Welcome! The Research in Osteochondritis of the Knee (ROCK) study group was founded in 2009 to provide a forum for patients, health care providers, and researchers to better understand and treat this challenging problem. ROCK consists of a group of orthopaedic surgeons, physical therapists, musculoskeletal radiologists, and professional researchers who work together to design research projects to add better science and evidence to our recommendations for diagnosing and treating the condition. One goal of the ROCK website is to provide a way to communicate what is and is not known about OCD. This website, like our knowledge about OCD, will be continuously updated to reflect new findings and controversies.