Affiliation: | aService de neurochirurgie, The Spine and Spinal Cord Institute, Gangnam Severance Spine Hospital, Yonsei University College of Medicine, Seoul, Corée;bService de neurochirurgie, Spine Center, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, 153, Kyo-dong, Kangwon-do, Chuncheon-shi, République de Corée |