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Objective: Both two‐level anterior cervical corpectomy and fusion (t‐ACCF) and posterior open‐door laminoplasty (ODLP) are effective surgical procedures for the treatment of ossification of the posterior longitudinal ligament (OPLL). Previous studies have identified different effects of different surgical procedures on the upper and subaxial cervical spine (UCS, SCS), however, there are no studies on the effects of t‐ACCF and ODLP on the occipito‐atlantoaxial complex. Therefore, the purpose of this study is to compare the changes in sagittal parameters and range of motion (ROM) of the occipito‐atlantoaxial complex in OPLL patients treated with t‐ACCF and ODLP. Methods: This was a retrospective study that included 74 patients who underwent t‐ACCF or ODLP for the treatment of OPLL from January 2012 to August 2022 at our institution. Preoperative, 3‐month, and 1‐year postoperative cervical neutral, flexion‐extension, and lateral flexion radiographs were taken. Sagittal parameters including Cobb angle of C2‐7, C0‐2, C0‐1, C1‐2, C2 slope, and the ROM were measured. The clinical outcome was assessed using the JOA, VAS, and NDI scores preoperatively and at 3 and 12 months postoperatively. Multiple linear regression was employed to identify factors influencing changes in UCS. Results: In the ODLP group, the SCS (C2‐7) Cobb angle was significantly reduced (12.85 ± 10.0 to 7.68 ± 11.27; p < 0.05), and the UCS (C0‐2) Cobb angle was significantly compensated for at 1 year postoperatively compared with the t‐ACCF group (3.05 ± 4.09 vs 0.79 ± 2.62; p < 0.01). The SCS and lateral flexion ROM of the ODLP group was better maintained than t‐ACCF (14.51 ± 6.00 vs 10.72 ± 3.79; 6.87 ± 4.56 vs 3.81 ± 1.67; p < 0.01). The compensatory increase in C0‐2, C0‐1, and C1‐2 ROM was pronounced in both groups, especially in the ODLP group. The results of multiple linear regression showed that only the surgical procedure was a significant factor influencing UCS. Conclusion: The loss of the SCS Cobb angle was more pronounced in ODLP relative to t‐ACCF, resulting in a significant compensatory increase in UCS and atlantoaxial Cobb angle. The ROM of the UCS, atlantooccipital, and atlantoaxial joints was significantly increased in both groups, this may accelerate degenerative changes in the occipital‐atlantoaxial complex, may leading to poorer outcomes in the long‐term; of these, ODLP should receive more attention. In contrast, t‐ACCF better maintains normal curvature of the SCS and occipito‐atlantoaxial complex but loses more ROM. [ABSTRACT FROM AUTHOR]

Objective Both two‐level anterior cervical corpectomy and fusion (t‐ACCF) and posterior open‐door laminoplasty (ODLP) are effective surgical procedures for the treatment of ossification of the posterior longitudinal ligament (OPLL). Previous studies have identified different effects of different surgical procedures on the upper and subaxial cervical spine (UCS, SCS), however, there are no studies on the effects of t‐ACCF and ODLP on the occipito‐atlantoaxial complex. Therefore, the purpose of this study is to compare the changes in sagittal parameters and range of motion (ROM) of the occipito‐atlantoaxial complex in OPLL patients treated with t‐ACCF and ODLP. Methods This was a retrospective study that included 74 patients who underwent t‐ACCF or ODLP for the treatment of OPLL from January 2012 to August 2022 at our institution. Preoperative, 3‐month, and 1‐year postoperative cervical neutral, flexion‐extension, and lateral flexion radiographs were taken. Sagittal parameters including Cobb angle of C2‐7, C0‐2, C0‐1, C1‐2, C2 slope, and the ROM were measured. The clinical outcome was assessed using the JOA, VAS, and NDI scores preoperatively and at 3 and 12 months postoperatively. Multiple linear regression was employed to identify factors influencing changes in UCS. Results In the ODLP group, the SCS (C2‐7) Cobb angle was significantly reduced (12.85 ± 10.0 to 7.68 ± 11.27; p

Objective: Rare disease Background: Bow hunter syndrome is a rare disease that is often overlooked. It presents with complex and variable clinical symptoms and causes, making diagnosis and treatment challenging. This case report focuses on a young patient with bilateral bow hunter syndrome, possibly caused by the loss of cervical physiological curvature. The aim is to enhance understanding and awareness of the disease. It is important to consider the possibility of bow hunter syndrome in young patients with long-term poor neck posture and symptoms such as dizziness, nausea, vomiting, and neck rotation-related symptoms. In such cases, thorough examination of posterior circulation hemodynamics and vascular morphology is recommended. Case Report: A 25-year-old woman was admitted to the hospital mainly because of "dizziness for 10 hours." The dizziness was aggravated when the right side of the neck was turned and the body position changed. This was accompanied by visual rotation, nausea, and vomiting. Bow hunter syndrome was diagnosed based on the clinical symptoms and hemodynamic examination of the posterior circulation. The patient was given a cervical collar to limit excessive twisting of the neck and instructed to avoid large-angle deflection of the neck after discharge. During the 3-month follow-up, no characteristic symptoms (such as dizziness) reappeared. Conclusions: Bow hunter syndrome is a rare clinical posterior circulation compression syndrome with complex etiology. This case suggests that the simple disappearance of cervical curvature may be related to the occurrence of bow hunter syndrome. The dynamic monitoring of blood flow by color Doppler ultrasound and transcranial Doppler in different head positions provides clear clues to suspected bow hunter syndrome. With the help of computed tomography angiography, the diagnosis of bow hunter syndrome may be obtained by noninvasive examination. [ABSTRACT FROM AUTHOR]

