O2124: But it Got Better! Modern 3D Bracing Reduced the Curve Magnitude at the End of Treatment in 20% of Patients with Idiopathic Scoliosis

Background: The primary goal of pediatric spinal deformity management is to prevent deformity progression. Prior studies show the most compliant brace wearers with well-fitting braces complete treatment without curve progression or the need for surgery. While the aim of bracing is to halt or significantly delay curve progression, we’ve observed that recent advances in brace technology are resulting in patients with smaller curves at the end of treatment. There is little to no published evidence confirming that “curves can end up smaller”, and surgeons lack information regarding the patient or radiographic profiles of those with the largest potential of their curve getting “better”. Therefore, this study seeks to determine the frequency and characteristics of patients who end bracing treatment with a smaller coronal Cobb angle measurement using a novel bracing compliance database.

Methods: A retrospectively collected brace compliance database from a single center was queried for patients aged 6-18 at brace initiation who completed treatment for idiopathic scoliosis and had at least 6-months of post-bracing follow-up. Skeletal maturity (Sanders ≥7 or Risser ≥4), brace compliance data, Cobb angle, and in-brace coronal curve correction were required for inclusion. Only patients treated with a 3D brace were included, and heat-sensitive compliance monitors were used to measure average brace wear hours. Patients were classified into 3 groups based on whether their curve had progressed (change ≥ 6⁰), remained stable (-5⁰ ≤ change ≤ 5⁰), or got smaller (change ≤ -6⁰) at skeletal maturity. The data were analyzed using descriptive statistics and Wilcoxon rank sum test.

Results: 112 patients met inclusion criteria. At skeletal maturity, 24 patients’ curves (6 M, 18 F) had progressed, 65 (7 M, 58 F) remained stable, and 23 (4 M, 19 F) got smaller. Brace initiation age (12.7 years) and major coronal Cobb angle (31.8⁰) were comparable across groups; right-sided curves and primary thoracic curves predominated. Total months of bracing did not significantly differ between the three groups (p=0.784). Patients whose curves got smaller had statistically significantly greater in-brace correction (56.7%) versus patients whose curves progressed (42.5%) (p=0.024). Patients whose curves got smaller averaged 80.0% compliance with prescribed brace wear hours, and 60.9% of these patients were over 75% compliant. Patients whose curves progressed averaged 67.5% compliance with brace wear instructions, and only 41.7% of patients achieved greater than 75% compliance. With our sample size to date, this finding did not reach statistical significance (p=0.165).

Conclusion: 20.5% of idiopathic scoliosis patients treated with a modern 3D brace reached skeletal maturity with a deformity significantly smaller in magnitude than at original presentation. This will be very encouraging to families as they initiate bracing. In-brace correction is a key factor, and further work will aim to determine how brace compliance contributes to this excellent result.