E498 www.spinejournal.com April 2015 HEALTH SERVICES RESEARCH SPINE Volume 40, Number 8, pp E498-E503 ©2015, Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/BRS.0000000000000824 Study Design. Survey of spine surgeons. Objective. To develop a validated regional and global injury severity scoring system for thoracolumbar trauma. Summary of Background Data. The AOSpine Thoracolumbar Spine Injury Classification System was recently published and combines elements of both the Magerl system and the Thoracolumbar Injury Classification System; however, the injury severity of each fracture has yet to be established. Methods. A survey was sent to 100 AOSpine members from all 6 AO regions of the world (North America, South America, Europe, Africa, Asia, and the Middle East). Each respondent was asked to numerically grade the severity of each variable of the AOSpine Thoracolumbar Spine Injury Classification System including the morphology, neurological grade, and patient specific modifiers. A grade of zero was considered to be not severe at all, and a grade of 100 was the most severe injury possible. From *Rothman Institute at Thomas Jefferson University, Philadelphia, PA; †University Medical Center, Utrecht, the Netherlands; ‡The University of British Columbia, Vancouver, British Columbia, Canada; §Catholic University, Curitiba, Brazil; ¶University of Maryland School of Medicine, Baltimore, MD; University of Washington/Harborview Medical Center, Seattle WA; **University of Toronto, Ontario, Canada; ††Schön Klinik Nürnberg Fürth, Center for Spinal Surgery, Fürth, Germany; and ‡‡Berufsgenossenschaftliche Unfallklinik Frankfurt, Center for Spinal Surgery and Neurotraumatology, Frankfurt/Main, Germany. Acknowledgment date: October 16, 2014. Revision date: January 6, 2015. Acceptance date: January 20, 2015. The manuscript submitted does not contain information about medical device(s)/drug(s). AOSpine funds were received to support this work. Relevant financial activities outside the submitted work: grants, board membership, consultancy, payment for lectures, royalties, travel/ accommodations/meeting expenses, payment for development of educational presentation, royalties. Address correspondence and reprint requests to Gregory D. Schroeder, MD, Department of Orthopaedic Surgery, The Rothman Institute at Thomas Jefferson University, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107; E-mail: gregdschroeder@gmail.com D uring the last 3 decades, since Denis proposed the classification of thoracolumbar injuries on the basis of the concept of 3 spinal columns, 1 many additional classifications have been developed, but none have been uni- versally accepted. 2–5 Magerl et al 2 published a morphologi- cally based graduated classification system, designed such that subsequent grades indicated an increase in injury sever- ity, mechanical instability, and the risk of neurological injury. However, in spite of more than 50 fracture subtypes, the clas- sification system still does not formally account for the neu- rological status of the patient, a clinical feature of the injury which is often the primary driver of specific treatment. 3,6 Because of its complexity, the Magerl system has only fair reproducibility and has not been clinically validated. 7,8 Results. Seventy-four AOSpine surgeons from all 6 AO regions of the world numerically graded the severity of each variable of the AOSpine Thoracolumbar Spine Injury Classification System to establish the injury severity score. The reported fracture severity increased significantly ( P < 0.0001) as the subtypes of fracture type A and type B increased, and a significant difference ( P < 0.0001) in severity was established for burst fractures with involvement of 2 versus 1 endplates. Finally, no regional or experiential difference in severity or classification was identified. Conclusion. Development of a globally applicable injury severity scoring system for thoracolumbar trauma is possible. This study demonstrates no regional or experiential difference in perceived severity or thoracolumbar spine trauma. The AOSpine Thoracolumbar Spine Injury Classification System provides a logical approach to assessing these injuries and enables rational strategies for treatment. Key words: AOSpine Thoracolumbar Spine Injury Classification System, injury severity score, severity of burst fractures, severity of thoracolumbar trauma. Level of Evidence: 4 Spine 2015;40:E498–E503 Establishing the Injury Severity of Thoracolumbar Trauma Confirmation of the Hierarchical Structure of the AOSpine Thoracolumbar Spine Injury Classification System Gregory D. Schroeder, MD,* Alexander R. Vaccaro, MD, PhD,* Christopher K. Kepler, MD, MBA,* John D. Koerner, MD,* F. Cumhur Oner, MD, PhD,† Marcel F. Dvorak, MD,‡ Luiz R. Vialle, MD, PhD,§ Bizhan Aarabi, MD,¶ Carlo Bellabarba, MD,  Michael G. Fehlings, MD, PhD,** Klaus J. Schnake, MD,†† and Frank Kandziora, MD, PhD‡‡ Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.