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。本规程中概述的方法允许在相对较短的时间内（例如，几周）制备UHMWPE以评估氧化稳定性。 4.3 本规程也可用于在表征UHMWPE试样的物理和化学特性之前对其进行预处理。 特别是，本规程可用于在试验方法中概述的氧化诱导时间（OIT）试验之前用脂质进行预处理 D3895 .

1.1 It is the intent of this practice to permit an investigator to incorporate lipids found in the synovial environment into polymeric specimens. This can be used as a preconditioning step to evaluate the oxidative stability of ultra-high-molecular-weight polyethylene (UHMWPE) materials. This practice describes a laboratory procedure for preconditioning of UHMWPE specimens. 1.2 The preconditioned UHMWPE can be aged at elevated temperature and at elevated oxygen pressure following methods of accelerated aging described in Practice F2003 , to accelerate oxidation of the material and thereby allow for the evaluation of its long-term chemical stability. 1.3 The preconditioned UHMWPE can be tested without further aging using a method to evaluate oxidative stability such as oxidation induction time as described in Test Method D3895 . 1.4 The methods of this practice may be used on any type of UHMWPE material intended for use in total joint arthroplasty in a synovial joint (for example, conventional, cross-linked, antioxidant stabilized, etc.). See Appendix X1 . 1.5 Although the preconditioning method followed by accelerated aging described by this practice will permit an investigator to compare the oxidative stability of different UHMWPE materials, it is recognized that this method is not known to simulate the degradative mechanisms for an implant during real-time shelf aging or in vivo . The described methods have not been evaluated for mechanical testing under cyclic loading. 1.6 The preconditioning and accelerated aging methods specified herein are intended to rank the resistance to oxidation of materials as a result of the absorption of lipids, which may occur in UHMWPE following implantation, and to determine susceptibility to oxidative changes. The methods have not been evaluated for use in preconditioning of UHMWPE components for subsequent testing of mechanical or wear properties. Procedure A should not be used for preconditioning of UHMWPE components for subsequent testing of mechanical or wear properties. 1.7 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. 1.8 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. 1.9 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 two methods that may be used to precondition UHMWPE by the absorption of lipids to differentiate the simulated in vitro oxidative stability of UHMWPEs, after lipid exposure. 4.1.1 Procedure A, High Squalene Absorption— This method of preconditioning with lipids may be used for comparative oxidative stability testing to screen different materials under aggressive conditions. 4.1.2 Procedure B, Mixed Lipid Absorption— This method of preconditioning may be used for comparative oxidative stability testing under mild conditions that more closely simulate in-vivo conditions. 4.2 This practice may be used to accelerate the oxidation of UHMWPE components when using elevated temperature and elevated oxygen pressure according to the methods of Practice F2003 . Under real-time conditions such as implantation, oxidative changes to UHMWPE formulations may take months or years to produce changes that may result in deleterious mechanical performance. The method outlined in this practice permits the preparation of UHMWPE for evaluation of oxidative stability in a relatively short period of time (for example, weeks). 4.3 This practice may also be used to precondition UHMWPE test specimens prior to characterization of their physical and chemical properties. In particular, this practice may be used for preconditioning with lipids prior to oxidation induction time (OIT) testing as outlined in Test Method D3895 .