AO Spine Thoracolumbar and Sacral Injury Classification for the Radiologist

Over 1000 patients with traumatic paraplegia or tetraplegia and many more with fractures and dislocations of the spine without damage to the central nervous system have been observed and treated at the Sheffield Spinal Injuries Centre. The vertebral lesions with or without injury to the spinal cord or nerve roots have been classified on the basis of the clinical and roentgenographic findings into five groups: 1. Pure flexion which causes a wedge fracture which is stable. 2. Flexion-rotation which produces an unstable fracture-dislocation with rupture of tue posterior ligament complex, separation of the spinous processes, a slice fracture near the upper border of the lower vertebra, and dislocation of the lower articular processes of the upper vertebra. 3. Extension which causes rupture of the intervertebral disc and the anterior common ligament along with avulsion of a small bone fragment from the anterior border of the dislocated vertebra. The dislocation almost always reduces spontaneously and is stable in flexion. 4. Vertebral compression which results in a fracture of the end plate as the nucleus of the intervertebral disc is forced into the vertebral body and causes it to burst with outward displacement of fragments of the body. Since the ligaments remain intact this comminuted fracture is stable. 5. Shearing which results in forward displacement of the whole vertebra and an unstable fracture of the articular processes or pedicles. Accurate diagnosis and prognosis of the neurological lesion depend on knowledge of the anatomy of the spinal cord and nerve roots, a careful neurological examination shortly after the original injury and repeated examinations thereafter, comparison of the level of spinal injury with the level of paraplegia or tetraplegia, differentiation between paraplegia and tetraplegia of immediate and delayed onset, and the appropriate therapy of the various types and levels of lesion. Simple wedge fractures were treated by bed rest for two to three weeks, mobilization of the back, and ambulation with a back support. Rotational fracture-dislocations in the cervical, thoracolumbar, or lumbar spine were almost invariably associated with tetraplegia or paraplegia. Cervical fracture-dislocations with or without tetraplegia were treated by skull-caliper traction. Thoracolumbar or lumbar fracture-dislocations without paraplegia were treated on a plaster bed for twelve weeks followed by a back support for a few weeks. The thoracolumbar fracture-dislocations with paraplegia were never treated by the plaster bed method but rather by open reduction of the dislocation, and maintenance of the reduction by internal fixation with double plating of the spinous processes. Spontaneous fusion was sufficiently advanced after eight to twelve weeks to get the patient out of bed. If the plates cut out of the bone after twelve weeks, they were removed. Patients with loss of sensation resulting from paraplegia or tetraplegia were turned every two hours to avoid pressure sores. Extension dislocations in the cervical spine, if they had reduced spontaneously, were fitted with a collar to hold the head and neck in sligh flexion for a period of eight to twelve weeks. For dislocations in this region which had not reduced spontaneously, manual manipulation under endotracheal anesthesia was employed. Reduction was maintained by skull tongs applied prior to manipulation. If after four weeks there was roentgenographic evidence of new bone indicating Spontaneous fusion, traction was continued for four to six weeks more followed by a neck collar for an additional six weeks. If new bone did not appear on the roentgenograms after four weeks, anterior fusion was performed followed by skull traction for an additional eight weeks. Vertical compression burst fractures in the cervical spine were treated by skull traction for six weeks followed by a neck collar. In the lumbar spine, burst fractures without paraplegia were treated by immobilization in a plaster bed for eight to twelve weeks followed by back support. The plaster bed was never used in burst fractures with paraplegia. Shear fractures were always associated with complete paraplegia. These fractures were usually stable and did not require operative reduction except when the displacement was great.

