1. The Ohio State University Sports Medicine Center and Cartilage Restoration Program, Columbus, Ohio
2. Department of Orthopedic Surgery, Washington University School of Medicine, St Louis, Missouri
3. Penn Center for Advanced Cartilage Repair and Osteochondritis Dissecans Treatment Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
4. Department of Orthopaedic Surgery and Sports Medicine, University of Kentucky, Lexington, Kentucky