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 idiopathic scoliosis using spinal stereoradiographs was performed. The top view, which was obtained from stereoscopic anteroposterior and lateral radiographs, was analyzed for predicting the progression of spinal deformity.

OBJECTIVES

To show that the top view facilitates prediction of curve progression in idiopathic scoliosis at the initial examination.

SUMMARY OF BACKGROUND DATA

Four progression factors were set up using the top view and were analyzed statistically for predicting progression. No previous study has assessed this concept.

METHODS

Fifty-one patients with idiopathic thoracic scoliosis or combined thoracic and lumbar scoliosis were studied longitudinally. There were 24 untreated patients and 27 patients treated with braces. Four potential progression factors were evaluated using the top view: 1) the ratio of the frontal 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 describing the plane of maximum curvature in the lumbar spine, and 4) the balance of these vectors between the thoracic and lumbar curve. All cases were classified into five groups according to these four factors.

RESULTS

The probability of the progression was evaluated statistically, and the prevalence of curve progression was found in each group. The probability of progression of a scoliosis curve increased according to the increase of these four factors. No significant difference was found 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 braces showed progression of curvature despite brace treatment.

CONCLUSION

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.