1. Department of Orthopaedic Surgery, Kagawa Rosai Hospital, 3-3-1, Jyoto-cho, Marugame 763-8502, Japan.
2. Department of Orthopaedic Surgery, School of Medicine, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.