Objective: To compare the treatment recommendations of the thoracolumbar injury classification and severity score system and the thoracolumbar Arbeitsgemeinschaft für Osteosynthesefragen spine injury score in case of thoracolumbar spine injury. Method: The cross-sectional study was conducted at the Shaheed Mohtarma Benazir Bhutto Institute of Trauma, Karachi, from July to December 2023, and comprised patients aged at least 18 irrespective of gender, who had traumatic thoracic and lumbar vertebral spine fractures. Data regarding age, gender, mode of trauma, findings of neurological examination and imaging was collected. All cases were independently scored by an experienced spine surgeon, and a radiologist provided standardised imaging interpretation. The scorers were blinded to clinical outcomes and treatment decisions. Inter-rater agreement between thoracolumbar injury classification and severity score system and the thoracolumbar Arbeitsgemeinschaft für Osteosynthesefragen spine injury score was assessed using Cohen's kappa coefficient. Data was analysed using SPSS 23. Results: Of the 335 patients with mean age 32.24±13.32 years, 279(83.3%) were males. The most common mode of trauma was fall from height 189(56.4%), and the most common site of fracture was L1 vertebrae 109(32.5%). Based on the thoracolumbar injury classification and severity score system, the most common fracture morphology was burst fracture 257(76.7%). The most common fracture type based on the thoracolumbar Arbeitsgemeinschaft für Osteosynthesefragen spine injury score was Type A compression injuries 300(89.6%). The thoracolumbar Arbeitsgemeinschaft für Osteosynthesefragen spine injury score had more patients in the grey zone 30(9%) compared to thoracolumbar injury classification and severity score system 22(6.6%). Treatment recommendations were the same in both the classification systems for 306(91.3%) patients (Cohen's kappa = 0.812, p<0.001). Conclusion: There was no significant difference between the treatment recommendations suggested by the thoracolumbar injury classification and severity score system and the thoracolumbar Arbeitsgemeinschaft für Osteosynthesefragen spine injury score. The differences in grey zone classification highlighted the complexity of thoracolumbar injury assessment. Key Words: TLICSS, TLAOSIS, Thoracolumbar spine, Fracture.

Reliability and Clinical Usefulness of Current Classifications in Traumatic Thoracolumbar Fractures: A Systematic Review of the Literature.

Chapter 22 - Biomechanics of Vertebral Fractures and Their Treatment

The aim of this multicentre study was to determine whether the recently introduced AOSpine Classification and Injury Severity System has better interrater and intrarater reliability than the already existing Thoracolumbar Injury Classification and Severity Score (TLICS) for thoracolumbar spine injuries. 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 6weeks, 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. Recently 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.

Spinal trauma in DISH and AS: is MRI essential following the detection of vertebral fractures on CT?

BackgroundThe thoracic segment represents the most common area fractured in the whole spine. Complete neurological deficits are commonly associated with thoracic injuries possibly due to a relatively small canal diameter as compared to the cervical or lumbar spine. Magnetic resonance is the gold standard of imaging, especially in patients suffering from neurological deficits as well as in soft tissue assessment mainly the disc, ligaments, and neural elements. The thoracolumbar injury classification and severity score system (TLICS) and the thoracolumbar AO Spine injury score (TLAOSIS), are two scoring systems designed to help surgeons in management plans of thoraco-lumbar injuries. The aim of our study is to compare these two main thoracolumbar injury classification systems in deciding the management strategies in thoraco-lumbar injuries. This study is a retrospective study that included 70 patients (42 males and 28 females) who suffered acute traumatic vertebral fractures. All patients underwent MRI including T1WI, T2W and STIR sequences. The MRI was viewed by two independent radiologists of 5- and 10-years’ experience and compared to surgical decisions.ResultsOut of 70 patients included in our study, the TL AOSIS matched treatment recommendation in 62 patients (88.6%), and the TLICS matched in 60 patients (85.7%). The TL AOSIS achieved sensitivity 95%, specificity 80%, while the TLICS achieved sensitivity 72.2%, specificity 100%.ConclusionBoth TL AOSIS and TLICS have very close results in their reliability for guiding treatment strategy, yet TL AOSIS matched treatment recommendation more than TLICS, with sensitivity more than TLICS, while TLICS had more specificity.

