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.

The Influence of Comminution and Posterior Ligamentous Complex Integrity on Treatment Decision Making in Thoracolumbar Burst Fractures Without Neurologic Deficit?

STUDY DESIGN

A prospective study.

OBJECTIVE

to evaluate the impact of vertebral body comminution and Posterior Ligamentous Complex (PLC) integrity on the treatment recommendations of thoracolumbar fractures among an expert panel of 22 spine surgeons.

METHODS

A review of 183 prospectively collected thoracolumbar burst fracture computed tomography (CT) scans by an expert panel of 22 trauma spine surgeons to assess vertebral body comminution and PLC integrity. This study is a sub-study of a prospective observational study of thoracolumbar burst fractures (Spine TL A3/A4). Each expert was asked to grade the degree of comminution and certainty about the PLC disruption from 0 to 100, with 0 representing the intact vertebral body or intact PLC and 100 representing complete comminution or complete PLC disruption, respectively.

RESULTS

≥45% comminution had a 74% chance of having surgery recommended, while <25% comminution had an 86.3% chance of non-surgical treatment. A comminution from 25 to 45% had a 57% chance of non-surgical management. ≥55% PLC injury certainity had a 97% chance of having surgery, and ≥45-55% PLC injury certainty had a 65%. <20% PLC injury had a 64% chance of having non-operative treatment. A 20 to 45% PLC injury certainity had a 56% chance of non-surgical management. There was fair inter-rater agreement on the degree of comminution (ICC .57 [95% CI 0.52-.63]) and the PLC integrity (ICC .42 [95% CI 0.37-.48]).

CONCLUSION

The study concludes that vetebral comminution and PLC integrity are major dterminant in decision making of thoracolumbar fractures without neurological deficit. However, more objective, reliable, and accurate methods of assessment of these variables are warranted.

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.

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.

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.

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.

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.

Surgical outcome of spinal schwannoma and neurofibroma

OBJECTIVE

The aim of this study was to evaluate the outcome and surgical complications in patients with spinal schwannoma or neurofibroma surgically treated at the Hospital das Clínicas of the State University of Campinas.

METHODS

This was a retrospective cohort study, using medical records of patients operated between 2011 and 2021. The sample distribution was verified using the Kolmogorov-Smirnov test. The dynamics between qualitative variables were assessed using Fisher's exact test. We used means analysis to assess patient improvement based on Frankel scores.

RESULTS

A total of 16 patients were evaluated, of whom 56.25% (9) were men and 43.75% (7) were women. There were 13 (81.25%) patients with schwannomas and 3 (18.75%) with neurofibromas. Patients with deficits had neurological improvement, such as walking or with at least Frankel D or E after surgery. Laminectomy, performed in 8 patients (50%), and laminoplasty, used in 9 patients (56.25%), were the main techniques.

CONCLUSION

The surgical approach was proved to be an effective and safe alternative to the treatment of these tumors, with neurological improvement and minor surgical complications.

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.

How Knowledgeable Are Spine Surgeons Regarding EMG-NCS for Cervical Spine Conditions? An International Aospine Survey

STUDY DESIGN

Cross-sectional, international survey.

OBJECTIVES

To evaluate the knowledge of spine surgeons regarding the use of electromyography (EMG) and nerve conduction studies (NCS) for degenerative cervical spine conditions (DCC).

METHODS

All members of AO Spine International were emailed an anonymous survey to evaluate their clinical knowledge about the use of EMG and nerve conduction studies for DCC. Descriptive statistics were used to analyze the results, as well as to compare the answers among different groups of surgeons and assess demographic characteristics.

RESULTS

A total of 402 participants answered the survey, 91.79% were men from the 5 continents. There were 221 orthopedic surgeons (55.39%) and 171 neurosurgeons (42.86%), more than a half of them with a complete spinal fellowship (56.44%). The most common reasons that surgeons obtain the test is to differentiate a radiculopathy from a peripheral nerve compression (88.06%). As a group, the responding surgeons' knowledge regarding EMG-NCS was poor. Only 53.46% of surgeons correctly answered that EMG-NCS is unable to differentiate a C5 from a C6 radiculopathy. Only 23.47% of the surgeons knew that EMG-NCS are not able to diagnose a pre vs a post-fixed brachial plexus. Only 25% of the surgeons correctly answered a question regarding the test's ability to diagnose other neurological diseases.

CONCLUSIONS

We found that our respondents' knowledge regarding EMG-NCS for DCC was poor. Identifying the weak points of knowledge about EMG-NCS may help to educate surgeons on the indications for the test and the proper way to interpret the results.

Temporopolar amygdalohippocampectomy for mesial temporal lobe epilepsy: a 2D anatomical operative video

Mesial temporal lobe epilepsy (MTLE) is the most frequent type of focal epilepsy in young adults and the most commonly reported in surgical series worldwide^1,2. When seizures become refractory to drug therapy, they are unlikely to remit spontaneously, and for those 30% of patients with epilepsy that are refractory to antiepileptic drugs, it is well stated that resection of the mesial temporal lobe structures provides great rate (70-80%) of seizure control^3,4. The transsylvian route for amygdalohippocampectomy has been used at our institution for many years, evolving from the first description of Yasargil through the inferior circular sulcus of insula to the most recent one through the amygdala trying to preserve the temporal stem^5,6. Despite of good Engel outcomes, the analysis of late postoperative MRIs of our patients showed a high incidence of temporal pole atrophy and potential gliosis^7,8. Therefore, we decided to keep the transsylvian route, but taking out the portion of the temporal pole anterior to the limen insula, resulting in what we called temporopolar amygdalohippocampectomy (TP-AH)^4,9,. TP-AH analysis suggested a good temporal stem preservation, good visual outcomes and good memory results⁴. We also advocate that the transsylvian route has the potential to provide a superior view and resection of the piriform cortex, that is associated with seizure outcome after surgery¹⁰. We present a case of a 42-yr-old woman who had refractory seizures secondary to a MTLE and underwent to a TP-AH with good outcome, persisting seizure-free (Engel IA). The patient consented for surgery and photo publication.

