1.1 This guide is intended as a resource for individuals and organizations when designing clinical trials and/or clinical registries and addresses the selection of patient-reported outcomes, safety outcomes, imaging outcomes and other topics related to knee reconstructive surgery (KRS) including: (1) knee replacement systems, (2) anterior cruciate ligament reconstruction, (3) knee meniscus implants or tissue engineered medical products (TEMPs), (4) articular cartilage implants or TEMPS, (5) peri-articular knee osteotomies, (6) peri-articular knee fractures (including distal femur, patella, and proximal tibia fractures), or other knee surgeries. 1.2 In this guide, methods to measure the efficacy, effectiveness, and safety of KRS devices through standardizing clinical outcome measures are provided for designing, reviewing, and accepting human clinical trial protocols. 1.3 This guide is intended to provide consistency in study design, review, regulatory approval, and health insurance coverage approval for knee reconstructive surgery to the health care market. 1.4 For the purpose of this guide, KRS pertains to any device or TEMP that is intended to replace, resurface, reconstruct, and/or provide fixation of the knee joint, in part or in total, as a treatment for joint disease, trauma, or dysfunction, where long-term improvement in function and pain relief without major adverse events are the desired outcomes. 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.