Retrospective Cohort Study. To determine how historical management of thoracolumbar spine injuries compares to the recently proposed AO Spine Thoracolumbar Injury Classification System treatment algorithm. Classifications of the thoracolumbar spine are not uncommon. The frequent advent of new classifications is typically due to previous classifications being primarily descriptive or unreliable. Thus, AO Spine created a classification with an associated treatment algorithm to guide injury classification and management. Thoracolumbar spine injuries were retrospectively identified from a prospectively collected spine trauma database at a single, urban, academic medical center during the years 2006 to 2021. Each injury was classified and assigned points based on the AO Spine Thoracolumbar Injury Classification System injury severity score. Patients were grouped into scores of 3 or less (preferred initial conservative treatment) and greater than 6 (preferred initial surgical intervention). Either operative or non-operative treatment was considered appropriate for injury severity scores of 4 or 5. A total of 815 patients (TL AOSIS 0-3: 486, TL AOSIS 4-5: 150, TL AOSIS 6+: 179) met inclusion status. Injury severity scores of 0-3 were more likely to undergo non-operative management compared to scores of 4-5 or 6+ (99.0% vs. 74.7% vs. 13.4%, P <0.001). Thus, guideline congruent treatment was 99.0%, 100%, and 86.6%, respectively ( P <0.001). Most injuries determined to be a 4 or 5 were treated non-operatively (74.7%). Based on the treatment algorithm, 97.5% of patients who received operative treatment and 96.1% who received non-operative treatment were managed in accordance with the algorithm. Of the 29 patients who did not receive algorithm congruent treatment, 5 (17.2%) were treated surgically. A retrospective review of thoracolumbar spine injuries at our urban academic medical center identified that patients are historically treated in accordance with the proposed AO Spine Thoracolumbar Injury Classification System treatment algorithm.

OBJECTIVE:To evaluate the epidemiology of thoracolumbar spine injuries when travelling by speedboat to our coastal tertiary trauma center, and to identify injury patterns and mechanism of injury of these specific injuries and to determine the link of the position when seated on board with the risk of thoracolumbar injury in this type of transportation.MATERIALS AND METHODS:A retrospective review of a consecutive series of 80 patients sustaining thoracolumbar spine injuries after travelling by speed boat was conducted. The enrolled patients were treated at a Level II trauma center over a 2-year period from July 1, 2016 to May 31, 2018. All the victims were unrestrained passengers on board a speedboat travelling at high speed without any safety regulation except a life jacket. Initially, a full evaluation with advance trauma life support protocol on arrival was performed. Plain radiographs, computed thermography or MRI study was obtained individually. Number, level and type of thoracolumbar injury were recorded and reported based on CT scan and Thoracolumbar Injury Classification by AO group. The link to the position when seated on board with the incidence of thoracolumbar spine injury was then analyzed and compared relatively.RESULTS:There were a total of 80 patients in our study, 48 (60%) were men and 32 (40%) were women with a mean age of 47.50 years (Min 20, Max 71). All the spinal fractures were a single level injury. The injury occurred only at the thoracolumbar area, these involved 6 cases (7.5%) of T11 vertebra, 20 cases (25%) of T12 vertebra, 44 cases (55%) of L1 vertebra and 10 cases (12.5%) of L2 vertebra respectively. No cervical or sacral region injury was observed nor other associated injuries such as traumatic brain injury, intra-abdominal organ injury or long bone fracture. A spinal cord/nerve root injury occurred in the lumbar region in 1 patient (1.25%). All of the 80 injuries were type A injury (compression type), classified by AO Spine Thoracolumbar Injury Classification, and included 32 levels (40%) of subtype A1, 18 levels (22.5%) of subtype A2, 8 levels (10%) of subtype A3 and 22 levels (27.5%) of subtype A4. 50 cases (62.5%) were treated non-operatively with bracing while 30 cases (37.5) were treated operatively with computer navigation spinal surgery using pedicle screws and rods construction before the patient was discharged or repatriated. Patients who sat in the front row seat were significantly at higher risk for thoracolumbar spine injury (p &lt; 0.05; odds ratio = 41.83; 95%CI: 15.24, 114.8). No patient who sat at the rear reported having had this kind of injury.CONCLUSIONS:Our data shows a high incidence of this unique compressive type of thoracolumbar spine injury in patients who sit in the front row seat while travelling on board a speed boat.As a result of an increasing recognition of these regional-specific injuries, practitioners who take responsibility for trauma patients on the coastal area should be aware of the high prevalence of these injuries. Proper universal spinal precautions must be followed to optimize treatment outcomes. Current safety regulations including speed limits, proper safety restraining techniques, bracing position on board and marine rescuers should be reviewed or changed to minimize the number of injuries and degree of damage.

