Department of Orthopedics, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100730, China. Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China. Department of Joint and Sports Medicine, Zaozhuang Municipal Hospital Affiliated to Jining Medical University, Shandong, 277100, China. Department of Orthopedics, Weishan People's Hospital, Shandong, 277600, China. Department of Orthopedics, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100730, China. bjyyxqy@163.com. Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China. bjyyxqy@163.com.