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Background: Ponticlus Posticus (PP) is a rare anomaly of the first cervical vertebra easily identifiable in lateral cephalometric radiograph and typically required for orthodontic diagnosis. The aim of this study is to evaluate the PP prevalence in lateral Cephalograms in a cohort of orthodontic patients treated at the Dental School of the University of Bari 'Aldo Moro', Italy, and to find possible connection between PP and other dental anomalies, as well as the patient's cephalometric characteristics. Methods: A total of 150 panoramic radiographs and 150 lateral Cephalograms, obtained for orthodontic use only, were evaluated. No patients were referred to for congenital syndromes or disease, or a history of previously occurred maxillofacial trauma. A detailed cephalometric study was performed for each patient, and the whole cohort was divided according to the common three dental malocclusion classes. The values obtained were analyzed using the Chi-Square Test. Results: PP prevalence was 8% (12 of 150 cases), where the complete and partial forms observed 4.7% and 3.3%, respectively. Although females were more affected (9.6%), no statistically significant sex-related difference was found. Furthermore, no statistically significant relationship regarding age or dental anomalies (dental agenesis/palatal impacted canines) among the groups was observed either. Cephalometric analyses revealed that half of the subjects with PP were sagittal skeletal class I and had vertical hyper-divergence. Conclusions: PP is a frequent anatomical variation of the cervical vertebra, apparently unrelated to the skeletal malocclusion type or dental anomalies. The current study needs to further confirm the congenital hypothesis of PP's origin already reported in literature. [ABSTRACT FROM AUTHOR]

Purpose: Ponticulus Posticus, atlantooccipital ligament ossification-induced anomaly, surrounds the vertebral artery and the first cervical nerve root. It is believed to wrap around the first cervical nerve root and the vertebral artery, causing compression. We hypothesized that it would also reduce the diameter of the vertebral artery., Methods: Between January 1, 2022, and December 31, 2022, cervical spine CT scans taken for any reason were retrospectively reviewed. The images of 1365 patients suitable for evaluation were evaluated by two expert radiologists in 3 dimensions. Among patients with PP, those who underwent cervical angiography were identified for vertebral artery diameter measurement., Results: The average age of the 1365 individuals included in the study (732 males, 633 females) was 55.78 (± 18.85) with an age range of 1-96. Among this group, PP was detected in 288 individuals, resulting in a total prevalence of 21.1%. Right and left vertebral artery diameters were significantly lower in patients with complete PP compared to the absent group (p < 0,001, p < 0,001, respectively). Additionally, it was observed that width and height diameters and artery diameters were positively correlated in patients with Complete PP., Conclusions: Ponticulus posticus can cause vertebrobasilar insufficiency by reducing the diameter of the vertebral artery. Therefore, imaging and detailed evaluation of this region are important in symptomatic patients., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Nablus mask-like facial syndrome (NMFLS) is an extremely rare genetic syndrome characterized by facial dysmorphia as well as developmental delay. In the present report we describe a potential association between non-traumatic atlanto-occipital dislocation and NMFLS in an 11-year old female lacking typical facial features of NMFLS., Case Description: An 11-year-old female with autism presented with symptoms of persistent headache and vomiting as well as neck stiffness. Further investigation and CT imaging revealed congenital malformation of the skull base and craniocervical junction with complete posterior subluxation of the left occipital condyle. MRI findings later corroborated the findings on CT., Conclusions: The patient was successfully treated with occipitocervical fusion. The findings in this case suggest the possibility that atlanto-occipital instability and generalized occipitocervical may be associated with NMFLS., Competing Interests: Declaration of Competing interest report no conflicts of interest. The authors alone are responsible for the content and writing of the article., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objective: Recent years have witnessed a rapidly growing interest in CVJ bony abnormalities, and a qualitative and quantitative analysis of relevant literatures is necessary. This study aims to identify and summarize the published articles related to craniovertebral junction bony abnormalities, to analyze and visualize the current research trends and major contributors., Methods: We collected data from Web of Science, excluding certain article types. Two researchers screened articles for relevance. Data were organized with EndnoteX9, and analyzed using VOSviewer and CiteSpace for co-authorship, co-occurrence, keyword burst, and co-citation analyses to identify research trends and collaborations., Results: A total of 2,776 articles were included, revealing an increasing trend in annual publications of CVJ bony abnormalities. The USA was the leading country. King Edward Memorial Hospital was the most prolific institution, and Seth GS Medical College had the most citations. The Spine is the most popular journal with the highest number of publications and citations. Professor Goel Atul from India emerged as the most influential pioneer in this field. Keyword analysis highlighted surgical techniques, diagnosis, and anatomy as the primary research hotspots and Fixation, Placement, and Basilar invagination gradually become the new research trend. However, there is a relative weakness in basic research and epidemiology., Conclusions: This study provides valuable insights into the current research trends and critical contributors in CVJ bony abnormalities, guiding evidence-based decisions and fostering international collaborations to advance knowledge in this field., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) following posterior fossa decompression (PFD). The objective of this study was to determine the prevalence of condylar hypoplasia and atlas anomalies in children with CM-I and syringomyelia. The authors also investigated the predictive contribution of these anomalies to the occurrence of OCF following PFD (PFD+OCF)., Methods: The authors analyzed the prevalence of condylar hypoplasia and atlas arch anomalies for patients in the Park-Reeves Syringomyelia Research Consortium database who underwent PFD+OCF. Condylar hypoplasia was defined by an atlanto-occipital joint axis angle (AOJAA) ≥ 130°. Atlas assimilation and arch anomalies were identified on presurgical radiographic imaging. This PFD+OCF cohort was compared with a control cohort of patients who underwent PFD alone. The control group was matched to the PFD+OCF cohort according to age, sex, and duration of symptoms at a 2:1 ratio., Results: Clinical features and radiographic atlanto-occipital joint parameters were compared between 19 patients in the PFD+OCF cohort and 38 patients in the PFD-only cohort. Demographic data were not significantly different between cohorts (p > 0.05). The mean AOJAA was significantly higher in the PFD+OCF group than in the PFD group (144° ± 12° vs 127° ± 6°, p < 0.0001). In the PFD+OCF group, atlas assimilation and atlas arch anomalies were identified in 10 (53%) and 5 (26%) patients, respectively. These anomalies were absent (n = 0) in the PFD group (p < 0.001). Multivariate regression analysis identified the following 3 CVJ radiographic variables that were predictive of OCF occurrence after PFD: AOJAA ≥ 130° (p = 0.01), clivoaxial angle < 125° (p = 0.02), and occipital condyle-C2 sagittal vertical alignment (C-C2SVA) ≥ 5 mm (p = 0.01). A predictive model based on these 3 factors accurately predicted OCF following PFD (C-statistic 0.95)., Conclusions: The authors' results indicate that the occipital condyle-atlas joint complex might affect the biomechanical integrity of the CVJ in children with CM-I and syringomyelia. They describe the role of the AOJAA metric as an independent predictive factor for occurrence of OCF following PFD. Preoperative identification of these skeletal abnormalities may be used to guide surgical planning and treatment of patients with complex CM-I and coexistent osseous pathology.

