Abstract
Purpose
A classification system was recently developed by the international association AO Spine for assessing subaxial cervical spine fractures. Significant variability exists between users of the facet component, which consists of four morphological types (F1–F4). The primary aims of this study were to assess the diagnostic accuracy and reliability of this new system’s facet injury morphological classifications.
Methods
A survey consisting of 16 computed tomography (CT) scans of patients with cervical facet fractures was distributed to spine surgeon members of AO Spine Latin America. To provide a gold standard diagnosis for comparison, all 16 injuries had been classified previously by six co-authors and only were included after total consensus was achieved. Demographic and surgical practice characteristics of all respondents were analyzed, and diagnostic accuracy calculated. Inter- and intra-observer agreement rates were calculated across two survey rounds, conducted one month apart.
Results
A total of 135 surgeons completed both surveys, among whom the mean age was 41.6 years (range 26–71), 130 (96.3%) were men, and 83 (61.5%) were orthopedic surgeons. The mean time in practice as a spine surgeon was 9.7 years (1–30). The overall diagnostic accuracy of all responses was 65.4%. Inter-observer and intra-observer agreement rates for F1/F2/F3/F4 were 55.4%/47.6%/64.0%/94.7% and 60.0%/49.1%/58.0%/93.0%, respectively.
Conclusion
This study evaluates the AO Spine Classification System specifically for facet injuries involving the subaxial cervical spine in a large sample of spine surgeons. There was significant variability in diagnostic accuracy for F1 through F3-type fractures, whereas almost universal agreement was achieved for F4-type injuries.
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References
Quarrington RD, Jones CF, Tcherveniakov P, Clark JM, Sandler SJI, Lee YC, Torabiardakani S, Costo JJ, Freeman BJC (2018) Traumatic subaxial cervical facet subluxation and dislocation: epidemiology, radiographic analyses, and risk factors for spinal cord injury. Spine Journal 18(3):387–398. https://doi.org/10.1016/j.spinee.2017.07.175
Bono CM, Schoenfeld A, Gupta G, Harrop JS, Anderson P, Patel AA, Dimar J, Aarabi B, Dailey A, Vaccaro AR, Gahr R, Shaffrey C, Anderson DG, Rampersaud R (2011) Reliability and reproducibility of subaxial cervical injury description system: a standardized nomenclature schema. Spine 36(17):1140–1144. https://doi.org/10.1097/BRS.0b013e318221a56d
Schnake KJ, Schroeder GD, Vaccaro AR, Oner C (2017) AOSpine classification systems (subaxial, thoracolumbar). J Orthop Trauma 31(9):S14–S23. https://doi.org/10.1097/BOT.0000000000000947
Vaccaro AR, Hulbert RJ, Patel AA, Fisher C, Dvorak M, Lehman RA, Anderson P, Harrop J, Oner FC, Arnold P, Fehlings M, Hedlund R, Madrazo I, Rechtine G, Aarabi B, Shainline M (2007) The subaxial cervical spine injury classification system: A novel approach to recognize the importance of morphology, neurology, and integrity of the disco-ligamentous complex. Spine 32(21):2365–2374. https://doi.org/10.1097/BRS.0b013e3181557b92
Vaccaro AR, Koerner JD, Radcliff KE, Oner FC, Reinhold M, Schnake KJ, Kandziora F, Fehlings M, Dvorak MF, Aarabi B, Rajasekaran S, Schroeder GD, Kepler CK, Vialle LR (2016) AOSpine subaxial cervical spine injury classification system. Eur Spine J 25(7):2173–2184. https://doi.org/10.1007/s00586-015-3831-3
Dvorak MF, Fisher CG, Aarabi B, Harris MB, Hurbert RJ, Rampersaud YR, Vaccaro A, Harrop JS, Nockels RP, Madrazo IN, Schwartz D, Kwon BK, Zhao Y, Fehlings MG (2007) Clinical outcomes of 90 isolated unilateral facet fractures, subluxations, and dislocations treated surgically and nonoperatively. Spine 32(26):3007–3013. https://doi.org/10.1097/BRS.0b013e31815cd439
Sime D, Gabbe B, Liew S (2017) Outcomes of halo immobilization in the management of subaxial cervical facet fractures. ANZ J Surg 87(3):159–164. https://doi.org/10.1111/ans.13656
Vedantam A, Fridley JS, Navarro JC, Gopinath SP (2018) Management of acute unilateral nondisplaced subaxial cervical facet fractures. Operative Neurosurgery 14(2):104–111. https://doi.org/10.1093/ons/opx069
Halliday AL, Henderson BR, Hart BL, Benzel EC (1997) The management of unilateral lateral mass/facet fractures of the subaxial cervical spine. Spine 22:2614–2621. https://doi.org/10.1097/00007632-199711150-00007