Effect of surgical experience and spine subspecialty on the reliability of the AO Spine Upper Cervical Injury Classification System

OBJECTIVE

The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery).

METHODS

A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson's chi-square or Fisher's exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.

RESULTS

The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5-10 years: 0.69 vs 10-20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5-10 years: 0.62 vs 10-20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5-10 years: 0.61 vs 10-20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36).

CONCLUSIONS

The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system.

SURG-36. EVALUATION OF SURGICAL RESULTS AND PREDICTIVE FACTORS OF HYDROCEPHALUS IN PEDIATRIC PATIENTS WITH POSTERIOR FOSSA TUMORS

INTRODUCTION

Infratentorial tumors represent 45 to 60% of all brain tumors in children and are associated with hydrocephalus in 70 to 90% of cases. The aim of this study is to describe and analyze the surgical results and correlate them with the incidence of hydrocephalus, as well as identify predictive factors of hydrocephalus in pediatric patients underwent to a surgical treatment of posterior fossa tumors.

METHODS

This is a retrospective observational study, based on demographic, clinical and radiological information of pediatric patients underwent to surgical resection of posterior fossa tumors by a single group between 2011 and 2019.

RESULTS

We included 135 patients with a mean age of 7.56 years, mean follow-up of 35.7 months and overall survival of 18.8 months. Considering the histology, most tumors were pilocytic astrocytomas (34.1%), followed by medulloblastomas (27.4%) Total resection was achieved in 77.8% and tumor recurrence was observed in 16.2%. The rate of hydrocephalus was 36.3%, with most shunt procedures performed preoperatively. There was a high rate of complications associated with shunting (42.9%), mostly represented by infection (71.5%). Patients with hydrocephalus were younger (p = 0.001), showing a faster evolution between the onset of symptoms and diagnosis (p = 0.008). Tumor volume (p = 0.1) and location (p = 0.32) were not statistically significant for hydrocephalus, however, the presence of leptomeningeal disease (p = 0.001) was. The resection rate was also significant, with lesions totally resected showing the best results (p = 0.009). Regarding tumor histology, 33.3% of patients with medulloblastoma and 62.5% of patients with ependymoma were shunted.

CONCLUSION

One third of children with posterior fossa tumors will require a shunt procedure. Some factors should guide the neurosurgeon during patient counseling and surgical planning to minimize the use of permanent shunts and avoid related complications.

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.

SURG-11. Evaluation of surgical results and predictive factors of hydrocephalus in pediatric patients with posterior fossa tumors

INTRODUCTION: Infratentorial tumors represent 45 to 60% of all brain tumors in children and are associated with hydrocephalus in 70 to 90% of cases. The aim of this study is to describe and analyze the surgical results and correlate them with the incidence of hydrocephalus, as well as identify predictive factors of hydrocephalus in patients underwent to a surgical treatment of posterior fossa tumors. METHODS: This is a retrospective observational study, based on demographic, clinical and radiological information of pediatric patients underwent to surgical resection of posterior fossa tumors by a single group between 2011 and 2019. RESULTS: We included 135 patients with a mean age of 7.56 years, mean follow-up of 35.7 months and overall survival of 18.8 months. Considering the histology, most tumors were pilocytic astrocytomas (34.1%), followed by medulloblastomas (27.4%) Total resection was achieved in 77.8% and tumor recurrence was observed in 16.2%. The rate of hydrocephalus was 36.3%, with most shunt procedures performed preoperatively. There was a high rate of complications associated with shunting (42.9%), mostly represented by infection (71.5%). Patients with hydrocephalus were younger (p = 0.001), showing a faster evolution between the onset of symptoms and diagnosis (p = 0.008). Tumor volume (p = 0.1) and location (p = 0.32) were not statistically significant for hydrocephalus, however, the presence of leptomeningeal disease (p = 0.001) was. The resection rate was also significant, with lesions totally resected showing the best results (p = 0.009). Regarding tumor histology, 33.3% of patients with medulloblastoma and 62.5% of patients with ependymoma were shunted. CONCLUSION: One third of children with posterior fossa tumors will require a shunt procedure. Some factors should guide the neurosurgeon during patient counseling and surgical planning to minimize the use of permanent shunts and avoid related complications.

Correlation between angioarchitectural characteristics of brain arteriovenous malformations and clinical presentation of 183 patients

BACKGROUND

The correlation between angioarchitecture and clinical presentation of brain arteriovenous malformation (bAVM) remains a subject of debate.

OBJECTIVE

The main purpose of the present study was to assess the correlation between angioarchitectural characteristics of bAVM and clinical presentation.

METHODS

A retrospective review of all consecutive patients presenting a bAVM who underwent a cerebral angiography at Beneficencia Portuguesa Hospital in São Paulo between January 2006 and October 2016 was carried out. Patients were divided in five groups: group 1 - hemorrhage; group 2 - seizure; group 3 - headache; group 4 - progressive neurological deficits (PND); group 5 - incidental).

RESULTS

A total of 183 patients were included, with group 1 comprising 56 cases, group 2 49 cases, group 3 41 cases, group 4 28 cases, and group 5 9 cases. Regarding hemorrhage presentation, a statistical correlation was observed with female gender (P < 0.02), Spetzler-Martin 3B (P < .0015), and lesions with low flow (P < 0.04). A positive association was found between group 2 and age less than 36 years (P < 0.001), male sex (P < 0.018), presence of superficial lesions not classified as SM 3B (P < 0.002), presence of venous ectasia (p <0.03), and arterial steal phenomenon (P < 0.03). Group 4 was associated with older age (P < 0.01).

