Ossification of the cervical anterior longitudinal ligament is an underdiagnosed cause of difficult airway: a case report and review of the literature

BACKGROUND: Ossification of the anterior longitudinal ligament (OALL) of the cervical spine is a common, but rarely symptomatic, condition mostly observed in the geriatric population. Although the condition usually requires no intervention, it could lead to a difficult airway and compromise the patient’s safety. CASE PRESENTATION: Here, we describe the case of a 50-year-old man with cervical myelopathy and OALL that resulted in difficult endotracheal intubation after induction of anesthesia. Radiography and magnetic resonance imaging findings showed OALL, with prominent osteophytes involving four cervical vertebrae, a bulge in the posterior pharyngeal wall, and a narrow pharyngeal space. Airtraq® laryngoscope-assisted intubation was accomplished with rapid induction under sevoflurane-inhaled anesthesia. CONCLUSION: Anesthesiologists should understand that OALL of the cervical spine could cause a difficult airway. However, it is difficult to recognize asymptomatic OALL on the basis of routine airway evaluation guidelines. For susceptible populations, a thorough evaluation of the airway, based on imaging studies and a history of compression symptoms, should be considered whenever possible. In case of unanticipated difficult intubation, anesthesiologists should refer to guidelines for unanticipated difficult airway management and identify OALL of the cervical spine as the cause.