[A myelographic study of idiopathic scoliosis--with special reference to its clinical significance].

The purpose of this study was to investigate the concealed anomaly of the spinal cord in the so-called idiopathic scoliosis. Thirty-three patients with idiopathic scoliotic curvatures underwent metrizamide myelography before surgery from 1979 through 1985. Spinal cord anomalies were found in 8 of the 33 patients (abnormal group). They were 3 patients with Arnold-Chiari malformation with syringomyelia, 3 with syringomyelia and 2 with "narrowed dural tube". The remaining 25 patients (normal group) gave us the standard values for myelographic measurements with which we compared quantitatively the size of dural tube and spinal cord in the normal and abnormal groups. The abnormal group was classified into three types: type I was swollen spinal cord with normal dural tube; type II was swollen spinal cord with narrowed dural tube; and type III was normal spinal cord with narrowed dural tube. In conclusion myelography and myelographic measurements are essential for idiopathic scoliotic patients who will undergo spinal correction and fusion operations.