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Anatomical Record (Hoboken, N.J. : 2007) Mar 2024Osteogenesis imperfecta (OI) is a disorder of type I collagen characterized by abnormal bone formation. The OI craniofacial phenotype includes midfacial...
Osteogenesis imperfecta (OI) is a disorder of type I collagen characterized by abnormal bone formation. The OI craniofacial phenotype includes midfacial underdevelopment, as well as neurocranial changes (e.g., macrocephaly and platybasia) that may also affect underlying nervous tissues. This study aims to better understand how OI affects the integrated development of the neurocranium and the brain. Juvenile and adult mice with OI (OIM) and unaffected wild type (WT) littermates were imaged using in vivo micro-computed tomography (microCT). Virtual endocast models were used to measure brain volume, and 3D landmarks were collected from the cranium and brain endocasts. Geometric morphometric analyses were used to compare brain shape and integration between the genotypes. OIM mice had increased brain volumes (relative to cranial centroid size) only at the juvenile stage. No significant difference was seen in cranial base angle (CBA) between OIM and WT mice. However, CBA was higher in juvenile than in adult OIM mice. Brain shape was significantly different between OIM and WT mice at both stages, with OIM mice having more globular brains than WT mice. Neurocranial and brain morphology were strongly integrated within both genotypes, while adult OIM mice tended to have lower levels of skull-brain integration than WT mice. These results suggest that neurocranial dysmorphologies in OI may be more severe at earlier stages of postnatal development. Decreased skull-brain integration in adult mice suggests that compensatory mechanisms may exist during postnatal growth to maintain neurological function despite significant changes in neurocranial morphology.
Topics: Mice; Animals; Osteogenesis Imperfecta; X-Ray Microtomography; Collagen Type I; Skull; Phenotype; Disease Models, Animal; Osteogenesis
PubMed: 37638403
DOI: 10.1002/ar.25307 -
European Spine Journal : Official... Oct 2023C1 transpedicular screw (C1TS) placement provided satisfactory pullout resistance and 3D stability, but its application might be limited in patients with basilar...
BACKGROUND
C1 transpedicular screw (C1TS) placement provided satisfactory pullout resistance and 3D stability, but its application might be limited in patients with basilar invagination (BI) due to the high incidences of the atlas anomaly and vertebral artery (VA) variation. However, no study has explored the classifications of C1 posterior arch variations and investigated their indications and ideal insertion trajectories for C1TS in BI.
PURPOSE
To investigate the bony and surrounding arterial characteristics of the atlas, classify posterior arch variations, identify indications for C1TS, evaluate ideal insertion trajectories for C1TS in BI patients without atlas occipitalization (AO), and compare them with those without BI and AO as control.
METHODS
A total of 130 non-AO patients with and without BI (52 patients and 78 patients, respectively) from two medical centers were included at a 1:1.5 ratio. The posterior arch variations were assessed using a modified C1 morphological classification. Comparisons regarding the bony and surrounding arterial characteristics, morphological classification distributions, and ideal insertion trajectories between BI and control groups were performed. The subgroup analyses based on different morphological classifications were also conducted. In addition, the factors possibly affecting the insertion parameters were investigated using multiple linear regression analyses.
