Introduction Fixes skull relative to the torso provides the most rigid form of external immobilization for the cervical spine ideal for upper cervical spine injury Allows intercalated paradoxical motion in the subaxial cervical spine not ideal for lower cervical spine injuries as lateral bending is the least controlled motion login to view 3 more bullets Indications Adult definitive treatment of cervical spine trauma including login to view 5 more bullets adjunctive postoperative stabilization following cervical spine surgery Pediatric definitive treatment for login to view 7 more bullets preoperative reduction in patients with spinal deformity Contraindications Absolute cranial fractures infection severe soft-tissue injury login to view 1 more bullet Relative polytrauma severe chest trauma barrel-shaped chest obesity advanced age login to view 1 more bullet Imaging CT scan prior to halo application indications login to view 2 more bullets Adult Technique Adults torque login to view 1 more bullet location login to view 7 more bullets followup care login to view 2 more bullets Pediatric Technique Pediatrics torque login to view 3 more bullets pin locations login to view 3 more bullets brace/vest login to view 2 more bullets CT scans may help in pin placement login to view 3 more bullets Complications Higher complication rates in children (70%) than adults (35%) Pin loosening (36%) can be treated with retightening if pin continues to loosen, should be treated with pin exchange Infection (20%) especially occurs with a posterior pin in the temporalis fossa login to view 3 more bullets can be treated with oral antibiotics if the pin is not loose login to view 1 more bullet Discomfort (18%) treated by loosening the skin around a pin Dural puncture (1%) Abducens nerve (cranial nerve VI) palsy epidemiology login to view 1 more bullet pathophysiology login to view 1 more bullet symptoms login to view 1 more bullet physical exam login to view 1 more bullet treatment login to view 1 more bullet Supraorbital nerve palsy injured by medially placed anterior pins Supratrochlear nerve palsy injured by medially placed anterior pins Medical complications pneumonia ARDS arrhythmia