1. Department of Orthopaedics, The First Rehabilitation Hospital of Shanghai, Shanghai 200090, P.R. China
2. Medical Laboratory Diagnosis Center, Jinan Central Hospital, Jinan, Shandong 250013, P.R. China
3. Department of Clinical Laboratory, The People's Hospital of Gaotang, Gaotang, Shandong 252800, P.R. China
4. Department of Spinal Bone, General Hospital of Xingtai Coal Mineral Company, Jizhong Energy Resource, Xingtai, Hebei 054000, P.R. China