Percutaneous spinopelvic fixation technique using external fixation for focal kyphosis reduction in U-type sacral fractures: a case report.

Background: Sacral fractures, particularly U-type fractures characterized by a transverse fracture line, result in significant instability and deformity, including focal kyphosis. These fractures challenge biomechanical integrity and neural structures, often leading to long-term disability if not corrected. Surgical approaches vary, but percutaneous spinopelvic fixation offers benefits like reduced soft tissue trauma and expedited recovery. This case report highlights managing a displaced U-type sacral fracture with focal kyphosis using a percutaneous spinopelvic reduction technique followed by fixation, demonstrating its efficacy and potential benefits. Case Description: A 30-year-old female with a complex medical history, including opioid use disorder managed with buprenorphine, housing instability, and hypothyroidism, presented with subacute back pain and impaired ambulation following a mechanical fall. The patient experienced persistent back pain, numbness, ambulatory difficulties, and intermittent urinary incontinence. An evaluation revealed pain-limited 4/5 motor strength bilaterally in lower extremity muscles, intact sensation, and preserved perianal sensation with normal rectal tone. Imaging confirmed a displaced U-type sacral fracture with 37.1 degrees of focal kyphosis and no ongoing nerve root compression. Given the focal kyphosis and associated complications, a multidisciplinary team with orthopaedic trauma and spine expertise recommended percutaneous reduction spinopelvic fixation to achieve reduction and stabilization. The patient's significant risk factors, including active drug use and housing instability, raised concerns with a traditional open approach. A percutaneous approach using an external fixator aided reduction, followed by transiliac trans-sacral screw placement and S1-pelvis fixation, was chosen. This technique achieved the desired reduction in sacral kyphosis, improving spinopelvic alignment and reducing postoperative soft tissue complications. Postoperative imaging showed appropriately placed hardware and a 20-degree reduction in sacral kyphosis. Conclusions: This case highlights the successful management of a displaced U-type sacral fracture with focal kyphosis using a percutaneous spinopelvic external fixator-based reduction technique. A minimally invasive approach can achieve significant reduction in deformity while minimizing soft tissue complications, making it viable for patients with complex medical histories. The clinical impact includes improved postoperative recovery and reduced risk of long-term disability. This case underscores the importance of individualized surgical planning and the potential benefits of percutaneous techniques in managing complex sacral fractures.