RESULTS
The BI group was associated with significantly smaller lateral mass height and width, sagittal length of posterior arch, pedicle height, vertical height of posterior arch, and distance between VA and VA groove (VAG) than control group. Four types of posterior arch variations with indications for different screw placement techniques were classified; Classifications I and II were suitable for C1TS. The BI cohort showed a significantly lower rate of Classification I than the control cohort. In the BI group, the subgroup of Classification I had significantly larger distance between the insertion point (IP) and inferior aspect of the posterior arch. In addition, it had the narrowest width along ideal screw trajectory, but a significantly more lateral ideal mediolateral angle than the subgroup of Classification II. Multiple linear regression indicated that the cephalad angle was significantly associated with the diagnosis of BI (B = 3.708, P < 0.001) and sagittal diameter of C1 (B = 3.417, P = 0.027); the ideal mediolateral angle was significantly associated with BMI (B = 0.264, P = 0.031), sagittal diameter of C1 (B = - 4.559, P = 0.002), and pedicle height (B = - 2.317, P < 0.001); the distance between the IP and inferior aspects of posterior arch was significantly associated with age (B = - 0.002, P = 0.035), BMI (B = - 0.007, P = 0.028), sagittal length of posterior arch (B = - 0.187, P = 0.032), pedicle height (B = - 0.392, P < 0.001), and middle and lower parts of posterior arch (B = 0.862, P < 0.001).
CONCLUSION
The incidence of posterior arch variation in BI patients without AO was remarkably higher than that in control patients. The insertion parameters of posterior screws were different between the morphological classification types in BI and control groups. The distance between VA V3 segments and VAG in BI cohort was substantially smaller than that in control cohort. Preoperative individual 3D computed tomography (CT), CT angiography and intraoperative navigation are recommended for BI patients receiving posterior screw placement.
Topics: Humans; Spinal Fusion; Bone Screws; Platybasia; Tomography, X-Ray Computed; Computed Tomography Angiography; Atlanto-Axial Joint
PubMed: 37530951
DOI: 10.1007/s00586-023-07873-4 -
World Neurosurgery Aug 2022Treatment of Chiari malformation (CM) is controversial, especially when it coexists with "stable" or Type II basilar invagination (CM + II-BI). Precise evaluation of... (Observational Study)
Observational Study
Evaluating Craniovertebral Stability in Chiari Malformation Coexisting with Type II Basilar Invagination: An Observational Study Based on Kinematic Computed Tomography and Its Clinical Application.
BACKGROUND
Treatment of Chiari malformation (CM) is controversial, especially when it coexists with "stable" or Type II basilar invagination (CM + II-BI). Precise evaluation of craniovertebral junction (CVJ) stability is crucial in such patients; however, this has never been validated. This study aimed to dynamically evaluate atlanto-condyle and atlantoaxial stability by kinematic computed tomography (CT) and report its surgical treatment.
METHODS
The study recruited 101 patients (control, CM, and CM + II-BI groups: 48, 34, and 19 patients, respectively). During kinematic CT, the CVJ stability-related parameters were measured and compared between the 3 groups. The surgical strategy for treating CM + II-BI was based on these results. Preoperative and postoperative images were acquired, and functional scores were used to assess the outcome.
RESULTS
Among the 3 groups, the length of the clivus and the height of the condyle were the shortest in the CM + II-BI group, which was accompanied by the greatest rotation of the atlas and atlanto-condyle facet movement on cervical flexion and extension. Moreover, in such patients, increased Chamberlain's baseline violation indicated the aggregate invagination of the odontoid in the flexed position, and asymmetric displacement of atlantoaxial facets was observed. Seventeen CM + II-BI patients underwent surgical treatment with atlantoaxial distraction and occipitocervical fusion. The syringomyelia width and tonsillar herniation decreased significantly, and functional scores indicated symptom relief and good outcomes.
CONCLUSIONS
CVJ instability, especially the ultramovement of atlanto-condyle facets, commonly exists in II-BI as evaluated using kinematic CT. The surgical strategy of atlantoaxial distraction and occipitocervical fusion should be considered to treat such patients.
Topics: Arnold-Chiari Malformation; Atlanto-Axial Joint; Biomechanical Phenomena; Decompression, Surgical; Humans; Platybasia; Spinal Fusion; Tomography, X-Ray Computed
PubMed: 35595047
DOI: 10.1016/j.wneu.2022.05.045 -
Neurological Sciences : Official... Jul 2020The craniovertebral junction is an anatomically well-defined transitional zone located between the skull and the cervical spine. Multiple malformations can affect this...
