1. Nara Medical University, Department of Orthopaedic Surgery, 840 Shijyo-cho, Kashihara Chity, Nara 634-8522, Japan.
2. Saiseikai Nara Hospital, Department of Orthopaedic Surgery, 4-643 Hachijo, Nara-shi, Nara 630-8145, Japan.
3. Ootemae Hospital, Department of Orthopaedic Surgery, 1-5-34 Ootemae, Chu-o ku, Osaka city, Japan.
4. Fukushima Medical University, Department of Orthopaedic Surgery, 1 Hikarigaoka, Fukushima city, Fukushima 960-1295, Japan.