1. Department of Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, P.R. China 250021
2. Department of Orthopaedics, Xiangya Hospital of Central South University, Xiangya Road 87, Changsha, Hunan, P.R. China 410008
3. Department of Clinical Medicine (8-Year Program), Xiangya Medicine School, Central South University, Changsha, Hunan, P.R. China 410013
4. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China 410008