The Feasibility of Endoscopic-Assisted Anterior Odontoid Screw Fixation in Ankylosing Spondylitis

This study aimed to describe the technical feasibility and clinical outcome of endoscope-assisted anterior odontoid lag screw fixation in a patient with ankylosing spondylitis, in whom the conventional open anterior approach was limited due to cervical rigidity. A 56-year-old man with longstanding ankylosing spondylitis presented with severe neck pain and right-sided tingling sensations following trauma. Imaging revealed a type III odontoid fracture. Because of rigid cervical alignment, adequate neck extension required for the conventional open anterior approach was not achievable. Endoscope-assisted anterior odontoid screw fixation was performed using a biplane C-arm. The procedure involved endoscopic dissection of the prevertebral corridor and insertion of the cannulated lag screw under fluoroscopic guidance. The screw was successfully placed across the fracture site without intraoperative complications. Postoperative imaging confirmed appropriate screw trajectory and fracture reduction. The patient’s pain improved immediately, allowing early ambulation. He was discharged uneventfully, and follow-up examinations demonstrated stable fixation. Endoscope-assisted anterior odontoid lag screw fixation appears to be a safe and effective alternative for treating odontoid fractures in patients with ankylosing spondylitis. This technique minimizes soft-tissue injury and facilitates optimal screw trajectory in cases where rigid cervical alignment precludes the conventional open approach.