1. Department of Anesthesia and Pain Medicine, Bio-Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
2. Department of Orthopaedic Surgery, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Korea.
3. Department of Orthopaedic Surgery, Bio-Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.