BACKGROUND
The craniovertebral junction is an anatomically well-defined transitional zone located between the skull and the cervical spine. Multiple malformations can affect this region with the most prominent being basilar invagination (BI) and Chiari malformation (CM). Despite numerous studies, the origin, pathophysiology, and classification of these pathologies remain controversial. The objective of this study was to evaluate the implication of cranial base flexion angle and clivus length in the development of these conditions.
METHODS
Midline tomography and magnetic resonance imaging of normal subjects and patients diagnosed with BI (types I and II) and Chiari malformation were evaluated. A craniometric study of the skull base was performed. Linear and angular measurements were used for comparisons between groups.
RESULTS
109 images from patients with craniovertebral junction malformation and controls were evaluated. Seventeen had BI-I, 26 had BI-II, 36 had CM, and 30 were normal subjects. Demographic data for the two groups were not significantly different. Craniometric analysis of images revealed a gradation in linear and angular variables from controls to CM, BI-I, and BI-II patients. Clivus length was significantly smaller in BI-II patients compared with other groups, while basal angle was greater. Moderate or strong correlations were noted among all variables analyzed.
CONCLUSION
Data suggest that clivus length and basal angle may play a role in pathophysiology of BI and CM.
Topics: Arnold-Chiari Malformation; Cephalometry; Cranial Fossa, Posterior; Humans; Magnetic Resonance Imaging; Platybasia; Skull Base
PubMed: 32002740
DOI: 10.1007/s10072-020-04248-1 -
Zhonghua Wai Ke Za Zhi [Chinese Journal... Sep 2022To examine the effect of posterior atlanto-axial intraarticular distraction technique as revision surgery for failed posterior fossa decompression in patients with...
To examine the effect of posterior atlanto-axial intraarticular distraction technique as revision surgery for failed posterior fossa decompression in patients with basilar invagination(BI) and atlanto-axial dislocation(AAD). The clinical data of 13 cases of AAD accompanied with BI treated at Department of Neurosurgery, Xuanwu Hospital, Capital Medical University were retrospectively analyzed. There were 3 males and 10 females,aged (42.6±9.5) years (range:30 to 63 years). All cases had assimilation of atlas and once underwent posterior fossa decompression. Anterior tissue was released through posterior approach followed by cage implantation into facet joint and occipital-cervical fixation with cantilever technique. The clinical results were evaluated using Japanese Orthopedic Association scale(JOA) and the main radiological measurements including atlantodental interval (ADI), the distance of odontoid tip above Chamberlain line(DCL),clivus-canal angle(CCA) and the length of syrinx were collected. Paired sample test was used to compared the data before and after operation. All patients underwent surgery successfully, the mean surgical time was (187.7±47.4) minutes (range from 116 to 261 minutes). Twenty occipital condyle screws, 26 C2 pedicle screws and 3 occipital plates were implanted. Clinical symptoms improved in all patients. Twelve patients had complete reduction of basilar invagination and atlanto-axial dislocation, 1 achieved near completely reduction of basilar invagination. The postoperative ADI, DCL and CCA significantly improved((4.3±1.1) mm (1.8±0.8) mm, (11.7±5.0) mm (6.4±2.8) mm, (142.4±7.9)° (133.3±7.9)°, all <0.01).There were 5 cases with syringomyelia before surgery, and shrinkage of syrinx was observed 1 week after surgery in all cases. Eight patients achieved bone fusion 3 months after surgery, all patients achieved bone fusion 6 months after surgery. The JOA score increased from 12.8±2.3 before surgery to 14.8±1.3 one year after surgery, with statistically significant difference (=4.416, 0.01).No implant failure, spacer subsidence and infection were observed. In cases of failure posterior fossa decompression of basilar invagination and atlanto-axial dislocation, using posterior atlanto-axial intraarticular distraction and cantilever technique with cage implantation could achieve complete reduction and symptomatic relief.
