Anatomical Variations and Morphometric Features of the Foramen Transversarium in the Cervical Vertebrae of a Latin American Population: A Brazilian Study

Background: Knowledge of the anatomy of the foramen transversarium (FT) is essential for performing surgical procedures on the cervical spine. The aim of the present study was to analyze the characteristics of the FT anatomy of the lower cervical spine and its anatomic variations using computed tomography (CT) in a Brazilian population.

Methods: Two independent observers performed linear measurements of the anteroposterior diameter (APD), lateral diameter (LD), and FT area (FTA) of 600 FTs of the lower cervical spine of 60 individuals (30 women and 30 men). The CT images were obtained from a database. The data were compared between genders and different age cohorts.

Results: The lowest average APD, LD, and FTA were found at the C7 level. The highest mean APD was found at the C6 level, and the highest mean LD was found at the C3 level. The highest mean FTA was at the C3 for the women and C6 for the men. The mean APD, LD, and FTA on the left side were greater than those on the right side at all levels. We found a tendency for the mean FTA to increase with increasing age. Finally, 95% of the whole sample had presented with ≥1 and 42% with >3 anatomical variations of the FT.

Conclusions: We determined the morphometric features of the FT using CT images. Anatomic variations were observed that justify their study before performing cervical surgical procedures.