Effectiveness of the Boston brace in treatment of large curves in adolescent idiopathic scoliosis

Study Design. This is a retrospective study of 50 patients with adolescent idiopathic scoliosis with curves measuring 35 degrees to 45 degrees who were treated with a Boston brace. Objectives. The purpose of this study was to determine whether the Boston brace could effectively halt long-term progression in skeletally immature adolescents with idiopathic scoliosis who had a curve between 35 degrees land 45 degrees. Summary of Background Data. The Boston brace has been Shown to be effective in preventing curve progression in adolescent idiopathic scoliosis, but its efficacy in large curves has not been fully studied. Methods. Fifty adolescents were treated with a Boston brace,for idiopathic scoliosis curves of 35-45 degrees (mean, 38.55 degrees), All were judged to be skeletally immature based on menarcheal status (mean, 2.6 months before menarche), Risser sign (mean, 0.90; range, 0-2), and chronologic age (mean, 13 +/- 1 years). Patients were recalled for long-term follow-up at a mean of 9.7 years (range, 6.23-13.22 years) after brace discontinuation. Three well-matched patient subsets were then identified based on compliance. Group 1 (n = 24) consisted of patients who were compliant with the brace program and wore the brace 18 or more hours per day, Group 2 (n = 14) contained patients who wore the brace 12-18 hours per day, and Group 3 (n = 12) contained patients who wore the brace 0-12 hours per day. Results. There was a significant difference in the amount of initial correction seen in the brace between :the groups: 49%, 45%, and 33% curve correction in the brace for Groups 1, 2, and 3, respectively (P < 0.05). At long-term follow-up there was a statistically significant difference between Groups 1,2, and 3 in the percentage of patients in whom the curve had progressed to more than 45 degrees (P < 0.001), who had more than 5 degrees of curve progression (P < 0.05), or who had undergone posterior spinal fusion (P i 0.001). Conclusions. These long-term data confirm that the Boston brace when used 18 or more hours per day is effective in preventing progression of large curves at a mean of 9.8 years after bracing is discontinued.