3D analysis of brace treatment in idiopathic scoliosis

We have evaluated the effect of bracing in scoliosis on coronal alignment in a cohort of patients. Current literature has not described the specific effect of bracing on the 3D shape of the scoliotic curves. The purpose of this study was to analyze the variability of the 3D effect of bracing on idiopathic scoliosis. The spines of 30 patients with adolescent idiopathic scoliosis were reconstructed using biplanar stereoradiography with and without the brace. The Cobb angle, sagittal and pelvic parameters and transverse plane parameters were calculated. The variability and the mean values of each parameter, with and without a brace, were analyzed and compared using a student t test. The Cobb angle improved in 50 % of patients but remained unchanged in 50 % cases. In 90 % of the cases lordosis was decreased. The thoracic kyphosis was decreased in 26 % cases, unchanged in 57 % of cases and increased in 17 % cases. The AVR was improved (> 5A degrees) in 26 % cases, worsened in 23 % and unchanged in 50 %. Only the differences of Cobb angle and the lordosis were statistically significant. Global statistics of this study concur with the literature. The Cobb angle was significantly improved. It also showed a significant hypolordotic effect. However, the results showed a high variability of the brace treatment effect in almost every parameter. Analysis of this variability by means of 3D reconstructions instead of global statistics should help characterize the mechanisms of correction of brace treatment.