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, National Hospital Organization, Sagamihara Hospital, Sagamihara, Japan;
4. Department of Rheumatology, JCHO Yugawara Hospital, Kanagawa, Japan