Subaxial Cervical Spine Injury Classification Research Articles

Validation of the Subaxial Cervical Spine Injury Classification score in children: a single-institution experience at a level 1 pediatric trauma center.

The Subaxial Cervical Spine Injury Classification (SLIC) score has not been previously validated for a pediatric population. The authors compared the SLIC treatment recommendations for pediatric subaxial cervical spine trauma with real-world pediatric spine surgery practice. A retrospective cohort study at a pediatric level 1 trauma center was conducted in patients < 18 years of age evaluated for trauma from 2012 to 2021. An SLIC score was calculated for each patient, and the subsequent recommendations were compared with actual treatment delivered. Percentage misclassification, sensitivity, specificity, positive (PPV) and negative predictive value (NPV), and area under the receiver operating characteristic (ROC) curve (AUC) were calculated. Two hundred forty-three pediatric patients with trauma were included. Twenty-five patients (10.3%) underwent surgery and 218 were managed conservatively. The median SLIC score was 2 (interquartile range = 2). Sixteen patients (6.6%) had an SLIC score of 4, for which either conservative or surgical treatment is recommended; 27 children had an SLIC score ≥ 5, indicating a recommendation for surgical treatment; and 200 children had an SLIC score ≤ 3, indicating a recommendation for conservative treatment. Of the 243 patients, 227 received treatment consistent with SLIC score recommendations (p < 0.001). SLIC sensitivity in determining surgically treated patients was 79.2% and the specificity for accurately determining who underwent conservative treatment was 96.1%. The PPV was 70.3% and the NPV was 97.5%. There was a 5.7% misclassification rate (n = 13) using SLIC. Among patients for whom surgical treatment would be recommended by the SLIC, 29.6% (n = 8) did not undergo surgery; similarly, 2.5% (n = 5) of patients for whom conservative management would be recommended by the SLIC had surgery. The ROC curve for determining treatment received demonstrated excellent discriminative ability, with an AUC of 0.96 (OR 3.12, p < 0.001). Sensitivity decreased when the cohort was split by age (< 10 and ≥ 10 years old) to 0.5 and 0.82, respectively; specificity remained high at 0.98 and 0.94. The SLIC scoring system recommended similar treatment when compared with the actual treatment delivered for traumatic subaxial cervical spine injuries in children, with a low misclassification rate and a specificity of 96%. These findings demonstrate that the SLIC can be useful in guiding treatment for pediatric patients with subaxial cervical spine injuries. Further investigation into the score in young children (< 10 years) using a multicenter cohort is warranted.

Fracture-dislocations of the subaxial cervical spine

Fracture-dislocations of the subaxial cervical spine are rare yet potentially devastating injuries often associated with high-energy trauma. These inherently unstable injuries frequently lead to neurologic compromise, necessitating urgent operative intervention. This review provides a comprehensive overview of subaxial cervical spine fracture-dislocations, addressing their epidemiology, anatomy, and classification systems. Classification schemes including Allen and Ferguson, Cervical Spine Injury Severity Score (CSISS), Subaxial Cervical Spine Injury Classification System (SLIC), and AO Spine Subaxial Cervical Spine Injury Classification System are discussed. Prompt recognition and management of these injuries is critical in optimizing long-term functional and neurologic outcomes. Rates of neurologic injury can exceed 50 %, with distractive flexion injuries and bilateral facet injuries often presenting with higher ASIA grades and lower neurologic recovery potential. Minimizing time to reduction is the most important factor in optimizing neurologic outcomes in these injury patterns. We discuss both closed and open reduction methods, timing considerations, technical pearls, and potential complications associated with each strategy. We also discuss the diagnosis and management of concurrent acute disk herniations, the role of advanced imaging, and the debated utility of pre-reduction MRI. Many subaxial cervical fracture-dislocations necessitate surgical intervention, which can be approached from an anterior, posterior, or combined approach. Although no standard surgical treatment algorithm exists, we discuss surgical options and situations where a preferred approach may exist. Selection of the approach depends on injury characteristics and surgeon preference, and there are no clearly defined surgical recommendations based on injury pattern.

Safety of tranexamic acid in surgically treated isolated spine trauma.

