1. Department of Rehabilitation Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
2. Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China
3. Rehabilitation Center, Lintong Sanatorium of The PLA, Xi'an, Shaanxi 710060, P.R. China
4. Orthopedic Center, General Hospital of Xinjiang Military Region, Urumqi, Xinjiang 830000, P.R. China