Association of success of brace treatment and various aspects of in-brace correction in patients with adolescent idiopathic scoliosis

Abstract

BackgroundAlthough skeletal maturity and brace wear time contribute to the success of brace treatment in adolescent idiopathic scoliosis (AIS), the extent of initial in-brace correction for ensuring successful outcomes remains unclear. We hypothesized that the degree of initial in-brace correction correlates with brace success in patients with AIS. MethodThe study included 135 AIS patients with a major Cobb angle of 20°–40° treated with a thoracic lumbosacral orthosis for at least one year and followed up for skeletal maturity. The subjects were divided into two groups: the skeletally immature group (group I, n = 72), who met the Bracing in Adolescent Idiopathic Scoliosis Trial study protocol at the start of brace treatment, and the skeletally mature group (group M, n = 63). Treatment success was defined as not needing surgical treatment and a major Cobb angle <40° at the end of brace treatment. ResultsIn both groups, the mean major Cobb angles before treatment, while wearing the brace, and at the end of brace treatment were 30.6°/31.7°, 22.9°/24.2°, and 38.8°/33.9° (p < 0.05), respectively, and the treatment success rate was 56.9% and 77.8%, respectively (p < 0.05).Univariate regression analysis revealed the following risk factors: Risser grade 0 in group I, major Cobb angles before treatment, initial in-brace major Cobb angle, and in-brace correction rate in both groups. Cutoff values of in-brace major Cobb angle for treatment success calculated by ROC curve in groups I and M were 24° and 29°, respectively. ConclusionsIn-brace major scoliosis correction of <25° in patients with immature skeletal status and <30° in patients with mature skeletal structure should be aimed at to achieve significant brace treatment success.