A study of arcuate foramen in Human Atlas Vertebrae: Incidence and clinical correlations

Background: Atlas is the first cervical vertebra. Arcuate foramen transmits vertebral vessels and sympathetic plexus. Any additional foramen on atlas other than foramen transversaria is termed as arcuate foramen. Presence of arcuate foramen in various countries giving an incidence from 8 to 24 % by various authors. Embryological variations in the presence and passage of the vertebral vessels will manifest as variant foramen. Objectives: To find the incidence of arcuate foramen in the first cervical vertebrae. Knowledge of this foramen is important in clinical diagnosis and surgical procedure for neurophysician and neurosurgeon. Material and Methods: The study was conducted in adult 45 dried atlas vertebrae of unknown sex in the Department of Anatomy, AIIMS Patna. Result: The incidence of as arcuate foramen was 17.77% and was bilateral in 11.11% whereas unilateral in 6.66%. Conclusion: Awareness of this type of variation is essential for orthopaedic surgeons, neurosurgeons and radiologists to avoid misdiagnosis in their clinical practice.