The craniovertebral junction not only contains anatomically important structures such as the medulla oblongata, upper cervical spinal cord, and vertebral artery, but also controls the dynamic movements of flexion, extension, and rotation of the head and neck. Consequently, instability and spinal deformities can easily occur in the craniovertebral region, and appropriate treatment should be selected based on the specificity of the lesion. Basilar invagination often involves bone and vascular anomalies and fusion surgery is often required. Therefore, careful pre-operative simulations are necessary. The creation and use of three-dimensional bone models, including image navigation, are useful for surgical simulation.

Objectives: Atlanto-occipital assimilation (AOA) is one of the most common skeletal anomalies of the craniovertebral junction (CVJ). Because its clinical symptomatology is non-specific and it has several variations, many cases go unnoticed which may lead to additional and unnecessary radiological examinations. In this study, we aimed to present CVJ abnormalities with MRI to improve diagnostic accuracy of AOA. Methods: Cervical MRIs of the patients registered in PACS between January 2008 and October 2011 were scanned and AOA was detected in 40 cases. Sagittal FSE T1 and T2-weighted cervical MRIs and axial T2*-GRE sequence images were re-evaluated for AOA typing, anterior atlantodental interval (AADI), posterior atlantodental interval (PADI) measurements, spine fusion anomalies, basilar invagination, tonsillar herniation, myelomalacia, suboccipital muscles and vertebral arteries (VAs). Results: CVJ abnormalities were present in all cases and the most frequent association was observed in suboccipital muscles (100%) and VAs (95%). 60% of the cases had decreased PADI, 32% C2-3 vertebrae fusion, 25% increased AADI, 22.5% basilar invagination, 15% myelomalacia and 5% tonsillar herniation. Conclusion: Suboccipital muscle abnormality was found in all AOA cases whatever the severity and type of the bony fusion. VA anomaly was observed as the second most common abnormality and accompanied preferably the cases with lateral body involvement. Being aware of additional CVJ abnormalities in MRI examinations may reduce unnecessary radiological examinations by increasing the AOA diagnosis rate. [ABSTRACT FROM AUTHOR]

Background: Unstable conditions of the craniocervical junction such as atlanto-occipital dislocation (AOD) or atlanto-axial instability (AAI) are severe injuries with a high risk of tetraplegia or death. Immobilization by a cervical collar to protect the patient from secondary damage is a standard procedure in trauma patients. If the application of a cervical collar to a patient with an unstable craniocervical condition may cause segmental motion and secondary injury to the spinal cord is unknown. The aim of the current study is (i) to analyze compression on the dural sac and (ii) to determine relative motion of the cervical spine during the procedure of applying a cervical collar in case of ligamentous unstable craniocervical junction. Methods and findings: Ligamentous AOD as well as AOD combined with ligamentous AAI was simulated in two newly developed cadaveric trauma models. Compression of the dural sac and segmental angulation in the upper cervical spine were measured on video fluoroscopy after myelography during the application of a cervical collar. Furthermore, overall three-dimensional motion of the cervical spine was measured by a motion tracking system. In six cadavers each, the two new trauma models on AOD and AOD combined with AAI could be implemented. Mean dural sac compression was significantly increased to -1.1 mm (-1.3 to -0.7 mm) in case of AOD and -1.2 mm (-1.6 to -0.6 mm) in the combined model of AOD and AAI. Furthermore, there is a significant increased angulation at the C0/C1 level in the AOD model. Immense three-dimensional movement up to 22.9° of cervical spine flexion was documented during the procedure. Conclusion: The current study pointed out that applying a cervical collar in general will cause immense three-dimensional movement. In case of unstable craniocervical junction, this leads to a dural sac compression and thus to possible damage to the spinal cord. [ABSTRACT FROM AUTHOR]

Objective : Craniovertebral junctional anomalies constitute a technical challenge. Surgical opening of atlantoaxial joint region is a complex procedure especially in patients with nuchal deformity like basilar invagination. This region has actually very complicated anatomical and functional characteristics, including multiple joints providing extension, flexion, and wide rotation. In fact, it is also a bottleneck region where bones, neural structures, and blood vessels are located. Stabilization surgery regarding this region should consider the fact that the area exposes excessive and life-long stress due to complex movements and human posture. Therefore, all options should be considered for surgical stabilization, and they could be interchanged during the surgery, if required. Methods : A 53-year-old male patient applied to outpatients’ clinic with complaints of head and neck pain persisting for a long time. Physical examination was normal except increased deep tendon reflexes. The patient was on long-term corticosteroid due to an allergic disease. Magnetic resonance imaging and computed tomography findings indicated basilar invagination and atlantoaxial dislocation.The patient underwent C0–C3–C4 (lateral mass) and additional C0–C2 (translaminar) stabilization surgery. Results : In routine practice, the sites where rods are bound to occipital plates were placed as paramedian. Instead, we inserted lateral mass screw to the sites where occipital screws were inserted on the occipital plate, thereby creating a site where extra rod could be bound.When C2 translaminar screw is inserted, screw caps remain on the median plane, which makes them difficult to bind to contralateral system. These bind directly to occipital plate without any connection from this region to the contralateral system.Advantages of this technique include easy insertion of C2 translaminar screws, presence of increased screw sizes, and exclusion of pullout forces onto the screw from neck movements. Another advantage of the technique is the median placement of the rod; i.e., thick part of the occipital bone is in alignment with axial loading. Conclusion : We believe that this technique, which could be easily performed as adjuvant to classical stabilization surgery with no need for special screw and rod, may improve distraction force in patients with low bone density. [ABSTRACT FROM AUTHOR]

Background: Although upper cervical and upper thoracic spine mobilization plus therapeutic exercises are common interventions for the management of forward head posture (FHP), no study has directly compared the effectiveness of cervical spine mobilization and stabilization exercise with that of thoracic spine mobilization and mobility exercise in individuals with FHP.Methods: Thirty-two participants with FHP were randomized into the cervical group or the thoracic group. The treatment period was 4 weeks, with follow-up assessment at 4 and 6 weeks after the initial examination. Outcome measures including the craniovertebral angle (CVA), cervical range of motion, numeric pain rating scale (NPRS), pressure pain threshold, neck disability index (NDI), and global rating of change (GRC) were collected. Data were examined with a two-way repeated-measures analysis of variance (group × time).Results: Participants in the thoracic group demonstrated significant improvements (p < .05) in CVA, cervical extension, NPRS, and NDI at the 6-week follow-up compared with those in the cervical group. In addition, 11 of 15 (68.8%) participants in the thoracic group compared with 8 of 16 participants (50%) in the cervical group showed a GRC score of +4 or higher at the 4-week follow-up.Conclusions: The combination of upper thoracic spine mobilization and mobility exercise demonstrated better overall short-term outcomes in CVA (standing position), cervical extension, NPRS, NDI, and GRC compared with upper cervical spine mobilization and stabilization exercise in individuals with FHP.Trial Registration: KCT0002307 , April 11, 2017 (retrospectively registered). [ABSTRACT FROM AUTHOR]

