1. Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, P. R. China
2. Ningxia Geriatric Disease Clinical Research Center, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan, P. R. China
3. National Clinical Research Center for Geriatric Disorders of Xiangya Hospital, Central South University (Sub-Center of Ningxia), Yinchuan, P. R. China
4. Department of Hunan Institute of Geriatrics, Hunan People’s Hospital, Changsha, P. R. China
5. Department of Dermatology, Xiangya Hospital, Central South University, Changsha, P. R. China
6. National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, P. R. China