Osteoarthritis (OA) is among the most common causes of pain and disability in middle age and older individuals. More than 12% of lower limb OA is caused by joint injury. This OA subset, referred to as posttraumatic osteoarthritis (PTOA), frequently affects young adults and can result in impairment comparable to that of advanced cardiac and kidney disease. The theme of the University of Iowa CORT, Innovations to Assess and Forestall Post-Traumatic Osteoarthritis, is that greater understanding of how joint injury and cumulative excessive articular surface contact stress due to post-traumatic joint instability and incongruity cause PTOA will lead to innovations in the assessment and treatment of joint injuries, which in turn will lead to effective strategies to forestall the disease. Information gained from CORT investigations, from the molecular level to the level of a patient with a joint injury, with emphasis on how acute joint injuries trigger joint responses that cause progressive tissue damage and on how cumulative excessive mechanical stress leads to articular cartilage loss, will contribute to the understanding of the onset and progression of OA in people without a history of joint injury. The multidisciplinary team of CORT investigators, including biologists, bioengineers, and clinicians, has developed a unique research base that will allow them to make rapid progress in translating basic research into improved clinical practice. CORT investigators and advisors have identified three critical research advances needed to move forward in forestalling OA in injured joints: 1) understanding of in vivo whole joint cellular and molecular processes that lead to PTOA, 2) clinically applicable diagnostic methods that reliably identify patients who will develop PTOA, and 3) biological and mechanical methods of preventing PTOA. Three projects were developed to realize these advances: 1)Targeting the Origins of Inflammation in Post-Traumatic Osteoarthritis, 2) Establishing Treatments and Diagnostic Tools for Post-Traumatic OA In Vivo, and 3) Diagnosing and Preventing Elevated Contact Stress to Avert Post-Traumatic OA. Three cores will support the projects: 1) Administrative, Biostatistics and Investigator Support Core, 2) Joint Trauma Biomarker Core, and 3) Biomechanics and Imaging Core.