Tranexamic acid (TXA), a synthetic antifibrinolytic drug, effectively reduces blood loss by inhibiting plasmin-induced fibrin breakdown. This is the first study in the United Kingdom to investigate the effectiveness of TXA in the surgical management of isolated spine trauma. To assess the safety of TXA in isolated spine trauma. The primary and secondary outcomes are to assess the rate of thromboembolic events and to evaluate blood loss and the incidence of blood transfusion, respectively. This prospective observational study included patients aged ≥ 17 years with isolated spine trauma requiring surgical intervention over a 6-month period at two major trauma centers in the United Kingdom. We identified 67 patients: 26 (39%) and 41 (61%) received and did not receive TXA, respectively. Both groups were matched in terms of age, gender, American Society of Anesthesiologists grade, and mechanism of injury. A higher proportion of patients who received TXA had a subaxial cervical spine injury classification or thoracolumbar injury classification score > 4 (74% vs 56%). All patients in the TXA group underwent an open approach with a mean of 5 spinal levels involved and an average operative time of 203 min, compared with 24 patients (58%) in the non-TXA group who underwent an open approach with an average of 3 spinal levels involved and a mean operative time of 159 min. Among patients who received TXA, blood loss was < 150 and 150-300 mL in 8 (31%) and 15 (58%) patients, respectively. There were no cases of thromboembolic events in any patient who received TXA. Our study demonstrated that TXA is safe for isolated spine trauma. It is challenging to determine whether TXA effectively reduces blood loss because most surgeons prefer TXA for open or multilevel cases. Further, larger studies are necessary to explore the rate, dosage, and mode of administration of TXA.

Is it true that treatment in patients with Subaxial Cervical Spine Injury Classification System (SLICS) 4 is the surgeon's choice?

The Subaxial Cervical Spine Injury Classification System (SLICS) is a commonly used algorithm for diagnosing and managing subaxial cervical spine trauma. A SLIC score 4 suggests either surgery or non-surgically treatment depending on the surgeon's experience and patient's conditions. Prognosis and treatment results were analyzed in patients with SLIC score 4. The patients with SLIC score 4 were retrospectively reviewed from 2012 to 2019. Forty-one patients were included and divided into two groups: non-surgically treated and surgically treated. Demographic data and radiographs were analyzed. Statistical analysis was performed to determine the difference between the two clinical groups. Twenty-two patients were non-surgically treated, and nineteen patients were surgically treated. There was no neurological deterioration in both groups. However, there was no statistically significant difference in the last follow-up AISA and Nurick grade (p> 0.05). There was no significant difference in the number of patients who showed improvement when comparing the initial and the last follow-up neurological status (p> 0.05). Regardless of the treatment method, the spinal cord injury patients with SLICS point 4 showed a relatively good prognosis. Patients with SLIC score 4 could be treated non-surgically or surgically based on the surgeon's experience and factors associated with the patient's acute health status and chronic comorbidities.

Teachability of lower cervical spine injury classifications

ObjectivesTo compare the teachability of the Allen–Ferguson, Harris, Argenson, AOSpine, Subaxial Cervical Spine Injury Classification (SLIC), Subaxial Cervical Spine Injury Classification (CSISS) and to identify the classification that a group of residents and junior neurosurgeons find easiest to learn. MethodsWe used data from 64 consecutive patients. Answers of nine residents and junior neurosurgeons and four experienced surgeons in two assessment procedures were used. Six raters (workshop group) participated in special seminars between assessments. Three other raters formed the control group. Experienced surgeon's answers were used for comparison. Teachability was measured as the median value of the difference (ΔK) in the interrater agreement on the same patients by the same pairs of subjects. ResultsMedian Δ K for the Allen–Ferguson, Harris, Argenson and AOSpine classifications were: (1) 0.01, 0.02, 0.29, and 0.39 for the workshop group; (2). 0.09, −0.03, 0.06 and 0.04 for the control group, respectively. Between numerical scales, median ΔK was higher for SLIC but did not exceed 0.16. Interrater consistency with expert's opinion was increased in the workshop group for Allen–Ferguson, Argenson and AOSpine and did not differ in either group for SLIC and CSISS. ConclusionThe AOSpine classification was the most teachable. Among numeric scales, SLIC demonstrated better results. The successful application of these classifications by residents and junior neurosurgeons was possible after a short educational course. The use of these scales in educational cycles at the stage of residency can significantly simplify the communication between specialists, especially at the stage of patient admission.

Operative Outcomes After Cervical Diffuse Idiopathic Skeletal Hyperostosis Fracture in the Elderly.

