Yijian Zhang1, Fan He1, Huilin Yang1, Xuesong Zhu2. 1. Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006, China; Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China. 2. Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006, China; Orthopaedic Institute, Medical College, Soochow University, Suzhou 215007, China. Electronic address: sudazxs@sina.com.