1 Department of Orthopaedic Surgery, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.
2 Department of Orthopaedic Surgery, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan. Electronic address: jichi@sb4.so-net.ne.jp.
3 Department of Pathology Saitama Medical University International Medical Center, Saitama, Japan.
4 Department of Radiology, University of Yamanashi, Yamanashi, Japan.