Anatomy of the posterior Fossa: a comprehensive description for pediatric brain tumors.

Posterior fossa tumors are the most common pediatric brain tumors, and present unique challenges in terms of their location and surgical management. The posterior fossa comprehends complex anatomy and represents the smallest and deepest of the three cranial base fossae. An in-depth understanding of posterior fossa anatomy is crucial when it comes to the surgical resection of pediatric brain tumors. Mastering the knowledge of posterior fossa anatomy helps the neurosurgeon in achieving a maximal and safe volumetric resection, that impacts in both overall and progression free survival. With the advancements in microsurgery, the telovelar approach has emerged as the workhorse technique for the resection of posterior fossa tumors in pediatric patients. This approach involves meticulously dissecting of the natural clefts present in the cerebellomedullary fissure, making a comprehensive understanding of the underlying anatomy key for its success.

Doing more with less: surgical results of pediatric posterior fossa tumors from a single center in Latin America.

OBJECTIVE: We aim to report the epidemiology, surgical outcomes, and survival rates of pediatric patients with posterior fossa tumors in a large single-center case series. METHODS: A retrospective analysis was conducted on pediatric patients who underwent surgical treatment for posterior fossa tumors between January 2011 and January 2019. RESULTS: A total of 135 pediatric patients, with an average age of 7.5 years at diagnosis and a mean follow-up of 35.7 months, were included in the study. Most tumors were located within the midline, with ventriculomegaly observed in 71.4% of the patients. Pilocytic astrocytomas encompassed the majority of tumors (34.1%), followed by medulloblastomas (27.4%) and ependymomas (11.8%). Gross total resection (GTR) was achieved in 71.8% of the patients, with a recurrence rate of 20%. Surgical complications were observed in 25.9% of the patients. GTR significantly impacted 5-year overall survival (OS) and 4-year progression-free survival (PFS) in patients with posterior fossa tumors. Patients who underwent GTR had a 5-year OS of 89.7%, compared to 72.7% for near-total resection and 70.8% for subtotal resection. The 4-year PFS for patients who underwent GTR was 82.5%, whereas it was 63.6% for patients who underwent near-total resection and 54.2% for patients who underwent subtotal resection. CONCLUSION: Surgical resection remains the main treatment for pediatric posterior fossa tumors, and higher resection rates are linked to better survival outcomes. Despite limited resources for molecular diagnosis, our institution has demonstrated that a specialized neurooncological center with a high surgical volume can still achieve favorable survival outcomes for these patients.

Posterior fossa tumors in children: current insights.

While in adults most intracranial tumors develop around the cerebral hemispheres, 45 to 60% of pediatric lesions are found in the posterior fossa, although this anatomical region represents only 10% of the intracranial volume. The latest edition of the WHO classification for CNS tumors presented some fundamental paradigm shifts that particularly affected the classification of pediatric tumors, also influencing those that affect posterior fossa. Molecular biomarkers play an important role in the diagnosis, prognosis, and treatment of childhood posterior fossa tumors and can be used to predict patient outcomes and response to treatment and monitor its effectiveness. Although genetic studies have identified several posterior fossa tumor types, differing in terms of their location, cell of origin, genetic mechanisms, and clinical behavior, recent management strategies still depend on uniform approaches, mainly based on the extent of resection. However, significant progress has been made in guiding therapy decisions with biological or molecular stratification criteria and utilizing molecularly targeted treatments that address specific tumor biological characteristics. The primary focus of this review is on the latest advances in the diagnosis and treatment of common subtypes of posterior fossa tumors in children, as well as potential therapeutic approaches in the future.   Conclusion: Molecular biomarkers play a central role, not only in the diagnosis and prognosis of posterior fossa tumors in children but also in customizing treatment plans. They anticipate patient outcomes, measure treatment responses, and assess therapeutic effectiveness. Advances in neuroimaging and treatment have significantly enhanced outcomes for children with these tumors. What is Known: • Central nervous system tumors are the most common solid neoplasms in children and adolescents, with approximately 45 to 60% of them located in the posterior fossa. • Multimodal approaches that include neurosurgery, radiation therapy, and chemotherapy are typically used to manage childhood posterior fossa tumors What is New: • Notable progress has been achieved in the diagnosis, categorization and management of posterior fossa tumors in children, leading to improvement in survival and quality of life.

Growing skull fracture in a child with Ehlers-Danlos syndrome: case report and literature review.