Objective For many years, the microsurgical transoral approach has been accepted as the gold standard for anterior decompressions of the craniovertebral junction (CVJ). The introduction of the endoscopic endonasal approach (EEA) has gained wide recognition and overwhelming support in recent years, including for diseases of the CVJ. The aim of this study was to critically analyze and discuss all cases of CVJ diseases approached by means of an EEA so far reported in the literature, including our institutional experience consisting of 6 consecutive patients. Methods Six consecutive patients affected by CVJ disease underwent an EEA. Three patients had a tumor (2 chordomas and 1 myeloma) and 3 had impressio basilaris. Results Five patients had an uncomplicated postoperative course and 1 developed an intraoperative cerebrospinal fluid leak and subsequent meningitis and died 5 weeks after surgery. A total of 107 patients (including our 6) affected by CVJ disease and treated with EEA have been reported so far. Among these patients, cerebrospinal fluid leak was reported in 13 (12.4%), transient velopharyngeal incompetence in 6 (5.6%), postoperative epistaxis in 2 (1.86%), and respiratory dysfunction requiring a tracheostomy in 2 (1.86%). In our extended institutional series of more than 20 consecutive anterior decompressions for CVJ diseases (including transoral and transnasal microsurgical approaches), the only fatal complication was associated with EEA. Conclusions On the basis of the reviewed literature and our personal experience, the reported increased safety of the EEA needs to be reassessed and discussed. [ABSTRACT FROM AUTHOR]

Purpose: To describe vertebral artery (VA) course at the C0-C1-C2 complex in patients with congenital bony craniovertebral junction (CVJ) anomalies.Methods: We studied the course of 169 VAs in 86 patients with congenital bony CVJ anomalies [basilar invagination (42), os odontoideum (33), and irreducible atlantoaxial dislocation (11)]. Occipitalized atlas occurred in 41 patients (30 complete and 11 partial). Using axial, coronal and sagittal three-dimensional computed tomography (3D-CT) angiograms, we traced the VA bilaterally at the CVJ and correlated the course to the presence or absence of occipitalization of the atlas.Results: Of the 73 arteries associated with occipitalization of atlas, all had an abnormal course-58 (78.4 %) coursed through a canal within the C0-C1 fused complex and 15 (20.3 %) coursed below the C1 posterior arch, and it was absent unilaterally in one patient. There were 96 arteries associated with a non-occipitalized atlas and only 15 (15.3 %) were abnormal-eight coursed below the C1 posterior arch, four coursed above the C1 arch in the absence of a C1 foramen transversarium, one passed through a canal in C0-C1 and two arteries were absent unilaterally. Sixty vertebral arteries (34 on the right and 26 on the left side) had a redundant loop situated at a distance of ≥5 mm from the C1 lateral mass in patients with os odontoideum and irreducible atlantoaxial dislocation.Conclusions: In occipitalization of the atlas, the VA course is usually abnormal-typically passing through a canal within the C0-C1 fused complex or below the C1 arch. A redundant VA loop is more likely to be seen in os odontoideum and irreducible atlantoaxial dislocation. Careful study of the vertebral artery course with 3D CT angiography is mandatory while contemplating CVJ realignment surgery in congenital anomalies of the CVJ. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to assess the effects of 4-week postural corrective exercise program on forward head posture in college-aged females. Materials and Methods: This is a randomized controlled study. Twenty-one female students with craniovertebral angle measured less than or equal to 50 degrees were selected and randomly assigned to intervention (n=12) or control (n=9) group. Intervention group performed forward head posture corrective exercises in the form of stretching and strengthening exercises. The craniovertebral angle, active neck flexion range of motion and strength of lower and middle trapezius were measured before and after 4 weeks exercise program. Results: After four weeks, significant increases were observed in the intervention group regarding the means of craniovertebral angle (P=0.0001), active neck flexion range of motion (P=0.04) and lower trapezius strength (P=0.03), while the mean strength of middle trapezius had not changed significantly (P>0.05). Conclusion: Four week intervention protocol successfully improved postural alignment related to forward head posture. Thus, corrective exercise program for 4 weeks is effective to decrease forward head posture. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective study.Objective: To investigate whether clivodens angle (CDA) could diagnose basilar invagination (BI) at computed tomography (CT).Summary Of Background Data: Over the years, multiple craniometric methods such as Chamberlain line, McGregor line, McRae line, Wackenheim clivus baseline, and Welcher basal angle have been described for evaluation of craniovertebral junction anomalies, initially with radiography and later with CT. However, such a variety of measurements in turn reflects the difficulty in making a definite diagnosis of BI and there is a certain disadvantage in all of these criteria because the anatomic landmarks vary within a normal range.Methods: CDA, described an angle formed at the intersetion of a line that runs along the long axis of the clivus and one that runs along the long axis of the dens, was measured on mid-sagittal reconstructed CT images from 63 BI patients and 100 control participants to compare the two groups by using independent-sample t test. Interobserver reliability was evaluated with Kendall correlation coefficient. For evaluating the diagnostic performance and determining the cutoff value of CDA, receiver operating characteristic curve was utilized.Results: The measurement of CDA showed good interobserver agreement (KCC = 0.891). Compared with control participants whose mean value was 135.8 degrees ± 9.2 (range, 118-156°), BI patients had a significantly smaller one (P < 0.001), 110.4 degrees ± 15.8 (range, 55-140°). The area under receiver operating characteristic curve was 0.937 (95% confidence interval: 0.901, 0.973), and the cutoff value of 125 degrees had the largest Youden index (J), 0.715.Conclusion: Having a better diagnostic performance than clivoaxial angle, CDA can be utilized for diagnosing BI.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Introduction: A rigid construct that employs an occipital plate and upper cervical screws and rods is the current standard treatment for craniovertebral junction (CVJ) instability. A rod is contoured to accommodate the occipitocervical angle. Fatigue failure has been associated these acute bends. Hinged rod systems have been developed to obviate intraoperative rod contouring. Object: The aim of this study is to determine the safety and efficacy of the hinged rod system in occipitocervical fusion. Materials and Methods: This study retrospectively evaluated 39 patients who underwent occipitocervical arthrodesis. Twenty patients were treated with hinged rods versus 19 with contoured rods. Clinical and radiographic data were compared and analyzed. Results: Preoperative and postoperative Nurick and Frankel scores were similar between both groups. The use of allograft, autograft or bone morphogenetic protein was similar in both groups. The average number of levels fused was 4.1 (±2.4) and 3.4 (±2) for hinged and contoured rods, respectively. The operative time, estimated blood loss, and length of stay were similar between both groups. The occiput to C2 angle was similarly maintained in both groups and all patients demonstrated no movement across the CVJ on flexion-extension X-rays during their last follow-up. The average follow-up for the hinged and contoured rod groups was 12.2 months and 15.9 months, respectively. Conclusion: Hinged rods provide a safe and effective alternative to contoured rods during occipitocervical arthrodesis. [ABSTRACT FROM AUTHOR]

