1. Department of Rehabilitation Medicine, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510700, P.R. China
2. Department of Spine Surgery, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
3. Department of Pathology, The First Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
4. Department of Orthopaedics, Air Force General Hospital, Beijing 100142, P.R. China