Wen-Chih Liu1,2, Yin-Chih Fu2,3, Chun-Kuan Lu2. 1. Division of Orthopedic Surgery, Kaohsiung Municipal Siaogang Hospital, Taiwan. 2. Department Orthopedic Surgery, Kaohsiung Medical University Hospital, Taiwan. 3. School of Medicine, College of Medicine, Kaohsiung Medical University, Taiwan.