Transoral unilateral lag screw osteosynthesis for coronal split fracture of the lateral mass of the atlas - case report, operative technique and review of the literature.

Introduction: Atlas ring fractures, which account for 1.3% of all spinal fractures, are predominantly managed conservatively. However, in certain cases, surgical treatment may be necessary depending on the type of fracture, degree of comminution, fracture location, and associated ligamentous injuries. Surgical stabilization frequently results in a posterior C1-2 or C0-2 fusion, which restricts movement, particularly craniocervical rotation. Coronal split fractures of the lateral mass need to be reduced and fixed due to dislocation, instability and secondary osteoarthritis. The preferred treatment approach involves internal fixation of the reduced fracture fragments, while avoiding restriction of the upper cervical spine's range of motion (ROM). Research question: Is unilateral anterior transoral lag screw for treatment of unstable coronal split fracture of lateral mass of the atlas feasible and a safe treatment option? Case Report Material and Methods: We report on a 55-year-old female suffering from polytrauma with multiple spinal and extremity injuries. Results: A coronal split fracture of the lateral mass of the atlas was treated minimally invasive with a transoral lag screw technique to reduce and fix the fracture that has a tendency for fracture gap widening. Stable fixation and fracture union and thus restoration of function was achieved. Discussion and conclusion: Transoral lag screw osteosynthesis for coronal split fracture of the lateral mass of the atlas is a potential treatment option in selected cases to preserve mobility in the upper cervical spine after spinal trauma.