The cervical halo provides the most rigid form of external immobilization for the cervical spine especially the upper cervical spine. Halo placement is not idea for treatment of lower cervical spine injuries.
Pin loosening is a complication of the halo and occurs in about 36% of the cases. If the pin becomes loose, it can be treated by retightening. If it continues to loosen, remove the pin and replace it in a different location.
Infection may also occur as a complication. If infection occurs at the pin site then bacteria cultures should be obtained. The proper antibiotics and meticulous pin care should be started. If infection is resistant to treatment, then the pin site can be changed with placement of a new pin in a different location.
Another obstacle associated with the halo brace is over penetration of the pins. The pins should only penetrate the outer table of the skull. Dural puncture can occur with over penetration of the pins through the inner table of the skull. If infection occurs, it may cause a brain abscess.
Redislocation with halo immobilization may occur in about 10% of cases. A more rigid open reduction and internal fixation should be considered.
The head and neck are placed in hyperextension for use of the halo brace, which may also cause difficulty in swallowing. Readjustment of the halo will solve this problem.
Halo placement in the elderly patient is not advisable. Some people believe halo placement is a death sentence for the elderly. Some of these patients will have respiratory failure and cardiovascular collapse. The mortality rate is higher in elderly patients with a halo placement. Soft collar placement is better for the elderly patient.
Supraorbital and supratrochlear nerve palsy may also occur. Proper placement of the halo pins will avoid injury to these nerves.
Abducens nerve palsy is the most common cranial nerve injured due to halo pin placement. The sixth cranial nerve is injured due to traction. The abducens nerve innervates the lateral rectus muscle of the eye. The patient will develop diplopia (double vision) and loss of the lateral gaze on the affected side. Treatment is usually observation and the condition will resolve itself.
