Accessory Transverse Foramen in Cervical Vertebrae: A Morphological Study

Background Cervical vertebrae are irregular bone. Seven cervical vertebrae form the cervical region of the vertebral column, which encloses the spinal cord and meninges. The cervical vertebra has a characteristic feature that is presence of foramen in transverse process. Out of seven cervical vertebrae, 3rd - 6th cervical vertebrae are typical and remaining are atypical ones. Objective To observe the presence of accessory transverse foramen and shape of accessory foramen. Method The study was conducted on forty-eight cervical vertebrae available at Department of Anatomy, School of Basic Sciences, and Chitwan Medical College from July 2023 to January 2024. Total dry forty-seven human cervical vertebrae were included in the study. Out of them five were atypical (four atlas and one axis). The ethical approval was provided by CMC IRC on 4th January 2024 (CMC-IRC/080/081-078). All observations were taken by same investigator. All observations were recorded in preformed proforma. All observations were taken by same investigator. All observations were recorded as data in preformed proforma. Data entered in Epidata 3.1 version. Statistical analyses were done using SPSS 20. Result Total dry forty-seven human cervical vertebrae were included in the study. Out of them five were atypical cervical vertebrae (four axis and one atlas). One was excluded due to observed defect and damaged vertebrae. Out of forty-two accessory foramens of typical cervical vertebrae two were bilateral complete, two were one complete and other incomplete, one right sided unilateral complete and one left sided unilateral incomplete. Accessory foramen transversarium was absent in all five atypical cervical vertebrae. Conclusion Knowledge of variations of the presence of accessory transverse foramen in the typical cervical vertebrae is not only important to anatomist but also to radiologist in identifying the presence of duplicate vertebral artery and hence helping the neuro surgeons in preventing accidental bleeding from the vertebral artery while performing surgery on the cervical spine.