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.