INTRODUCTION: Growing skull fracture (GSF) is a rare complication of head trauma in the pediatric population, commonly observed in children younger than 3 years. DISCUSSION: In this report, the authors describe a case of a 3-year-old male child, with clinical features of Ehlers-Danlos syndrome (EDS), who developed a GSF in frontal bone after a crib fall, treated with duraplasty and cranioplasty with autologous craft. Here, pertinent literature was reviewed with an emphasis on surgical techniques, and correlation with the mentioned syndrome. CONCLUSION: This is the first case of GSF in association with EDS in the literature. The relevance of the case described concerns the rarity of the condition itself, the atypical presentation, and the intraoperative findings, which showed the important fragility of the dura mater, probably due to EDS. Therefore, this syndrome, besides having influenced the pathogenesis, was also a challenging factor in the surgical treatment.

Peritoneal metastasis of a brainstem anaplastic ganglioglioma in a 2-year-old boy: case report and literature review.

Anaplastic gangliogliomas (AGG) are rare tumors of the central nervous system (CNS) that commonly affect children and young adults, with an unusual infratentorial presentation, which is related to hydrocephalus and a worse prognosis. We report a case of a brainstem AGG in a 2-year-old boy who underwent a ventriculoperitoneal shunting (VPS) and later presented peritoneal metastasis. We also reviewed the related literature. Even though rare, disease dissemination through VPS should be sought in patients with CNS tumors and VPS who develop new abdominal symptoms. The early diagnosis and intervention may minimize morbidity and improve quality of life of such patients.

The impact of traumatic herniated discs in cervical facets dislocations treatments: systematic review and meta-analysis.

BACKGROUND: Traumatic facet dislocations in the subaxial cervical spine, also known as locked facets, are commonly associated with neurological deficits. The fear of the presence of an associated traumatic disc herniation and consequent neurological worsening usually causes a delay in the spinal realignment. This study's aim is an analysis of safety and efficacy when treating acute cervical traumatic facet dislocations using cranial-cervical traction or posterior open reduction and fixation in the presence of disc herniations. METHODS: Inclusion criteria addressed the following patient groups: (1) MRI diagnosis of traumatic cervical facet dislocations with disc herniation, (2) intervention: either cranial-cervical traction or posterior open reduction and fixation, (4) neurological outcomes after treatment, (5) adult 18 plus years of age, (6) sample sizes greater than 20 patients, (7) English language publication. The following databases and search tools were analyzed: MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and the clinical trial registries (ClinicalTrials.gov), October 2021. RESULTS: Six studies were found, 2 with posterior open reduction and fixation and 4 with cranial-cervical traction, totalizing 197 patients. Neurological worsening was reported only in 1 case (0.5%). CONCLUSIONS: Traumatic disc herniation in cervical facet dislocations is not an absolute contraindication of cranial-cervical traction or posterior open reduction. Early realignment of the spine could bring more neurological benefits than waiting for an MRI or surgical discectomy. However, caution is needed in this review's data interpretation until prospective and well-designed studies are performed.

The effect of filum terminale sectioning for Chiari 1 malformation treatment: systematic review.

PURPOSE: Symptomatic Chiari type I malformation (CM) is treated with posterior fossa decompression with/ without duroplasty. Few authors suggested cerebellar tonsil caudal migration due to a supposed "caudal traction" of cranial nerve structures in a so-called occult tethered cord syndrome. For these authors, filum terminale (FT) sectioning may improve CM symptoms. The objective of this review is to evaluate the effect of FT sectioning on the treatment of CM. METHODS: Using the PRISMA guidelines for systematic reviews, we reviewed studies to evaluate patient's outcomes with CM who underwent FT sectioning. The MINORS instrument was used for methodological quality assessment. The included studies' levels of evidence (LOE) were classified according to the Oxford Centre of Evidence-Based Medicine. RESULTS: Two studies from the same group of authors were included. We cannot assure if the cited cases in the first study were also included in their latter published study. The described results suggest that outcomes were not collected in a standardized fashion. Outcomes are described vaguely as a percentage of improvement. Case series samples were small and included not only patients with CM but also patients with scoliosis and syringomyelia. The MINORS score reported that both studies had low methodological quality. Both included studies were classified as level 4 of evidence. CONCLUSION: There is no scientific support for filum terminale sectioning in patients with CM without evidence of tethered cord. This procedure may be considered experimental and should be validated in a strict criterion of inclusion clinical trial comparing outcomes in posterior fossa decompression.

