A NEW METHOD USING TOP VIEWS OF THE SPINE TO PREDICT THE PROGRESSION OF CURVES IN IDIOPATHIC SCOLIOSIS DURING GROWTH

Study Design. A prospective longitudinal study of 51 patients with idi opathic scoliosis using spinal stereoradiographs was performed. The to p view, which was obtained from stereoscopic anteroposterior and later al radiographs, was analyzed for predicting the progression of spinal deformity. Objectives. To show that the top view facilitates predictio n of curve progression in idiopathic scoliosis at the initial examinat ion. Summary of Background Data. Four progression factors were set up using the top view and were analyzed statistically for predicting prog ression. No previous study has assessed this concept. Methods. Fifty-o ne patients with idiopathic thoracic scoliosis or combined thoracic an d lumbar scoliosis were studied longitudinally. There were 24 untreate d patients and 27 patients treated with braces. four potential progres sion factors were evaluated using the top view: 1) the ratio of the fr ontal size and the sagittal size in the top view, 2) the magnitude and direction of the vector describing the plane of maximum curvature in the thoracic spine, 3) the magnitude and direction of the vector descr ibing the plane of maximum curvature in the lumbar spine, and 4) the b alance of these vectors between the thoracic and lumbar curve. All cas es were classified into five groups according to these four factors. T he probability of the progression was evaluated statistically, and the prevalence of curve progression was found in each group. Results. The probability of progression of a scoliosis curve increased according t o the increase of these four factors. No significant difference was fo und between Cobb angle at the initial examination and that at skeletal maturity in untreated patients with a small risk of progression. The patients with a large risk of progression and who were treated with br aces showed progression of curvature despite brace treatment. Conclusi on. The present study has evaluated factors relating to progression in scoliosis using the top view. These results may help predict the risk of progression in idiopathic scoliosis.