Congenital anomalies of the odontoid process

摘要: Anomalous development of the odontoid is uncommon, and its clinical significance lies in potential for producing serious neurologic sequelae due to atlantoaxial instability. Although there are several recognized variations (aplasia, hypoplasia, os odontoideum), clinically they share same signs symptoms, treatment identical. Symptoms usually instability joint, with compression spinal cord anteriorly against axis or posteriorly from ring atlas. Patients may present no persistent neck complaints, transient permanent deficits, sudden death. cranial nerve irritation seldom occur, but occasionally symptoms cerebral brain stem ischemia noted as a result vertebral arteries area If condition suspected, diagnosis can be confirmed on lateral flexion-extension roentgenograms. Special techniques often required, particularly laminagrams, stress roentgenograms necessary determine presence degree The role prophylactic surgical stabilization not yet established. greater than 5 mm. demonstrated patient has findings compromise, fusion should performed.