Honggang Xu1, Ruipeng Guo2, Bin Xu3. 1. Department of Sports Medicine and Arthroscopic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China. 2. Department of Sports Medicine and Arthroscopic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China; Laboratory for Biomechanics and Biomaterials, Hannover Medical School, Hannover, Germany. 3. Department of Sports Medicine and Arthroscopic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China. Electronic address: docxb@outlook.com.