Odontoid fracture complicating ankylosing spondylitis presenting with cervical canal stenosis and quadriparesis: A case report with 5-year follow-up and review of the literature

Introduction and importance: Spinal fractures, especially cervical fractures, are more common in patients with ankylosing spondylitis in comparison with unaffected patients. However, odontoid fractures are relatively rare in these patients. Also, neurological symptoms are not common in odontoid fractures due to the larger diameter of the spinal canal at this level.Case presentation: Here, we presented a 41 year-old man known case of ankylosing spondylitis who develop odontoid fracture and severe cervical stenosis after falling trauma. Quadriparesis and positive Hoffman sign as well as significant thoracolumbar kyphosis were diagnosed in further investigation. Laminectomy and posterior fixation were executed primary and pedicular subtraction osteotomy was performed two years later to manage the kyphosis and sagittal imbalance. On the follow-up period of five years the patient was fully functional. Clinical discussion: There are a few cases of odontoid fractures complicating ankylosing spondylitis in the literature. Neurological symptoms are relatively uncommon in odontoid fractures; however, cases with AS can present with neck pain, weakness, and hyperreflexia when having unstable fractures.Conclusion: Although there is not any gold standard for the treatment of the odontoid fracture in AS, surgical intervention is preferred.