Ten patients who had Down syndrome and had had a posterior arthrodesis
of the upper cervical spine were studied. The mean age at the time of the
operation was 8.9 years, and the patients had been followed for three days
to forty-nine months. Complications related to the operation occurred in
all patients. They included infection and dehiscence at the site of the
wound, incomplete reduction of the atlanto-axial joint, instability of the
adjacent motion segment, neurological sequelae, resorption of the
autogenous bone graft, and death in the postoperative period. Resorption of
the bone graft, which occurred in six of the patients, has not previously
been reported in patients who have Down syndrome, to our knowledge. Several
theoretical mechanisms for this complication are proposed. We recommend
non-operative management for patients who have Down syndrome and
atlanto-axial instability without neurological signs or symptoms. If the
severity of symptoms necessitates a posterior arthrodesis, a high rate of
complications must be anticipated.