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