Complications of Occipitocervical Fixation

Occipitocervical fixation (OCF) is indicated for OC instability, or atlantoaxial instability where the patient is not a candidate for atlantoaxial arthrodesis or has failed prior C1-C2 fusion. Most commonly, OC instability is caused by trauma, rheumatoid arthritis (RA), and tumors/tumor excision, and can be associated with significant vertical migration of the odontoid and cranial settling (eg, RA). In this review, we discuss complications that can occur during stabilization of the craniovertebral junction (CVJ), providing the reader some pearls on how to avoid them and how to manage them should they occur. Complications discussed include those related to fixation and/or pseudarthrosis, neurologic injuries, craniocervical alignment, screw placement, and vascular injuries. We reference the biomechanics and evolution of OC constructs, and provide detailed figures, diagrams, and tables to demonstrate OC anatomy, and the typical starting points, screw insertion angles and screw lengths for stabilizing the OC junction. Although less common and technically demanding, OCF can be performed safely with a thorough understanding of patient-specific anatomy as it correlates with preoperative imaging studies, the indication for surgery, and how surgery may alter OC anatomy. Preoperative planning is essential, and familiarity with different surgical techniques and implants allows the surgeon to choose the correct fixation method, giving patients the best chance to heal. Applying these principles can help surgeons achieve stable, rigid OCF, with newer implants and/or designs demonstrating increased success rates in more complex instabilities.

Keywords: occipitocervical fixation, complications, craniocervical junction, vertebral artery, atlantoaxial instability