Since 1974 six patients with atlanto-axial instability (non-union of an odontoid fracture in three, secondary to os odontoideum in one, and rheumatoid arthritis in two) were treated by posterior arthrodesis of the atlanto-axial joint, in which Gallie's modification methods and McGraw methods were used.
One of the rheumatoid cases died at our hospital four months after fusion due to pneumonia.
A follow-up study for one to five years revealed that the fusion of the atlanto-axial joint was complete in the remaining five cases.
Flexion and rotation of the neck movement were limited to about a half of the normal range of motion but extention remained almost normal.
From the above experience it is thought that the Brooks procedure modified by Griswold is the most satisfactory method.