Cervical diffuse idiopathic skeletal hyperostosis (DISH) fractures are frequently unstable and carry significant risk of neurologic injury and death. Most patients with DISH fractures are elderly (>70 years) with significant comorbidities. We assessed factors that contribute to outcomes in elderly patients with cervical DISH fractures. Elderly patients with cervical DISH fractures from 2008 to 2017 were included in this retrospective multi-institutional cohort study. Predictor variables included injury level, surgical approach, preinjury comorbidities, American Society of Anesthesiologists (ASA) score, American Spinal Injury Association (ASIA) impairment scale grade, preoperative anticoagulation status, and the subaxial cervical spine injury classification system (SLIC) score. Univariate and multivariate analyses were utilized to identify factors associated with 30-day mortality and ambulatory status at discharge. A total of 48 patients, mean age 74.7 years old (range 60-96), underwent cervical fixation for DISH fractures. Average SLIC score was 6.30 ± 1.2 (range 5-8), and most frequent fracture level was at C6 to -C7 (31.3%) followed by C7-T1 (25.0%). Forty (83.3%) patients underwent posterior fixation, 7 (14.6%) with anterior fixation, and 1 (2.1%) had combined approach. Ten (20.4%) patients died within 30 days of surgery. Multivariate analysis demonstrated that poorer preoperative ASIA grade (OR 2.35, P = 0.003, CI = 1.33-4.14) and ASA score >3 (P = 0.027) had increased risk of being nonambulatory at discharge. Higher SLIC score was associated with increased 30-day mortality (P = 0.021, CI = 1.20-9.60). Cervical DISH fractures can be highly unstable, for which instrumentation and fixation are indicated. Surgical decision-making should focus on preoperative ASIA grade, SLIC score, and ASA score. The study is relevant due to an aging poulation predisposed to cervical DISH fractures.

The state of the sagittal balance of the injured cervical spine depending on the nature of the damage to the subaxial level

Background. Three main interrelated principles form the basis for modern surgery of traumatic cervical spine injuries, namely decompression, reconstruction and stabilization. Restoration of the sagittal profile is one of the basic tasks of the reconstructive stage. Currently, there are no clear recommendations for surgical management in traumatic injuries depending on the degree of deformation, and the state of sagittal balance of the injured cervical spine in the preoperative period has practically not been studied. The purpose of the work is to study the state of the sagittal profile and the degree of segmental deformation of the cervical spine following traumatic injury at the subaxial level, to determine the relationship between them and the type of injury. Materials and methods. We performed a retrospective analysis of X-ray data from 140 patients with subaxial cervical spine traumatic injury who were hospitalized at the Department of Spinal Cord Pathology of the Romodanov Neurosurgery Institute of the National Academy of Medical Sciences of Ukraine in the period from 2008 to 2018. We calculated indicators of segmental kyphosis and general cervical lordosis and determined the type of damage according to AO Spine Subaxial Cervical Spine Injury Classification System. Results. We found that the type of the damage affects the degree of segmental deformation (p &lt; 0.001). Type A1, A2 and C injuries show the maximum kyphotic angulation: 13.51° (8.18; 20.07), 21.8° (20.12; 22.96) and 20.01° (17.52; 21.99), respectively. Injuries of type A2 and C statistically significantly differ from other types of lesions. We registered maximum values of deviations from the normal sagittal circuit in patients with injuries types A2 and C: ‒26.77° (‒32.78; ‒20.91) and ‒26.70° (‒36.30; ‒16.77), respectively. The parameters of segmental kyphosis and general cervical lordosis reveal high interdependence (r2=0.766, p &lt; 0.001). We found maximum correlation in type A3, A4 and B3 injuries: ‒0.93, ‒0.91 and ‒0.97, respectively (p &lt; 0.001). And types A1 and A2 injuries demonstrated statistically insignificant relationship (p &gt; 0.05). Conclusions. The results show that traumatic injury of the subaxial cervical spine is characterized by a wide range of kyphotic segmental angulation values, which is largely determined by the type of injury. General cervical lordosis tends to flatten in most cases, but the degree of physiological curvature loss correlates with local deformation to some extent.

