Craniocervical abnormalities. Modern diagnosis and a comprehensive surgical approach.

A retrospective study of 41 patients operated on between 1975 and 1983 is presented including guidelines for surgical management with some alternative technique both in anterior and posterior approaches and modern diagnostic procedures. A proposed base-line inclined--10 degrees from Reid's base-line proved to be adequate to obtain the true shape and size of the foramen magnum on CT-scan. The normal range of the clivo -axial angle in adults is reported and its clinical significance is stressed.