A morphometric study of foramen transversarium of dried cervical vertebrae

Background: Variation in number, size & shape of foramen transversarium affects the anatomical course of the vertebral vessels, which may cause pathological conditions like vertebrobasilar insufficiency.Since, inner ear derive it’s blood supply from vertebral and basilar arteries, any spasm of these arteries due to irritation of sympathetic plexus, may causes labyrinthine or hearing disturbances along with neurological symptoms. The objective of present study is to study the incidence of accessory foramen transversarium in dried cervical vertebrae in Indian population & compare it with incidence among various races of world.Methods: A total of 174 cervical vertebrae (Typical-126 & Atypical-48) of unknown sex & age are analyzed to see the accessory foramen transversarium.Results: Out of the 174 cervical vertebrae, accessory foramen transversarium is found in 25 (14.36%) vertebrae. Among these 25 vertebrae, 16 (9.19%) are typical and 9 (5.17%) are atypical cervical vertebrae. We observed in these 16 typical cervical vertebrae, 10 (5.75%) vertebrae have accessory FT on right side while 3 (1.72%) vertebrae have on left side and 3 (1.72%) vertebrae have bilateral accessory FT. Among 9 atypical cervical vertebrae, 4 (2.3%) vertebrae have accessory FT on right side while 3 (1.72%) vertebrae have on left side and 2 (1.15%) vertebrae have bilateral accessory FT. Accessory foramen transversarium are more common on right side in both typical & atypical cervical vertebrae. No any accessory FT is found on axis vertebra.Conclusion: Knowledge of accessory foramen transversarium is important for clinicians because it may affect the course of vertebral vessels & nerves, which causes various symptoms to patients. It is also helpful for spine surgeons in planning surgery around the cervical vertebrae and to avoid post-operative complications. These variations are also of importance and helpful for anatomist, anthropologist and radiologist.