A bony tissue variation called Ponticulus posticus (PP) is described in the posterior arch of the atlas, which has been associated with the development of cervical pain. The aim of this study was to determine the frequency of PP in digital lateral cephalograms. This study was an observational descriptive study, in which 450 digital lateral cephalograms obtained from the database of the Oral and Maxillofacial Imaging Service of the Faculty of Dentistry of the Andrés Bello University, Viña del Mar, Chile, were analyzed. The presence of PP was analyzed in each cephalogram, and the Cederberg and Stubbs classification was used to determine the degrees of ossification. The Chi-square test was applied to establish an association between the presence of PP with gender and age. Of the 450 lateral cephalograms, 42.4 % presented PP, with a higher prevalence in the 21-40 year range. In terms of the degree of ossification, grade 2 was the most prevalent type (25 %), followed by grade 4 (9.5 %), and grade 3 (8 %). No association was found between the presence of PP with age and gender (P > 0.05). PP is common in the population and is observed at different ages without a sex preference. [ABSTRACT FROM AUTHOR]

BackgroundLaminotomy and laminar replantation have emerged as novel treatment modalities for intraspinal tumors, aiming to minimize postoperative complications and retain spinal mobility. However, existing research predominantly emphasizes their application in the thoracolumbar spine. The unique anatomy of the atlantoaxial segments necessitates surgical techniques that differ from those used in other spinal regions, and the clinical effect of such procedure remains unknown.Case presentationA 61-year-old male patient with intradural schwannoma at the atlantoaxial level was operated on. The patient underwent posterior laminectomy, as well as a combined replantation of the posterior arch of the atlas and bilateral axial laminae. Postoperatively, the patient experienced significant neurological improvement, with no deformities or instability on the radiological assessments during the follow-up.ConclusionLaminotomy with combined replantation of the posterior arch of the atlas and bilateral axial lamina emerges as an effective approach for managing intraspinal tumors at the atlantoaxial level. This technique not only offers ample operating space but also restores the stability of the spinal canal. Moreover, it preserves the mobility of the atlantoaxial segment, minimizes impact on adjacent segments, and mitigates the formation of postoperative fibrosis.

Complex craniovertebral junction (CVJ) defects account for a considerable proportion of CVJ diseases. Given the heavily assimilated C1, an unfavorable C1–C2 joint orientation, an overriding C2 superior facet, a low-hanging occiput, and an abnormal vertebral artery course with a high-riding vertebral artery, placement of C1 lateral mass screws might be difficult. To address this, a novel technique for placing C1 lateral mass screws that avoid vertebral artery injury, low-hanging occiput, and overriding C2 superior facet was developed in this study. This approach enables firm fixation of C1–C2 even in difficult situations where the placement of the C1 lateral mass is challenging.

This study consists of a retrospective cohort study, a systematic review, and a meta-analysis which were separately conducted. This study aimed to investigate the prevalence of atlas arch defects, generate an evidence-based synthesis, and propose a common classification system for the anterior and combined atlas arch defects. Atlas arch defects are well-corticated gaps in the anterior or posterior arch of the atlas. When both arches are involved, it is known as a combined arch defect. Awareness of these defects is essential for avoiding complications during surgical procedures on the upper spine. The prevalence of arch defects was investigated in an open-access OPC-Radiomics (Radiomic Biomarkers in Oropharyngeal Carcinoma) dataset comprising 606 head and neck computed tomography scans from oropharyngeal cancer patients. A systematic review and meta-analysis were performed to generate prevalence estimates of atlas arch defects and propose a classification system for the anterior and combined atlas arch defects. The posterior arch defect was found in 20 patients (3.3%) out of the 606 patients investigated. The anterior arch defect was not observed in any patient, while a combined arch defect was observed in one patient (0.2%). A meta-analysis of 13,539 participants from 14 studies, including the present study, yielded a pooled-posterior arch defect prevalence of 2.07% (95% confidence interval [CI], 1.22%–2.92%). The prevalences of anterior and combined arch defects were 0.00% (95% CI, 0.00%–0.10%) and 0.14% (95% CI, 0.04%–0.25%), respectively. The anterior and combined arch defects were classified into five subtypes based on their morphology and frequency. The present study showed that atlas arch defects were present in approximately 2% of the general population. For future studies, larger sample sizes should be used for studying arch defects to avoid the small-study effect and to predict the prevalence accurately.

Complex craniovertebral junction (CVJ) defects account for a considerable proportion of CVJ diseases. Given the heavily assimilated C1, an unfavorable C1-C2 joint orientation, an overriding C2 superior facet, a low-hanging occiput, and an abnormal vertebral artery course with a high-riding vertebral artery, placement of C1 lateral mass screws might be difficult. To address this, a novel technique for placing C1 lateral mass screws that avoid vertebral artery injury, low-hanging occiput, and overriding C2 superior facet was developed in this study. This approach enables firm fixation of C1-C2 even in difficult situations where the placement of the C1 lateral mass is challenging. [ABSTRACT FROM AUTHOR]

Objective To study the feasibility of small titanium plate fixation through oropharyngeal approach in the treatment of unstable atlas fracture. Methods Sixty-four patients with unstable atlas fracture were selected, of which 30 patients were treated with small titanium plate fixation through oropharyngeal approach were used as the observation group, and 34 patients were treated with posterior atlantoaxial pedicle screw internal fixation were used as the control group. Intraoperative indexes including operation time, blood loss, postoperative indicators, length of hospital stay, occurrence of complications (chronic neck pain, incision infection and dysphagia), visual analogue pain (VAS) score, Japanese Orthopaedic Association (JOA) score before surgery, 1 month after surgery and at the last follow-up and cervical extension, flexion, left and right rotation range of motion were compared between the two groups. Results The operation time and blood loss were significantly lower in the observation group than those in the control group (P＜0.05), and there was no significant difference in the length of hospital stay between the two groups. There were no significant differences in the incidence of chronic neck pain, incision infection and dysphagia between the two groups. The VAS score was lower and the JOA score was higher 1 month after surgery and at the last follow-up than those before surgery (P＜0.05), and there was no significant difference between the two groups. The extension, flexion, dextral and dextral movements were all increased one month after surgery and at the last follow-up in the two groups (P＜0.05). The cervical extension, flexion, left rotation and right rotation of the observation group were higher than those of the control group one month after surgery and the last follow-up (P＜0.05). Conclusion The oropharyngeal approach with small titanium plate fixation for unstable atlantic fracture is less invasive and shorter operation time, and can retain cervical spine mobility to the greatest extent than traditional posterior atlantoaxial pedicle screw fixation. [ABSTRACT FROM AUTHOR]

