Congenital anomalies of the cervical spine.

Congenital anomalies of the cervical spine are uncommon. The majority of afflicted individuals are asymptomatic or have only mild restriction of neck motion. If symptoms develop, they are usually due to cervical instability or degenerative osteoarthrosis. Recent information indicates that patients with upper cervical anomalies such as atlantooccipital fusion, anomalies of the odontoid, or the transverse atlantal ligament have a great propensity to develop early instability and neurologic problems secondary to minor traumatic events. If symptoms occurs in the lower cervical spine, it is usually in adult life and due to degenerative arthritis in the hypermobile articulations adjacent to the area of synostosis. The relatively good prognosis of cervical lesions is overshadowed by the "hidden" or unrecognized associated anomalies. There is a high incidence of significant scoliosis, Sprengel's deformity, renal anomalies, deafness, and neurologic malformations. Early recognition and treatment of these problems may be of substantial benefit, sparing the patient further deformity or serious illness.