Osteolysis after cervical disc arthroplasty.

PURPOSE: Cervical disc arthroplasty (CDA) has become an increasingly popular treatment for cervical degenerative disc disease. One potential complication is osteolysis. However, current literature on this topic appears limited. The purpose of this study is to elucidate the incidence, aetiology, consequence, and subsequent treatment of this complication. METHODS: A systematic literature review was performed according to the PRISMA guidelines. Studies discussing the causes, incidence and management of osteolysis after a CA were included. RESULTS: A total of nine studies were included. We divided these studies into two groups: (1) large case series in which an active radiological evaluation for osteolysis was performed (total = six studies), (2) case report studies, which discussed symptomatic cases of osteolysis (total = three). The incidence of asymptomatic osteolysis ranged from 8 to 64%; however, only one study reported an incidence of < 10% and when this case was excluded the incidence ranged from 44 to 64%. Severe asymptomatic bone loss (exposure of the implant) was found in less than 4% of patients. Bone loss from osteolysis appeared to occur early (< 1 year) after surgery and late (> 1 year) as well. Symptomatic patients with osteolysis often required revision surgery. These patients required removal of implant and conversion to fusion in the majority of the cases. CONCLUSIONS: Osteolysis after CDA is common; however, the majority of cases have only mild or asymptomatic presentations that do not require revision surgery. The timing of osteolysis varies significantly. This may be due to differences in the aetiology of osteolysis.

Temporal lobe structural evaluation after transsylvian selective amygdalohippocampectomy.

OBJECTIVE: Mesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy in adolescents and adults, and in 65% of cases, it is related to hippocampal sclerosis (HS). Selective surgical approaches to the treatment of MTLE have as their main goal resection of the amygdala and hippocampus with minimal damage to the neocortex, temporal stem, and optic radiations (ORs). The object of this study was to evaluate late postoperative imaging findings on the temporal lobe from a structural point of view. METHODS: The authors conducted a retrospective evaluation of all patients with refractory MTLE who had undergone transsylvian selective amygdalohippocampectomy (SAH) in the period from 2002 to 2015. A surgical group was compared to a control group (i.e., adults with refractory MTLE with an indication for surgical treatment of epilepsy but who did not undergo the surgical procedure). The inferior frontooccipital fasciculus (IFOF), uncinate fasciculus (UF), and ORs were evaluated on diffusion tensor imaging analysis. The temporal pole neocortex was evaluated using T2 relaxometry. RESULTS: For the IFOF and UF, there was a decrease in anisotropy, voxels, and fibers in the surgical group compared with those in the control group (p < 0.001). An increase in relaxometry time in the surgical group compared to that in the control group (p < 0.001) was documented, suggesting gliosis and neuronal loss in the temporal pole. CONCLUSIONS: SAH techniques do not seem to totally preserve the temporal stem or even spare the neocortex of the temporal pole. Therefore, although the transsylvian approaches have been considered to be anatomically selective, there is evidence that the temporal pole neocortex suffers structural damage and potentially functional damage with these approaches.

Fractional anisotropy of the optic radiations correlates with the visual field after epilepsy surgery.

PURPOSE: This study assessed whether optic radiations (OR) microstructure after temporal lobe epilepsy (TLE) surgery correlated with visual field defects (VFD). METHODS: Patients were subjected to diffusion tensor imaging (DTI) tractography of the OR and Humphrey perimetry after TLE surgery. We used Spearman's test to verify correlations between tractographic parameters and perimetry mean deviation. Tractographic variables were compared between patients with VFD or intact perimetry. Multiple logistic regression was applied between DTI and perimetry values. DTI sensitivity and specificity were assessed with a receiver operating characteristic (ROC) curve to evaluate VFD. RESULTS: Thirty-nine patients had reliable perimetry and OR tractography. There was a significant correlation between (1) fractional anisotropy (FA) and both total (rho = 0.569, p = 0.0002) and quadrant (rho = 0.453, p = 0.0037) mean deviation and (2) radial diffusivity and total mean deviation (rho = - 0.350, p = 0.0286). There was no other significant correlation. Patients with VFD showed a significantly lower FA compared with patients with normal perimetry (p = 0.0055), and a 0.01 reduction in FA was associated with a 44% increase in presenting VFD after surgery (confidence interval, CI = 1.10-1.88; p = 0.0082). Using a FA of 0.457, DTI tractography showed a specificity of 95.2% and a sensitivity of 50% to detect VFD after surgery (area under the curve = 0.7619, CI = 0.6020-0.9218). CONCLUSION: The postoperative OR microstructure correlated with visual loss after epilepsy surgery. DTI postoperative OR tractography may be helpful in evaluating VFD.

