1. Department of Orthopedics, Queen Savang Vadhana Memorial Hospital, Thai Red Cross Society, Sriracha, Chonburi, Thailand;
2. Department of Orthopedics, Rayong Hospital, Rayong, Thailand;
3. Department of Orthopedics, The First Affiliated Hospital of Xiamen University, Xiamen, People’s Republic of China;
4. Department of Orthopedics, Lerdsin General Hospital, Bangkok, Thailand;
5. Department of Orthopaedics, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand; and
6. Department of Neurosurgery, Seoul St. Mary’s Hospital, Spine Center, College of Medicine, The Catholic University of Korea, Seoul, South Korea