Reduction and fixation of displaced U-shaped sacral fractures using lumbopelvic fixation: technical recommendations

Purpose U-shaped sacral fractures are extremely rare injuries that usually occur as a result of falls from considerable heights. Almost all treatment methods described to date aim solely at stabilizing the fracture but do not contribute to supporting the reduction of such fractures. Using existing implants the purpose of this study is to present a surgical technique that facilitates both the reduction and the stabilization of these injuries. The presented technique was evaluated in a series of three cases. Methods Polyaxial pedicle screws were placed through vertebral bodies L4 and L5. Two long pedicle screws were implanted in the posterior iliac spine. The lumbar pedicle screws were held with two longitudinal rods, and the pelvic screws with one transverse connecting rod. The lumbar longitudinal and pelvic transverse rods were connected via two hinge-like connecting elements. First, distraction was performed between lumbar pedicle screws L5 and the sacral transverse rod. Lordosis was then restored via the hinge joint, thereby eliminating kyphosis. After tightening all moving elements, the fracture was reduced and stabilized. Results Computed tomography documented anatomical reduction and fracture healing was achieved in all cases. Two of three patients could be fully mobilized immediately; mobilization of the third patient was delayed due to multiple injuries. Two patients showed neurological symptoms. In one case, complete remission was achieved within 3 weeks, while in the other patient a clear improvement was observed. In all cases, the implant was removed after 8-12 months. There were no post-operative complications, such as infections, wound-healing disorders, neurological deterioration, implant failure, or premature loosening. Conclusions The surgical procedure was successful, since it considerably facilitated reduction, thereby shortening surgery time. The stabilization was sufficient to fully mobilize the patients. The procedure is based on existing implant components and is thus routinely available.