1. Department of Orthopedic Surgery, Konan Kosei Hospital, Konan 483-8704, Japan
2. Department of Orthopedic Surgery, Anjo Kosei Hospital, Anjo 446-8602, Japan
3. Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai, Shouwa-ku, Nagoya 466-8560, Japan