Posterior locked lateral compression injury of the pelvis: report of three cases

Lateral compression injuries to the pelvis typically result in a rotationally unstable and vertically stable condition including an impaction and compression fracture of the posterior pelvic ring. The operative and postoperative management, as well as the morbidity and mortality, of these fractures differs significantly from vertical shear injuries to the pelvis, which are characterized by vertical and rotational instability. We report on three unusual lateral compression injuries to the pelvis, resulting in a complete disruption of the pelvic ring with vertical and rotational instability, by definition. Nevertheless, in these patients, locking of the posterior pelvic ring with medial translation of the iliac wing anterior to the sacrum resulted in a pseudostable condition. Their high rate of fracture-related associated injuries and possible complications, as well as the malalignment of the pelvis, required surgical restoration of the pelvic ring. Fracture reduction was successfully performed through an anterior approach in one patient and a posterior approach in two patients; the posterior approach was preferred. Open reduction and internal fixation of these pelvic ring fractures can result in a satisfactory outcome if the associated injuries are successfully dealt with.