Sacral fractures are either transverse or longitudinal (vertical). Transverse fractures may be isolated and can be subdivided into two types. Upper transverse fractures occur in younger people and result from severe traumatic flexion of the upper body on the fixed pelvis. Lower transverse fractures result from a hard blow to the coccyx, as in a fall. Vertical fractures are essentially never isolated, always being associated with an anterior break in the pelvic ring. These result from extreme forces transmitted through the ilium. Any of these fractures can cause injury to neural elements, and surgical decompression may be indicated in certain of the transverse types.