Topics: Atlanto-Axial Joint; Female; Humans; Joint Dislocations; Male; Pedicle Screws; Platybasia; Reoperation; Retrospective Studies; Spinal Fusion
PubMed: 36058708
DOI: 10.3760/cma.j.cn112139-20220228-00086 -
Endocrinologia, Diabetes Y Nutricion Mar 2024Secondary basilar invagination or basilar impression is an anomaly at the craniovertebral junction where the odontoid process prolapses into the foramen magnum with the... (Review)
Review
Secondary basilar invagination or basilar impression is an anomaly at the craniovertebral junction where the odontoid process prolapses into the foramen magnum with the risk of compressing adjacent structures and obstructing the proper flow of cerebrospinal fluid (CSF). The incidence is less than 1% in the general population and occurs mainly in the first three decades of life when it is associated with malformations of the neuroaxis. In older age, the main aetiologies are diseases that alter bone mineral density. The clinical course is usually progressive and the most common symptoms are asthenia, cervical pain and restricted movement, but also dysphonia, dyspnoea and dysphagia. It is a progressive disease which, if left untreated, can cause severe neurological damage and death. We report the case of a 79-year-old woman with osteoporosis and progressive dysphagia leading to severe malnutrition, which conditioned the decision not to intervene due to the high perioperative risk.
Topics: Female; Humans; Aged; Platybasia; Deglutition Disorders; Foramen Magnum; Odontoid Process
PubMed: 38555110
DOI: 10.1016/j.endien.2024.03.013 -
Zhonghua Wai Ke Za Zhi [Chinese Journal... Sep 2023Cranio-cervical junction (CVJ) anomalies encompass a spectrum of bone,soft tissue,and neural structural abnormalities,including basilar...
Cranio-cervical junction (CVJ) anomalies encompass a spectrum of bone,soft tissue,and neural structural abnormalities,including basilar invagination,platybasia,atlantoaxial dislocation,tonsillar herniation,and occipito-cervical fusion.Given the frequent coexistence of these anomalies and the intricate anatomical variations involved,precise imaging techniques and evaluation parameters are crucial for accurate disease characterization and treatment assessment.Since the 1930s,various parameters,such as the McRae line,Chamberlain line,Wackenheim line,and clivo-axial angle,have been widely employed for evaluating basilar invagination and platybasia.The advent of MRI and CT has further expanded the repertoire of parameters,including sagittal tilt,coronal tilt,medullary spinal angle,and intricate multi-axis evaluation systems.In this review,we summarize the relevant imaging parameters and their corresponding measurement techniques from previous literature,emphasizing high-sensitivity,consistent,and evidence-based parameters.This study aims to provide valuable insights for the imaging evaluation of CVJ anomalies.
PubMed: 37767671
DOI: 10.3760/cma.j.cn112139-20230713-00007 -
World Neurosurgery May 2022A 32-year-old woman presented with chronically progressive spastic quadriparesis. Detailed clinicoradiological evaluation led to the diagnosis of irreducible...
A 32-year-old woman presented with chronically progressive spastic quadriparesis. Detailed clinicoradiological evaluation led to the diagnosis of irreducible atlantoaxial dislocation and basilar invagination, with associated "kissing" carotids and an anomalous right vertebral artery (VA). Both internal carotid arteries had an abnormally tortuous course, "kissing" retropharyngeally at the level of C1-C2. The right VA became intradural at the level of C2-C3, an extremely rare anomaly-C3 segmental artery. Despite the deformed joints and the possibility of injuring the anomalous right VA during C2-C3 instrumentation, a tailored posterior-only approach was used to circumvent the arterial fence created by both vascular anomalies. The patient underwent bilateral C1-C2 joint opening and left C1-C2 joint spacer placement, followed by bilateral occipito-C3-C4 fixation. This is possibly the first reported case of a complex craniovertebral junction anomaly associated with both kissing carotids and a C3 segmental VA.