Оцінка рівня нестабільності ушкоджень, класифікованих за AOSpine Subaxial Cervical Spine Injury Classification System

Актуальність. При визначенні спрямованості та обсягу хірургічного лікування у хворих із травматичним ушкодженням шийного відділу на субаксіальному рівні основними є такі критерії: характер і ступінь ушкодження остеолігаментозного апарату шийного відділу хребта, що визначає рівень нестабільності; ступінь компресії структур хребетного каналу; стан сагітального профілю. Метою цієї роботи є оцінка ступеня нестабільності різних типів ушкоджень шийного відділу хребта, класифікованих відповідно до AOSpine Subaxial Cervical Spine Injury Classification System. Матеріали та методи. Проведено ретроспективний аналіз даних спондилограм, комп’ютерних і магнітно-резонансних томограм 168 пацієнтів із травматичним ушкодженням шийного відділу хребта на субаксіальному рівні, які перебували на стаціонарному лікуванні у відділенні патології спинного мозку ДУ «Інститут нейрохірургії ім. акад. А.П. Ромоданова НАМН України» в період з 2008 по 2018 р. Виконувалася кількісна оцінка ступеня нестабільності із застосуванням Cervical Spine Injury Severity Score і визначення типу ушкодження згідно з AOSpine Subaxial Cervical Spine Injury Classification System. Результати. Виявлено, що медіана показника нестабільності прогресивно наростає зі збільшенням ступеня тяжкості типу ушкодження. Найбільш широкий діапазон значень показника рівня нестабільності відзначається при компресійному типі ушкоджень: від 6 балів (95% довірчий інтервал (ДІ) 4,76–6,84) при типі А1 до 11 балів (95% ДІ 9,48–11,81) при А4. Для типів А2 і А3 зареєстровано 7 балів (95% ДІ 6,68–7,53) і 8 балів (95% ДІ 7,97–9,01) відповідно. Флексійно-екстензійні ушкодження характеризуються меншим діапазоном значень. Медіана прогресивно зростає від типу В1 — 13 балів (95% ДІ 12,4–13,92) до B3 — 15,5 бала (95% ДІ 14,5–16,35). Показник для В2 займає проміжне значення і становить 15 (95% ДІ 13,59–15,52). Максимальні значення при згинально-розгинальних ушкодженнях — 18 балів, зареєстровані як при типі В2, так і В3. Тип С демонструє найбільший рівень нестабільності — 17 балів (95% ДІ 16,58–17,86) та досить широкий діапазон розрахованих значень — від 13 до 20 балів. Висновки. Загальною тенденцією є збільшення рівня нестабільності в низці підтипів від А1 до С, проте навіть ушкодження типу А1 за певних умов виявляються досить нестабільними і вимагають хірургічного втручання. На противагу класичним уявленням ушкодження типу А досить часто супроводжуються ураженням фасеткових суглобів, що також необхідно враховувати при визначенні індивідуальної тактики терапії постраждалих.

A Prognostic Factor for Prolonged Mechanical Ventilator-Dependent Respiratory Failure after Cervical Spinal Cord Injury : Maximal Canal Compromise on Magnetic Resonance Imaging

ObjectiveThe period of mechanical ventilator (MV)-dependent respiratory failure after cervical spinal cord injury (CSCI) varies from patient to patient. This study aimed to identify predictors of MV at hospital discharge (MVDC) due to prolonged respiratory failure among patients with MV after CSCI. MethodsTwo hundred forty-three patients with CSCI were admitted to our institution between May 2006 and April 2018. Their medical records and radiographic data were retrospectively reviewed. Level and completeness of injury were defined according to the American Spinal Injury Association (ASIA) standards. Respiratory failure was defined as the requirement for definitive airway and assistance of MV. We also evaluated magnetic resonance imaging characteristics of the cervical spine. These characteristics included : maximum canal compromise (MCC); intramedullary hematoma or cord transection; and integrity of the disco-ligamentous complex for assessment of the Subaxial Cervical Spine Injury Classification (SLIC) scoring. The inclusion criteria were patients with CSCI who underwent decompression surgery within 48 hours after trauma with respiratory failure during hospital stay. Patients with Glasgow coma scale 12 or lower, major fatal trauma of vital organs, or stroke caused by vertebral artery injury were excluded from the study. ResultsOut of 243 patients with CSCI, 30 required MV during their hospital stay, and 27 met the inclusion criteria. Among them, 48.1% (13/27) of patients had MVDC with greater than 30 days MV or death caused by aspiration pneumonia. In total, 51.9% (14/27) of patients could be weaned from MV during 30 days or less of hospital stay (MV days : MVDC 38.23±20.79 vs. MV weaning, 13.57±8.40; p<0.001). Vital signs at hospital arrival, smoking, the American Society of Anesthesiologists classification, Associated injury with Injury Severity Score, SLIC score, and length of cord edema did not differ between the MVDC and MV weaning groups. The ASIA impairment scale, level of injury within C3 to C6, and MCC significantly affected MVDC. The MCC significantly correlated with MVDC, and the optimal cutoff value was 51.40%, with 76.9% sensitivity and 78.6% specificity. In multivariate logistic regression analysis, MCC >51.4% was a significant risk factor for MVDC (odds ratio, 7.574; p=0.039). ConclusionAs a method of predicting which patients would be able to undergo weaning from MV early, the MCC is a valid factor. If the MCC exceeds 51.4%, prognosis of respiratory function becomes poor and the probability of MVDC is increased.

