1. Department of Orthopaedic Surgery, Graduate School of Medical Sciences; Kyushu University; 3-1-1 Maidashi Higashi-ku Fukuoka 812-8582 Japan
2. Faculty of Medicine, Department of Orthopaedic Surgery; Fukuoka University; 7-45-1 Nanakuma Jonan-ku Fukuoka 814-0180 Japan