1.1 本规程涵盖基于实验室的 体外试验 用于评估在移动支承膝系统中的人类膝关节置换假体中用于置换胫股关节的材料和设备的机械性能的方法。 1.2 移动轴承膝盖系统允许在一个或两个关节面上进行内/外旋转。一些设计对旋转量进行了物理限制或停止。其他设计可能会随着旋转的增加而增加阻力。 1.3 虽然该方法描述了识别生理相关运动和力条件的尝试，但结果的解释仅限于 在- 体外培养 在规定的测试条件下，比较移动式支撑膝关节设计及其保持旋转止动功能和胫骨支撑组件完整性的能力。 1.4 本规程仅适用于带旋转止动块的移动式膝-胫骨系统。 1.5 以国际单位制表示的数值视为标准值。 1.6 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。 1.7 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 该实践的基本方面包括在日常生活活动（深度屈曲）期间使用代表人类膝关节的动态旋转力和运动，以及这些力和运动对设计特征的影响，这些设计特征在移动轴承膝关节设计中停止或限制旋转。 4.2 如果旋转挡块设计为将运动限制在±20°或以下，则需要进行该试验；或者在±20°范围内存在其他旋转阻力。在某些情况下，旋转位移可能发生在下界面和上界面。 图1 测试设置示意图

1.1 This practice covers a laboratory-based in-vitro method for evaluating the mechanical performance of materials and devices being considered for replacement of the tibio-femoral joint in human knee joint replacement prostheses in mobile bearing knee systems. 1.2 Mobile bearing knee systems permit internal/external rotation to take place on one or both articulating surfaces. Some designs place physical limits or stops to the amount of rotation. Other designs may have increases of a resistance force with increases in rotation. 1.3 Although the methodology describes attempts to identify physiologically relevant motions and force conditions, the interpretation of results is limited to an in-vitro comparison between mobile bearing knee designs and their ability to maintain the integrity of the rotational stop feature and tibial bearing component under the stated test conditions. 1.4 This practice is only applicable to mobile knee tibial systems with a rotational stop. 1.5 The values stated in SI units are regarded as standard. 1.6 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. 1.7 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 Fundamental aspects of this practice include the use of dynamic rotational force and motion representative of the human knee joint during an activity of daily living (deep flexion) and the effect of these forces and motions on the design features which stop or limit rotation in a mobile bearing knee design. 4.2 This test is required if rotational stops are designed to limit motion to ±20° or less; or there are other resistances to rotational motion with this ±20° range. In some instances, the rotational displacement could occur in both the inferior and superior interfaces. FIG. 1 Schematic of Test Setup