Os odontoideum in children: neurological manifestations and surgical management

The os odontoideum is a congenital anomaly of the 2nd cervical vertebra. It is an ossicle that is separated from the body of the axis by a variable transverse gap. This weakens atlantoaxial stability. When ligamentous support also fails, subluxation ensues. Compressive myelopathy and vertebral artery obliteration may occur. Eight cases, all in children, were studied prospectively. The neurological manifestations and surgical indications and treatment are discussed.