Complications of posterior arthrodesis of the cervical spine in patients who have Down syndrome.

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.