Study Design: This is a cross-sectional analysis of resonance magnetic images of 111 patients with craniocervical malformations and those of normal subjects.Objective: To test the hypothesis that atlas assimilation is associated with basilar invagination (BI) and atlas's anterior arch assimilation is associated with craniocervical instability and type I BI.Summary Of Background Data: Atlas assimilation is the most common malformation in the craniocervical junction. This condition has been associated with craniocervical instability and BI in isolated cases.Methods: We evaluated midline Magnetic Resonance Images (MRIs) (and/or CT scans) from patients with craniocervical junction malformation and normal subjects. The patients were separated into 3 groups: Chiari type I malformation, BI type I, and type II. The atlas assimilations were classified according to their embryological origins as follows: posterior, anterior, and both arches assimilation.Results: We studied the craniometric values of 111 subjects, 78 with craniocervical junction malformation and 33 without malformations. Of the 78 malformations, 51 patients had Chiari type I and 27 had BI, of whom 10 presented with type I and 17 with type II BI. In the Chiari group, 41 showed no assimilation of the atlas. In the type I BI group, all patients presented with anterior arch assimilation, either in isolation or associated with assimilation of the posterior arch. 63% of the patients with type II BI presented with posterior arch assimilation, either in isolation or associated with anterior arch assimilation. In the control group, no patients had atlas assimilation.Conclusion: Anterior atlas assimilation leads to type I BI. Posterior atlas assimilation more frequently leads to type II BI. Separation in terms of anterior versus posterior atlas assimilation reflects a more accurate understanding of the clinical and embryological differences in craniocervical junction malformations.Level Of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Background: Craniovertebral junction (CVJ) abnormalities constitute an important group of treatable neurological disorders with diagnostic dilemma. Their precise diagnosis, identification of probable etiology, and pretreatment evaluation significantly affects prognosis and quality of life of patients. Aims: The study was to classify various craniovertebral junction disorders according to their etiology and to define the importance of precise diagnosis for pretreatment evaluation with multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI). Materials and Methods: This is a prospective observational study of 62 patients referred to our department between October 2012 and September 2014. All patients suspected to have a craniovertebral junction disorder were included in the study, from all age groups and both genders. Detailed clinical history was taken. Radiographs of cervical spine were collected if available. All patients were subjected to MDCT and/or MRI. Results: In our study of 62 patients; 39 were males and 23 were females, with male to female ratio of 1.6:1. Most common age group was 2nd-3rd decade (19 patients, 30.64%). Developmental anomalies (33 patients, 53.22%) were the most common etiology group followed by traumatic (10 patients, 16.12%), degenerative (eight patients, 12.90%), infective (four patients, 6.45%), inflammatory and neoplastic (three patients each, 4.8%), and no cause found in one patient. Conclusions: CVJ abnormalities constitute an important group of treatable neurological disorders, especially in certain ethnic groups and are approached with much caution by clinicians. Thus, it is essential that radiologists should be able to make a precise diagnosis of craniovertebral junction abnormalities, classify them into etiological group, and rule out important mimickers on MDCT and/or MRI, as this information ultimately helps determine the management of such abnormalities, prognosis, and quality of life of patients. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to review cases of paediatric patients with craniovertebral junction (CVJ) tuberculosis with a view to try and stratify the cases into different groups which would help plan treatment and hence develop a protocol for treatment of a fairly uncommon condition still widely seen in the developing world. Methods: Twenty-three cases of paediatric craniovertebral tuberculosis had their clinical features and radiology reviewed. The treatment plan in each case was analyzed according to their presentation. The results of treatment after 1 year were assessed in each case. Results: The clinical presentations varied from neck pain with hypoglossal nerve palsy to frank spastic quadriparesis, and frank instability at the atlanto-axial junction was seen in five out of 23 patients. Cold abscesses were seen in 18/23 cases, and severe torticollis was the presentation in 6/23. We graded the children with this condition into three groups: Only one child in group 3 required delayed intervention for instability which developed after completion of the course of anti-tubercular medication. Conclusions: We concluded that children with craniovertebral tuberculosis should be treated according to their clinical presentation coupled with evidence of radiological instability. Those with gross deficit and instability need early stabilization, those with minimal deficit and no instability but severe pain or torticollis need aspiration of the cold abscess with external immobilization, whereas those without deficit, instability or severe pain may be managed by external orthoses alone. Of course, medical treatment for tuberculosis is necessary in each case. [ABSTRACT FROM AUTHOR]

Craniovertebral junction surgery involves an appropriate philosophical, biomechanical and anatomical understanding apart from high degree of technical skill and ability of controlling venous and arterial bleeding. The author presents his 30-year experience with treating complex craniovertebral junction instability related surgical issues. The facets of atlas and axis form the primary site of movements at the craniovertebral junction. All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint. Direct manipulation and fixation of the facets forms the basis of treatment for instability. [ABSTRACT FROM AUTHOR]

Purpose: Among extraosseous abnormalities of the vertebral artery (VA) at the craniovertebral junction (CVJ), available evidence regarding "posterolateral protrusion," the VA running distant from the groove over the superior surface of the posterior arch of the atlas, is limited. The purpose of this study was to determine the optimal measurement to indicate posterolateral protrusion of the VA. Materials and Methods: Computed tomography angiography (CTA) images of 40 consecutive patients with cervical disease were reviewed. Ultimately, 66 arteries were included in this study. Five parameters predicted to indicate posterolateral protrusion of the VA were defined (A-E) and measured by two surgeons twice over a 2-week interval. Intraclass correlation coefficients (ICC) were used to examine intra-observer reproducibility and inter-observer reliability. Receiver operating characteristic (ROC) curve analysis was performed to determine the most optimal parameter to predict posterolateral protrusion of the VA. Results: Excellent inter-observer reliability and intra-observer reproducibility were obtained for all parameters (ICC = 0.87-0.99). Among them, parameter A, defined as the maximal length from the outer surface of the VA to the outer surface of the posterior arch of the atlas, was most accurately described posterolateral protrusion of the VA. The optimal cut-off value of parameter A obtained with ROC curves was 8.3 mm (sensitivity 97.5%, specificity 100%). Conclusions: The measurement in this study can quantitatively evaluate the posterolateral protrusion of the VA. Before posterior surgery at the CVJ, pre-operative CTA can help surgeons detect anomalous VA and reduce the risk of intra-operative VA injury. [ABSTRACT FROM AUTHOR]

The author explains a proposed alternative concept in the management of basilar invagination and an analysis of the clinical course and management issues in approximately 1000 surgically treated cases. He describes the role of long-stading instability in structural alterations in soft tissues and bones which lead to basilar invagination. He also discusses surgical management procedures for all basilar invagination cases.

