On the morphological features of the arcuate foramen in the population of Azerbaijan

Abstract

This study aimed to evaluate the morphological characteristics of the arcuate foramen (foramen arcuate, FA) of the atlas vertebra and to analyze its morphometric parameters. The material consisted of 54 adult human first cervical vertebrae obtained from the anatomical bone collection of the Department of Human Anatomy and Medical Terminology at Azerbaijan Medical University. The anteroposterior and craniocaudal diameters of the arcuate foramen were measured using a digital caliper with an accuracy of 0.01 mm, and the area of the foramina was calculated. The area of the FA was determined using the formula S = π × A × B / 4, where A represents the craniocaudal diameter and B represents the anteroposterior diameter of the arcuate foramen. Statistical analysis was performed using SPSS software version 16.0. Descriptive statistics included mean ± standard deviation (SD), median, minimum, and maximum values. Comparative analysis was performed using the Mann–Whitney U test due to unequal sample sizes. A p-value < 0.05 was considered statistically significant. According to the study, 24% of the examined atlas vertebrae demonstrated different types of arcuate foramen variations: 5.5% unilateral arcuate foramen, 13% unilateral bony protrusion, 1.9% bilateral arcuate foramen, and 3.4% bilateral bony protrusions. The area of the arcuate foramen was greater than that of the transverse foramen, reaching approximately twofold larger values in some specimens. The findings demonstrate notable anatomical variability of the arcuate foramen in the studied sample. Further studies with larger sample sizes and clinical correlations are required to clarify the functional significance of this anatomical variation.

Keywords

• foramen arcuale (FA)
• vertebral artery (VA)
• transverse foramen (TF)
• unilateral bone protusion (UBP)
• bilateral bone protusion (BBP)

Supporting Institution

Azerbaijan Medical University

Ethical Statement

Since this study involved the analysis of bone specimens and not live human participants, ethical approval from an ethics committee was not required. The study adhered to ethical guidelines for research involving human anatomical specimens, and all specimens used were handled in accordance with appropriate standards for anatomical research. No personal data were collected, and all samples were anonymized to ensure confidentiality and privacy.

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