An international validation of the AO spine subaxial injury classification system
Brian A. Karamian, Gregory D. Schroeder, Mark J. Lambrechts, José A. Canseco, F. Cumhur Öner, Emiliano Vialle, Shanmuganathan Rajasekaran, Marcel R. Dvorak, Lorin M. Benneker, Frank Kandziora, Klaus John Schnake, Christopher K. Kepler, Alexander R. Vaccaro, AO Spine Subaxial Classification Group Members, Bruno Lourenço Costa, Martín Estefan, Ahmed Dawoud, Ariel Kaen, Sung-Joo Yuh, Segundo Fuego, Francisco A. Mannará, Gunaseelan Ponnusamy, Tarun Suri, Subiiah Jayakumar, Luis Rodríguez, Derek T. Cawley, Amauri Godinho, Johnny Duerinck, Nicola Montemurro, Kubilay Ozdener, Zachary L. Hickman, Wael Alsammak, Dilip Gopalakrishnan, Bruno Fernandes de Oliveira Santos, Olga Morillo, Yasunori Sorimachi, Naohisa Miyakoshi, Mahmoud Alkharsawi, Nimrod Rahamimov, Vijay Kumar Loya, Peter Loughenbury, José F. Rodrigues, Ankur Nanda, Olger Alarcon, Nishanth Ampar, Kai Sprengel, Macherla Haribabu Subramaniam, Kyaw Linn, P Subramanian, Georg Osterhoff, Sergey Mlyavykh, Elias Javier Martinez, Uri Hadelsberg, Álvaro Silva, Parmenion Tsitsopoulos, Satyashiva Munjal, Selim Ayhan, N Gummerson, Anna Rienmüller, Joachim Vahl, Gonzalo Pérez, Eugene Park, P. Alvin, Kartigeyan Madhivanan, Andrey Pershin, Bernhard Ullrich, Nasser Khan, Olver Lermen, Hisco Robijn, Nicolás Gonzalez Masanés, Ali Abdel Aziz, Takeshi Aoyama, Norberto Fernandez, Aaron HJills, Héctor Roldán, Alessandro Longo, Takeo Furuya, Tomi Kunej, Vaibhav Jain, Juan Delgado-Fernández, Guillermo Espinosa Hernandez, Alessandro Ramieri, Lingjie Fu, Andrea Redaelli, Jibin Francis, Claudio Bernucci, Ankit A. Desai, Pedro Luis Bazán, Rui Manilha, Máximo-Alberto Díez-Ulloa, Lady Lozano, Thami Benzakour, John D. Koerner, Fabricio Medina, Rian Souza Vieira, O. Clark West, Mohammad El‐Sharkawi, Christina Cheng, Rodolfo Paez, Sofien Benzarti
Abstract
PURPOSE: To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions. METHODS: A live webinar was organized in 2020 for validation of the AO Spine Subaxial Injury Classification System. The validation consisted of 41 unique subaxial cervical spine injuries with associated computed tomography scans and key images. Intraobserver reproducibility and interobserver reliability of the AO Spine Subaxial Injury Classification System were calculated for injury morphology, injury subtype, and facet injury. The reliability and reproducibility of the classification system were categorized as slight (ƙ = 0-0.20), fair (ƙ = 0.21-0.40), moderate (ƙ = 0.41-0.60), substantial (ƙ = 0.61-0.80), or excellent (ƙ = > 0.80) as determined by the Landis and Koch classification. RESULTS: A total of 203 AO Spine members participated in the AO Spine Subaxial Injury Classification System validation. The percent of participants accurately classifying each injury was over 90% for fracture morphology and fracture subtype on both assessments. The interobserver reliability for fracture morphology was excellent (ƙ = 0.87), while fracture subtype (ƙ = 0.80) and facet injury were substantial (ƙ = 0.74). The intraobserver reproducibility for fracture morphology and subtype were excellent (ƙ = 0.85, 0.88, respectively), while reproducibility for facet injuries was substantial (ƙ = 0.76). CONCLUSION: The AO Spine Subaxial Injury Classification System demonstrated excellent interobserver reliability and intraobserver reproducibility for fracture morphology, substantial reliability and reproducibility for facet injuries, and excellent reproducibility with substantial reliability for injury subtype.