1. Department of Orthopaedic Surgery; Peking Union Medical College Hospital; Chinese Academy of Medical Sciences and Peking Union Medical College; Beijing 100042 China
2. State-Key Laboratory of Digestive Diseases; LKS Institute of Health Sciences and Department of Medicine and Therapeutics; The Chinese University of Hong Kong; Hong Kong 999077 China
3. Department of Anaesthesia and Intensive Care; The Chinese University of Hong Kong; Hong Kong 999077 China