Purpose: The purpose of this study was to review our experience of rigid internal fixation of craniovertebral junction in pediatric population. A new technique of reduction of basilar invagination with atlantoaxial dislocation is described. To the best of our knowledge and available scientific literature, this technique has not yet been described in younger patients. Methods: We have managed 27 children by rigid variety of occiput/C1-C2-C3 internal fixation of various craniovertebral junction pathologies. All patients were subjected to thin cuts of computed tomography with 3D reconstruction for selecting appropriate rigid construct. Eight children had occiput-C2, 3 had occiput-C2-C3, and 16 had C1-C2 hardware constuct. One patient of C1-C2-plate fixation had section of C2 nerve root ganglia. Basilar invagination with atlantoaxial dislocation was reduced by new distraction/compression techniques. Results: Improvement in clinical features and correction of deformity with solid hardware construct were seen in all patients. Follow-up period ranged from 5-72 months. One patient was lost to follow-up, and one case died of compression of vertebral artery at C1 lateral mass. Patients of myelopathy had recovery rate of 90.9 %. Hardware failure was seen in one patient, and wound infection was observed in two cases. Conclusions: Rigid variety of occiput/C1-C2 internal fixation is a safe and effective method in the management of variety of craniovertebral pathologies in pediatric population. This new technique of reduction of basilar invagination with atlantoaxilal dislocation from posterior approach may alleviate the need of high morbity associated with surgical procedure like transoral odontoidectomy in younger patients. [ABSTRACT FROM AUTHOR]

Abstract: Background context: Atlantooccipital dislocation (AOD) results in profound patient morbidity and mortality and is difficult to accurately diagnose using current evaluation techniques. Purpose: To evaluate the utility of computed tomography (CT) images in the diagnosis of AOD and compare the revised occipital condyle–C1 interval (CCI) and the condylar sum to the current radiographic criteria used to detect AOD. Study design: Retrospective review to evaluate the sensitivity, specificity, and the interobserver reliability of eight radiographic criteria as applied to CT imaging. Patient sample: Ten cases of clinical AOD and 10 cases of non-AOD cervical injury. Outcome measures: Measured values: revised CCI, Wholey basion-dens interval (BDI), and Harris basion-axis interval (BAI). Calculated values: Sun interspinous ratio, Powers ratio, and condylar sum. Assessment of Lee X-line and atlantooccipital joint asymmetry. Methods: A board certified neuroradiologist, two orthopedic spine surgeons, and two medical students reviewed the CT images for each patient in the series and applied the aforementioned criteria. Results: Average sensitivity between all reviewers for CCI, condylar sum, and atlantooccipital asymmetry was highest at 1.0, 1.0, and 0.96, respectively. Basion-dens interval, X-line, Sun ratio, BAI, and Powers ratio had sensitivities of 0.72, 0.54, 0.32, 0.26, and 0.26, respectively. Revised CCI and condylar sum had significantly better sensitivity than any other test (vs. BDI, p=.014, all others, p<.001) except atlantooccipital asymmetry (p>.99). Specificity for all measurements was 0.78 or greater, except X-line at 0.38. Interobserver reliabilities were the greatest for CCI, condylar sum, atlantooccipital asymmetry, and BDI. Conclusions: The revised CCI (>2.5 mm abnormal) and condylar sum (≥5 mm abnormal) are highly sensitive and reliable radiographic criteria for the detection of AOD when applied to CT imaging. [Copyright &y& Elsevier]

Background: Congenital partial anterior arch defect of the atlas is extremely rare. It could be found as an incidental radiological finding or patients can present with neurological deficit after head or neck trauma. Objective: To describe an extremely rare presentation of anterior midline cleft at the atlas and congenital posterior atlanto-occipital fusion with symptomatic anterior atlantoaxial subluxation. This report includes a feasible hypothesis for the development of this anomaly on the basis of previous hypotheses and surgical findings. Methods: A 46-year-old female presented with a 6-day history of right limbs numb and left upper and lower extremities paraparesis (Frankel D). Radiographs of the cervical spine showed anterior atlantoaxial subluxation with congenital posterior atlanto-occipital fusion. Computed tomography subsequently revealed partial midline absence of the anterior arch of the atlas and the odontoid tip ahead of the anterior arch of the atlas. Magnetic resonance imaging showed that the cervical dura was compressed by the remnant of anterior arch of the atlas. The patient underwent Gardner-Wells tong traction and surgery of occipitocervical fusion with autogenous iliac bone graft because she had definite neurological symptom and congenital posterior atlanto-occipital fusion. Results: Atlantoaxial reduction was confirmed with fluoroscopic X-ray evaluation by bed, her neurological deficit was resolved from Frankel D to E, and numb of right limbs completely disappeared 6 days postoperation. No instability has been observed during 2-year follow-up. Conclusion: We describe the association between compressive myelopathy and congenital defect of the anterior arch of the atlas with symptomatic anterior atlantoaxial subluxation. Both computed tomography and magnetic resonance image were required to demonstrate the bony configuration and cord compression. And Gardner-Wells tong traction and surgery of occipitocervical fusion with autogenous iliac bone graft were effective as a treatment for this compressive myelopathy caused by the remnant of anterior arch of the atlas. [ABSTRACT FROM AUTHOR]

Abstract: Behavior problems in horses are often thought to be due to the horse’s bad attitude, which commonly results in them being punished. However, when these cases are carefully worked up, there may be an underlying physical problem, and pain may play an important role. A 5-year-old Dutch Warmblood mare was presented for rearing and flipping over backward. The mare had been repeatedly examined by an equine veterinarian and a nonveterinarian equine dentist who found no abnormalities. Several different bits were tried, and side reins were used to keep her head down. The mare was whipped every time she reared. None of these measures helped. On presentation to our equine teaching hospital, no abnormalities were detected on routine physical examination. The behavior was observed when the mare was lunged; as soon as a small amount of tension was put on the lunge rein, the mare shook her head horizontally for approximately 1-2 seconds, reared, and flipped over onto her back. Neurological examination revealed that the mare was slow to resume a normal stance when her hind legs were placed in an abnormal position. Dental examination and endoscopy of the upper airways proved unremarkable. Radiography of the atlanto-occipital joint area revealed fractures of the first and second cervical vertebrae and fracture fragments, which are both suggestive for the presence of cervical instability and the possible presence of spinal cord compression. These suggestions were further supported by identification of delayed postural reflexes during neurological examination. The mare was deemed unfit for dressage and was successfully kept for breeding. Horses are frequently punished for “bad behavior.” These behaviors are frequently due to underlying physical problems and not a “nasty” horse. This case highlights the importance of careful history taking and a thorough veterinary examination with the use of further diagnostics (if necessary) when dealing with equine behavior problems. [Copyright &y& Elsevier]

