1. Department of Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
2. Department of Orthopaedic Surgery, Tokushima Red Cross Hospital, Komatsushima, Japan.
3. Department of Orthopaedic Surgery, Tokushima Prefectural Central Hospital, Tokushima, Japan.
4. Department of Preventive Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.