257. Patient specific predictive factors of vertebral artery injury following blunt cervical spine trauma

<h3>BACKGROUND CONTEXT</h3> Computed topography angiography (CTA) is routinely used in evaluation for vascular injury in patients that have sustained blunt cervical spine trauma. Current screening criteria often leads to over utilization of imaging in patients who are already receiving antithrombic therapy or have clear contraindications due to concomitant injuries. <h3>PURPOSE</h3> This study sought to identify patient and injury characteristics predictive of vascular injury (VAI) in blunt cervical spine trauma in order to identify high-risk patients and propose alternative screening criteria. <h3>STUDY DESIGN/SETTING</h3> This was a retrospective cohort study collected from patients presenting for blunt cervical spine injury between 2014-2018 at a level I trauma tertiary care center. <h3>PATIENT SAMPLE</h3> A total of 475 patients over the age of 18 who sustained blunt cervical spine trauma and had available cervical spine CT were included in analysis. <h3>OUTCOME MEASURES</h3> 1) Incidence of vertebral artery injuries (VAI) in blunt cervical spine injury. 2) In patients with VAI, percentage of patients with contraindication to anti-platelet therapy OR receiving anti-platelet therapy prior to injury. 3) In patients with VAI, percentage of patients that developed acute kidney injury. 4) Injury and patient characteristics associated with higher risk of sustaining VAI. <h3>METHODS</h3> This was a retrospective cohort study collected from patients presenting for blunt cervical spine injury between 2014-2018. Patients were included who sustained a cervical spine injury and cervical spine CT was available. Demographics including age, gender, outpatient aspirin use, presence of kidney disease was recorded. Injury characteristics including mechanism of action, level of cervical spine injury, type of injury, concomitant thoracic and/or lumbar spine injury, if CTA was obtained, presence of VAI, operative interventions, and subaxial-cervical spine injury classification (SLIC) was collected. Data was evaluated using univariate and multivariate analyses to determine risk factors for VAI. <h3>RESULTS</h3> A total of 475 patients were included, average age 60.2 years. Motor vehicle accident was the most common cause of injury in 225 (47.4%) patients. CTA of the neck was performed in 264 (55.5%) patients. In patients who received CTA, 48 (18.2%) had a contraindication to receiving anti-platelet therapy and 66 (25%) were already receiving anti-platelet therapy as an outpatient medication. 26 (5.5%) patients were found to have VAI, and in patients with VAI, 4 (14.3%) patents were already receiving ASA as an outpatient medication, and no patients required secondary vascular interventions. Acute kidney injury was found in 28 (10.5%) patients who had received CTA. Factors associated with greater odds of having VAI included transverse foramen involvement (OR4.27, CI 2.05-8.89, p=0.0001), multilevel cervical spine fractures (OR2.09, CI 0.97-4.99), subluxation/displacement/dislocation of fracture (OR2.23, CI 1.08-4.59,p=0.03), high energy mechanism (OR2.38, CI 1.14-4.96), SLIC score >4 (OR2.65, CI 1.07-6.55,p=0.04), and concomitant lumbar spine injury (OR4.37, CI 1.13-16.9,p=0.03). <h3>CONCLUSIONS</h3> Updated protocols utilizing evidence-based clinical parameters to predict chance of VAI may avoid unnecessary advanced imaging and contrast load to patients in the setting of blunt cervical spine trauma. Further prospective studies are needed to determine if identified risk factors could be used as specific screening criteria to identify high-risk patients who would benefit most from further advanced imaging. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Variation in global treatment for subaxial cervical spine isolated unilateral facet fractures