This study consists of a retrospective cohort study, a systematic review, and a meta-analysis which were separately conducted. This study aimed to investigate the prevalence of atlas arch defects, generate an evidence-based synthesis, and propose a common classi- fication system for the anterior and combined atlas arch defects. Atlas arch defects are well-corticated gaps in the anterior or posterior arch of the atlas. When both arches are involved, it is known as a combined arch defect. Awareness of these defects is essential for avoiding complications during surgical procedures on the upper spine. The prevalence of arch defects was investigated in an open-access OPC-Radiomics (Radiomic Biomarkers in Oropharyngeal Carcinoma) dataset comprising 606 head and neck computed tomography scans from oropharyngeal cancer patients. A systematic review and meta-analysis were performed to generate prevalence estimates of atlas arch defects and propose a classification system for the anterior and combined atlas arch defects. The posterior arch defect was found in 20 patients (3.3%) out of the 606 patients investigated. The anterior arch defect was not observed in any patient, while a combined arch defect was observed in one patient (0.2%). A meta-analysis of 13,539 participants from 14 studies, including the present study, yielded a pooled-posterior arch defect prevalence of 2.07% (95% confidence interval [CI], 1.22%-2.92%). The prevalences of anterior and combined arch defects were 0.00% (95% CI, 0.00%-0.10%) and 0.14% (95% CI, 0.04%-0.25%), respectively. The anterior and combined arch defects were classified into five subtypes based on their morphology and frequency. The present study showed that atlas arch defects were present in approximately 2% of the general population. For future studies, larger sample sizes should be used for studying arch defects to avoid the small-study effect and to predict the prevalence accurately. [ABSTRACT FROM AUTHOR]

Background: This study was a prospective cadaver-derived skeletal study looking at the skeletal remains of a modern human population. The complete arcuate foramen (AF) is an anatomical variant of the atlas vertebra with a complete osseous bridge over the groove for the vertebral artery (VA). Awareness of the anatomic variations of the atlas related to the course of the VA, such as the AF, is important because the course and variations of VAs are critical to spine surgeons. We aimed to detect the prevalence of AF in sub-Saharan African subjects. Materials and methods: We analyzed the prevalence of AF in 120 atlas vertebrae from the Raymond A Dart Collection of the University of the Witwatersrand, Johannesburg, South Africa. Results: Twelve (13.3 %) atlases of the 90 that were from sub-Saharan African ancestry subjects presented at least one AF: the presence of AF frequency was 6.7 % in the Sotho sample, 23.3 % in the Xhosa sample and 10.0 % in the Zulu sample. However, no significant difference was found in their distribution regarding the presence of AF ratios (p = 0.221). The AF frequency was 3.3 % in the South African Caucasian subjects. No significant differences were found in their distribution regarding the presence of AF ratios between the Caucasian and the Sotho (p = 1.000), Zulu (p = 0.612) and Xhosa (p = 0.052) samples. Conclusions: Our research shows a tendency for a higher AF presence in Xhosa subjects. It has increased the knowledge of the AF prevalence in sub-Saharan Africa, drastically increasing the population.

ABSTRACT Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate–PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

Introduction: the hypoglossal nerve, XII cranial nerve, is a motor nerve for the muscles of the tongue that arises from the medulla and crosses the hypoglossal nerve canal in the occipital bone. This canal may present variations that induce changes in the path of the nerve and vascular structures related to it. This understanding is essential for choosing the best surgical techniques to avoid injuries to the components that transit through the canal. Objectives: to analyze the morphology of the hypoglossal nerve canal in skulls from a population in northeastern Brazil. Method: fifty dry adult human skulls (25 male and 25 female) belonging to 2 anatomy laboratories in northeastern Brazil were analyzed. The morphological analysis was performed according to the classification by Kumar et al.9 regarding the presence of septa and spores. The morphometric analysis was performed with a digital caliper with a precision of 0.01mm. Student's t test was applied to assess sexual dimorphism using IBM SPSS Statistics for Windows version 21.0. Results: twenty-three skulls were classified as type l (no changes in the canal), of which 10 are female and 13 male (46% of the sample). No type 2a and 2b skulls were found. The most prevalent variations were type 3, with 11 skulls 3a (22%) and 5 3b (10%). Five skulls corresponded to type 4 (10%) and another 5 to type 5 (a combination of spore and septum), which is a variation discovered and adapted to the classification used in this study. In the morphometric analysis, there was no difference between the analyzed parameters, except for extracranial width, in males (p=0.003). Conclusion: a peculiar anatomy of the hypoglossal nerve canal was observed in this population from northeastern Brazil. It is essential to recognize these variations to guide professionals in their surgical interventions, avoiding injuries to the hypoglossal nerve and associated structures. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the accuracy of palpation methods for locating the transverse processes of the first cervical vertebra and masseter muscle using radiographic images as the gold-standard method and the association between personal characteristics with the observed accuracy. This was a single-blinded, diagnostic accuracy study. Ninety-five participants (49 women, 58 ± 16 years of age) were enrolled in this study. A single examiner palpated the neck and face region of all participants to identify the transverse processes of the first cervical vertebra and masseter muscles bilaterally. In sequence, participants underwent a multislice computed tomography scan for assessment of the superimposed inner body structure. Two radiologists assessed the computed tomography images using the same criteria and were blinded regarding each other's assessment and the anatomic landmarks under investigation. The palpation accuracy was calculated as the proportion of the correctly identified landmarks in the studied sample. The correlation of the palpation outcome (correct = 1; incorrect = 0) with age, sex (male = 1; female = 0), and body mass index was investigated using the point-biserial correlation coefficient. The right and left transverse processes were correctly located in 76 (80%) and 81 (85%) participants, respectively, and bilaterally in 157 events (83%), as evaluated by the consensus of the 2 radiologists. The masseter muscles were correctly localized bilaterally in 95 of 95 (100%) participants. Body mass showed statistical evidence of a weak, positive correlation with the correct location of the transverse processes of the first cervical vertebra at the right body side (r =.219; 95% confidence interval, 0.018-0.403; P =.033). Palpation methods used in this study accurately identified the location of the first cervical vertebra spinous processes and the masseter muscles. [ABSTRACT FROM AUTHOR]