CONCLUSIONS

Angioarchitectural characteristics can be correlated with some clinical presentations as well as with some clinical data, making it possible to create predictive models to differentiate clinical presentations.

Quality Assessment for Reporting Complications and Adverse Events in Spinal Surgery: A Proposed 5-Item Checklist

BACKGROUND

Reporting complications and/or adverse events after spinal surgical procedures enables the estimation of their prevalence and of their impact on patient outcomes. However, the documentation of complications is relatively infrequent and highly heterogeneous. The purpose of this study was to evaluate the quality of complication and adverse event reporting in spinal surgery literature.

METHODS

A systematic review of the literature from 5 international, peer-reviewed, indexed spinal journals was performed. Included studies were published between January and December 2020 and reported the surgical results of spinal procedures. Data on the level of evidence and study design were collected and analyzed as well as whether the studies were single-center or multicenter studies. The quality of complication reports was evaluated through a 5-item checklist, with 5 questions divided into 3 parts: definition, evaluation, and report.

RESULTS

Complications associated with spinal surgical procedures were reported in 292 studies. According to the level of evidence, significantly higher reporting quality was seen in level I and II studies compared with level III and IV studies (P = 0.003). Regarding the 5-item checklist, 49% (143/292) of studies fulfilled the definition section, 16.4% (48/292) fulfilled the evaluation section, and 92% (270/292) fulfilled the report section.

CONCLUSIONS

Overall quality assessment when reporting complications in surgical spinal studies showed that only 13% (38/292) of publications that reported complications as part of the outcomes exhibited all items of the 5-item checklist. Additionally, significantly better reports were observed in level I studies compared with level II-IV studies.

Traumatic Atlanto-Occipital Dislocation-A Comprehensive Analysis of All Case Series Found in the Spinal Trauma Literature

BACKGROUND

Traumatic atlanto-occipital dislocation (TAOD) is one of the most devastating traumatic injuries, generally associated with immediate death after high-energy trauma. The aim of this study was to perform a systematic literature review of all cases series of TAOD and present the current state of this entity.

METHODS

A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only case series with at least 5 cases were included in the analysis. We focused on survival rates, diagnostic methods, delays in diagnosis, outcomes, and cases successfully treated nonoperatively.

RESULTS

A total of 17 articles were included (16 retrospective and 1 prospective study) with 341 patients. Six studies included pediatric patients only. The mean Glasgow Coma Scale at admission was ≤8 in all studies. Many different diagnostic criteria were used, but none of them had high accuracy. The overall mortality rate was 34.8%, but the studies' designs were heterogeneous (some included only survivors). A high rate of concomitant traumatic brain injury was documented in some studies. We found it interesting that some patients were treated with cervical immobilization (37/341; 10.8%), which was generally used in less unstable injuries; however, the majority of patients were managed with an occipito-cervical fusion (193/341; 56.5%).

CONCLUSIONS

TAOD is a devastating traumatic injury, with a high mortality rate. An MRI may be recommended when there are subtle findings of TAOD and a normal computed tomography scan, such as subarachnoid hemorrhage in the posterior fossa, upper cervical injuries, or consistent neurological findings. Further studies are necessary to identify patients with mild MRI findings and TAOD that may be managed nonoperatively.

Review of best classification systems for diagnosing and treating thoracolumbar spine trauma

Background

Improved thoracolumbar spine trauma classification (TLSTC) systems can better help diagnose and treat thoracolumbar spine trauma (TLT). Here, we identified the types of injury (rationale and description), instability criteria, and treatment guidelines of TLSTC.

Methods

We used the PubMed/MEDLINE database to assess TLSTC according to the following variables: injury morphology, injury mechanism, spinal instability criteria, neurological status, and treatment guidelines.

Results

Twenty-one studies, 18 case series and three reviews were included in the study. Treatment guidelines were proposed in 16 studies. The following three major parameters were identified in TLSTC studies: injury morphology (19/21 studies), posterior ligamentous complex (PLC) disruption alone as the main spinal instability criterion (15 studies), and neurological damage (12 studies). Most classification systems neglected the severity of vertebral body comminution.

Conclusion

We identified here the 3 main parameters for the evaluation of diagnosis and treatment of TLT: injury morphology, PLC disruption, and neurological damage. Based on our review, we may conclude that further clinical validation studies of TLSTC are warranted.

Role of Atlas Assimilation in the Context of Craniocervical Junction Anomalies

Atlas assimilation (AA) may be associated with atlantoaxial dislocation, Chiari malformation (CM), and basilar invagination. The importance of AA in the context of craniocervical junction (CVJ) anomalies is unclear. Considering this context, this study's objective is to discuss the role of AA in the management of CVJ anomalies, especially in CM. A comprehensive literature review was performed. In addition, some illustrative cases were discussed on the basis of our review. Finally, we propose a theoretic algorithm to evaluate patients with AA and CM. AA is a proatlas segmentation anomaly that may be complete or incomplete. It may be totally asymptomatic or symptomatic as the result of transferred shifted forces onto the C1-2 joints, leading to clear instability (atlantoaxial dislocation) or mild C1-2 instability. Cautious surgical planning may be required due to associated vertebral artery anomalies. AA with concomitant C2-C3 segmentation failure is highly associated with late C1-C2 instability. CVJ decompression failure was reported in patients with CM and a low clivus canal angle (<130-135 degrees). Patients with assimilated anterior C1 arches usually have evident AAD. CM patients with AA generally have type 1 BI or type 2 BI and are reported with higher rates of CVJ instabilities when compared with those "pure" CM. Dynamic examinations may provide additional evidence of atlantoaxial instability. Although AA per se is not considered an unstable configuration, further and detailed evaluations of patients with CM associated with AA are necessary. Some associated unstable configurations required concomitant CVJ fixation.