Topics: Adult; Atlanto-Axial Joint; Brachiocephalic Trunk; Carotid Artery, Internal; Female; Humans; Joint Dislocations; Platybasia; Spinal Fusion; Vascular Malformations; Vertebral Artery
PubMed: 35248774
DOI: 10.1016/j.wneu.2022.02.111 -
World Neurosurgery Jul 2022Basilar invagination usually shows a decrease of clivus axis angle (CAA), which could give rise to progressive neural compression. Exploring a safe and effective...
OBJECTIVE
Basilar invagination usually shows a decrease of clivus axis angle (CAA), which could give rise to progressive neural compression. Exploring a safe and effective fixation technique to achieve atlantoaxial stability and neural decompression remains necessary. In this study, we introduce a modified posterior C1-C2 distraction and fixation technique by which we obtained indirect ventral neural decompression and atlantoaxial stability in a series of patients with decreased CAA.
METHODS
Thirty patients of basilar invagination were enrolled in our series. All patients underwent thin-slice computed tomography (CT) scan, magnetic resonance imaging, and dynamic plain radiography examinations before surgery, at discharge and during the follow-ups. Posterior C1-C2 facet joint release and intraoperative reduction by fastening rods were performed in all patients. The CAA was measured on midsagittal CT scans. Patients' neurologic status was evaluated by the Japanese Orthopaedic Association score.
RESULTS
No neurovascular injury and serious postoperative complication occurred in all patients. Complete ventral brainstem decompression was achieved in 20 patients and partial in 10 patients. The mean postoperative CAA significantly improved to 132.6 degrees compared with the preoperative 123.6 degrees (P < 0.01). The bone fusion was confirmed in all patients on the basis of the last follow-up spine CT scans.
CONCLUSIONS
Indirect ventral brainstem decompression by posterior C1-C2 distraction and fixation is a safe and effective technique for treatment of basilar invagination.
Topics: Atlanto-Axial Joint; Brain Stem; Decompression, Surgical; Humans; Joint Dislocations; Platybasia; Spinal Fusion
PubMed: 35314410
DOI: 10.1016/j.wneu.2022.03.064 -
Clinical Neurology and Neurosurgery Sep 2023In economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet...
PURPOSE
In economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet technique for the treatment of BI using shaped autologous occipital bone mass to reduce BI and to save economical expenditure.
METHODS
The data of 6 patients with BI who underwent modified interfacet technique using shaped autologous occipital bone mass in our hospital from April 2020 to February 2021 were retrospectively analyzed. During the operation, osteotomy at the external occipital protuberance was performed using ultrasonic osteotome, followed by interfacet release and implantation of shaped autologous occipital bone mass to complete vertical reduction. The atlantodental interval (ADI), Chamberlain's line violation (CLV), clivo-axial angle (CXA) and cervico-medullary angle (CMA) were compared before and after surgery. Additionally, we observed implant stability during the follow-up period to assess the long-term success of the modified interfacet technique.
RESULTS
The surgical procedure was successful in all six patients, with no reported incidents of vascular injury, spinal cord injury, or dural tear. Following the operation, improvements were observed in the ADI, CLV, CXA, and CMA. Throughout the follow-up period, the implants remained stable, demonstrating no complications such as bone resorption of the autologous occipital bone mass, implant fracture, or displacement.
CONCLUSION
The utilization of shaped autologous occipital bone mass in atlantoaxial interfacet bone grafting has demonstrated effectiveness and feasibility. This technique offers simplicity, ease of preparation, and cost-effectiveness, making it a viable option for treating BI.
Topics: Humans; Retrospective Studies; Joint Dislocations; Atlanto-Axial Joint; Platybasia; Occipital Bone; Spinal Fusion
PubMed: 37419081
DOI: 10.1016/j.clineuro.2023.107848