[A case of upper airway obstruction associated with flexed cervical position after posterior occipito-cervical fusion--a retrospective radiographic analysis by the O-C2 angle].

Abstract A 71-year-old female developed upper airway obstruction due to flexed cervical position after posterior occipito-cervical fusion. After the operation, she was re-intubated with the air-Q intubating laryngeal airway. Revision surgery allowing the angle to return to the neutral position was performed to attenuate the overflexion of the cervical position. After revision surgery, the upper airway obstruction disappeared. From the retrospective radiographic analysis, we suggest that the decrease of 18 degrees in the O-C2 angle causes the upper airway obstruction. On the extubation after occipito-cervical fusion, we should take care of the possibility of re-intubation and its difficulty based on the O-C2 angle.