Reporting Complications in Spinal Surgery-a Systematic Literature Review

BACKGROUND

Many efforts are expended to improve health care quality in the surgical treatment of spinal conditions. However, the prevalence of reporting complications in spinal surgeries is highly heterogeneous, which is partially due to the lack of a universal and comprehensive system.

METHODS

A systematic review of the literature was performed in 5 international and indexed spine journals from January to December 2020. All clinical studies that had surgical procedures in any spinal region were classified according to level of evidence, study design, category of spinal condition, and primary outcome. The prevalence and quality of complication reporting were evaluated through a checklist.

RESULTS

Of 455 articles screened, complications were reported in 64.2% (292 articles). A significant higher prevalence of reports was observed in randomized compared with nonrandomized studies (P < 0.05). In 89 articles, at least 1 classification was used to report complications, with 12 different classification systems employed in the total sample. Timing to record complications was as follows: 47 (16.1%) articles reported complications at 30 days, 31 (10.6%) reported complications at 90 days, and 88 (30.1%) reported complications during all follow-ups. In 126 (43.1%) articles, complications were not mentioned.

CONCLUSIONS

Almost one-third of spine surgical studies did not report complications in their results despite reporting clinical outcomes. The evidence quality of the study was directly related with the reporting of complications. A high heterogeneity regarding complication reporting was seen in the literature.

Circumferential Operations of the Cervical Spine

Generally, a combined anterior and posterior cervical approach is associated with significant morbidity since it requires an extended operative time, greater intraoperative blood loss, and both anterior- and posterior-related surgical complications. However, there are some instances where a circumferential cervical fusion can be advantageous. Our objective is to discuss the indications for circumferential cervical spine procedures. A narrative review of the literature was performed. We include the indications for circumferential cervical approaches of the senior author (KDR). Indications for circumferential approaches include: (1) high-risk patients for pseudoarthrosis, (2) cervical deformity (e.g., degenerative, posttraumatic, cervicothoracic kyphosis), (3) cervical spine metastases (especially those with multilevel involvement), (4) cervical spine infection, (5) unstable cervical trauma, (6) movement disorders and cerebral palsy, (7) Multiply operated patient (especially postlaminectomy kyphosis and patients with massive ossification of the posterior longitudinal ligament), and when (8) early fusion is desirable. Circumferential procedures may be useful in many different cervical spine conditions requiring surgery. Despite its advantages, particularly with reducing the risk for pseudarthrosis, the benefits of a combined approach must be weighed against the risks associated with a dual approach. With appropriate preoperative planning, intraoperative decision-making, and surgical techniques, excellent clinical outcomes can be achieved.

Revision Surgeries at the Index Level After Cervical Disc Arthroplasty - A Systematic Review

Objective

To perform a systematic literature review on revision surgeries at the index level after cervical disc arthroplasty (CDA) failure.

Methods

A systematic literature review was performed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Prospective studies on patients who required a secondary surgery after CDA failure were included for analysis. The minimum follow-up for these studies was 5 years.

Results

Out of 864 studies in the original search group, a total of 20 studies were included. From a total of 4,087 patients, 161 patients required a reoperation at the index level. A total of 170 surgeries were performed, as some patients required multiple surgeries. The most common secondary procedures were anterior cervical discectomy and fusion (ACDF) (68%, N = 61) and posterior cervical fusion (15.5%, N = 14), followed by other reoperation (13.3%, N = 12). The associated outcomes for those who required a revision surgery were rarely mentioned in the included literature.

Conclusion

The long-term revision rate at the index level of failed CDA surgery was 3.9%, with a minimum 5-year follow-up. ACDF was the most commonly performed procedure to salvage a failed CDA. Some patients who required a new surgery after CDA failure may require a more extensive salvage procedure and even subsequent surgeries.

Risk of Seizures after Endovascular Management of Ruptured Intracranial Aneurysms: A Systematic Review and Meta-analysis

Seizures in aneurysmal subarachnoid haemorrhage (aSAH) have been described secondary to SAH, changes in cortical function, vasospasm and as a result of treatment effects. Seizures are one of the important clinical determinants in neurological outcome of aSAH. Various studies support the notion of less risk of future seizures in endovascular treatment as compared to the microsurgical clipping, yet there is no conclusive evidence in favour or against the seizure occurrence in aSAH patients after endovascular treatment as compared to the microsurgical treatment. To carry out a systematic review and meta-analysis of the risk of seizures after endovascular management (coiling) of ruptured intracranial aneurysms. A literature search was performed in electronic database of PubMed, MEDLINE, Embase, and Scopus from inception to February 2020, using the terms Seizure, Intracranial aneurysms, embolization, with no constraints applied. Data were pooled using a random-effect model, results were abstracted as odds ratios (ORs) and 95% confidence interval (CI), and heterogeneity was reported as Chi-square. Five studies involving 3,077 patients were included in the meta-analysis. After endovascular management of aSAH, seizure risk was increased by a worse clinical severity (World Federation of Neurosurgery scale or Hunt and Hess) (OR, 3.34; 95% CI, 2.69–4.16; p<0.00001), severe vasospasm (OR, 2.20; 95% CI, 1.67–2.92; p<0.00001), cerebral infarction (OR, 5.19; 95% CI, 3.23–8.35; p<0.00001), and cerebral edema (OR, 1.79; 95% CI, 1.37–2.34; p<0.0000). Worse clinical severity, vasospasm, cerebral infarction and cerebral oedema are significant risk factors for the development of seizures after endovascular intervention in aSAH. The mechanism for this correlation is not clear.

