Atlantoaxial dislocation associated with the maldevelopment of the posterior neural arch of axis causing compressive myelopathy.

The craniovertebral junction has a predilection for a variety of congenital anomalies due to its complex development. The association of atlantoaxial dislocation (AAD) with the maldevelopment of the posterior arch of axis is extremely rare. We report two such cases and present the management strategy.