The anterior dislocation of the sacroiliac joint: a report of four cases and review of the literature and treatment algorism.

Pelvic fractures are an uncommon injury in pediatric trauma patients, but the morbidity and mortality associated with these injuries can be profound. Of the posterior pelvic ring disruptions, the posterior dislocation of sacroiliac joint, which is the traditional dislocation of the sacroiliac joint, occurs in most incidences of pediatric trauma patients. There are few reports, however, on the "anterior" dislocation of sacroiliac joint, in which the ilium dislocates anterior to the sacrum and often combines with symphyseal diastasis and fractures of pubic rami and ilia. The distinct fracture-dislocation of sacroiliac joint is a subtype of completed posterior pelvic fracture. Literature review contains little information about such type of dislocation. We present four cases of pediatric trauma patients with the "anterior" dislocation of sacroiliac joint. After a thorough literature review of existing classification of pelvic fractures, we name it as the anterior dislocation of sacroiliac joint.