Anatomical Variations of Accessory Foramina Transversaria in Cervical Vertebrae

Abstract

Introduction: The cervical vertebrae are cranially placed, moveable vertebrae in the human body. The characteristic feature of these vertebrae are the presence of a Foramen Transversarium (FT) in each lateral mass. A plexus of sympathetic nerves surrounding the Vertebral Artery (VA) and Vertebral Veins (VV) passes through the FT. The variable number and size of FT may lead to clinically significant conditions.It may be due to variable course of the VA which implicates an embryological basis.Aims: The objective of the present study is to find out the incidence of accessory FT in the cervical vertebrae and its morphological and clinical significance.Material and Methods:There were 117 dried cervical vertebrae available in the Department of Anatomy of Medical Sciences Stip. They were macroscopically studied to find variations in the number of FT.Results: Out of 117 cervical vertebrae accessory FT were found in 25 vertebrae (21.3%). The accessory FT were unilateral in 15 vertebrae (12.8%) and bilateral in 10 vertebrae (8.7%). The unilateral foramina were more common than the bilateral one. The accessory FT were smaller and posteriorly placed compared to the regular FT. Conclusions: In the present study 21.3% of cervical vertebrae showed accessory FT. Among them the unilateral accessory FT was more common than the bilateral variety. The accessory foramina were mostly observed in the lower cervical vertebrae. These anatomical variations and morphology of the FT is useful in the operations involving spine surgeries. It is also of great value to the radiologists in the interpretation of X-ray films and CT-scans.