Anatomical Variations in Foramen Transversarium of Typical Cervical Vertebrae and Clinical Significance

Objectives: To observe anatomical variations in the foramen transversarium of typical cervical vertebrae.Methods: We studied 220 dry typical (C3-C6) cervical vertebrae of both sexes.During our study we excluded all broken/damaged cervical vertebrae and observed the variations of foramen transversarium present in both transverse processes of each cervical vertebra.Results: We found double foramen transversarium in 31 (14.09%)vertebrae.Among these 21(9.54%)vertebrae were having bilateral and 10 (4.54%) vertebrae had unilateral double foramen transversarium.In the case where the foramen transversarium was double, one was ma in foramen transversarium and other was accessory foramen transversarium.We also found and noted variations in accessory foramen transversarium like bilateral and complete, bilateral but incomplete, unilateral complete, unilateral incomplete and these were observed in 18(8.1%),3(1.3%), 6(2.7%), 4(1.8%) vertebrae respectively.Conclusions: Anatomical knowledge of these variations are helpful for spine surgeons in preoperative planning and for preventing injury of vertebral vessel along with sympathetic nerves during cervical surgical approaches.