With an estimated 200,000 anterior cruciate ligament reconstructions performed annually in the United States, there is an emphasis on determining patient-specific information to help educate patients on expected clinically relevant outcomes. The Multicenter Orthopaedic Outcomes Network consortium was created in 2002 to enroll and longitudinally follow a large population cohort of anterior cruciate ligament reconstructions. The study group has enrolled >4,400 anterior cruciate ligament reconstructions from seven institutions to establish the large level I prospective anterior cruciate ligament reconstruction outcomes cohort. The group has become more than a database with information regarding anterior cruciate ligament injuries; it has helped to establish a new benchmark for conducting multicenter, multisurgeon orthopaedic research. The changes in anterior cruciate ligament reconstruction practice resulting from the group include the use of autograft for high school, college, and competitive athletes in their primary anterior cruciate ligament reconstructions. Other modifications include treatment options for meniscus and cartilage injuries, as well as lifestyle choices made after anterior cruciate ligament reconstruction.