Factors affecting diagnosis of primary pediatric central nervous system neoplasias in a developing country.

PURPOSE: Understand the variables that could interfere with diagnosis and prompt treatment in CNS childhood cancer in Brazil, a developing country with continental dimensions. METHODS: From 2005 to 2010, we retrospectively evaluated factors, which could represent a negative influence on the time period elapsing from the onset of symptoms until the diagnosis of the central nervous system (CNS) neoplasia in children and adolescents attended in our service. RESULTS: Two hundred seventeen records were analyzed retrospectively. Factors of the households were evaluated, and this data was related to the time period elapsing from presentation of the first symptoms until the diagnosis of CNS neoplasia. The average time elapsed from the onset of the symptoms until seeking medical assistance was 96 days, and from medical assistance to patient referral to a reference service was 33 days. The symptoms which most contributed to a shorter delay in diagnosis were changes in gait and paresis, mother's occupation, father's education level, patient gender, and living in the state of São Paulo. Besides that, variables such as male gender, mother's education level, and lower patient age were associated with an early diagnosis time. CONCLUSION: There is great difficulty in performing early diagnosis of CNS tumors, partly due to parent's inability to recognize signs and symptoms, and in part due to an educational deficit among healthcare professionals. Identification of measures that can minimize these causes of delay is fundamental to increasing the chance of cure and survival of these patients.

Reliability of the evaluation of posterior ligamentous complex injury in thoracolumbar spine trauma with the use of computed tomography scan.

PURPOSE: The AOSpine thoracolumbar (TL) spine injury classification system is based mainly on computed tomography (CT). The main purpose of this study was to evaluate the reliability of CT scan in the diagnosis of posterior ligamentous complex (PLC) injury in thoracolumbar spine trauma (TLST). METHODS: We performed a cross-sectional study of 43 patients with TLST. CT scans were evaluated independently by three spine surgeons on two separate occasions, 2 months apart. The reliability of PLC injury parameters was assessed by the Kappa coefficient (κ) and the average percentage of these parameters was established. Injuries were classified according to the AOSpine classification as type A (compression), B (anterior and/or posterior tension band injuries) or C (dislocation) injury and the reliability of the classification was calculated. RESULTS: On average, PLC injury was identified in 91.4% of type B or C injuries. Tension band injury and dislocation were found in 90.5% of type B and 93.2% of type C injuries. The intraobserver reliability for the PLC injury parameters ranged from 0.518 to 1.000, except for increased interspinous distance (IID). Interobserver reliability ranged from 0.303 to 0.688. When the patients were evaluated as a whole, dislocation showed the highest κ (0.656 and 0.688). When type A or B injuries were assessed, the highest κ were found for IID (0.533 and 0.511) and tension band injury (0.486 and 0.452). The κ for AOSpine classification was 0.526 and 0.645 in both assessments. CONCLUSIONS: In this study, the use of CT scan as the only diagnostic tool could identify PLC injury in most cases and demonstrated satisfactory reliability. Dislocation could satisfactorily diagnose type C injury, while IID was the best parameter to differentiate between type A and B injuries.

Relationship between spinal alignment and functional disability after thoracolumbar spinal fractures: A systematic review.

Background: Thoracolumbar spinal fractures (TLSF) can cause pain, neurological deficits, and functional disability. Operative treatments aim to preserve neurological function, improve functional status, and restore spinal alignment and stability. In this review, we evaluate the relationship between spinal alignment and functional impairment in patients with TLSF. Methods: We performed a systematic review in accordance with the PRISMA guidelines to identify full-text articles that evaluate the correlation between spinal alignment and functional outcomes of TLSF. The artificial intelligence software Rayyan assisted the screening process. Functional outcomes referred to activity/disability, quality of life, and pain scores, as well as return to work metrics. Radiological assessments included were vertebral compression angle, Cobb and Gardner angles, sagittal vertical axis, pelvic incidence, and pelvic tilt. Statistical analyses were performed for the data provided by articles using the SPSS v24. Results: Of 1,616 articles reviewed, 6 were included for final analysis. Only 1 study primarily addressed the effects of spinopelvic parameters and functional outcomes. Four studies correlated Cobb angles with functional outcome, while 3 others compared vertebral compression angles with functional outcomes. Outcomes were assessed using work status or a combination of VAS pain and spine score, ODI, SF-36, and RMDQ-24. Neither the analysis done within the articles, nor the one made with the raw data provided by them, showed a significant correlation between the radiological measurements assessed at time of injury and final functional outcomes. Conclusions: A correlation between the assessed spinal radiological measurements assessed with the functional outcomes of TLSF was not found in this review. Further well-designed prospective studies are necessary to evaluate spinal alignment measurements in TLSF with functional outcomes.

