Posterior C1–C2 Fusion: Surgical Technique and Case Illustration

A BSTRACT Atlantoaxial injuries, comprising 25%–40% of cervical traumas, carry a significant risk of instability and neurological complications. This review focuses on the biomechanical advantages and specific indications of posterior C1–C2 fusion utilizing a screw and rod system. A case study of a 40-year-old female with a type II odontoid fracture illustrates the surgical technique, emphasizing anatomical considerations and the utility of the freehand method. The atlantoaxial complex, characterized by unique features such as the absence of a vertebral body in the atlas, demands careful anatomical comprehension. The ligamentous network plays a crucial role in stability, and biomechanics involve intricate interactions between osseous, ligamentous, vascular, and neural elements. Surgical intervention for atlantoaxial instability, often stemming from fractures like type II odontoid fractures, necessitates careful consideration of the fixation method. Posterior techniques, particularly the C1 lateral mass and C2 pars screw with rod systems, offer a stable alternative to anterior approaches and transarticular screws, particularly in patients with specific vascular anatomy or those requiring intraoperative reduction. The presented case utilizes a freehand technique to reduce radiation exposure. In conclusion, posterior C1–C2 fusion with a screw and rod system provides superior mechanical stability with reduced operative time and radiation exposure. The technique’s success hinges on a comprehensive understanding of the atlantoaxial complex and careful patient selection.