1. Department of Neurosurgery, Seoul Medical Center, Seoul, Korea.
2. Department of Orthopaedic Surgery, Fujian Provincial Hospital, Fujian, China.
3. Department of Neurosurgery, I-Shou University, Kaohsiung County, Taiwan.
4. Division of Neurosurgery, Department of Surgery, Kaohsiung Armed Forces General Hospital, Kaohsiung City, Taiwan.
5. Department of Orthopaedic Surgery, Mahidol University, Bangkok, Thailand.
6. Department of Orthopaedic Surgery, University of California at Los Angeles, Los Angeles, California, USA.