Isolated fracture-dislocation of the sacrum: case report.

An unusual case of isolated fracture-dislocation of the sacrum is reported. A 19-year-old woman had a fracture-dislocation of S-1-2 combined with two longitudinal fractures of the sacrum, but no other pelvic fractures were identified. The possible mechanisms of fracture-dislocation of the sacrum are discussed. The fracture site was identified accurately on a CT scan. Pain relief was obtained by application of an external fixator. A mild neurologic deficit in the S-1 root distribution disappeared uneventfully.