Congenital anomalies of the cervical spine.

A wide variety of congenital pathology affects the cervical spine and underlying spinal cord. This article discusses commonly encountered conditions under the categories of osseous anomalies, Chiari malformations, dysraphic conditions, and skeletal dysplasias. Osseous anomalies tend to involve the upper cervical spine to a greater degree than the lower cervical spine. Chiari malformations warrant inclusion on the basis that they have many manifestations within the cervical spine. Dysraphic conditions resulting from failure of either primary or secondary neurulation are distinctly uncommon in the cervical spine compared with the lumbar spine and are, therefore, only briefly discussed. Skeletal dysplasias encompass a diverse group of uncommon entities but may produce significant radiographic abnormalities and may be associated with clinical symptomatology.