PurposeTo determine the variation in the global treatment practices for subaxial unilateral cervical spine facet fractures based on surgeon experience, practice setting, and surgical subspecialty.MethodsA survey was sent to 272 members of the AO Spine Subaxial Injury Classification System Validation Group worldwide. Questions surveyed surgeon preferences with regard to diagnostic work-up and treatment of fracture types F1–F3, according to the AO Spine Subaxial Cervical Spine Injury Classification System, with various associated neurologic injuries.ResultsA total of 161 responses were received. Academic surgeons use the facet portion of the AO Spine classification system less frequently (61.6%) compared to hospital-employed and private practice surgeons (81.1% and 81.8%, respectively) (p = 0.029). The overall consensus was in favor of operative treatment for any facet fracture with radicular symptoms (N2) and for any fractures categorized as F2N2 and above. For F3N0 fractures, significantly less surgeons from Africa/Asia/Middle East (49%) and Europe (59.2%) chose operative treatment than from North/Latin/South America (74.1%) (p = 0.025). For F3N1 fractures, significantly less surgeons from Africa/Asia/Middle East (52%) and Europe (63.3%) recommended operative treatment than from North/Latin/South America (84.5%) (p = 0.001). More than 95% of surgeons included CT in their work-up of facet fractures, regardless of the type. No statistically significant differences were seen in the need for MRI to decide treatment.ConclusionConsiderable agreement exists between surgeon preferences with regard to unilateral facet fracture management with few exceptions. F2N2 fracture subtypes and subtypes with radiculopathy (N2) appear to be the threshold for operative treatment.

Correlation of blunt cervical spinal cord injury magnetic resonance imaging tractography with the American Spinal Injury Association impairment scale motor scores.

BackgroundThe introduction of the Subaxial Cervical Spine Injury Classification system has created the need for a holistic imaging approach that encompasses both functional (neurological) and morphological information.ObjectivesThis study aimed to determine if there was a correlation between the blunt cervical spinal cord injury diffusion tensor imaging (DTI) fraction anisotropy (FA) value and the American Spine Injury Association (ASIA) impairment scale motor score.MethodDiffusion tensor imaging was performed on 26 patients with blunt cervical spine injury (all men with a median age of 46 years) admitted to the Pelonomi Tertiary Hospital spinal unit. Imaging was performed using the 1.5T Siemens Magnetom Aera machine’s built-in spine DTI protocol. Sagittal FA values were acquired at four different cervical spine regions (medulla oblongata, above the injury site, at the injury site and below the injury site).ResultsEight of the 26 patients had complete neurological fallout. Of the participants, 30% had injuries at the C4/C5 level, whilst injuries involving segments below and above C4/C5 affected 15% and 55% of participants, respectively. Injury site FA values (median 0.30) were significantly lower (p < 0.001) than the above injury site FA (median 0.46, p = 0.26) and below injury site FA (median 0.42 and p = 0.019). A significant correlation was noted between the injury site FA values and the ASIA impairment scale motor scores (p = 0.001, r = 0.87).ConclusionFA value showed excellent correlation with the ASIA impairment scale motor scores.

The classifications of subaxial cervical spine traumatic injuries. Part 4. AOSpine Subaxial Classification System

Cervical spine injuries are a fairly common consequence of mechanical impact on the human body. The subaxial level of the cervical spine accounts for approximately half to 2/3 of these injuries. Despite the numerous classification systems that exist for describing these injuries, the recommendations for treatment strategy are very limited, and currently none of them is universal and generally accepted. Consequently, treatment decisions are based on the individual experience of the specialist, but not on evidence or algorithms. While the classification system based on the mechanism of trauma originally proposed by B.L. Allen et al. and subsequently modified by J.H. Harris Jr et al., was comprehensive, but lacked evidence, which to some extent limited its clinical applicability. Similarly, the Subaxial Injury Classification System proposed by the Spine Trauma Group, had no distinct and clinically significant patterns of morphological damage. This fact hindered the standardization and unification of tactical approaches. As an attempt to solve this problem, in 2016 Alexander Vaccaro, together with AO Spine, proposed the AO Spine subaxial cervical spine injury classification system, using the principle of already existing AOSpine classification of thoracolumbar injuries. The aim of the project was to develop an effective system that provides clear, clinically relevant morphological descriptions of trauma patterns, which should contribute to the determination of treatment strategy. The proposed classification of cervical spine injuries at the subaxial level follows the same hierarchical approach as previous AO classifications, namely, it characterizes injuries based on 4 parameters: (1) injury morphology, (2) facet damage, (3) neurological status, and (4) specific modifiers. The morphology of injuries is divided into 3 subgroups of injuries: A (compression), B (flexion-distraction), and C (dislocations and displacements). Damage types A and B are divided into 5 (A0-A4) and 3 (B1-B3) subtypes, respectively. When describing damage of the facet joints, 4 subtypes are distinguished: F1 (fracture without displacement), F2 (unstable fracture), F3 (floating lateral mass) and F4 (dislocation). The system also integrates the assessment of neurological status, which is divided into 6 subtype). In addition, the classification includes 4 specific modifiers designed to better detail a number of pathological conditions. The performance evaluation of AOSpine SCICS showed a moderate to significant range of consistency and reproducibility. Currently, a quantitative scale for assessing the severity of classification classes has been proposed, which also, to a certain extent, contributes to decision-making regarding treatment strategy.

CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?

Cross-sectional survey. Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture. A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures. There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%. Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures.

Traumatic subaxial cervical spine injury - Improving initial evaluation through correlation of diffusion tensor imaging and subaxial cervical spine injury classification SLIC score.

Background: Traumatic injury to spine and spinal cord represents a devastating condition, with a huge risk for permanent severe disabilities. Predicting the long-term outcome in this type of trauma is a very difficult task being under the influence of a wide spectrum of biomechanical and pathophysiological factors. The advent of magnetic resonance imaging (MRI) structural evaluation of the spinal cord brought critical supplementary data in the initial evaluation of these cases. Although edema and hemorrhage proved to be valuable in predicting the outcome, there is a well-documented discrepancy between MRI findings and clinical status.Methods: We performed diffusion tensor imaging (DTI) MR in 22 symptomatic patients with traumatic cervical spine injuries (mean age 49.6 ± 16, range from 17 to 74 years, 20 males and 2 females). DTI parameters were computed in 15 patients. Regional apparent diffusion coefficient, fractional anisotropy (FA), and fiber length (FL) were calculated in the region of interest defined as the region of maximum structural MR alterations and in the normal cord (above or below the level of the injury). The values for normal and pathological cord were compared. The clinical deficit was assessed with ASIA and subaxial cervical spine injury classification (SLIC) scores. We looked at the correlation between the DTI measures and clinical scores.Results: There is a highly significant difference between normal and pathological spinal cord for all DTI properties measured. There is also a strong correlation between DTI measures and SLIC clinical score, especially for FA. Significant results were obtained for CDA and FL as well although with lesser statistical power.Conclusion: Our results suggest that DTI measures, especially FA, represent a strong indicator of the severity of the traumatic cervical cord injury. It correlates very well with SLCI score and can be used as an additional confirmation of the real degree of level lesioning and as a prognostic factor for the neurological outcome regardless of the choice of treatment.

Subaxial Cervical Spine Injuries: WFNS Spine Committee Recommendations.

To formulate specific guidelines for the recommendation of subaxial cervical spine injuries concerning classification, management, posttraumatic locked facets and vertebral artery injury. Computerized literature was searched on PubMed and google scholar database from 2009 to 2020. For classification, keywords “Sub Axial Cervical Spine Classification,” resulting in 22 articles related to subaxial cervical spine injury classification system (SLICS) system and 11 articles related to AO (Arbeitsgemeinschaft für Osteosynthesefragen, German for “Association for the Study of Internal Fixation”) Spine system. The literature search yielded 210 and 78 articles on “management of subaxial cervical spine injuries” and the role of “SLICS” and “AO Spine” respectively. Keywords “management of traumatic facet locks” were searched and closed reduction, traction, approaches and techniques were studied. “Vertebral artery injury and cervical fracture” exhibited 2,328 references from the last 15 years. The objective was to identify the appropriate diagnostic tests and optimal treatment. Up-to-date information was reviewed, and statements were produced to reach a consensus in 2 separate consensus meetings of World Federation of Neurosurgical Societies (WFNS) Spine Committee. The statements were voted and reached a positive or negative consensus using Delphi method. Based on the most relevant literature, panelists in Moscow consensus meeting conducted in May 2019 drafted the statements, and after a preliminary voting session, the consensus was identified on various statements. Another meeting was conducted at Peshawar in November 2019, where in addition to previous statements, few other statements were discussed and voted. Specific recommendations were then formulated guiding classification, management, locked facets and vertebral artery injuries. This review summarizes the WFNS Spine Committee recommendations on subaxial cervical spine injuries.

Establishing the Injury Severity of Subaxial Cervical Spine Trauma: Validating the Hierarchical Nature of the AO Spine Subaxial Cervical Spine Injury Classification System.