Schleicher P, Kobbe P, Kandziora F, Scholz M, Badke A, Brakopp F, et al (2018) Treatment of Injuries to the Subaxial Cervical Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU). Global Spine J 8(2_suppl): 25S-33S Doi: https://doi.org/10.1177/2192568217745062
Woodring J, Lee C (1993) Limitations of cervical radiography in the evaluation of acute cervical trauma. J Trauma 34(1):32–39. https://doi.org/10.1097/00005373-199301000-00006
Spector LR, Kim DH, Affonso J, Albert TJ, Hilibrand AS, Vaccaro AR (2006) Use of computed tomography to predict failure of nonoperative treatment of unilateral facet fractures of the cervical spine. Spine 31(24):2827–2835. https://doi.org/10.1097/01.brs.0000245864.72372.8f
Canseco JA, Schroeder GD, Patel PD, Grasso G, Chang M, Kandziora F, Vialle EN, Oner FC, Schnake KJ, Dvorak MF, Chapman JR, Benneker LM, Rajasekaran S, Kepler CK, Vaccaro AR (2020) Regional and experiential differences in surgeon preference for the treatment of cervical facet injuries: a case study survey with the ao spine cervical classification validation group. Eur Spine J. https://doi.org/10.1007/s00586-020-06535-z
Urrutia J, Zamora T, Yurac R, Campos M, Palma J, Mobarec S, Prada C (2017) An independent inter-and intraobserver agreement evaluation of the AOSpine subaxial cervical spine injury classification system. Spine 42(5):298–303. https://doi.org/10.1097/BRS.0000000000001302
Urrutia J, Zamora T, Campos M, Yurac R, Palma J, Mobarec S, Prada C (2016) A comparative agreement evaluation of two subaxial cervical spine injury classification systems: the AOSpine and the Allen and ferguson schemes. Eur Spine J 25(7):2185–2192. https://doi.org/10.1007/s00586-016-4498-0
Da Silva OT, Sabba MF, Lira HIG, Ghizoni E, Tedeschi H, Patel AA, Joaquim AF (2016) Evaluation of the reliability and validity of the newer AOSpine subaxial cervical injury classification (C-3 to C-7). J Neurosurg Spine 25(3):303–308. https://doi.org/10.3171/2016.2.SPINE151039
Van Middendorp JJ, Audigé L, Bartels RH, Bolger C, Deverall H, Dhoke, et al (2013) The subaxial cervical spine injury classification system: an external agreement validation study. Spine Journal 13(9):1055–1063. https://doi.org/10.1016/j.spinee.2013.02.040
Du JP, Fan Y, Zhang JN, Liu JJ, Meng YB, Hao DJ (2019) Early versus delayed decompression for traumatic cervical spinal cord injury: application of the AOSpine subaxial cervical spinal injury classification system to guide surgical timing. Eur Spine J 28(8):1855–1863. https://doi.org/10.1007/s00586-019-05959-6
Jenjitranant P, Beckmann NM, Cai C, Cheekatla SK, West OC (2019) There has to be an easier way: facet fracture characteristics that reliably differentiate AOSpine F1 and F2 injuries. Emerg Radiol 26(4):391–399. https://doi.org/10.1007/s10140-019-01684-1
Cabrera JP, Yurac R, Joaquim AF, Guiroy A, Carazzo CA, Zamorano JJ, Valacco M (2021) CT scan in subaxial cervical facet injury: is it enough for decision-making? Global Spine J. https://doi.org/10.1177/2192568221995491
Grin A, Krylov V, Lvov I, Talypov A, Dzukaev D, Kordonskiy A et al (2020) External multicenter study of reliability and reproducibility for lower cervical spine injuries classification systems—part 1: a comparison of morphological schemes. Global Spine J 10(6):682–691. https://doi.org/10.1177/2192568219868218
Grin A, Krylov V, Lvov I, Talypov A, Dzukaev D, Kordonskiy A et al (2019) External multicenter study of reliability and reproducibility for lower cervical spine injuries classification systems—part 2: an analysis of the subaxial cervical spine injury classification and cervical spine injury severity score scale. Global Spine J. https://doi.org/10.1177/2192568219896546
Acknowledgements
This study was organized by the AO Spine Latin America Trauma Study Group. AO Spine is a clinical division of the AO Foundation, which is an independent medically-guided not-for-profit organization. Study support was provided directly through AO Spine Latin America regarding data collection, data analysis and proofreading.
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Cabrera, J.P., Yurac, R., Guiroy, A. et al. Accuracy and reliability of the AO Spine subaxial cervical spine classification system grading subaxial cervical facet injury morphology. Eur Spine J 30, 1607–1614 (2021). https://doi.org/10.1007/s00586-021-06837-w
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DOI: https://doi.org/10.1007/s00586-021-06837-w