1. Department of Orthopaedic Surgery, Okayama University Hospital , Okayama, Japan
2. Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Science , Okayama, Japan
3. Department of Rheumatology, Mabi Memorial Hospital , Kurashiki, Japan
4. Department of Orthopaedic Surgery, Kurashiki Sweet Hospital , Kurashiki, Japan