1. Departments of Orthopaedics and
2. Department of Neurosurgery, Wooridul Spine Hospital, Seoul;
3. Department of Cardiovascular Surgery, Wooridul Spine Hospital, Gimpo Airport, Seoul, Korea;
4. Neurosurgery, Wooridul Spine Hospital, Busan;
5. Department of General Surgery, Buddhist Dalin Tzu Chi Hospital, Chia-Yi; and
6. School of Medicine, Tzu Chi University, Hualien, Taiwan