Ponticulus posticus- a case report

Introduction: The atlas vertebra consists of two lateral masses connected by a short anterior and a longer posterior arch. The superior surface of the posterior arch bears a wide groove for the vertebral artery and the first cervical spinal nerve. An anomalous bony bridge between the posterior portion of superior articular process and the superior margin of the posterior arch of atlas is known as “Ponticulus posticus” and the foramen formed by it is known as “Arcuate foramen” Observation: During routine dissection for the undergraduate students it was found that there was a bony outgrowth over the third part of the vertebral artery converting the vertebral groove into a foramen. Conclusion: Patients with ponticulus often show symptoms of vertebrobasilar insufficiency such as headache, vertigo and diplopia. It can also be mistaken for broad posterior arch during surgeries which could cause injury to vertebral artery. Hence knowledge of ponticulus posticus is very useful for the neurophysician, neurosurgeons and radiologist who deal with such patients.