Critical Appraisal of Traumatic Brain Injury and Its Management

Critical appraisal of traumatic brain injury (TBI) management has always been marred with a conflict of differential approaches, with claims and counterclaims of outcomes among the research groups. We performed this study to review the management of TBI from risk factors to outcomes including the comorbidities and final clinical status. In conjunction with the aforesaid stabilization of TBI cases, prophylactic and definitive surgical approaches and other supporting interventions will ultimately decide the final outcomes in the long run. Improvements in the quality of care for patients with severe TBI, with the reduction in mortality, have been demonstrated in high-income areas due to improvements in the health care system and not just in one isolated intervention. In the management of TBI, a fast and high index of suspicion is the key to success, from the initial assessment to the final rehabilitation of the cases, from the victim of risk factors to the victims of situation. The research groups feel that TBI prophylactic measures and primary care mitigation models are as important as definitive care, starting from prehospital care to dedicated care.

Cerebrospinal fluid dynamics with its surgical implications

Cerebrospinal fluid (CSF) is largely (70-80%) produced by the choroids plexus of the ventricles and is considered as the plasma ultrafiltrate. While CSF formation, circulation, and composition appear to be physiological and physical, its absorption appears to be mainly physical. The formation, composition, circulation, absorption, and changes in pathological conditions of CSF are discussed briefly in this review article. The CSF pressure dynamics studies provide information about the tightness, elastance, or outflow resistance of the CSF in the CNS. We believe that the present study shall help to provide essential details of CSF physiology which are important to many disciplines including radiology, neurology, and neurosurgery.

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.

Occipitocervical Fixation: General Considerations and Surgical Technique

STUDY DESIGN

Narrative literature review.

OBJECTIVE

To review and present details on the occipitocervical fixation (OCF) technique as well as considerations for planning the procedure.

METHODS

We present the surgical technique of OCF in a step-by-step didactic and practical manner with surgical tips and tricks, including C1 and C2 screw fixation techniques. Additionally, we discuss complications, the extension of fusion, types of OCF, and how to avoid common side effects associated with OCF.

RESULTS

The complex and mobile anatomy of the craniocervical junction, when requiring fixation and fusion, warrants rigid instrumentation that can be achieve using a modern screw-plate-rod construct. Indications for OCF are craniocervical instability, and atlantoaxial instability when selective atlantoaxial fusion is not feasible. OCF generally involves occiput-C2 fusion. C1 fixation is generally unnecessary, since it increases the surgical time and is associated with the risk of vascular complications. Selective occiput-C2 fusion is recommended when there is no need for including the cervical subaxial region (eg, when stenosis or fractures coexist in the subaxial spine), and good fixation is achieved at C2. Most instrumentation systems now have occipital plates that are not pre-integrated to rods, making fixation much simpler. Surgical steps, from position to wound closure, are presented in detail, with pearls for practice and discussion of cervical alignment.

CONCLUSIONS

OCF is a challenging procedure, with potential risk of severe adverse effects. Understanding the surgical indications, as well as the nuances of the surgical technique, is required to improve patient outcomes and avoid complications.

Survival in patients with surgically treated spinal metastases

BACKGROUND

Despite the various treatment protocols available, survival evaluation is a fundamental criterion for the definition of surgical management; there are still many inconsistencies in the literature on this topic, especially in terms of the value of surgery and its morbidity in patients with very short survival.

OBJECTIVE

The objective was to analyze the association of clinical, oncological, and surgical factors in the survival of patients undergoing spinal surgery for spinal metastases (SM).

MATERIALS AND METHODS

A retrospective cohort of forty patients who were surgically treated at our institution for SM between 2010 and 2018 were included in the study. We applied the prognostic scales of Tomita and Tokuhashi in each patient and evaluated the systemic status using Karnofsky Performance Scale (KPS) and Eastern Cooperative Oncology Group Performance Scale. Survival rate in months was estimated using the Kaplan-Meier curve, with death considered as primary outcome and, for the evaluation of the association between the variables, the Chi-square test, Fisher's exact test, or Fisher-Freeman-Halton test was applied for better survival. The level of statistical significance was considered as 5% (P ≤ 0.05).

RESULTS

The mean survival was 8.4 months. Patients with KPS <70 had a mean survival of 6.36 months, while those with KPS >70 had a mean survival of 14.48 months (P = 0.04). The mean survival of patients classified as ECOG 2 was 7.05 months (95% confidence interval [CI]: 3.4-10.7), and that of patients classified as ECOG 3 and 4 was 1.24 months (95% CI: 0.8-1.59). The mean survival rate among the patients with unresectable metastases in other organs was 6.3 months (95% CI: 3.9-8.9), while the survival rate of those who did not have metastases was 13.8 months (95% CI: 10.0-17.68; P = 0.022).

CONCLUSION

Survival was associated with the preoperative functional status defined by the KPS and ECOG scales and with the presence of nonresectable visceral metastases.

Severe Cerebellar Degeneration and Chiari I Malformation - Speculative pathophysiology based on a systematic review

BACKGROUND

Symptomatic Chiari Type I Malformation (CM) is treated with posterior fossa decompression with or without duroplasty. We have noticed some cases with concomitant severe cerebellar ataxia due to cerebellar atrophy. The aim of this study is to review the literature of CM associated with severe cerebellar atrophy and discuss its potential physiopathology.

METHODS

A systematic literature review in the Pubmed Database was performed using the following key-terms: "cerebellar atrophy Chiari", and "cerebellar degeneration Chiari". Articles reporting the presence of cerebellar degeneration/atrophy associated with CM were included.

RESULTS

We found only six studies directly discussing the association of cerebellar atrophy with CM, with a total of seven cases. We added one case of our own practice for additional discussion. Only speculative causes were described to justify cerebellar atrophy. The potential causes of cerebellar atrophy were diffuse cerebellar ischemia from chronic compression of small vessels (the most mentioned speculative cause), chronic raised intracranial pressure due to CSF block, chronic venous hypertension, and association with platybasia with ventral compression of the brainstem resulting in injury of the inferior olivary nuclei leading to mutual trophic effects in the cerebellum. Additionally, it is not impossible to rule out a degenerative cause for cerebellar atrophy without a causative reason.

