[Treatment of lumbar and dorso-lumbar scoliosis using the Boston orthosis and the 3-valve orthosis. Comparative study of the results in the frontal and horizontal planes].

A study was made of 30 patients presenting with lumbar and thoracolumbar scoliosis; 15 patients had been treated with a 3-valve orthosis and 15 with a Boston brace. The mean age at the commencement of treatment was 14 years for the 3-valve orthosis and 14 years 4 months for the Boston brace. The total duration of treatment was 11.1 months for the 3-valve orthosis and 11.8 months for the Boston brace. The patients with the 3-valve orthoses presented with an initial mean curve of 30 degrees and with the Boston braces a curve of 24 degrees. The mean follow-up after removal of the brace was 17 months for the 3-valve orthosis and 12 months for the Boston braces. The efficacy of the two orthoses was studied in the frontal and horizontal planes, taking into account the overall rotation of the curve and the segmental rotation of each vertebra in the curve. The Boston brace and the 3-valve orthosis were identical in the correction of the curve. The overall derotation was better with the 3-valve orthosis. Segmentally, the 3-valve orthosis was more effective at the apex of the curve whilst the Boston brace was more effective at the extremities of the curve. The ilio-lumbar angle and the trunk instability were corrected better by the Boston brace. The specific indication for the 3-valve orthosis seems, therefore, to be scolioses in which there is a predominance of rotation at the apex of the curve. The Boston brace has its main indication in cases where rotation is considerably close to or at the ends of the curve.