1.1   The objective of this guide is to advise researchers on the possible high demand wear test features that should be included in evaluation of hard-on-hard articulations. This guide makes suggestions for high demand test features that may need to be added to an overall wear test regime. Device articulating components manufactured from other metallic alloys, ceramics, or with coated or elementally modified surfaces without significant clinical use could possibly be evaluated with this guide. However, such materials may include risks and failure mechanisms that are not addressed in this guide.