Foramen magnum is a large opening through which vital structures pass. The foramen magnum is an important landmark of the skull base. Posterior condylar canal, Posterior condylar vein and Occipital emissary vein are of utmost importance for postero-lateral surgical approaches to foramen magnum. Aim: To provide a database of dimensions of foramen magnum and posterior condylar foramen to help in various surgical procedures. Methods and Materials: Seventy five dry human skull of unspecified gender and age obtained from Department of Anatomy of Medical colleges. Various parameters of foramen magnum and presence or absence of posterior condylar foramina were noted. Results and Conclusions: The mean antero-posterior distance through the centre of foramen magnum was 33.56mm, mean transverse distance was 28.38mm, Foramen magnum index was 84.89 and Foramen magnum surface area was 751.46 mm2. The posterior condylar foramina were present bilaterally in 66.66% of skulls, absent bilaterally in 14.66% and were unilateral in 18.66%. This study will be helpful to clinicians and surgeons dealing with the region of posterior cranial fossa before planning a surgery in the occipital condylar region.
Keywords : Foramen Magnum; Posterior Condylar Foramen; Foramen Magnum Index; Foramen Magnum Surface Area.
Corresponding Author : Nagaraja V. Pai, Assistant Professor, Department of Anatomy, T.N. Medical College and B.Y.L. Nair Hospital, A.L Nair Road, Mumbai Central, Mumbai- 400008, Maharastra, India.