Background: The intervertebral disc extrusion resorption has been described in the literature by various authors. It occurs in up to 75% of patients with symptomatic extruded lumbar discs. The Atlasprofilax method favors osteo-musculo- articular rehabilitation processes, mainly impacting on 2 levels: the first is the bone anatomy of the atlanto- occipital joint, and the second is the fasciae located in the cervical region. Case Report: A 42-year-old male patient diagnosed by MRI with dehydration of L2-L3 to L5-S1 intervertebral discs, disc bulging at L2-L3 and L3-L4, and disc extrusion at L4-L5, received a one-time neuromuscular treatment, called the Atlasprofilax method, to the suboccipital region. In a repeat MRI 6 months later, the disc extrusion at L4-L5 was totally resorbed and improvement in the L3-L4 and L4-L5 disc bulges was seen. The patient's symptoms prior to the Atlasprofilax treatment included bilateral trapezius pain, right brachialgia, constant chronic low back pain, right sciatica, gait claudication, and paresthesia and dysesthesias in the lower limbs with associated pain and numbness in the calves. These symptoms were ameliorated after the treatment. The sciatica disappeared 1 week after the treatment and did not recur. In a follow-up 5 years later, the remaining symptoms had improved even further. Conclusions: We propose that alterations of the cervical musculature and deep fascia could predispose to the development of lumbar disc abnormalities. We therefore also propose that improvements in this patient, both in symptoms and in imaging findings, are due to a reduction of the asymmetric distribution of forces and elastic loading as a result of the Atlasprofilax treatment. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the radiologic and clinical outcomes of direct internal fixation for unstable atlas fractures. Materials and Methods: This retrospective study included 12 patients with unstable atlas fractures surgically treated using C1 lateral mass screws, rods, and transverse connector constructs. Nine lateral mass fractures with transverse atlantal ligament (TAL) avulsion injury and three 4-part fractures with TAL injury (two avulsion injuries, one TAL substance tear) were treated. Radiologic outcomes included the anterior atlantodental interval (AADI) in flexion and extension cervical spine lateral radiographs at 6 months and 1 year after treatment. CT was also performed to visualize bony healing of the atlas at 6 months and 1 year. Visual Analog Scale (VAS) scores for neck pain, Neck Disability Index (NDI) values, and cervical range of motion (flexion, extension, and rotation) were recorded at 6 months after surgery. Results: The mean postoperative extension and flexion AADIs were 3.79±1.56 (mean±SD) and 3.13±1.01 mm, respectively. Then mean AADI was 3.42±1.34 and 3.33±1.24 mm at 6 months and 1 year after surgery, respectively. At 1 year after surgery, 11 patients showed bony healing of the atlas on CT images. Only one patient underwent revision surgery 8 months after primary surgery due to nonunion and instability findings. The mean VAS score for neck pain was 0.92±0.99, and the mean NDI value was 8.08±5.70. Conclusion: C1 motion-preserving direct internal fixation technique results in good reduction and stabilization of unstable atlas fractures. This technique allows for the preservation of craniocervical and atlantoaxial motion. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate changes in the sagittal parameters of the occipito-atlantoaxial complex after three-level anterior cervical decompression and fusion (ACDF) and identify the influential factors by comparing ACDF with a zero-profile anchored spacer (ACDF-Z) versus a cage-plate construct (ACDF-P). Methods: The cohort comprised 106 patients who underwent three-level contiguous ACDF-Z or ACDF-P for cervical radiculopathy and/or myelopathy. Standing, flexion, and extension radiographs of cervical spine were obtained preoperatively, and 3 and 12 months postoperatively. The assessed cervical sagittal parameters were the platform angle of the axis, Cobb angle, and range of motion (ROM) of C2⁃7, C0⁃1, and C1⁃2. Results: In both the ACDF-Z and ACDF-P groups, the Cobb angle of the upper cervical spine decreased and the C0-1 ROM increased from preoperatively to 3 and 12 months postoperatively (P < 0.01). The alignment restoration was lost at 12 months compared with 3 months in the ACDF-Z group, but not in the ACDF-P group (P < 0.01). The ACDF-P group showed more loss of C2-7 ROM and more compensatory changes in C0-2 ROM than the ACDF-Z group (P < 0.05). Conclusion: The Cobb angle decreased and ROM increased significantly as compensatory changes of the atlantooccipital or atlantoaxial joint after both types of ACDF, which may accelerate degeneration. The zero-profile anchored spacer had less impact on the occipito-atlantoaxial complex but was worse at maintaining the alignment restoration, which were contrary to the cage-plate construct. Surgeons should be aware of the impact of multi-level ACDFs on the occipito-atlantoaxial complex. [ABSTRACT FROM AUTHOR]

Study Design Case series. Purpose To evaluate the radiographic and clinical results of C1 laminoplasty without fusion. Overview of Literature C1 laminectomy has been the standard procedure for decompression at the C1 level. However, there have been some reports of trouble cases after C1 laminectomy. C1 laminoplasty might be superior to C1 laminectomy with regard to maintaining the original C1 anatomical shape, preventing compression from the posterior soft tissue, and ensuring an adequate bone-grafting site around the C1 posterior part if additional salvage fusion surgery is necessary afterward. Methods Seven patients with spinal cord compression without obvious segmental instability at the C1/2 level treated by C1 laminoplasty were included. The indication of C1 laminoplasty was same as that of C1 laminectomy. C1 laminoplasty was performed in the same way as subaxial double-door laminoplasty. The imaging findings were evaluated using X-ray, computed tomography, and magnetic resonance imaging. The clinical results were evaluated using the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) and JOA score. Peri- and postoperative complications were also investigated. Results No patient showed increased C1/2 segmental instability after the surgery. The mean pre- and postoperative JOA scores were 8.6 and 11.7, respectively. The mean recovery rate was 40.2%. The effective rate in the JOACMEQ was 50% for the cervical spine function, 33% for the upper extremity function, 50% for the lower extremity function, 17% for the bladder function, and 17% for the quality of life. No major complication that seemed to be unique to C1 laminoplasty was observed over a period of about 4 years follow-up. Conclusions C1 laminoplasty for patients without obvious segmental instability might be a viable alternative procedure to C1 laminectomy.

