Pelvic disruptions in children.

The patterns of traumatic pelvic disruption in children usually follow those found in the adult. There are, however, exceptions which create unique problems. Lateral compression injury may result in quadrant displacement of the pelvic ring through the triradiate cartilage. No mini-acetabulae have as yet been seen as a result of triradiate injury. Sacroiliac injury can progress to sacroiliac fusion with an associated undergrowth of that side of the pelvis. Uncorrected vertical shear displacement of the hemipelvis results in significant clinical pelvic deformity as well as leg-length discrepancy.