Spinal growth and progression of adolescent idiopathic scoliosis.

The spinal growth in scoliotic segments (T4-L4) of 110 girls with untreated idiopathic scoliosis was measured from two successive radiographs taken at a mean interval of 1.1 years. At the first visit the mean age of the patients was 14 years (range 11-16 years), the mean magnitude of the major curves 24 degrees (range 9 degrees-38 degrees) and that of the minor curves 14 degrees (range 2 degrees-38 degrees). Spinal growth was most rapid at the age of 11-12 years. The progression of the curves (major plus minor) correlated with the spinal growth (r = 0.384). The greater the initial curves were, the stronger the correlation was between the spinal growth and the progression of the curves (r = 0.046-0.639), and the correlation was more significant in thoracic scoliosis (r = 0.560) than in thoracolumbar and lumbar scoliosis (r = 0.152).