Percutaneous Vertebroplasty versus Nonoperative Treatment of Osteoporotic Vertebral Fractures: A Meta-Analysis of Randomized Controlled Trials.

Osteoporotic vertebral fractures frequently result in pain and decreased quality of life (QoL). The management of these fractures remains a topic of debate. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we analyzed randomized controlled trials comparing percutaneous vertebroplasty (PV) with non-operative treatment (non-OT). The outcomes of interest included pain, QoL, cement leakage, and new osteoporotic vertebral fractures after 1 year. Compared to non-OT regarding pain relief, PV yielded significant improvement at 1-2 weeks, 1 month, 6 months (standard mean difference [SMD] = -0.67 (6/14; 95% confidence interval [CI]: -1.29 to -0.06; I2 = 92%, random effects) and 1 year (mean difference = -1.07 (4/14; 95% CI: -1.97 to -0.18; I2 = 97%, random effects). For QoL, notable improvements were observed at 1 week (standard mean difference = -2.10 (5/14; 95% CI: -3.77 to -0.42; I2 = 98%, random effects) and 3 months (mean difference = -1.58 (4/14; 95% CI: -3.07 to -0.09; I2 = 96%, random effects), with 1 month, 6 months and 1 year being inconclusive. A cement leakage rate of 42% (10/14; 95% CI: 25% to 59%; I2 = 99%, random effects) was found. Further, PV did not significantly heighten the risk of new fractures within a year (odds ratio = 1.26 (6/14; 95% CI: 0.63 to 2.53; I2 = 74%, random effects). PV emerges as a promising intervention for specific time intervals regarding pain relief, especially in the extended-term analysis, and QoL, especially in the short-term analysis, compared to non-OT. However, clinicians must consider cement leakage risks. Heterogeneity among studies underscores careful patient selection.

Understanding Decision Making as It Influences Treatment in Thoracolumbar Burst Fractures Without Neurological Deficit: Conceptual Framework and Methodology.

STUDY DESIGN: This paper presents a description of a conceptual framework and methodology that is applicable to the manuscripts that comprise this focus issue. OBJECTIVES: Our goal is to present a conceptual framework which is relied upon to better understand the processes through which surgeons make therapeutic decisions around how to treat thoracolumbar burst fractures (TL) fractures. METHODS: We will describe the methodology used in the AO Spine TL A3/4 Study prospective observational study and how the radiographs collected for this study were utilized to study the relationships between various variables that factor into surgeon decision making. RESULTS: With 22 expert spine trauma surgeons analyzing the acute CT scans of 183 patients with TL fractures we were able to perform pairwise analyses, look at reliability and correlations between responses and develop frequency tables, and regression models to assess the relationships and interactions between variables. We also used machine learning to develop decision trees. CONCLUSIONS: This paper outlines the overall methodological elements that are common to the subsequent papers in this focus issue.

Using Equipoise to Determine the Radiographic Characteristics Leading to Agreement on Best Treatment for Thoracolumbar Burst Fractures Without Neurologic Deficits.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVES: Our goal was to assess radiographic characteristics associated with agreement and disagreement in treatment recommendation in thoracolumbar (TL) burst fractures. METHODS: A panel of 22 AO Spine Knowledge Forum Trauma experts reviewed 183 cases and were asked to: (1) classify the fracture; (2) assess degree of certainty of PLC disruption; (3) assess degree of comminution; and (4) make a treatment recommendation. Equipoise threshold used was 77% (77:23 distribution of uncertainty or 17 vs 5 experts). Two groups were created: consensus vs equipoise. RESULTS: Of the 183 cases reviewed, the experts reached full consensus in only 8 cases (4.4%). Eighty-one cases (44.3%) were included in the agreement group and 102 cases (55.7%) in the equipoise group. A3/A4 fractures were more common in the equipoise group (92.0% vs 83.7%, P < .001). The agreement group had higher degree of certainty of PLC disruption [35.8% (SD 34.2) vs 27.6 (SD 27.3), P < .001] and more common use of the M1 modifier (44.3% vs 38.3%, P < .001). Overall, the degree of comminution was slightly higher in the equipoise group [47.8 (SD 20.5) vs 45.7 (SD 23.4), P < .001]. CONCLUSIONS: The agreement group had a higher degree of certainty of PLC injury and more common use of M1 modifier (more type B fractures). The equipoise group had more A3/A4 type fractures. Future studies are required to identify the role of comminution in decision making as degree of comminution was slightly higher in the equipoise group.

