Congenital malformations of the craniovertebral junction: classification and surgical treatment.

The clinical, radiological and surgical findings of 56 patients with congenital malformations of the craniovertebral junction who underwent surgical intervention in the Department of Neurosurgery, Hacettepe University Medical School were reviewed. The anomalies were classified according to their embryonic origin. Forty-two cases of the series were major abnormalities formed by the combination of more than one germ layer.