Background: Published descriptions of the tectorial membrane have been inconsistent. Descriptions vary from a simple ligamentous band extending between the axis and occiput to a more complex layered structure composed of bands of fibers. The purpose of this study was to examine and document the macrostructure of the tectorial membrane. Materials and Methods: The tectorial membrane was examined by fine dissection in 11 formalin-fixed human adult cadavers. Detailed descriptions of the macrostructure and attachments were recorded. Results: Each tectorial membrane examined consisted of two distinct layers. The superficial layer was composed variably of three or four bands. Its fibers extend caudally over multiple spinal levels, becoming continuous with the posterior longitudinal ligament. The deeper layer routinely consisted of three bands, each being firmly adherent to the posterior aspect of the body of the second cervical vertebra. Attachments of fibers from both layers extended beyond the foramen magnum to create a semicircular attachment onto the base of the skull. Conclusions: The tectorial membrane has a more complex structure than has been described to date in standard anatomical texts. The existence of a layered and banded composition may have implications for understanding its function and for the clinical assessment of this structure.

Study Design A cross-sectional observational study involved the analysis of computed tomography (CT) scan data from 125 Indian subjects of 18 years or older with normal imaging findings. Scans were obtained from patients with head injuries as a part of the screening process along with brain CT scans. Purpose To establish the dimensions of lateral masses of the atlas vertebrae in normal disease-free Indian individuals. Overview of Literature Lateral mass fixation has become the standard of care in fixation of the supra-axial cervical spine. Many studies have investigated the dimensions of lateral masses in cadaveric specimens; however, studies involving the radiological morphometric analysis of the lateral masses of the atlas vertebra in living patients are lacking. Methods Subjects underwent craniovertebral junction CT scans during evaluations of head injury. All had normal radiology reports. The CT scans were obtained using a CT Philips Brilliance 64 machine (Philips, Amsterdam, Netherlands) with a slice thickness of 1 mm and then analyzed using Horos software ver. 2.0.2 (Horos Project, Annapolis, MD, USA) on a MacBook. Results Lateral masses of the atlas vertebrae were found to be larger in males than females and larger on the right than the left side. The angle of permissible medialization was found to be larger on the right side. The analysis of the average dimensions indicated the conventionally described screw positions to be safe. Conclusions The present study provides information that may help to establish standard dimensions of lateral masses of the atlas vertebrae among the normal Indian population. We demonstrate that there is no significant difference when compared with the Western population. The results presented here will be of use to clinicians as they may inform preoperative planning for lateral mass fixation surgeries.

Background: Laminotomy and laminar replantation have emerged as novel treatment modalities for intraspinal tumors, aiming to minimize postoperative complications and retain spinal mobility. However, existing research predominantly emphasizes their application in the thoracolumbar spine. The unique anatomy of the atlantoaxial segments necessitates surgical techniques that differ from those used in other spinal regions, and the clinical effect of such procedure remains unknown., Case Presentation: A 61-year-old male patient with intradural schwannoma at the atlantoaxial level was operated on. The patient underwent posterior laminectomy, as well as a combined replantation of the posterior arch of the atlas and bilateral axial laminae. Postoperatively, the patient experienced significant neurological improvement, with no deformities or instability on the radiological assessments during the follow-up., Conclusion: Laminotomy with combined replantation of the posterior arch of the atlas and bilateral axial lamina emerges as an effective approach for managing intraspinal tumors at the atlantoaxial level. This technique not only offers ample operating space but also restores the stability of the spinal canal. Moreover, it preserves the mobility of the atlantoaxial segment, minimizes impact on adjacent segments, and mitigates the formation of postoperative fibrosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Leng, Li, Meng and Wang.)

In this report, atlantooccipital assimilation (AS), anterior arch defect (AAD), and posterior arch defect (PAD) of the atlas, and several variations around the craniocervical junction were identified on computed tomography (CT) of a patient of unknown sex and age. Coronal and sagittal CT scans showed AS and bilateral fusion of the atlas and the base of occipital bone. Axial CT scan at the atlas revealed PAD type B on the left side and midline AAD. Morphometric measurements indicated a potential ventral spinal cord compression. In addition, mid-sagittal CT revealed the presence of fossa navicularis magna and incomplete formation of the transverse foramen on the right side. This study reports an extremely rare AS associated with AAD, PAD, and other variations of the clivus and the atlas. To our knowledge, no similar case has been reported in the literature.

