The Denis classification is a system of categorizing sacral fractures.[1]
Classification
Zone
Description
I
Fracture lateral to the sacral foramen
II
Fracture through the sacral foramen
III
Fracture medial to the sacral foramen extending into the spinal canal
Notes and References
Sacral fractures: an important problem. Retrospective analysis of 236 cases . Denis F, Davis S, Comfort T . Clin Orthop Relat Res . Feb 1988 . 227 . 67–81 . 3338224.