The surgical findings observed in a series of 260 patients with craniovertebral anomaly are presented. There were 29 (11.1%) patients only with basilar impression, 18 (6.9%) cases of pure Arnold-Chiari malformation and 213 (81.9%) cases of basilar impression associated with Chiari malformation. The surgical findings on bone, dura-mater, nervous tissue and blood vessels of this region are reported.
basilar impression; Arnold-Chiari malformation; craniovertebral abnormality; surgical findings