The craniocervical flexion test (CCFT) is commonly used for assessing the performance and function of the deep cervical flexor muscles; however, objective measurements of cervical segmental motion during craniocervical flexion (CCF) are lacking. Therefore, the purpose of this study aimed to investigate cervical segmental motions during CCFT and determine the relationship between changes of cervical segmental motions and the cervical lordotic angle. A cross-sectional study of prospectively collected data. Twenty healthy participants without neck pain underwent standing cervical radiography (lateral view) to measure the cervical lordotic angle, followed by radiography in supine position during the CCFT. The occipito-atlantal (OA) joint angle, atlantoaxial (AA) joint angle, and cervical spinous process posterior displacement (CSPPD) of the C1-C6 vertebrae were measured using lateral cervical radiographs taken during the initial (20 mm Hg) and low-stage (24 mm Hg) CCFT conditions. The CCF motion during the low-stage CCFT was characterized by a significantly increased OA joint angle, decreased AA joint angle, and increased C1-C6 CSPPD compared with the initial stage (P < .05). The change in the value of C1-C6 CSPPD at low-stage CCFT showed a significant positive correlation with the cervical lordotic angle. These results indicate that the cervical lordotic angle is important in minimizing CSPPD and performing appropriately-isolated CCF motion during CCFT., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

To examine the agreement and interrater reliability of a palpation method for locating the C1 transverse processes (C1TP) and the association between personal characteristics with the observed agreement. Single-blinded, inter-rater reliability study. Ninety-nine participants (58 women, age 44 ± 10 years, body mass index 26.1 ± 4.3 kg/m2, neck disability index = 8.4 ± 7.3 points) were enrolled in this study. Two raters blinded to each other's assessment performed the palpation for locating the C1TP and marked it with invisible ultra-violet ink. A research assistant measured the distance between the skin marks labeled as C1TP. The association between sex, age, body mass index, neck pain intensity and disability on the interrater agreement was verified using a point-serial correlation coefficient. Absolute and percent agreement for the right and left body sides were 90/99 (90.9 %, 95%CI 83.4 to 95.8) and 96/99 (97.0 %, 95%CI [91.4 to 99.4]), respectively. Interrater reliability was excellent for both right (Gwet's AC1 0.883, 95%CI [0.881 to 0.885]) and left body sides (Gwet's AC1 0.894, 95%CI [0.894 to 0.896]). After adjustment for multiple comparisons, no statistical evidence of correlation was observed for age, sex, body mass index, and NDI with the agreement for location of C1TP (r = −0.206 or lower, adjusted P-value = 0.328 or higher). The palpatory method for the location of C1TP has excellent interrater agreement and reliability. Age, sex, body mass index, and disability show weak-to-negligible correlation with the agreement for location of C1TP. • A palpation method should be accurate and reliable for being introduced in clinical and laboratory settings • This is the first study to report interrater reliability results for locating C1 and the reliability is excellent • The result of our study increases our confidence in recommending the location of C1 in clinical practices when performing mobility tests for C0–C1–C2, the great nerve occipital palpation, as a start landmark for suboccipital muscle palpation and when applying direct manual procedures to restore mobility in C1–C2 segments as muscle energy technique, high-velocity low amplitude (HVLA) manipulation and mobilization with movement techniques • These results benefit the manual therapist's education process as palpatory skills and surface anatomy are core subjects in manual therapy education, including osteopathy, despite the lack of validation of most palpation methods [ABSTRACT FROM AUTHOR]

Background contextNonunion of the posterior arch of the atlas is an uncommon but normal developmental variant. It is usually asymptomatic in the patient but may be associated with greater incidence of fracture because of increased stress on the anterior arch.PurposeWe sought to determine whether anterior arch hypertrophy is present in cases of congenital nonunion of the posterior arch of the atlas.Study design/settingA retrospective analysis of 1 year (February 2005-January 2006) of computed tomography cervical spine studies requested by the University of California San Diego Medical Center Trauma Department was undertaken.Patient sampleAll patients matching the search criteria (see Study design) were included.Outcome measuresArea density product, defined as the midline cross-sectional area of the anterior arch on sagittal reformat multiplied by the average areal radiodensity in Hounsfield units (HU) as measured by two raters, was calculated for cases and controls.MethodsCases of posterior arch nonunion were identified and matched to controls. The significance of differences in area density product between cases and controls were established by the Student t test. Interrater correlation was calculated.ResultsPosterior arch nonunion was identified in 26 individuals (3.1% of 839 studies reviewed). Compared with age- and sex-matched controls, a 21% increase in area density product of the midline anterior arch was observed in posterior arch nonunion cases (773 HU-cm2 in cases vs. 637 HU-cm2 in controls; p

Objective This study was conducted to clarify the validity of the short posterior arch screw (S-PAS). The S-PAS is inserted only in the pedicle-analogue portion of the posterior arch. The S-PAS screw length is almost half that conventional C1 lateral mass screws inserted via the posterior arch (via-PAS). S-PAS reduces the risk of vertebral artery injury (VAI) because it never reaches the transverse foramen. Although the biomechanical validity of various C1 lateral mass screws (C1LMS) analyzed in young specimens have been published, that of unicortically inserted C1LMS such as the unicortical Harms screw, S-PAS, and via-PAS for elderly patients is concerning because of the high prevalence of osteoporosis in the elderly. Methods Nine fresh frozen cadavers (average age at death, 72.1 years) were used for pullout testing. The bone mineral density of each specimen was evaluated using quantitative computed tomography. Results The pullout strength of via-PAS (1,048.5 N) was significantly greater than that of the unicortical Harms screw (257.9 N) (p

It is difficult to treat atlantoaxial instability in patients with a high-riding vertebral artery or anomalies of the craniocervical junction. We report 2 successful cases in which the transspinal canal screwing technique was used because of difficulties performing conventional fixation methods. Case 1: A 78-year-old woman suffered from progressive myelopathy due to severe spinal cord compression with a congenital anomaly of the craniovertebral junction. Bilateral transspinal canal screws from the axis body with spondylolisthesis to the dens were inserted by retracting the dural sac medially after foramen magnum decompression and cervical laminoplasty. Case 2: A 20-year-old man with a spinal deformity due to Loeys-Dietz syndrome presented to our hospital for treatment of syringomyelia. He had no obvious neurological deficits, but spinal cord compression due to right atlantoaxial rotating dislocation was observed. A screw was inserted from the vertebral body of the axis to the right lateral mass of the atlas via the spinal canal after laminectomy of the atlas. The transspinal canal screwing technique is useful for treating atlantoaxial instability in cases where other fixation methods are difficult.

