AOSpine thoracolumbar spine injury classification system [Neurosurgery Wiki]

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====== AOSpine thoracolumbar spine injury classification system ======

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1VA-U_2oiXyq9lMoV7mdoNujlNdGWgdRrG9H00mUGL6ZC4H90t/?limit=15&utm_campaign=pubmed-2&fc=20240119064511}}

Picture: {{ ::aos_injury_classification_systems_poster_thoracolumbar.pdf |AOSpine thoracolumbar spine injury classification system}}

{{::aospinethoracolumbaralgorithm.jpg|}}

see also [[Thoracolumbar spine fracture classification]].

This [[classification]] allows adequate agreement among different [[observer]]s and by the same observer on separate occasions
((Urrutia J, Zamora T, Yurac R, Campos M, Palma J, Mobarec S, Prada C. An independent interobserver reliability and intraobserver reproducibility evaluation of the new AOSpine Thoracolumbar Spine Injury Classification System. Spine (Phila Pa 1976). 2015 Jan 1;40(1):E54-8. doi: 10.1097/BRS.0000000000000656. PMID: 25341990.)).

The AOSpine thoracolumbar and subaxial [[cervical spine injury]] systems show substantial reliability, thus being valuable tools for clinical and research purposes
((Schnake KJ, Schroeder GD, Vaccaro AR, Oner C. AOSpine Classification Systems (Subaxial, Thoracolumbar). J Orthop Trauma. 2017 Sep;31 Suppl 4:S14-S23. doi: 10.1097/BOT.0000000000000947. PMID: 28816871.)).

The reliability of the AOSpine fracture classification is superior to the [[TLICS]] and the [[LSC]]. Therefore, this classification system could best be applied within clinical practice
((Pishnamaz M, Balosu S, Curfs I, Uhing D, Laubach M, Herren C, Weber C, Hildebrand F, Willems P, Kobbe P. Reliability and Agreement of Different Spine Fracture Classification Systems: An Independent Intraobserver and Interobserver Study. World Neurosurg. 2018 Jul;115:e695-e702. doi: 10.1016/j.wneu.2018.04.138. Epub 2018 Apr 27. PMID: 29709750.)).

Given a lack of a uniform [[classification]] in the pediatric population, the [[AOSpine]] [[thoracolumbar]] [[spine injury]] [[classification]] system has the potential to be used as the first universal [[spine fracture]] classification in [[child]]ren
((Mo AZ, Miller PE, Glotzbecker MP, Li Y, Fletcher ND, Upasani VV, Riccio AI, Hresko MT, Krengel WF, Spence D, Garg S, Hedequist DJ. The Reliability of the AOSpine thoracolumbar spine injury classification system in Children: Results of a Multicenter Study. J Pediatr Orthop. 2020 May/Jun;40(5):e352-e356. doi: 10.1097/BPO.0000000000001521. PMID: 32032218.)).
----
The inter- and intraobserver reliability for the AOSpine Thoracolumbar Spine Injury Classification System was high amongst pediatric orthopedic surgeons. The AOSpine Thoracolumbar Spine Injury Classification System is a promising option as a uniform fracture classification in children
((Mo AZ, Miller PE, Pizones J, Helenius I, Ruf M, El-Hawary R, de Oliveira RG, Ovadia D, Kawakami N, Crawford H, Odent T, Yazici M, Johnson MB, Miyanji F, Hedequist DJ. The reliability of the AOSpine Thoracolumbar Spine Injury Classification System in children: an international validation study. J Child Orthop. 2021 Oct 1;15(5):472-478. doi: 10.1302/1863-2548.15.200188. PMID: 34858534; PMCID: PMC8582611.))



===== AOSpine thoracolumbar spine injury classification system Subtype A0 =====

see [[AOSpine thoracolumbar spine injury classification system Subtype A0]]. 

===== AOSpine thoracolumbar spine injury classification system Subtype A1 =====

see [[AOSpine thoracolumbar spine injury classification system Subtype A1]]. 

===== AOSpine thoracolumbar spine injury classification system Subtype A2 =====

see [[AOSpine thoracolumbar spine injury classification system Subtype A2]]. 

===== AOSpine thoracolumbar spine injury classification system Subtype A3 =====

see [[AOSpine thoracolumbar spine injury classification system Subtype A3]]. 

===== AOSpine thoracolumbar spine injury classification system Subtype A4 =====

see [[AOSpine thoracolumbar spine injury classification system Subtype A4]]. 

===== AOSpine thoracolumbar spine injury classification system Subtype B =====
see [[AOSpine thoracolumbar spine injury classification system Subtype B]].

