Early fixation of the vertically unstable pelvis: the role of iliosacral screw fixation of the posterior lesion.

OBJECTIVES To evaluate the effectiveness of the use of iliosacral screw fixation in the management of the vertically unstable pelvis. STUDY DESIGN Retrospective analysis with clinical follow-up of patients to assess functional outcome. METHODS Thirty-eight vertically unstable pelvic fractures were treated using iliosacral screw fixation. Anterior fixation was by means of plating in sixteen pelves and by external fixation in fifteen pelves. Four pelves had no anterior fixation. Complications were recorded and radiographs were analyzed to classify fractures and identify screw misplacement and malunion. Twenty-six patients had a functional evaluation. RESULTS Five patients (13 percent) suffered a pulmonary embolus in the early postoperative period, one of which was fatal, a hospital mortality of 2.6 percent. Screw misplacement occurred in five patients but there were no adverse sequelae. In thirty-four cases with radiographic follow-up, malunion was noted in fifteen cases (44 percent). A lower rate of malunion (36 percent) was noted with internal fixation of the anterior lesion. Of twenty-six patients with long-term follow-up, only four (15 percent) had no pain. Sacroiliac fusion for pain was performed in three patients (11 percent). Twelve patients (46 percent) returned to their preinjury occupation, six patients (23 percent) changed occupation, and nine patients (30 percent) had not yet returned to work by last follow-up. CONCLUSIONS Iliosacral screw fixation is a useful method of fixation in the vertically unstable pelvis but needs to be augmented by rigid anterior fixation to minimize malunion.