Absent posterior element of axis vertebra with myelopathy treated with C2, C3, and C4 arthrodesis: A case report and review of literature.

A congenital abnormality of the posterior element of the axis (C2) vertebra is extremely unusual, with just a few occurrences documented in the literature. The majority of individuals have no symptoms and are discovered by chance on plain radiography for neck discomfort, radiculopathy, or trauma. We describe a case of a 13-year-old boy who was born without the posterior element of the C2 vertebrae, resulting in C2-C3 spinal instability and compressive myelopathy.