The purpose of this study is to reveal the incidence of double foramen transversarium constituting variational conditions at the foramen transversarium vertebrae cervicales located at the processus transversus of cervical vertebrae; and emphasize the dimensions, shape variations of foramen transversarium as well as the clinical symptoms that may be caused by these conditions. For this study, a total of 82 cervical vertebrae available at the laboratory of the Gülhane Medical Faculty Department of Anatomy were studied. Variations of foramen transversarium on all vertebrae were recorded. Foramen transversarium was present in all vertebrae. Double foramen transversarium were observed in 18 of 82 cervical vertebrae. Of them, 6 vertebrae exhibited unilateral, and 12 vertebrae exhibited bilateral double foramen transversarium . Of the unilateral transversarium, 1 was on the right side and 5 were on the left side. Foramen transversarium observed were predominantly in round form. Anterior-posterior and medial-lateral diameters of right foramen transversarium was 5.7 mm and 6.5 mm respectively while the anterior-posterior and medial-lateral diameters of left foramen transversarium were 5.5 mm and 6.6 mm respectively. In this study, incidence of double foramen transversarium was found as 23.95%. Among all double foramen transversarium, the incidence of the bilateral group was observed to be doubling the unilateral group. It's significant for clinicians to have a knowledge of this variation. Morphological variations in foreman transversarium are significant as they lead to neurological conditions due to the flow of blood passing through these openings except for C7.

Keywords: Vertebrae cervicales, double foramen transversarium, accessory foramen transversarium, morphometry.