Abstract: We aim to report our experience treating craniovertebral junction malformations (CVJM) and to investigate the management of this uncommon condition. Between 2000 and 2009, 629 patients with CVJM underwent surgery in our department. Fifty-three patients were lost to follow-up; therefore 576 patients completed follow-up, for an average period of 3years and 2months. All patients were diagnosed on the basis of clinical presentation and imaging features, and we found that anomalies of the occipitocervical junction manifested as four major types. Different microsurgical treatments were carried out in these patients according to disease type, and the effectiveness of individualised treatments was analysed. Categorizing patients with CVJM into these four types to simplify this somewhat unclear area could provide insight into the pathogenesis of the anomaly and a basis for rational surgical treatment. [Copyright &y& Elsevier]

The aim of the study was to evaluate the results of instrumented rod and wire fusion in children with craniovertebral junction (CVJ) instability and os odontoideum. We evaluated seven children (mean age 9.85 years) with Down and Morquio’s syndromes and primary os odontoideum. X-ray, computerized tomography (CT) scan and magnetic resonance (MR) imaging of the CVJ showed reducible instability in all of the cases but one. All the children underwent surgical correction by means of posterior wiring, instrumentation, fusion and external orthosis. A posterior wiring technique was also utilized in the only child with irreducible preoperative atlantoaxial instability, which, however, proved to be reducible under general anesthesia. At maximum follow-up (observation range 28 to 106 months, mean 59.42 months), the clinical picture was improved in all the patients. The postoperative neuroradiological investigations demonstrated satisfactory bony fusion with neural decompression in all patients. A wiring technique to correct atlantoaxial instabilities has been shown to be more relevant in these children with syndromic atlantoaxial dislocation and os odontoideum due to its simplicity, safety (continuous fluoroscopic assistance is not necessary and there is no risk of neuro-vascular injuries) and lower costs (no complex hardware devices; no neuronavigation systems are required). Preoperative irreducibility of the C1-C2 shift is not an absolute criterion for transoral decompression in children since os odontoideum can be reduced under general anesthesia. [ABSTRACT FROM AUTHOR]

The article presents abstracts related to pediatric neurosurgery which include an assessment of the occipito-cervical junction and cervical spine fusion in children at Great Ormond Street Hospital in Great Britain, craniovertebral junction anomalies among children in India, and treatment of lumbar disc prolapse in children.

Abstract Introduction  The craniocervical junction is affected by numerous pathological processes. This involves congenital, developmental, and acquired abnormalities. It can result in neurological deficit secondary to neurovascular compression, abnormal cerebrospinal fluid dynamics, and craniovertebral instability. A physiological approach based on an understanding of the craniovertebral junction dynamics, the site of encroachment and stability was formulated in 1977 and has stood the test of time. The author has reviewed 5,300 patients with neurological symptoms and signs secondary to an abnormality of the craniocervical junction. This includes 2,100 children. Treatment of craniovertebral junction abnormalities  The factors that influence the specific treatment are: (1) reducibility of the lesion, (2) mechanics of compression and the direction of encroachment, (3) the presence of abnormal ossification centers and epiphyseal growth plates, and (4) the cause of the pathological process. Stability at the craniocervical junction  Instability at the craniocervical junction is considered when the predental space is more than 5 mm in children below the age of 8, when the separation of the lateral atlantal masses is more than 6 mm where the cruciate ligament is felt to be disrupted, and if there is vertical translation of more than 2 mm between the clivus and the odontoid process signifying occipital instability. The gap between the occipital condyle and the lateral atlas facet should never be visible on lateral cervical radiographs. Present day magnetic resonance imaging can visualize disrupted transverse cruciate ligament, alar ligaments, tectorial membrane, and bony malalignment. The primary aim of treatment is to relieve compression at the cervicomedullary junction. Hence, stabilization is paramount in reducible lesions to maintain neural decompression. Irreducible lesions require decompression at the site where the compression has occurred; these were divided into ventral and dorsal compression states. In the former compression state, the operative procedure was a ventral decompression through a palatopharyngeal route, LeForte dropdown maxillotomy, or the lateral extrapharyngeal approach. In dorsal or dorsolateral compression states, a posterolateral decompression is required. If instability is present after decompression, posterior fixation is mandated. [ABSTRACT FROM AUTHOR]

The upper cervical spine is a common focus of destruction from rheumatoid arthritis (RA). Atlanto-axial subluxation (AAS) presents with marked frequency among patients with instability. However, there are occasional patients who show no motion between the occipital bone and atlas on a dynamic cervical radiograph in AAS patients. This study investigated the morphology of the atlanto-occipital joint (AOJ) in AAS patients due to RA using computed tomography, and examined the relationship between its morphology and other radiographic results. Twenty-six consecutive patients with AAS due to RA treated by surgery were reviewed. The subjects included 18 females and 8 males. The average patient age was 59.3 years. The mean duration of RA was 14.3 years. In all the patients, the AOJ was morphologically evaluated using sagittal reconstruction view on computed tomography before surgery. Moreover, the ADI value was investigated at the neutral and maximal flexion position, and atlanto-axial angle (AAA) at the neutral position in preoperative lateral cervical radiographs. The morphology of the AOJ on a CT sagittal reconstruction view was classified into three types as follows: a normal type which showed a maintenance of the joint space, a narrow type which showed a disappearance of the joint space and a fused type which showed the fusion of the AOJ. The pre-operative CT sagittal reconstruction image of the AOJ demonstrated a normal type bilaterally in six cases (Group A). In 15 cases (Group B), CT image demonstrated narrowing on at least one side of the AOJ. In five cases (Group C), CT images demonstrated fusion on at least one side of the AOJ. The average ADI value at the flexion position was 10.7 mm in Group A, 11.7 mm in Group B, and 12.6 mm in Group C. There was no significant difference among those groups. The average ADI value at the neutral position before surgery was 2.8 mm in Group A, 5.9 mm in Group B, and 10.4 mm in Group C. There was no significant difference between Group A and B ( P > 0.105), and Groups B and C ( P > 0.032), however, there was a significant difference between Groups A and C ( P < 0.004). The average AAA value was 25.3° in Group A, 19.3° in Group B and 3.4° in Group C. There was no significant difference between Groups A and B ( P > 0.230), however, there was a significant difference between Groups A and C ( P < 0.002), and Groups B and C ( P < 0.007). This study showed that fusion or ankylosis of the AOJ induced an enlargement of the ADI and anterior inclination of the atlas in the neutral position, despite the fact that normal findings of AOJ showed a slight displacement of the atlas to axis in RA patients showing AAS involvement. This morphology may progress to SAS and VS due to AOJ after atlanto-axial arthrodesis. [ABSTRACT FROM AUTHOR]

We determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies. The course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale. Of the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome. In planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance. [ABSTRACT FROM AUTHOR]

The article presents information for healthcare providers on atlanto-occipital and atlanto-axial instability and subluxation. A description of the pathology of the cervical spine as it transpires in Down Syndrome is also presented. The article also reviews guidelines on spine clearance and tackles the details and controversy which surrounds The Special Olympics Inc mandate. Recommendations on how to improve screening to ensure the safety of Special Olympians with Down Syndrome are also included.

