1. Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences , Okayama, Japan
2. Department of Pathology, Okayama University Hospital , Okayama, Japan
3. Department of Orthopaedic Surgery, Mie University , Tsu, Japan
4. Department of Advanced Medical Sciences, Oita University , Yufu, Japan