Congenital posterior arch defects of the Atlas

Abstract

Congenital anomalies of the posterior arch of the atlas vertebrae are very rare ranging from partial clefts to total aplasia. The congenital defects of the posterior arch of the atlas have been classified by currarino et al into five types (A to E), with type A being most common affecting 4% of general population and type B-E being found only in 0.69% of the general population. In the present study the incidence of congenital posterior arch defect type A is 2.75% and type B-E is 1.83%(type B;0.91% , type E; 0.91%). The clefts of the atlas may be mistaken for fracture in patients who have sustained cervical spine injuries. The clinical presentation of the patients with congenital defect of the posterior arch of atlas can be variable from asymptomatic to symptomatic, it is worthy to recognize and classify the exact type to prevent further neurological complications, diagnostic error and for proper management.