3-DIMENSIONAL EFFECT OF THE BOSTON BRACE ON THE THORACIC SPINE AND RIB CAGE

Study Design. Three-dimensional reconstructions of the spine and rib c age were done and compared just before and 1 month after initiation of treatment with a Boston brace in a group of adolescents with idiopath ic scoliosis. Objectives. To document the immediate changes in shape o f the thoracic spine and rib cage induced by the original Boston brace design. Summary of Background Data. The effect of the Boston brace ha s been well documented in the frontal plane but is poorly understood i n the other planes of deformity. Methods. Three-dimensional reconstruc tions were obtained with and without the brace using a stereoradiograp hic technique in a group of 40 adolescents with idiopathic scoliosis. Several geometric indices of the spine and rib cage were compared usin g Student t tests. Results. The brace produced significant curve corre ction of the spinal deformity in the frontal plane at the expense of a significant reduction of thoracic kyphosis in the sagittal plane, as well as in the plane of minimum deformity. No significant effect on ro tation of the thoracic apical vertebra, on the rib hump, or on frontal balance could be documented, but changes were noted in the sagittal o rientation of the rib cage and in the sagittal balance of the spine. C onclusions. The original Boston brace does not completely correct the three-dimensional deformities associated with thoracic idiopathic scol iosis, although it reduces Cobb angles in the frontal plane.