Study Design Retrospective radiological study. Purpose We aimed to determine the prevalence of ponticulus posticus (PP) and high-riding vertebral artery (HRVA) occurring simultaneously on the same side (PP+HRVA) and in cases of PP+HRVA, to assess C2 radio-anatomical measurements for C2 pars length, pedicle width, and laminar thickness. Overview of Literature PP and HRVA predispose individuals to vertebral artery injuries during atlantoaxial fixation. In cases of PP+HRVA, the construct options thus become limited. Methods Consecutive computed tomography scans (n=210) were reviewed for PP and HRVA (defined as an internal height of

The proatlas, a bone located between the skull and the neural spines of the cervical vertebrae, is best known from reptiles. Most previous studies of the proatlas have centered on its developmental, debating the relationship between the proatlas and the cervical neural arches. The present study was intended as a description of the proatlas in the American alligator (Alligator mississippiensis) and an experimental test of its hypothesized role in venous blood and cerebrospinal fluid (CSF) distribution. In Alligator, the proatlas is chevron-shaped; ventrally it has a loose connection to the dorsal surface of the first cervical vertebrae, dorsally it has a robust elastic tissue tether on the otoccipital and supraoccipital bones. The ventral surface of the proatlas parallels the dorsal margin of the foramen magnum and rests on the dorsal surface of the spinal venous sinus. Experimental manipulation of the proatlas demonstrated that displacement of the proatlas causes pressure changes in both the spinal venous sinus and the enclosed spinal CSF. The results of this study represent the first demonstration of an explicit functional role for the proatlas, the circulation of fluids between the cranial and spinal compartments of the central nervous system., (© 2024 The Authors. Journal of Morphology published by Wiley Periodicals LLC.)

Purpose: Bridging veins (BVs) serve as a route of pial venous reflux, and its anatomy is essential to understand the pathophysiology of dural arteriovenous shunts (dAVSs) around the craniocervical junction (CCJ) (from the jugular foramen level to the atlantal level). However, the anatomical variations of the BVs and their proximal connections remained poorly elucidated. This study aimed to radiologically investigate the anatomy of the bridging veins around CCJ and discuss the clinical significance of these BVs in the dAVS., Methods: We investigated normal venous anatomy of the BVs from the jugular foramen level to the atlantal level using preoperative computed tomography digital subtraction venography in patients undergoing elective neurosurgery. BVs affected by the dAVSs in the same region were also evaluated. The three types of dAVS, craniocervical junction, anterior condylar, and proximal sigmoid sinus, were investigated., Results: We identified six BV groups: superolateral, anterolateral, lateral, posterior, inferolateral, and inferoposterior. The superolateral and inferolateral groups, connected with the proximal sigmoid sinus and suboccipital cavernous sinus, respectively, were the largest groups. Each group has a specific downstream venous connection. The association with dVASs was observed only in the inferolateral group, which was typically the sole venous drainage in most dAVSs at the CCJ., Conclusion: We reported detailed anatomy of BVs from the jugular level to the atlantal level, which enhanced our understanding of the pathophysiology of dAVSs in the corresponding region., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To determine the frequency of Ponticulus posticus and Ponticulus lateralis among patients admitted to a24-hour emergency hospital., Material and Methods: The study included 2887 patients with a traumatic history who were admitted to the hospital for emergency reasons. This principle of sampling allowed us to exclude a high concentration of studies of patients with chronic neurological diseases, the cause of which could be symptomatic Kimmerle's anomaly (KA). During the period 01.01.20 to 31.12.20, primary CT was performed on an emergency basis in 7348 patients. Of these, CT scans of the brain and cervical spine were performed in 2965 patients. Some patients (78 people) were excluded from the study due to the presence of cervical vertebral fractures and metal artifacts in the craniovertebral region., Results: The Ponticulus posticus was detected in 1162 (40.2%) patients, among them class 3 and 4 was detected in 27.7%, and class 2 ossification in 12.5%. This Ponticulus posticus was significantly more common (χ 2 test, p =0.0005) in men. The Ponticulus lateralis was identified in 231 patients (8%), among them 94 patients (3.3%) had complete ponticulus on both sides, 29 patients (1%) - on one side, and 108 patients (3.7%) - two-sided incomplete ponticulus. In patients with class 2-3-4, Ponticulus lateralis were detected significantly more often (χ 2 test, p <0.0001)., Conclusion: The cumulative incidence of KA was 42%, 17% of patients are carriers of a complete KA bridge, which is significantly higher than in the European or Asian regions. The data suggest that KA is not the result of ossification of the posterior atlanto-occipital membrane, since different classes of KA occur equally often at different ages. Further studies of KA are needed, including its occurrence in patients of the neurological department and its correlation with individual neurological syndromes to determine the need for surgical treatment in the population.

Introduction: The Ponticulus Posticus (PP) is a bony arch produced by ossification of the ligament that connects retroglenoid tubercle located posterior to the superior articular fossa of the atlas (C1) with their posterior arch. Objectives: to establish frequency of PP in the patient's lateral cervical spine radiographies in the district of Moreno in the Province of Buenos Aires. Materials and methods: randomly collected from "Consultorio radiológico Moreno SRL" s X-ray archive, located in Moreno-GBA between May and August of 2019. Two hundred and sixty-three lateral cervical spine radiographs were obtained to be used as aim units, 53 units were excluded because they did not show the criteria for inclusion. Results: In lateral cervical spine radiographs analyzed (n=210), the presence of PP was found in 30 (CRF =14.29%). The female's predominance over the males and the high presentation of PP in a complete form (53.3%) over the incomplete ones (46.7%) were highlighted without having a relevant significance (p>0.01) both carried out through Fisher's exact test. Finally, in groups 2 and 3 there were higher presences of PP than the rest of the groups (Chi-square p>0.01). Conclusion: We were able to establish data about frequency of Pon-ticulus Posticus and found that there is no morphological predominance and its finding is no significant age and sex-related. [ABSTRACT FROM AUTHOR]