Breath-holding or reflex anoxic seizures predominantly occur in preschool children and usually resolve by late childhood, rarely persisting through adolescence and into adulthood. Investigations are generally unnecessary. Education and reassurance is the mainstay of management. In this report, the author describes a case in which an infant presented with breath-holding spells due to a significant craniovertebral anomaly, and underwent a C1-C2 posterior stabilization. Following the stabilization of his dislocation the breath-holding spells never reappeared. Authors have previously described a rare manifestation of craniovertebral junction anomaly. Additionally, it is important to recognize that in a subset of patients breath-holding spells may be hazardous and not benign. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The article presents a case study of a three-month-old male ferret with a history of acute nonambulatory tetraparesis and head tilt. The ferret underwent into neurological examination and was diagnosed with cervical scoliosis. The article discusses occipitoatlantoaxial malformation, computed tomography (CT), and postmortem myelography.

The article describes the case of a 26-year-old male who presented with progressive compressive myelopathy and left shoulder numbness since last 6 months. He was diagnosed with Klippel Feil syndrome (KFS) with vertebral artery (VA) anomaly at craniovertebral junction (CVJ). Direct posterior open reduction and fusion was conducted on the patient.

COMMENTARY ON: Gire JD, Roberto RF, Bobinski M, et al. The utility and accuracy of computed tomography in the diagnosis of occipitocervical dissociation. Spine J 2013;13:510–9 (in this issue). [Copyright &y& Elsevier]

The article offers the author's insights on the study conducted by C. M. Bach, D. Arbab, and M. Thaler on the treatment for a 13-year-old girl with progressive quadriparesis. The author states that the need for surgery in such case will depend on clinical symptoms and presence of cord signal variations on magnetic resonance imaging (MRI). The author mentions that the facets of craniovertebral junction of C1, C1, and C2 joint are the strongest of all facets.

Atlas occipitalization (AO) is a spinal anomaly, characterized by the fusion of the first cervical vertebra and occipital bone, with a complex etiology that can arise from congenital and environmental causes. AO has been reported in three regions of pre-Hispanic Peru in skeletal remains with artificial cranial modification (ACM), which involves the use of compression devices to permanently alter cranial shape and may have affected the fusion of the atlas and occipital bone. The aims of this study were to gain insights into AO's etiology by testing correlations between AO and ACM presence/type and geographic region as well as to characterize morphological variation associated with AO. We investigated the geographic distribution of AO and its potential relationship to ACM in a large sample of human crania from eight coastal and highland regions of pre-Hispanic Peru, held at the Smithsonian's National Museum of Natural History (n = 608, 1300-1500 CE). Eleven cases of AO were observed in three coastal regions-including two previously unreported regions-at an overall frequency of 1.8%. The frequency of AO did not differ significantly between crania with and without ACM, in general or by type, suggesting that ACM is not an etiological factor that influences AO in this sample. AO was observed at a significantly higher rate in the southern coastal region of Arequipa than in any other region. Genetic, dietary, and epidemiological conditions are evaluated as factors possibly shaping the geographic distribution of AO along the central and southern coasts of Peru., Competing Interests: The authors have declared that no competing interests exist.

Objective: To assess the correlation between craniovertebral junction (CVJ) abnormalities and syringomyelia in patients with Chiari malformation type-1 (CM1)., Methods: This was a retrospective study including patients with CM1. Identification of cases was done by searching a radiology database at a university hospital from 2012 to 2017. Patients were divided into 2 groups based on whether CVJ abnormalities were present (CVJ+) or absent (CVJ-). The patients` demographic and clinical data were reviewed. All magnetic resonance imaging studies were examined by a certified neuroradiologist., Results: Sixty-four consecutive patients with CM1 were included. The mean age was 24+/-17 years; 59% were females. The CVJ+ group had more female patients (p=0.012). The most frequent CVJ abnormality was platybasia (71%), followed by short clivus (44%) and cervical kyphosis (33%). The CVJ abnormalities were more in Syringomyelia cases (p=0.045). However, the results were not significant when hydrocephalus cases were excluded., Conclusion: Among CM1 patients, CVJ abnormalities were found more in patients with syringomyelia. Future studies with larger sample size are required to further study the correlation between CVJ abnormalities and both syringomyelia and hydrocephalus in CM1 patients.

Objective: To analyze the association between basilar invagination (BI) and stenosis in the hypoglossal canal (HC)., Methods: A case-control study with magnetic resonance images (MRIs) of the head from a local database was performed. The study used MRIs of 31 patients with BI (type B) and 36 controls, both groups over 18 years of age and without sex distinction. The internal (ID) and external (ED) diameters of the HC were measured on the coronal plane using the Osirix in its free version 3.9.2 (Mac-Apple platform). We used the Kolmogorov-Smirnov test (with Lilliefors adjustment) to evaluate the normality of the variables, the Levine test to verify the homogeneity of the variances, and Student's t test to verify differences between groups. All analyses were within the 95% confidence interval., Results: Control group presented right and left ED values of 4.7 ± 0.8 mm and 4.6 ± 0.9 mm, respectively, while the right and left ID showed 4.4 ± 0.9 mm and 4.3 ± 0.8 mm, respectively. The group with BI showed right and left ED values of 3.3 ± 0.9 mm and 3.1 ± 0.9 mm, and the right and left ID had values of 2.8 ± 0.7 mm and 2.7 ± 0.7 mm, respectively. Both ED and ID were smaller in the group with BI (P < 0.001)., Conclusions: Patients with BI of type B presented the narrowing of HC when compared with control participants., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The article discusses complex craniovertebral junction anomalies. It mentions cases of pan‑cervical fusion with atlantoaxial dislocation (AAD). It mentions that congenital AAD is often multiplanar and the deformity of C1‑2 joints decides the plane of dislocation and reveals that combination of abnormal sagittal and coronal inclination leads to vertical dislocation.

The authors discuss the treatment strategies for craniovertebral junction abnormalities that have undergone a change since it came to light that atlantoaxial dislocation is rarely fixed or irreducible. They mention that they advocated the use of intra‑articular spacers for fixation and stabilization of the atlantoaxial joint. Moreover, they state that the exact indication of intra‑articular spacers needs to be clarified and that bone graft impaction can also be used for stabilization.