BackgroundAcute vertebral fracture is usually caused by low-energy injury with osteoporosis and high-energy trauma. The AOSpine thoracolumbar spine injury classification system (AO classification) plays an important role in the diagnosis and treatment of the disease. The diagnosis and description of vertebral fractures according to the classification scheme requires a great deal of time and energy for radiologists.PurposeTo design and validate a multistage deep learning system (multistage AO system) for the automatic detection, localization and classification of acute thoracolumbar vertebral body fractures according to AO classification on computed tomography.Materials and MethodsThe CT images of 1,217 patients who came to our hospital from January 2015 to December 2019 were collected retrospectively. The fractures were marked and classified by 2 junior radiology residents according to the type A standard in the AO classification. Marked fracture sites included the upper endplate, lower endplate and posterior wall. When there were inconsistent opinions on classification labels, the final result was determined by a director radiologist. We integrated different networks into different stages of the overall framework. U-net and a graph convolutional neural network (U-GCN) are used to realize the location and classification of the thoracolumbar spine. Next, a classification network is used to detect whether the thoracolumbar spine has a fracture. In the third stage, we detect fractures in different parts of the thoracolumbar spine by using a multibranch output network and finally obtain the AO types.ResultsThe mean age of the patients was 61.87 years with a standard deviation of 17.04 years, consisting of 760 female patients and 457 male patients. On vertebrae level, sensitivity for fracture detection was 95.23% in test dataset, with an accuracy of 97.93% and a specificity of 98.35%. For the classification of vertebral body fractures, the balanced accuracy was 79.56%, with an AUC of 0.904 for type A1, 0.945 for type A2, 0.878 for type A3 and 0.942 for type A4.ConclusionThe multistage AO system can automatically detect and classify acute vertebral body fractures in the thoracolumbar spine on CT images according to AO classification with high accuracy.

Objective To evaluate the thoracolumbar injury severity score [ thoracolumbar injury classifica-tion and severity score（TLICS）]and repeatability,and analyze its clinical significance in the treatment of injury of thoracolumbar.Methods The clinical and imaging data of our hospital （thoracolumbar X ray,CT examination,MRI examination） of intact thoracolumbar fractures in 90 patients were retrospectively analyzed ,respectively,TLICS score were made for their site of spinal injury morphology ,neural function and the posterior ligament complex three .Three months after reviewed ,TLICS was analyzed by using Cohen weighted kappa coefficient score .Its repeatability was ana-lyzed.Results According to the TLICS system ,spinal injury body ,nerve function and the integrity of the posterior ligamentous complex were evaluated , respectively, the repeatability coefficient of Kappa , the calculated total to 0.47 non operation group,operation group,the total score was 0.46,with a moderate consistency.The neural function evaluation of the highest high consistency ,consistency .No significant differences between the two groups of repetitive Kappa coefficient（statistical values =0.674 5,P〉0.05）.According to the TLICS system of statistical accuracy ,the diagnostic sensitivity,specificity ratios was 95.8%,86.4%,97.6%,respectively.Conclusion The reliability of TLICS system for thoracolumbar treatment and recovery is higher ,relative comprehensive evaluation ,which can effec-tively guide the clinical treatment . Key words: Spinal injuries; Repeatability,results; Kappa coefficient; Thoracolumbar injury classification and severity score system

P152. Is short segment fracture fixation appropriate for AO spine type B and C injuries?