Background: Published descriptions of the tectorial membrane have been inconsistent. Descriptions vary from a simple ligamentous band extending between the axis and occiput to a more complex layered structure composed of bands of fibers. The purpose of this study was to examine and document the macrostructure of the tectorial membrane. Materials and Methods: The tectorial membrane was examined by fine dissection in 11 formalin-fixed human adult cadavers. Detailed descriptions of the macrostructure and attachments were recorded. Results: Each tectorial membrane examined consisted of two distinct layers. The superficial layer was composed variably of three or four bands. Its fibers extend caudally over multiple spinal levels, becoming continuous with the posterior longitudinal ligament. The deeper layer routinely consisted of three bands, each being firmly adherent to the posterior aspect of the body of the second cervical vertebra. Attachments of fibers from both layers extended beyond the foramen magnum to create a semicircular attachment onto the base of the skull. Conclusions: The tectorial membrane has a more complex structure than has been described to date in standard anatomical texts. The existence of a layered and banded composition may have implications for understanding its function and for the clinical assessment of this structure. [ABSTRACT FROM AUTHOR]

Copyright of Manuelle Medizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Manuelle Medizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Study Design: A cross-sectional observational study involved the analysis of computed tomography (CT) scan data from 125 Indian subjects of 18 years or older with normal imaging findings. Scans were obtained from patients with head injuries as a part of the screening process along with brain CT scans. Purpose: To establish the dimensions of lateral masses of the atlas vertebrae in normal disease-free Indian individuals. Overview of Literature: Lateral mass fixation has become the standard of care in fixation of the supra-axial cervical spine. Many studies have investigated the dimensions of lateral masses in cadaveric specimens; however, studies involving the radiological morphometric analysis of the lateral masses of the atlas vertebra in living patients are lacking. Methods: Subjects underwent craniovertebral junction CT scans during evaluations of head injury. All had normal radiology reports. The CT scans were obtained using a CT Philips Brilliance 64 machine (Philips, Amsterdam, Netherlands) with a slice thickness of 1 mm and then analyzed using Horos software ver. 2.0.2 (Horos Project, Annapolis, MD, USA) on a MacBook. Results: Lateral masses of the atlas vertebrae were found to be larger in males than females and larger on the right than the left side. The angle of permissible medialization was found to be larger on the right side. The analysis of the average dimensions indicated the conventionally described screw positions to be safe. Conclusions: The present study provides information that may help to establish standard dimensions of lateral masses of the atlas vertebrae among the normal Indian population. We demonstrate that there is no significant difference when compared with the Western population. The results presented here will be of use to clinicians as they may inform preoperative planning for lateral mass fixation surgeries. [ABSTRACT FROM AUTHOR]

Competing Interests: None

Surgical approaches for posterior C1–C2 arthrodesis, such as C1–C2 transarticular and C1–C2 screw stabilization, are known to be demanding because of the anatomic close proximity of cervical vertebrae to neurovascular structures. Currently, navigation by fluoroscopy or intraoperative computed tomography (ICT) is the standard practice. However, fluoroscopy has various limitations, and ICT is time consuming and not available in many centers; furthermore, both diagnostic tools lead to exposure of the operating room staff to radiation exposure. We evaluate the safety, efficacy, and facility of a navigation system using only preoperative cervical computed tomography and computed tomographic angiography (CT/CTA), to prevent the risk of neurovascular damage in atlantoaxial stabilization. The authors report a series of 21 patients who underwent posterior upper cervical spine fixation using a navigation system with intraoperative single-level vertebral registration on preoperative cervical CT/CTA (software BrainLab IPlan Spine 3.0). Intraoperative and postoperative comparative analysis was performed to verify the correspondence between the virtual anatomic position of the surgical instruments and screws represented on the neuronavigator, and the actual positions verified intraoperatively and on postoperative CT. Thirteen patients underwent C1–C2 arthrodesis with a Harms construct, 1 patient with transarticular screw fixation and 4 patients with occipitocervical stabilization. Three patients underwent C1–C2–C3 stabilization with C1 hooks, C2–C3 screws, and rod construct. On postoperative CT, the position of all screws appeared satisfactory. No neurovascular damage occurred in any patients. The use of a neuronavigation system, based on preoperative acquired cervical CT and intraoperative single-vertebra registration, may provide a valuable support for the improvement of the surgical accuracy of posterior C1–C2 screw fixation. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective radiological study. Purpose: We aimed to determine the prevalence of ponticulus posticus (PP) and high-riding vertebral artery (HRVA) occurring simultaneously on the same side (PP+HRVA) and in cases of PP+HRVA, to assess C2 radio-anatomical measurements for C2 pars length, pedicle width, and laminar thickness. Overview of Literature: PP and HRVA predispose individuals to vertebral artery injuries during atlantoaxial fixation. In cases of PP+HRVA, the construct options thus become limited. Methods: Consecutive computed tomography scans (n=210) were reviewed for PP and HRVA (defined as an internal height of <2 mm and an isthmus height of <5 mm). In scans with PP+HRVA, we measured the ipsilateral pedicle width, pars length, and laminar thickness and compared them with controls (those without PP or HRVA). Results: PP was present in 14.76% and HRVA in 20% of scans. Of the 420 sides in 210 scans, PP+HRVA was present on 13 sides (seven right and six left). In scans with PP+HRVA, the C2 pars length was shorter compared with controls (13.69 mm in PP+HRVA vs. 20.65 mm in controls, p <0.001). The mean C2 pedicle width was 2.53 mm in scans with PP+HRVA vs. 5.83 mm in controls (p <0.001). The mean laminar thickness was 4.92 and 5.48 mm in scans with PP+HRVA and controls, respectively (p =0.209). Conclusions: The prevalence of PP+HRVA was approximately 3% in the present study. Our data suggest that, in such situations, C2 pedicle width and pars length create important safety limitations for a proposed screw, whereas the translaminar thickness appears safe for a proposed screw. [ABSTRACT FROM AUTHOR]

Copyright of Manuelle Medizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)