1. Orthopaedic Research Laboratory, Departments of Biomedical Engineering and Orthopedic Surgery, Virginia Commonwealth University, Richmond, Virginia.
2. Hunter H. McGuire Veterans Affairs Medical Center, Richmond, Virginia.
3. Cartilage Biology and Orthopedics Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.