CONCLUSIONS

Severe cerebellar atrophy is found in some patients with CM. Although chronic ischemia due to compression is the most presumed cause, other etiologies were proposed. The real reasons for cerebellar degeneration are not known. Further studies are necessary.

Temporopolar amygdalohippocampectomy: seizure control and postoperative outcomes

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of a modified surgical approach for the treatment of temporal lobe epilepsy secondary to hippocampal sclerosis (HS). This modified approach, called temporopolar amygdalohippocampectomy (TP-AH), includes a transsylvian resection of the temporal pole and subsequent amygdalohippocampectomy utilizing the limen insula as an anatomical landmark.

METHODS

A total of 61 patients who were diagnosed with HS and underwent TP-AH between 2013 and 2017 were enrolled. Patients performed pre- and postoperative diffusion tensor imaging and were classified according to Engel's scale for seizure control. To evaluate the functional preservation of the temporal stem white-matter fiber tracts, the authors analyzed postoperative Humphrey perimetries and pre- and postoperative neurocognitive performance (Rey Auditory Verbal Learning Test [RAVLT], Weschler Memory Scale-Revised [WMS-R], intelligence quotient [IQ], Boston Naming Test [BNT], and semantic and phonemic fluency). Demographic data and surgical complications were also recorded and described.

RESULTS

After a median follow-up of 36 ± 16 months, 46 patients (75.4%) achieved Engel class I, of whom 37 (60.6%) were Engel class IA. No significant changes in either the inferior frontooccipital fasciculus and optic radiation tractography were observed postoperatively for both left- and right-side surgeries. Reliable perimetry was obtained in 40 patients (65.6%), of whom 27 (67.5%) did not present any visual field defects (VFDs) attributable to surgery, while 12 patients (30%) presented with quadrant VFD, and 1 patient (2.5%) presented with hemifield VFD. Despite a significant decline in verbal memory (p = 0.007 for WMS-R, p = 0.02 for RAVLT recognition), there were significant improvements in both IQ (p < 0.001) and visual memory (p = 0.007). Semantic and phonemic fluency, and scores on the BNT, did not change postoperatively.

CONCLUSIONS

TP-AH provided seizure control similar to historical temporal lobe approaches, with a tendency to preserve the temporal stem and a satisfactory incidence of VFD. Despite a significant decline in verbal memory, there were significant improvements in both IQ and visual memory, along with preservation of executive function. This approach can be considered a natural evolution of the selective transsylvian approach.

Idiopathic Ventral Spinal Cord Herniation: Video Report and Systematic Review

BACKGROUND

Idiopathic ventral spinal cord herniation (ISCH) is a rare disease; however, it is an important differential diagnosis. Its treatment presents some controversies.

CASE DESCRIPTION

We report on a 55-year-old woman who had been presenting with relevant back pain and leg weakness for the past 3 years and urinary incontinence for the past 3 months. Clinical examination disclosed paresis on the right inferior limb and right foot, as well as a T6-level painful hypoesthesia. Magnetic resonance imaging disclosed a T4/T5 ISCH. The patient underwent surgical decompression. During the procedure, we opened the arachnoid and cut the dentate ligaments of the spine, which considerably improved the mobility and safety of the procedure. In the early follow-up, our patient presented a partial improvement regarding the paresis grades and hypoesthesia pain relief on the left side. A video showing the surgical procedure and case evolution is presented. We also assembled literature reviews to compare our case with others. ISCH is becoming a more recognized cause of progressive thoracic myelopathy. However, this condition is still frequently misdiagnosed. Magnetic resonance imaging is the key for diagnosis. The objective of surgical treatment is to prevent myelopathy progression. The technique presented in this report is an appropriate surgical option, once it is a safer way to identify and treat the defect. The neurologic condition usually improves greatly after surgical treatment, especially when the patient presents positive predictive factors.

CONCLUSIONS

ISCH is being more recognized. The technique presented is an appropriate surgical option.

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.

Reliability of the New AOSpine Classification System for Upper Cervical Traumatic Injuries

BACKGROUND

The new AOSpine Upper Cervical Classification System (UCCS) was recently proposed by the AOSpine Knowledge Forum Trauma team to standardize the treatment of upper cervical traumatic injuries (UCI). In this context, evaluating its reliability is paramount prior to clinical use.

OBJECTIVE

To evaluate the reliability of the new AOSpine UCCS.

METHODS

A total of 32 patients with UCI treated either nonoperatively or with surgery by one of the authors were included in the study. Injuries were classified based on the new AO UCCS according to site and injury type using computed tomography scan images in 3 planes by 8 researchers at 2 different times, with a minimum interval of 4 wk between assessments. Intra- and interobserver reliability was assessed using the kappa index (K). Treatment options suggested by the evaluators were also assessed.

RESULTS

Intraobserver agreement for sites ranged from 0.830 to 0.999, 0.691 to 0.983 for types, and 0.679 to 0.982 for the recommended treatment. Interobserver analysis at the first assessment was 0.862 for injury sites, 0.660 for types, and 0.585 for the treatment, and at the second assessment, it was 0.883 for injury sites, 0.603 for types, and 0.580 for the treatment. These results correspond to a high level of agreement of answers for the site and type analysis and a moderate agreement for the recommended treatment.

CONCLUSION

This study reported an acceptable reproducibility of the new AO UCCS and safety in recommending the treatment. Further clinical studies with a larger patient sample, multicenter and international, are necessary to sustain the universal and homogeneity quality of the new AO UCCS.

