Investigation of accessory transverse foramen in dry cervical vertebrae: incidence, variations, types, locations, and diagnostic implications

Assessing the frequency and variability of accessory zygomatic sutures in dry skulls: clinical insights and potential implications

PURPOSE

This study aimed to determine the presence and incidence of accessory sutures and bipartite zygomatic bone types, and their effects on population affinity and clinical significance.

METHODS

We examined 120 dry skulls and 50 zygomatic bones to evaluate the presence, frequency, and location of accessory zygomatic sutures as well as subtypes of bipartite zygomatic bones. Morphometric analysis included measuring the total width and length of the zygomatic bone with accessory sutures (ASs), the total length of the AS, and the shortest distance between the AS and various anatomical landmarks.

RESULTS

Bipartite zygomatic bone was observed in 14 of 120 dry skulls (11.6%) and 1 of 50 zygomatic bones (2%), indicating an overall incidence of 16 occurrences (8.82%). The ASs were predominantly located posterolaterally in 11 cases (six males, five females), anteromedially in two cases (one male, one female), superiorly in one case (male), and superolaterally in one case (male). Significant differences were noted in the distribution of the ASs (p < 0.001). Notably, a vertical inferior bipartite zygomatic type, which has not been reported in the literature, was identified. Correlations were observed between the various anatomical landmarks. Among females, the length of AS was significantly different (p = 0.038). Significant differences were also noted in the shortest distance between the AS and the zygomaticofacial foramen (ZFF) based on the body side (p = 0.034).

CONCLUSIONS

Our study suggests that the bipartite zygomatic bone is not a common occurrence, indicating its significance as a morphological variation present in certain individuals. The type VII bipartite zygomatic bone exhibited the highest incidence rate, suggesting potential ethnic-specific differences in the prevalence of certain subtypes. The consistent pattern of suture distribution, along with the asymmetry and variability in suture patterns, emphasizes its potential clinical relevance.

Thickness Asymmetry of the Vertebral Artery Groove: A Dried Vertebrae Study

BACKGROUND

The vertebral artery groove (VAG), located on the posterior arch of the first cervical (atlas) vertebra plays a pivotal role in guiding the vertebral artery's (VA) third part (V3). Deviations in VAG morphology and morphometry (dimensions) can influence vascular dynamics and pose clinical implications.

AIM

The current study delves into the morphometric variants and explores the less-explored morphometric variable of the VAG thickness, highlighting possible laterality (asymmetry).

METHODS

A morphometric investigation was conducted on 141 dried atlas (73 male and 68 female) vertebrae from a Greek adult population. The VAG's minimum thickness was investigated by considering the laterality (sides' differences), gender, and age impact on it. Measurements were performed by two independent researchers, ensuring the data reliability.

RESULTS

A significant asymmetry was identified in the VAG thickness between the left (3.9 ± 0.9 mm) and right (4.1 ± 1.1 mm) (p=0.005) sides, with the left side having the mean minimum thickness. Gender had a significant impact on VAG thickness only on the left side, with females presenting a significantly thinner left-sided VAG (3.6 ± 0.9 mm) than males (4.10 ± 0.7 mm) (p=0.001). Age had no significant impact on the VAG thickness.  Conclusion: The present study underscores the significance of asymmetry in the VAG thickness in craniocervical interventions. This less-explored morphometric variable warrants careful consideration by surgeons during preoperative planning to minimize potential complications. The current findings highlight the importance of understanding the VAG thickness asymmetry and its clinical implications, as this osseous variable may be an index of a different diameter of the VA by side. It is recommended that surgeons incorporate this variable into their preoperative assessments to improve the safety and efficacy of craniocervical interventions.

Anatomical variations of the atlas arches: prevalence assessment, systematic review and proposition for an updated classification system

Objective and background

This study focuses on the atlas, a pivotal component of the craniovertebral junction, bridging the cranium and spinal column. Notably, variations in its arches are documented globally, necessitating a thorough assessment and categorization due to their significant implications in clinical, diagnostic, functional, and therapeutic contexts. The primary objective is to ascertain the frequency of these anatomical deviations in the atlas arches among a Colombian cohort using cone-beam computed tomography (CBCT).

Methodology

Employing a descriptive, cross-sectional approach, this research scrutinizes the structural intricacies of the atlas arches in CBCT scans. Analytical parameters included sex distribution and the nature of anatomical deviations as per Currarino's classification. Statistical analyses were conducted to identify significant differences, including descriptive statistics and Chi-square tests. A systematic review of the literature was conducted in order to enhance the current Currarino's classification.

Results

The study examined 839 CBCT images, with a nearly equal sex distribution (49.7% female, 50.3% male). Anatomical variations were identified in 26 instances (3%), displaying a higher incidence in females (X2 [(1, N = 839) = 4.0933, p = 0.0430]). The most prevalent variation was Type A (2.5%), followed by Type B (0.4%), and Type G (0.2%) without documenting any other variation. The systematic review yielded 7 studies. A novel classification system for these variations is proposed, considering global prevalence data in the cervical region.

