Radiological screening for atlanto-axial instability in Down's syndrome.

Two hundred and twenty Down's sufferers of all ages in the Sheffield district had their cervical spine X-rayed as part of a screening programme to ascertain atlanto-axial instability. Fifteen patients (6.8%) had an abnormal predental distance with four (1.8%) showing atlanto-axial subluxation. Seventy per cent of abnormal findings were in the under-25 age group. Only one child had clinical manifestations. Patients under the age of 25 years are most likely to participate in sports and are thought to be the age group most at risk. Degenerative changes in the cervical spine were found at an early age in patients with Down's syndrome, and there is both an increased incidence and severity of degenerative change at higher levels with increasing age.