Posterior screw fixation in the subaxial cervical spine: a technique and literature review

Posterior cervical spine fixation is a key component in achieving spinal arthrodesis for treating various cervical spine pathologies including neoplastic, inflammatory, traumatic and degenerative diseases. Historically, various wiring techniques had played major roles in posterior cervical spine fixation. Today, posterior cervical screw fixation is utilized by most spine surgeons instead of wiring for its superior biomechanical strength. A review of lateral mass, pedicle, intralaminar and transfacet screw fixation techniques in the subaxial cervical spine is presented in a detailed fashion. A comparison among different posterior cervical subaxial fixation techniques is also included. Although the safety of freehand techniques was demonstrated in the majority of the existing studies, real-time navigation is becoming increasingly utilized for cervical screw insertion, especially for cervical pedicle screws, where the freehand technique is technically demanding and may carry a higher risk of neurovascular injury. Several different posterior screw fixation techniques exist for the subaxial cervical spine with generally low complication rate. Spine surgeons should be familiar with these techniques and choose the optimal technique based on each patient's individual anatomy and surgical needs.

Bariatric Surgery and Low Back Pain: A Systematic Literature Review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

It is estimated that one third of the world population is overweight and 20% of adults have some low back symptoms at some point of their lives. The association of obesity and low back pain and physical deterioration has been well established. We designed this study to evaluate the role of bariatric surgery (BS) for lumbar spine symptoms in obese patients.

METHODS

A systematic literature review was performed using the PubMed database identifying lumbar spine symptoms (pain, functional status, disability index) and/or complications of lumbar spine surgery before and after BS. Study quality was assessed according to the Oxford Centre for Evidence-Based Medicine.

RESULTS

Ten studies were identified. Nine evaluated the role of BS in low back pain and/or functional status before and after surgery: all reported that bariatric surgery had a positive impact in improving low back pain symptoms and decreasing disability in severely obese patients. One study evaluated the role of posterior lumbar surgery in patients who were obese at the time of surgery and those who had a previous bariatric procedure: bariatric surgery decreased postoperative surgical complications. The level of the evidence was low (III and IV).

CONCLUSIONS

Bariatric surgery in severely obese patients decreases the intensity of low back symptoms and also decreases disability secondary to back problems. Additionally, bariatric surgery may be advantageous for patients who need a posterior lumbar surgery and are severely obese. Prospective studies with longer follow-up are necessary to confirm this conclusion.

Correlation Between Different Interbody Grafts and Pseudarthrosis After Anterior Cervical Discectomy and Fusion Compared with Control Group: Systematic Review

BACKGROUND

Cervical spine degenerative disease is one of the main causes of myelopathy. Anterior cervical discectomy and fusion (ACDF) is the most common surgical procedure used to treat cervical myelopathy. Therefore, it is important to study pseudarthrosis rates after ACDF and correlate them with the graft used.

METHODS

We performed a systematic review to evaluate the relationship between pseudarthrosis after ACDF and the interbody graft used.

RESULTS

A total of 3732 patients were evaluated in 46 studies. The mean age of the included patients was 51.5 ± 4.18 years (range, 42-59.6 years). ACDF is most often perforemd as single-level surgery and the level most impaired is C5-C6. The use of titanium cages, zero profile, recombinant human bone morphogenetic protein 2, and carbon cages was seen as a protective factor for pseudarthrosis compared with the autograft group (control group); with an odds ratio of 0.29, 0.51, 0.03, and 0.3, respectively; the results were statistically relevant. The use of polyetheretherketone, poly(methyl methacrylate), and trabecular metal was a risk factor for development of pseudarthrosis compared with the control group, with an odds ratio of 1.7, 8.7, and 6.8, respectively; the results were statistically relevant. Radiologic follow-up was an important factor for the pseudarthrosis rate; paradoxically, a short follow-up (<1 year) had lower rates of pseudarthrosis and follow-up >2 years increased the chance of finding pseudarthrosis.

CONCLUSIONS

Different types of grafts lead to a significant difference in pseudarthrosis rates. Follow-up time is also an important factor that affects the rate of pseudarthrosis after ACDF.

Transoral and Endoscopic Endonasal Odontoidectomies – Surgical Techniques, Indications, and Complications

Odontoidectomy is indicated for some cases of ventral compression in the upper cervical spine. In this paper, we discuss the indications, surgical steps, and nuances of transoral odondoidectomy (TO) and endoscopic endonasal (EE) odontoidectomy. We compare both approaches and discuss the advantages and disadvantages of each. A broad narrative literature review was performed. We also added tips and surgical pearls of the senior author (KDR) in performing odontoidectomies. Surgical techniques were presented. EE is performed in patients where the dens is located above the nasopalatine line. Although technically more demanding, EE has less soft tissue injury and potentially less risk of dysphonia and dysphagia. The TO approach provides a wider exposure and is not limited by the nasopalatine line. Additionally, the TO approach allows the ability for a more extensive resection of C2; these could include the C2 body and the C2–3 disc space. Ventral reconstructions with cages and plates are also feasible via the TO approach. However, there are additional risks of prolonged intubation and tracheostomy with the TO approach. Surgeons who manage upper cervical spine disease should be comfortable performing both approaches, and selecting the best approach should be determined using patient-specific characteristics.

C1 Stenosis - An Easily Missed Cause for Cervical Myelopathy

C1 stenosis is often an easily missed cause for cervical myelopathy. The vast majority of cervical myelopathy occurs in the subaxial cervical spine. The cervical canal is generally largest at C1/2, explaining the relatively rare incidence of neurological deficits in patients with odontoid fractures. However, some subjects have anatomical anomalies of the atlas, which may cause stenosis and result in clinical symptoms similar to subaxial cord compression. Isolated pure atlas hypoplasia leading to stenosis is quite rare and may be associated with other anomalies, such as atlas clefts or transverse ligament calcification. It may also be more commonly associated with syndromic conditions such as Down or Turner syndrome. Although the diagnosis can be easily made with a cervical magnetic resonance imaging, the C3/2 spinolaminar test using a lateral cervical plain radiograph is a useful and sensitive tool for screening. Surgical treatment with a C1 laminectomy is generally necessary and any atlantoaxial or occipito-atlanto instability must be treated with spinal stabilization and fusion.

