1. Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
2. Department of Rheumatology, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan
3. Department of Orthopaedic Surgery, Itakura Hospital, Chiba, Japan
4. Department of Orthopaedic Surgery, Teikyo University Mizonokuchi Hospital, Kawasaki, Japan