Retrospective review on prospective cohort and explicit chart review. To identify early spine trauma predictors of functional disability and to assess management compliance to established spine trauma treatment algorithms. Identification of early (within 48 hours) spine trauma predictors of functional disability is novel and may assist in the management of patients with trauma. Also, with significant global variation, spine trauma treatment algorithms are essential. Analysis was performed on patients with spine trauma from May 1, 2009, to January 1, 2011. Functional outcomes were determined using the Glasgow Outcome Scale (GOS) at 1 year. Univariate and multivariate regressions were applied to investigate the effects of the injury severity score, age, blood sugar level, vital signs, traumatic brain injury, comorbidities, coagulation profile, neurology, and spine injury characteristics. A compliance study was performed using the SLIC and TLICS spine trauma algorithms. The completion rate for the GOS was 58.8%. The completed GOS cohort was 4.2 years younger in terms of mean age, had more number of patients with severe polytrauma, but less number of patients with severe spinal cord injuries (ASIA [American Spinal Injury Association] A, B, and C) in comparison with the uncompleted GOS cohort. Multivariate logistic regression revealed 3 independent early spine trauma predictors of functional disability with statistical significance (P < 0.05). They were (1) hypotension (OR [odds ratio] = 1.98; CI [confidence interval] = 1.13-3.49), (2) hyperglycemia (OR = 1.67; CI = 1.09-2.56), and (3) moderate/severe traumatic brain injury (OR = 5.88; CI = 1.71-20.16). There were 305 patients with subaxial cervical spine injuries and 653 patients with thoracolumbar spine injuries. The subaxial cervical spine injury classification and thoracolumbar injury classification and severity score compliance studies returned agreements of 96.1% and 98.9%, respectively. Early independent spine trauma predictors of functional disability identified in a level 1 trauma center with high compliance to the subaxial cervical spine injury classification and thoracolumbar injury classification and severity score algorithms were hypotension, hyperglycemia, and moderate or severe traumatic brain injury. Spine trauma injury variables alone were shown not to be predictive of functional disability. 3.

Objective:The purpose of our study was to identify adult trauma patients with an acute C1 burst fracture, evaluate for concomitant transverse atlantal ligament (TAL) injury, and apply the modified Gehweiler and AO spine classification systems to determine the utility of these classification systems in accurately defining C1 trauma.Materials and Methods:Adult trauma patients with an acute C1 fracture were identified retrospectively using Nuance mPower software. The C1 fracture was described based on whether the fracture involved the anterior arch, posterior arch, lateral mass, medial tubercle, and/or transverse process. If follow-up cervical magnetic resonance imaging (MRI) was performed, the presence and location of an associated TAL injury was recorded. The anatomic location of the C1 burst fracture and TAL injury, if present, were compared with the descriptive classification systems outlined by Gehweiler/Dickman (modified) and the AO Spine society. Any additional osseous trauma of the skull base and C1-C2 was also recorded along with relevant clinical history and management.Results:Thirty-nine patients were identified with an acute C1 burst fracture on cervical computed tomography (CT) with seventy-seven percent of patients undergoing follow-up cervical MRI. Observed fracture patterns were divided into five distinct types based on CT findings and further subdivided based on the integrity of the transverse altantal ligament on MRI. TAL tears were observed exclusively in type 3 fractures (anterior and posterior arch fractures) and type 4 fractures (anterior arch, posterior arch, and lateral mass fractures). The modified Gehweiler classification system failed to accurately describe the anatomic location of the C1 fracture in forty-four percent of patients, whereas the AO spine was too broad and failed to accurately describe fracture location in our cohort.Conclusions:The Gehweiler and AO spine classifications demonstrated significant shortcomings in the accurate description of patients with C1 trauma. Whereas the Gehweiler system did not accurately describe the anatomic location of the various C1 fractures, the AO spine system was too broad and failed to radiologically classify fracture location. Moreover, there was a high number of patients with AO spine type B injuries without atlantoaxial translation that nevertheless required C1-C2 fusion for atlantoaxial instability. We suggest the need for an updated classification system that takes into account both the CT (fracture location) and MRI (TAL integrity) appearance of C1 trauma. An updated classification strategy will offer a radiologic standardization of C1 trauma that will aid in future research studies and help optimize patient management.

Gunshot Spinal Injury: Factors Determining Treatment and Outcome.