Hemi-atlas is a rare congenital anomaly in the formation of the first
cervical vertebra. It may cause a rather severe and progressive
torticollis. When a child is young, the neck, despite the deformity, is
flexible and the torticollis can be passively corrected. However, in some
patients it becomes increasingly severe and fixed. I describe the findings
in seventeen patients, seven of whom were operated on between 1975 and
1983. Treatment with a brace was shown to be ineffective. In patients with
severe deformities, fusion of the upper part of the cervical spine is
recommended. Fusion was obtained in all seven patients in whom it was
attempted, and there was good postural correction in all. Early operation
is recommended if the deformity is increasing. Gradual correction in a halo
cast followed by posterior fusion is recommended as the treatment of choice
in patients with severe torticollis.