===== AOSpine thoracolumbar spine injury classification system Subtype C =====

[[AOSpine thoracolumbar spine injury classification system Subtype C]]


----


Historically, [[classification]]s focused only on the osseous injuries; more recent classifications focused on the injury morphology and other critical determinants of treatment, including the posterior ligamentous complex integrity and the patient's neurologic status
((Schroeder GD, Harrop JS, Vaccaro AR. Thoracolumbar Trauma Classification.
Neurosurg Clin N Am. 2017 Jan;28(1):23-29. doi: 10.1016/j.nec.2016.07.007.
Review. PubMed PMID: 27886879.
)).

Although the [[Magerl classification of thoracolumbar spinal fractures]] and thoracolumbar injury classification system ([[TLICS]]) are both well-known schemes to describe [[Thoracolumbar spine fracture]]s, no [[thoracolumbar injury]] classification system has achieved universal international adoption. This lack of consensus limits communication between clinicians and researchers complicating the study of these injuries and the development of [[treatment algorithm]]s
((Schnake KJ, Schroeder GD, Vaccaro AR, Oner C. AOSpine Classification Systems
(Subaxial, Thoracolumbar). J Orthop Trauma. 2017 Sep;31 Suppl 4:S14-S23. doi:
10.1097/BOT.0000000000000947. PubMed PMID: 28816871.
)).

A simple and reproducible classification system of TL injuries was developed using a structured international consensus process. This classification system consists of a morphologic classification of the fracture, a grading system for the neurological status, and description of relevant patient-specific modifiers. Forty cases with a broad range of injuries were classified independently twice by group members 1 month apart and analyzed for classification reliability using the [[Kappa coefficient]] (κ).

The morphologic classification is based on 3 main injury patterns: type A (compression), type B (tension band disruption), and [[AOSpine Thoracolumbar type C fracture]] (displacement/translation) injuries. Reliability in the identification of a morphologic injury type was substantial (κ= 0.72).

The AOSpine TL injury classification system is clinically relevant according to the consensus agreement of our international team of spine trauma experts. Final evaluation data showed reasonable reliability and accuracy, but further clinical validation of the proposed system requires prospective observational data collection documenting use of the classification system, therapeutic decision making, and clinical follow-up evaluation by a large number of surgeons from different countries
((Vaccaro AR, Oner C, Kepler CK, Dvorak M, Schnake K, Bellabarba C, Reinhold M, 
Aarabi B, Kandziora F, Chapman J, Shanmuganathan R, Fehlings M, Vialle L; AOSpine
Spinal Cord Injury & Trauma Knowledge Forum. AOSpine thoracolumbar spine injury
classification system: fracture description, neurological status, and key
modifiers. Spine (Phila Pa 1976). 2013 Nov 1;38(23):2028-37. doi:
10.1097/BRS.0b013e3182a8a381. PubMed PMID: 23970107.
)).
----
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.

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.

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
((Schroeder GD, Vaccaro AR, Kepler CK, Koerner JD, Oner FC, Dvorak MF, Vialle
LR, Aarabi B, Bellabarba C, Fehlings MG, Schnake KJ, Kandziora F. Establishing
the injury severity of thoracolumbar trauma: confirmation of the hierarchical
structure of the AOSpine Thoracolumbar Spine Injury Classification System. Spine 
(Phila Pa 1976). 2015 Apr 15;40(8):E498-503. doi: 10.1097/BRS.0000000000000824.
PubMed PMID: 25868104.
)).

----
Surgeons' experience did not significantly affect overall fracture classification, evaluating stability and planning the treatment. Surgeons with less experience had a higher percentage of correct classification in A3 and A4 injuries. Despite variations between them in classification, the assessment of overall stability and management decisions were similar between the 2 groups
((Rajasekaran S, Kanna RM, Schroeder GD, Oner FC, Vialle L, Chapman J, Dvorak M,
Fehlings M, Shetty AP, Schnake K, Kandziora F, Vaccaro AR. Does the Spine
Surgeon's Experience Affect Fracture Classification, Assessment of Stability, and
Treatment Plan in Thoracolumbar Injuries? Global Spine J. 2017 Jun;7(4):309-316. 
doi: 10.1177/2192568217699209. Epub 2017 Apr 20. PubMed PMID: 28815158; PubMed
Central PMCID: PMC5546684.
)).
====Case series====
===2017===
The AOSpine thoracolumbar spine injury classification system was applied to 109 patients with acute, traumatic thoracolumbar spinal injuries by two groups of spinal surgeons with different levels of clinical experience. The Kappa coefficient was used to determine interobserver reliability and intraobserver reproducibility.
RESULTS:
The overall Kappa coefficient for all cases was 0.362, which represents fair reliability. The Kappa statistic was 0.385 for A-type injuries and 0.292 for B-type injuries, which represents fair reliability, and 0.552 for C-type injuries, which represents moderate reliability. The Kappa coefficient for intraobserver reproducibility was 0.442 for A-type injuries, 0.485 for B-type injuries, and 0.412 for C-type injuries. These values represent moderate reproducibility for all injury types. The raters in Group A provided significantly better interobserver reliability than Group B (P < 0.05). There were no between-group differences in intraobserver reproducibility.