Objective: To evaluate the usefulness of 3-dimensional (3D) printed models as an aid for the treatment of complex CVJ anomalies., Methods: 3D printed models were fabricated for 21 patients with complex CVJ anomalies, including vertebral artery anomaly, thin C2 pedicle, vertical atlantoaxial facet joint, or rotational dislocation combined with atlantoaxial dislocation and basilar invagination. Preoperative planning, surgical simulation, and intraoperative reference were achieved using the 3D model during the surgical treatment. The usefulness of 3D printed models, and postoperative clinical and radiological outcomes were assessed., Results: Direct posterior reduction and atlantoaxial fixation were achieved in 19 patients. Transoral odontoidectomy followed by posterior fixation was implemented for 2 patients with vertical facet joint and rotational dislocation. All screws were safely inserted with no complication, and 90% patients achieved a >60% reduction of both horizontal and vertical dislocation. Clinical symptoms improved in all patients, with the averaged Japanese Orthopedic Association scores increasing from 11.14 to 14.43 (P < 0.01)., Conclusions: The patient-specific 3D printed model would be an effective tool for evaluation of the reducibility of the atlantoaxial dislocation and basilar invagination, decision making in choosing the optimal surgical approach and way of fixation, and precise placement of the screw while protecting the vertebral artery and spinal cord. The risk of neurovascular injury was minimized, and encouraging outcomes were achieved with the aid of this technique., (Copyright © 2019 Elsevier Inc. All rights reserved.)

An adult male skeleton was submitted to the Department of Anatomy at the University of Belgrade for evaluation. It was believed to represent the remains of a second to third century Christian saint from the Lesje Monastery in central Serbia. Examination of the remains revealed an old crush fracture of a thoracic vertebra and an unusual, probably congenital, malformation of the atlanto-occipital joint with deformation of the left occipital condyle and resultant narrowing of the foramen magnum. Although the occipital malformations were most likely congenital, they may still have caused, or contributed to, death by compression of the underlying upper cervical spinal cord.

Background: Neurosurgical features of mucopolysaccharidosis (MPS) patients mainly involve the presence of cranio-vertebral junction (CVJ) abnormalities and the development of communicating hydrocephalus. CVJ pathology is a critical aspect that severely influences the morbidity and mortality of MPS patients. Hydrocephalus is slowly progressing; it must be differentiated from cerebral atrophy, and rarely requires treatment. The aim of this paper was to review the literature concerning these conditions, highlighting their clinical, radiological, and surgical aspects to provide a practical point of view for clinicians. Results: CVJ involvement may present with cervical pain, unsteady gait, frequent falls, and progressive impairment of autonomous ambulation, an acute tetraplegia even after minor trauma. Magnetic resonance imaging (MRI) of the cervical spine, including active dynamic flexion and extension scans, is the most powerful imaging technique for detecting spinal cord compression at the CVJ in MPS patients. The main radiological features include atlanto-axial subluxation, odontoid hypoplasia, periodontoid soft tissue masses, spinal canal narrowing, and spinal cord compression. Together with MRI, fine-cut computed tomography (CT) scans with coronal and sagittal three-dimensional reconstructions are important diagnostic tools in the preoperative workup thanks to the information gleaned about bone structure conformation and angles. Finally, angio-CT slices are equally useful in preoperative planning, defining vertebral artery position in relation to bony structures. Surgery of the CVJ is proposed both to treat cord compression with MRI signs of myelopathy or as a preventive treatment in patients at high risk of cord damage. Among different surgical options, we always suggest performing decompression and instrumented stabilization. Hydrocephalus may occasionally present clinically with intracranial hypertension symptoms such as headache, vomiting, and high sight impairment. Neurocognitive symptoms may be hidden by the constitutive cognitive impairment. MRI with a study of dynamic cerebrospinal fluid (CSF) flow is helpful to differentiate from ventriculomegaly, which does not require treatment. Ventriculo-peritoneal shunt placement is the gold standard to treat hydrocephalus, although endoscopic third ventriculostomy has recently shown good results in some patients. Conclusion: Early recognition of CVJ pathology and hydrocephalus is critical to avoid the development of severe complications. A multidisciplinary approach involving physicians, neuroradiologists, and neurosurgeons is needed to detect such conditions and to select patients eligible for surgery. [ABSTRACT FROM AUTHOR]

Background Os odontoideum is an uncommon abnormality of the craniovertebral junction where the tip of the odontoid process lacks continuity with the body of C2. The clinical presentation is variable, but severe neurologic impairment can result. Case Description We report the gross and radiologic findings of a cadaver found to harbor an os odontoideum. Conclusions To our knowledge, there are no cadaveric reports in the literature regarding an os odontoideum. Such a case allows a rare window into the anatomy and relationships of this pathologic structure. [ABSTRACT FROM AUTHOR]

The author reflects on the craniovertebral instability of the retro-odontoid tissue. The pathogenesis of the spondylotic spinal disease is explored, along with the posterior longitudinal ligaments' buckling. Also discussed is the visualization of the atlantoaxial instability through flexion-extension images.

Objective:  The main purpose of this study was to define criteria to systemically describe craniovertebral junction (CVJ) anomalies and to report the prevalence of CVJ anomalies in small breed dogs with and without atlantoaxial instability (AAI)., Materials and Methods:  Retrospective multicentre matched case-control study evaluating magnetic resonance imaging and computed tomographic images of small breed dogs with and without AAI for the presence of CVJ anomalies., Results:  One hundred and twenty-two dogs were enrolled (61 with and 61 without AAI). Only dogs with AAI had dens axis anomalies such as separation ( n  = 20) or a short-rounded conformation ( n  = 35). Patients with AAI were more likely to have atlantooccipital overlapping based on transection of McRae's line by the dorsal arch of the atlas (odds ratio [OR] = 5.62, p  < 0.01), a transection of Wackenheim's clivus line (OR = 41.62, p  < 0.01) and rostral indentation of the occipital bone (OR = 2.79, p  < 0.05). Patients with AAI were less likely to have a larger clivus canal angle (OR = 0.94, p  < 0.01) and larger occipital bone lengths (OR = 0.89, p  < 0.05)., Clinical Significance:  Small breed dogs with AAI are more likely to have other CVJ anomalies such as atlantooccipital overlapping or dens anomalies. The grade of brachycephaly does not differ between patients with and without AAI. Certain objective criteria from human literature were found useful for the assessment of both AAI and atlantooccipital overlapping such as McRae's line, Wackenheim's clivus line, and clivus canal angle. The classification criteria used can help to evaluate CVJ anomalies in a more systematic way., Competing Interests: The authors declare that they have no conflicts of interest in the research. Author Contribution Maja A. Waschk and Christina Precht contributed to conception of study, study design and acquisition of data and data analysis and interpretation. Beatriz Vidondo contributed to study design and data analysis and interpretation. Franck Forterre contributed to conception of study and study design. Inés Carrera, Angel M. Hernandez-Guerra, Pierre Moissonnier, Ioannis N. Plessas, Martin J. Schmidt and Dietmar Schnötzinger contributed to acquisition of data. All authors drafted, revised and approved the submitted manuscript., (Georg Thieme Verlag KG Stuttgart · New York.)