A modified technique of placing transpedicular screws into the S1 vertebrae--surgical technique note.

Anatomical variability of sacral bone as well as its diverse interpretations a surgical field prompted the authors to modify surgical technique in such manner to allow unequivocal identification of a starting point for introduction of transpedicular screws into the first sacral vertebra. The starting point is not located, as described in previous publications, inferiorly and laterally to the S1 articular process, but goes through a precisely defined place in the dorsal ridge of superior articular process following its partial resection.