1. Department of Spine Surgery, Xiangya Hospital of Central South University, Changsha City 410008, Hunan Province, China
2. Department of Orthopedic Surgery, Mount Meru Regional Referral Hospital, P.O Box 3092, Arusha City, Tanzania
3. Department of Orthopedic Surgery, Mwananyamala Regional Referral Hospital, P.O Box 61665, Dar-es-salaam City, Tanzania