1. Department of Orthopedics, The Second Affiliated Hospital of The Air Force Medical University (Tangdu Hospital of Fourth Military Medical University), Xi'an, Shaanxi 710038, P.R. China
2. Department of Rheumatology and Immunology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China
3. Department of Bone and Joint Diseases, Honghui Hospital of Xi'an Jiaotong University, College of Medicine, Xi'an, Shaanxi 710054, P.R. China