Predictive Algorithm for Surgery Recommendation in Thoracolumbar Burst Fractures Without Neurological Deficits.

STUDY DESIGN: Predictive algorithm via decision tree. OBJECTIVES: Artificial intelligence (AI) remain an emerging field and have not previously been used to guide therapeutic decision making in thoracolumbar burst fractures. Building such models may reduce the variability in treatment recommendations. The goal of this study was to build a mathematical prediction rule based upon radiographic variables to guide treatment decisions. METHODS: Twenty-two surgeons from the AO Knowledge Forum Trauma reviewed 183 cases from the Spine TL A3/A4 prospective study (classification, degree of certainty of posterior ligamentous complex (PLC) injury, use of M1 modifier, degree of comminution, treatment recommendation). Reviewers' regions were classified as Europe, North/South America and Asia. Classification and regression trees were used to create models that would predict the treatment recommendation based upon radiographic variables. We applied the decision tree model which accounts for the possibility of non-normal distributions of data. Cross-validation technique as used to validate the multivariable analyses. RESULTS: The accuracy of the model was excellent at 82.4%. Variables included in the algorithm were certainty of PLC injury (%), degree of comminution (%), the use of M1 modifier and geographical regions. The algorithm showed that if a patient has a certainty of PLC injury over 57.5%, then there is a 97.0% chance of receiving surgery. If certainty of PLC injury was low and comminution was above 37.5%, a patient had 74.2% chance of receiving surgery in Europe and Asia vs 22.7% chance in North/South America. Throughout the algorithm, the use of the M1 modifier increased the probability of receiving surgery by 21.4% on average. CONCLUSION: This study presents a predictive analytic algorithm to guide decision-making in the treatment of thoracolumbar burst fractures without neurological deficits. PLC injury assessment over 57.5% was highly predictive of receiving surgery (97.0%). A high degree of comminution resulted in a higher chance of receiving surgery in Europe or Asia vs North/South America. Future studies could include clinical and other variables to enhance predictive ability or use machine learning for outcomes prediction in thoracolumbar burst fractures.

Interobserver Reliability in the Classification of Thoracolumbar Fractures Using the AO Spine TL Injury Classification System Among 22 Clinical Experts in Spine Trauma Care.

STUDY DESIGN: Reliability study utilizing 183 injury CT scans by 22 spine trauma experts with assessment of radiographic features, classification of injuries and treatment recommendations. OBJECTIVES: To assess the reliability of the AOSpine TL Injury Classification System (TLICS) including the categories within the classification and the M1 modifier. METHODS: Kappa and Intraclass correlation coefficients were produced. Associations of various imaging characteristics (comminution, PLC status) and treatment recommendations were analyzed through regression analysis. Multivariable logistic regression modeling was used for making predictive algorithms. RESULTS: Reliability of the AO Spine TLICS at differentiating A3 and A4 injuries (N = 71) (K = .466; 95% CI .458 - .474; P < .001) demonstrated moderate agreement. Similarly, the average intraclass correlation coefficient (ICC) amongst A3 and A4 injuries was excellent (ICC = .934; 95% CI .919 - .947; P < .001) and the ICC between individual measures was moderate (ICC = .403; 95% CI .351 - .461; P < .001). The overall agreement on the utilization of the M1 modifier amongst A3 and A4 injuries was fair (K = .161; 95% CI .151 - .171; P < .001). The ICC for PLC status in A3 and A4 injuries averaged across all measures was excellent (ICC = .936; 95% CI .922 - .949; P < .001). The M1 modifier suggests respondents are nearly 40% more confident that the PLC is injured amongst all injuries. The M1 modifier was employed at a higher frequency as injuries were classified higher in the classification system. CONCLUSIONS: The reliability of surgeons differentiating between A3 and A4 injuries in the AOSpine TLICS is substantial and the utilization of the M1 modifier occurs more frequently with higher grades in the system.