Conclusion

The study highlights a statistically significant predominance of Type A variations in the female subset. Given the critical nature of the craniovertebral junction and supporting evidence, it recommends an amendment to Currarino's classification to better reflect these clinical observations. A thorough study of anatomical variations of the upper cervical spine is relevant as they can impact important functional aspects such as mobility as well as stability. Considering the intricate anatomy of this area and the pivotal function of the atlas, accurately categorizing the variations of its arches is crucial for clinical practice. This classification aids in diagnosis, surgical planning, preventing iatrogenic incidents, and designing rehabilitation strategies.

Degenerative Cervical Myelopathy: An Overview

Degenerative cervical myelopathy (DCM) is a spinal condition of growing importance due to its increasing prevalence within the ageing population. DCM involves the degeneration of the cervical spine due to various processes such as disc ageing, osteophyte formation, ligament hypertrophy or ossification, as well as coexisting congenital anomalies. This article provides an overview of the literature on DCM and considers areas of focus for future research. A patient with DCM can present with a variety of symptoms ranging from mild hand paraesthesia and loss of dexterity to a more severe presentation of gait disturbance and loss of bowel/bladder control. Hoffman's sign and the inverted brachioradialis reflex are also important signs of this disease. The gold standard imaging modality is MRI which can identify signs of degeneration of the cervical spine. Other modalities include dynamic MRI, myelography, and diffusion tensor imaging. One important scoring system to aid with the diagnosis and categorisation of the severity of DCM is the modified Japanese Orthopaedic Association score. This considers motor, sensory, and bowel/bladder dysfunction, and categorises patients into mild, moderate, or severe DCM. DCM is primarily treated with surgery as this can halt disease progression and may even allow for neurological recovery. The surgical approach will depend on the location of degeneration, the number of cervical levels involved and the pathophysiological process. Surgical approach options include anterior cervical discectomy and fusion, corpectomy, or posterior approach (laminectomy ± fusion). Conservative management is also considered for some patients with mild or non-progressive DCM or for patients where surgery is not an option. Conservative treatment may include physical therapy, traction, or neck immobilisation. Future recommendations include research into the prevalence rate of DCM and if there is a difference between populations. Further research on the benefit of conservative management for patients with mild or non-progressive DCM would be recommended.

A Retrospective Study of Degenerative Cervical Myelopathy and the Surgical Management Within Northern Ireland

INTRODUCTION

Degenerative cervical myelopathy (DCM) is a condition of growing concern due to its increasing incidence among the ageing population. It involves age-associated pathological changes of the cervical spine that can result in spinal cord compression. This can lead to deficits in motor and sensory function of the upper and lower limbs, issues with balance and dexterity, as well as bladder and bowel disturbance. Patients can be categorised as having mild, moderate, or severe degenerative cervical myelopathy depending on their modified Japanese Orthopaedic Association (mJOA) score. This condition is generally managed surgically; however, patients with mild degenerative cervical myelopathy may be offered or opt for non-surgical treatment initially.

AIMS

The main aim of this study is to evaluate the surgical management of patients with DCM and to ascertain the degree of mJOA improvement from pre-surgery and one-year post-surgery follow-up. The second aim of the study is to explore the demographics within Northern Ireland who are diagnosed with DCM and who undergo surgery. This information could allow for better planning of services in the future for this patient cohort.

METHODS

This is a retrospective review of the surgical management of degenerative cervical myelopathy within the Regional Spinal Orthopaedic Unit in Northern Ireland over three years with one-year follow-up. The data was retrospectively collected from the Fracture Outcome Research Database. A total of 102 patients (10:7, male:female) with DCM were retrospectively evaluated. Exclusion criteria included all patients diagnosed with spinal tumour, fracture, central cord syndrome, and dislocation. Two patients were removed due to incorrect coding of DCM diagnosis and were not included. Key variables assessed were gender, age, symptoms, type of surgery, complications, and MRC score and mJOA score pre-surgery, 48 hours, six months, and one year post surgery. The choice of surgery was guided by the maximal angle of compression, the number of vertebral levels involved, patient comorbidities, and anesthetic risk.

RESULTS

The sample consisted of 60 men (58.82%) and 42 women (41.17%) with an average age of 57.17 ± 12.13 years ranging from 27 to 83 years old. Statistical analysis was conducted to explore the effect of time before and after surgery up to one year on the mJOA score. There was a significant difference in mJOA score pre-surgery and at six months and one year post surgery (R = 0.579053, p <0.001). Of the patients, 61.8% with a length of stay greater than three days and 71.4% of patients with a length of stay greater than seven days had a posterior approach surgery. A multiple linear regression analysis revealed that the mJOA score pre-surgery and the presence of complications significantly predicted the length of stay post-surgery (β -1.044, p = .011 and β -5.791, p = .028).

CONCLUSION

The first key finding of this study is that the mJOA score tends to improve after surgery for the majority of patients, particularly at six months, which is consistent with the literature. The second key finding is that anterior approach surgery is associated with a lower rate of complications and shorter post-surgery length of stay in hospital compared to posterior approach surgery. The third key finding is that the pre-surgery mJOA score and the presence of complications post surgery significantly predict the post-surgery length of stay.