Midline Longitudinal Sacral Fracture in an Anterior-Posterior Compression Pelvic Injury -A Surgical Decision-making and Outcome.

Introduction: Anterior-posterior compression pelvic injuries occur from high-energy blunt trauma and can result in devastating outcomes. Often, widening of the pubic symphysis occurs with subsequent disruption of posterior pelvic ligamentous structures. Associated sacral fractures may increase the likelihood of neurologic injury and pelvic ring instability. The most common sacral fracture in this injury is an avulsion fracture of the sacral ala. Midline longitudinal sacral fractures into the spinal canal are an extremely rare variant of sacral injuries in conjunction with pelvic trauma. In contrast to traditional anterior-posterior pelvic ring injuries, those associated with this unique fracture type carry a decreased risk of neurologic injury. Only a small number of these cases exist in English literature. Given its rarity, further, investigation of the fracture mechanism and treatment protocol is warranted.

Case Report: A 67-year-old Caucasian male presented with an anterior-posterior compression pelvic ring injury after he was struck by an oncoming vehicle on his motorcycle. Radiographs revealed pubic symphyseal widening of 4.7 cm. A pelvic binder was placed as a temporary measure to minimize intrapelvic hemorrhage. Advanced imaging revealed a complete, midline sagittal sacral fracture through the posterior sacral elements. During his hospital admission, the patient required multiple procedures for sustained upper extremity fractures and subsequently underwent surgical fixation of his anterior and posterior pelvic ring injuries 2 days after admission. Our patient to date has achieved sacral fracture union, minimal residual pubic diastasis, and has no evidence of neurologic injury. He has some persistent impotence and is ambulating without assistance. Despite his significant injuries, his outcome to date has been quite impressive.

Conclusion: It is critical to always examine the posterior pelvis and sacrum when examining anterior-posterior compression injuries. While most cases have reported fixation of only the anterior pelvis, we explain the need for additional posterior pelvic fixation to address the inherent instability of these unique sacral fractures and ultimately decrease patient morbidity. The surgical fixation technique of this patient's pelvic injuries is described, as well as his post-operative course and outcome to date.