Odontoid fractures refer to a fracture involving the second vertebra which is high in the neck, near the base of the skull. Odontoid fractures can be dangerous or fatal because of their proximity to the critical brainstem. In older patients, these fractures are often the result of minor trauma. In younger patients, these fractures generally result from high force trauma such as fall from height or motor vehicle accident. Symptoms of an odontoid fracture include: neck pain, limited mobility of the neck, and numbness of the arms. Depending on the type of odontoid fracture, patients may need surgery to fuse the odontoid bone and prevent damage to the spinal column or brainstem. Patients who do not need surgery may be placed in a "halo" to immobilize them and allow the fracture to heal.