Magnetic resonance imaging for stenosis and subluxation in Klippel-Feil syndrome.

Magnetic resonance imaging and radiographs in neutral flexion and extension were used to evaluate 20 pediatric Klippel-Feil patients for subluxation and stenosis. Radiographs showed subluxation of 5 mm or greater in 5 (25%) of the 20 patients for an incidence of 25%. Magnetic resonance imaging documented stenosis of 9 mm or less below C1 in 5 (25%) of the 20 patients. Cord abnormalities were discovered in three (12%) of the patients: one hydromyelia with Arnold-Chiari I malformation and diplomyelia in two. The incidence of stenosis and subluxation was higher than the literature would suggest in this pediatric population. Magnetic resonance imaging is a useful tool and should be used to evaluate Klippel-Feil patients for cord abnormalities and cord compression.