This study suggests that the new AO spine injury classification system may be applied in day-to-day clinical practice in China following extensive training of healthcare providers. Further prospective studies in different healthcare providers and clinical settings are essential for validation of this classification system and to assess its utility
((Cheng J, Liu P, Sun D, Qin T, Ma Z, Liu J. Reliability and reproducibility
analysis of the AOSpine thoracolumbar spine injury classification system by
Chinese spinal surgeons. Eur Spine J. 2017 May;26(5):1477-1482. doi:
10.1007/s00586-016-4842-4. Epub 2016 Nov 2. PubMed PMID: 27807778.
)).

----

Clinical and radiological data of 50 consecutive patients admitted at a single centre with a diagnosis of an acute traumatic thoracolumbar spine injury were distributed to eleven attending spine surgeons from six different institutions in the form of PowerPoint presentation, who classified them according to both classifications. After time span of 6 weeks, cases were randomly rearranged and sent again to same surgeons for re-classification. Interobserver and intraobserver reliability for each component of TLICS and new AOSpine classification were evaluated using Fleiss Kappa coefficient (k value) and Spearman rank order correlation.

Moderate interrater and intrarater reliability was seen for grading fracture type and integrity of posterior ligamentous complex (Fracture type: k = 0.43 ± 0.01 and 0.59 ± 0.16, respectively, PLC: k = 0.47 ± 0.01 and 0.55 ± 0.15, respectively), and fair to moderate reliability (k = 0.29 ± 0.01 interobserver and 0.44+/0.10 intraobserver, respectively) for total score according to TLICS. Moderate interrater (k = 0.59 ± 0.01) and substantial intrarater reliability (k = 0.68 ± 0.13) was seen for grading fracture type regardless of subtype according to AOSpine classification. Near perfect interrater and intrarater agreement was seen concerning neurological status for both the classification systems.

The proposed AOSpine classification has better reliability for identifying fracture morphology than the existing TLICS. Additional studies are clearly necessary concerning the application of these classification systems across multiple physicians at different level of training and trauma centers to evaluate not only their reliability and reproducibility, but also the other attributes, especially the clinical significance of a good classification system
((Kaul R, Chhabra HS, Vaccaro AR, Abel R, Tuli S, Shetty AP, Das KD, Mohapatra
B, Nanda A, Sangondimath GM, Bansal ML, Patel N. Reliability assessment of
AOSpine thoracolumbar spine injury classification system and Thoracolumbar Injury
Classification and Severity Score (TLICS) for thoracolumbar spine injuries:
results of a multicentre study. Eur Spine J. 2017 May;26(5):1470-1476. doi:
10.1007/s00586-016-4663-5. Epub 2016 Jun 22. PubMed PMID: 27334493.
)).

----
Patients who suffered osteoporotic vertebral fractures (OVFs) between January 2012 and December 2014 underwent consecutive radiological assessments, including measurements of anterior height loss (AHL), posterior height loss (PHL), and the kyphotic angle (KA). The fracture morphology was classified by AOSpine thoracolumbar spine injury classification system. MRI was performed at the initial assessment and the extent of canal encroachment (CE) was calculated in all patients. Follow-up computed tomography (CT) or MRI was performed in patients exhibiting significant height loss in follow-up radiography. The fracture patterns in T1- and T2-weighted MRI were also assessed.

A total of 485 patients visited our institute for treatment of OVFs and 97 were enrolled; 15 were male and 82 were female. The mean age at initial visit was 70.3±14.6years. The initial spinal CE was correlated with the initial PHL and the initial AHL. The follow-up CE was correlated with age, the initial PHL, and the difference between the initial and last PHL (ΔPHL(initial-last)). OVFs with both endplate fractures have a greater tendency of posterior wall collapse than those with single endplate fracture. On initial T1-weighted sagittal MRI, a diffuse low signal change pattern of the fractured vertebra was correlated with PHL. Delayed neurological deficits developed in four patients. These patients underwent surgical intervention.

In patients with simple compression fractures, attention should be paid to the posterior vertebral body and both endplates as well as the T1-weighted MRI findings to allow early detection of spinal canal compromise, which can have devastating consequences
((Seo JY, Kwon YS, Kim KJ, Shin JY, Kim YH, Ha KY. Clinical importance of
posterior vertebral height loss on plain radiography when conservatively treating
osteoporotic vertebral fractures. Injury. 2017 Jul;48(7):1503-1509. doi:
10.1016/j.injury.2017.04.057. Epub 2017 Apr 26. PubMed PMID: 28477991.
)).