Case Report
Os odontoideum (OO) is a rare anatomic variant of the axis characterized by the separation of a part of the axis. It may cause cervical instability, atlantoaxial dislocation, myelopathy, or permanent paralysis. We present an extremely rare case of an OO with posterior atlantoaxial dislocation in a child./r/nA nine-year-old female with OO, cervical instability, and posterior atlantoaxial dislocation had intermittent neck pain for several years. The patient was surgically treated by performing a C2-C3 laminectomy with C1-C5 posterior fixation for stabilization./r/nOO can be symptomatic in pediatric patients and can present with significant cervical instability or posterior atlantoaxial dislocation. Surgical treatment can be applied successfully to pediatric patients to prevent potentially serious complications./r/nThis manuscript highlights the potential severity of cervical instability in pediatric patients with os odontoideum (OO). It emphasizes the rarity of posterior atlantoaxial subluxation in children with this condition. The presented case underscores the intraoperative failed reduction can cause spinal cord compression and a further extension of the posterior fixation with laminectomies can overcome this complication.