1. Department of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China
2. The Second Clinical Medical School, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China
3. Department of Clinical Skills Training Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China