1. Department of Orthopaedic Surgery, Nagoya City University Hospital, Nagoya, Japan
2. Department of Orthopedics, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
3. Division of Epidemiology, School of Public Health, Shizuoka Graduate University of Public Health, Shizuoka, Japan
4. Trauma and Microsurgery Center, Toyohashi Municipal Hospital, Toyohashi, Japan