Wen-Feng Xiong1, Sun-Jun Hu1, Shi-Min Chang2. 1. The Department of Orthopaedic Surgery, Yangpu Hospital, Tongji University School of Medicine, Shanghai 200090, People's Republic of China. 2. The Department of Orthopaedic Surgery, Yangpu Hospital, Tongji University School of Medicine, Shanghai 200090, People's Republic of China. Electronic address: shiminchang11@aliyun.com.