Percutaneous stabilization of U-shaped sacral fractures using iliosacral screws: Technique and early results

Purpose: To present the technique and early results of percutaneous stabili zation of U-shaped sacral fractures with attention to neurologic recovery a nd maintenance of fracture reduction of the sacrum. Design: Retrospective clinical study. Setting: Level I trauma center. Patients: During a thirty-eight-month period, 442 patients with pelvic ring disruptions were treated at a Level I trauma center. Thirteen (2.9 percent ) of these patients had displaced U-shaped sacral fractures treated with pe rcutaneous stabilization. Intervention: Fracture stabilization was accomplished using fluoroscopicall y guided iliosacral screws inserted percutaneously with the patient positio ned supine. Neurodiagnostic monitoring was not used during screw insertions . This technique was limited to patients with sacral kyphotic deformities, which allowed in situ fixation. Sacral neurologic decompression was not per formed. Main Outcome Measurements: Fracture healing and the stability of fixation w ere assessed on inlet and outlet radiographs and a lateral sacral view. Det ailed neurologic examinations were performed at injury and at follow-up. Results: The sacral fractures were classified based on plain pelvic radiogr aphs and computed tomography scans and included one Type 1, eight Type 2, a nd four Type 3 fracture patterns. Twenty-five fully threaded cancellous 7.0 -millimeter cannulated screws were used. Eleven patients had bilateral scre w fixations; one patient had unilateral double screw fixation; and one pati ent had unilateral single screw fixation. Operative time for screw insertio n averaged forty-eight minutes, with 2.1 minutes of fluoroscopy per screw. Accurate screw insertions without neuroforaminal or sacral spinal canal vio lations were confirmed in all patients with postoperative pelvic plain radi ographs and computed tomography scans. A paradoxical inlet view of the uppe r sacral segments on tile injury anteroposterior pelvis was seen in twelve of thirteen patients (92.3 percent), and the diagnosis was confirmed with t he lateral sacral view in all thirteen (100 percent) patients. Preoperative ly, sacral kyphosis averaged 29 degrees. whereas postoperative sacral kypho sis averaged 28 degrees. Screw disengagement occurred without a change in p osition of the sacral fracture in the only patient treated with a single un ilateral screw. All fractures healed clinically and radiographically. Of th e nine patients with preoperative neurologic abnormalities, two (22 percent ) patients hail residual neurologic deficits. Both patients had associated multiple level lumbar burst fractures, which required decompression and ins trumented stabilization. Conclusions: These sacral fractures are rare and occur after significant sp inal axial loading. A paradoxic inlet view of the upper sacrum on the anter oposterior plain pelvic radiograph heralds: the diagnosis. Delayed diagnosi s is avoided by a high clinical suspicion, early lateral sacral radiographs . and pelvic computed tomography scans. Surgical stabilization may assist i n early mobilization of tile patient from recumbency and prevents progressi ve deformity with associated nerve root injury. Percutaneous fixation dimin ishes potential blood loss and operative times, yet still allows subsequent sacral decompression of the local neural elements using open techniques wh en necessary. Early percutaneous iliosacral screw fixation is effective tre atment for these injuries.