Study Design.Global cross-sectional survey.Objective.The aim of this study was to validate the AO Spine Subaxial Cervical Spine Injury Classification by examining the perceived injury severity by surgeon across AO geographical regions and practice experience.Summary of Background Data.Previous subaxial cervical spine injury classifications have been limited by subpar interobserver reliability and clinical applicability. In an attempt to create a universally validated scheme with prognostic value, AO Spine established a subaxial cervical spine injury classification involving four elements: injury morphology, facet injury involvement, neurologic status, and case-specific modifiers.Methods.A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. Respondents graded the severity of each variable of the classification system on a scale from zero (low severity) to 100 (high severity). Primary outcome was to assess differences in perceived injury severity for each injury type over geographic regions and level of practice experience.Results.A total of 189 responses were received. Overall, the classification system exhibited a hierarchical progression in subtype injury severity scores. Only three subtypes showed a significant difference in injury severity score among geographic regions: F3 (floating lateral mass fracture, P = 0.04), N3 (incomplete spinal cord injury, P = 0.03), and M2 (critical disk herniation, P = 0.04). When stratified by surgeon experience, pairwise comparison showed only two morphological subtypes, B1 (bony posterior tension band injury, P = 0.02) and F2 (unstable facet fracture, P = 0.03), and one neurologic subtype (N3, P = 0.02) exhibited a significant difference in injury severity score.Conclusion.The AO Spine Subaxial Cervical Spine Injury Classification System has shown to be reliable and suitable for proper patient management. The study shows this classification is substantially generalizable by geographic region and surgeon experience, and provides a consistent method of communication among physicians while covering the majority of subaxial cervical spine traumatic injuries.Level of Evidence: 4

The Subaxial Cervical AO Spine Injury Score.

Study Design:Global cross-sectional survey.Objective:To develop an injury score for the AO Spine Subaxial Cervical Spine Injury Classification System.Methods:Respondents numerically graded each variable within the classification system for severity. Based on the results, and with input from the AO Spine Trauma Knowledge Forum, the Subaxial Cervical AO Spine Injury Score was developed.Results:An A0 injury was assigned an injury score of 0, A1 a score of 1, and A2 a score of 2. Given the significant increase in severity, A3 was given a score of 4. Based on equal severity assessment, A4 and B1 were both assigned a score of 5. B2 and B3 injuries were assigned a score of 6. Unstable C-type injuries were given a score of 7. Stable F1 injuries were assigned a score of 2, with a 2-point increase for F2 injuries. Likewise, F3 injuries received a score of 5, whereas more unstable F4 injuries a score of 7. Neurologic status severity rating scores increased stepwise, with scores of 0 for N0, 1 for N1, and 2 for N2. Consistent with the Thoracolumbar AO Spine Injury Score, N3 (incomplete) and N4 (complete) injuries were given a score of 4. Finally, case-specific modifiers M1 (PLC injury) received a score of 1, while M2 (critical disc herniation) and M3 (spine stiffening disease) received a score of 4.Conclusions:The Subaxial Cervical AO Spine Injury Score is an easy-to-use metric that can help develop a surgical algorithm to supplement the AO Spine Subaxial Cervical Spine Injury Classification System.

Classification in Brief: Subaxial Cervical Spine Injury Classification and Severity Score System.

Classification in Brief: Subaxial Cervical Spine Injury Classification and Severity Score System.

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.

Study Design:A multicenter observational survey.Objective:To quantify and compare inter- and intraobserver reliability of the subaxial cervical spine injury classification (SLIC) and the cervical spine injury severity score (CSISS) in a multicentric survey of neurosurgeons with different experience levels.Methods:Data concerning 64 consecutive patients who had undergone cervical spine surgery between 2013 and 2017 was evaluated, and we surveyed 37 neurosurgeons from 7 different clinics. All raters were divided into 3 groups depending on their level of experience. Two assessment procedures were performed.Results:For the SLIC, we observed excellent agreement regarding management among experienced surgeons, whereas agreement among less experienced neurosurgeons was moderate and almost twice as unlikely. The sensitivity of SLIC relating to treatment tactics reached as high as 92.2%. For the CSISS, agreement regarding management ranged from medium to substantial, depending on a neurosurgeon’s experience. For less experienced neurosurgeons, the level of agreement concerning surgical management was the same as for the SLIC in not exceeding a moderate level. However, this scale had insufficient sensitivity (slightly exceeding 50%). The reproducibility of both scales was excellent among all raters regardless of their experience level.Conclusions:Our study demonstrated better management reliability, sensitivity, and reproducibility for the SLIC, which provided moderate interrater agreement with moderate to excellent intraclass correlation coefficient indicators for all raters. The CSISS demonstrated high reproducibility; however, large variability in answers prevented raters from reaching a moderate level of agreement. Magnetic resonance imaging integration may increase sensitivity of CSISS in relation to fracture management.