Evaluation of safety, effectiveness and reproducibility of telemedicine for neurosurgical screening

Objective:

To ascertain the safety, effectiveness and reproducibility of screening potential neurosurgical patients by means of smartphones.

Methods:

This is a retrospective and multicentric study. Data were collected from the medical records of patients subjected to real emergency neurosurgical evaluations and compared with assessments by neurosurgeons using smartphones to determine the feasibility of identifying changes in cranial computed tomography scans, potentially serious conditions of patients, and the need for transfer to reference centers.

Results:

We analyzed 232 cases. The main diagnosis was traumatic brain injury, with 119 cases (51.3%). Of this, 105 (45.3%) patients were discharged immediately after the assessment. The telemedicine evaluators presented 95.69% accuracy in the identification of changes in computed tomography scans, with 0.858 concordance. Accuracy in the identification of severity was 95.26%, with 0.858 concordance. As for procedure, the concordance among evaluators was 0.672, increasing to 100% in cases that required surgical treatment.

Conclusion:

Our study indicated that the use of telemedicine for screening patients with acute neurological disorders was safe, effective and reproducible. Implementation of the method shows a promising potential to improve the patient's outcome by reducing unnecessary transfers and decreasing the time elapsed until a specialist can be consulted.

Dynamic Cord Compression Causing Cervical Myelopathy

The diagnosis of cervical spondylotic myelopathy (CSM) is made based on clinical signs and symptoms, and then confirmed with magnetic resonance imaging (MRI) or CT myelogram. Due to the highly mobile nature of the cervical spine, and the fact that most MRIs and CTs are obtained only in one single position, dynamic cord compression can be an elusive diagnosis that is often missed and not well-understood. In this context, dynamic MRI (dMRI) has been utilized to improve the diagnostic accuracy of cervical stenosis in cases where static MRI does not provide enough information to establish a diagnosis or to provide additional information. We performed a literature review on dynamic cord compression in the context of CSM, with particular emphasis on the role of dynamic MRI (dMRI). Cadaveric studies report that the spinal cord lengthens in flexion and the spinal canal dimension increases, whereas the spinal cord relaxes and shortens in extension and the spinal canal decreases. These changes may lead to biomechanical stress in the spinal cord with movement, especially in patients with critical cervical stenosis. The majority of the studies using dMRI in CSM reported that this imaging modality is more sensitive at detecting cervical cord compression compared to routine MRIs done in a neutral position, especially with the neck in extension. Occult anterior compression has also been reported by some authors in flexion, but occurs less frequently. DMRI was also useful to diagnose dynamic cervical cord compression after laminectomies in patients with clinical deterioration without evident cord compression on neutral static MRI. Finally, dMRI are more sensitive in detecting stenosis in patients with CSM than in those with OPLL, likely because OPLL patients often have a more limited ROM than CSM patients. Thus, dMRI is a promising new tool that can help spine surgeons in diagnosing and treating CSM. However, further studies are needed to establish the utilization criteria and the clinical value of dMRI.

Dynamic Cord Compression Causing Cervical Myelopathy

Due to the highly mobile nature of the cervical spine, and the fact that most magnetic resonance imagings (MRIs) and computed tomography scans are obtained only in one single position, dynamic cord compression can be an elusive diagnosis that is often missed and not well-understood. In this context, dynamic MRI (dMRI) has been utilized to improve the diagnostic accuracy of cervical stenosis. We performed a literature review on dynamic cord compression in the context of cervical spondylotic myelopathy (CSM), with particular emphasis on the role of dMRI. Cadaveric studies report that the spinal cord lengthens in flexion and the spinal canal dimension increases, whereas the spinal cord relaxes and shortens in extension and the spinal canal decreases. These changes may lead to biomechanical stress in the spinal cord with movement, especially in patients with critical cervical stenosis. The majority of the studies using dMRI in CSM reported that this imaging modality is more sensitive at detecting cervical cord compression compared to routine MRIs done in a neutral position, especially with the neck in extension. Dynamic MRI was also useful to diagnose dynamic cervical cord compression after laminectomies in patients with clinical deterioration without evident cord compression on neutral static MRI. Finally, dMRI is more sensitive in detecting stenosis in patients with CSM than in those with ossification of the posterior longitudinal ligament (OPLL), likely because OPLL patients often have a more limited range of motion than CSM patients. Thus, dMRI is a promising new tool that can help spine surgeons in diagnosing and treating CSM.

Vertebral body chondrosarcoma with metastasis to the scalp

We present a case of a 30-year-old man who had a 3-year history of low back pain. MRI demonstrated an infiltrative mass, affecting the vertebral body and pedicles of L4, with some extension to the vertebral canal. There was also tumor invasion in the inferior vena cava and in the left iliopsoas muscle. The anatomopathological examination of the resected L4 vertebral body was of a malignant neoplasia compatible with mesenchymal chondrosarcoma (high histological grade). About 2 months after surgery, he developed a progressive bladder incontinence, bilateral leg weakness and severe back pain. A new MRI was obtained, confirming progression of the disease. An occipital scalp lesion was detected and biopsy confirmed cutaneous metastasis. Primary malignant bone tumors are rare but should be ruled out in young patients with persistent low back pain. We present a case of a confirmed mesenchymal chondrosarcoma affecting lumbar spine, with MRI and pathological illustrations. Early diagnosis may improve the chances of local disease control and even cure.