[The progression of untreated idiopathic scoliosis in the x-ray image].

The natural history of scoliosis, or lateral curvature of the spine, was followed up in 135 patients (111 girls, 24 boys) for a total average period of 52.4 months. We observed patients with a curvature of between 5 degrees and 30 degrees none of whom had been treated specifically as orthotics or with electrical stimulation or by surgery. Two groups of patients with progressive curvature were differentiated: 1) in 62.2% of the patients the curvature progressed by more than 5 degrees during the entire observation period; 2) in 36% of the patients we found an increase in curvature by more than 5 degrees within one year. Another result of our study was that idiopathic scoliosis is particularly dangerous in young patients with a "0" Risser sign. Thoracic curvatures and double major curvatures were more liable to progress than lumbar and thoracolumbar curvatures. Even a small angle of curvature in young patients must be taken seriously.