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 and 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 < 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.