A case of midline defect of posterior arch of atlas in a cadaver

Abstract

During a routine osteology class for undergraduate students in Government Medical College, Kozhikode, Kerala, a median defect of posterior arch was found in the atlas of a cadaver. It was not a fracture as the edges were regular, round and smooth.There was no associated anomalies. These midline defects of posterior arch of atlas are sub divided both morphologically (types A-E) and clinically (sub groups 1-5) depending on the extent of absence of posterior arch and presence or absence of the posterior tubercle. The author presents a rare anomaly of a posterior arch partial aplasia which could be congenital. Since major neurologic deficits can be produced by a minor trauma, it is crucial to recognize this anomaly

Keywords

• aplasia
• posterior tubercle
• anomalies