1. Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong 999077, P. R. China
2. .Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong 999077, P. R. China
3. Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin second Road, Shanghai 200025, P. R. China