A United States multi-site randomized control trial of Schroth-based therapy in adolescents with mild idiopathic scoliosis

Purpose: The purpose of this study was to determine the feasibility and efficacy of a United States multi-site randomized control trial (RCT) of the Schroth-based therapy program in Risser 0 patients with mild adolescent idiopathic scoliosis (AIS) curves. Methods: Six sites enrolled 98 Risser 0 patients with single AIS curves between 12° and 24°. Patients were randomized to Exercise:Control group in a 2:1 ratio. Exercise group patients were instructed on the Schroth-based method and a home exercise program of 75 min/week for 1 year. Results: Enrollment across 6 institutions averaged 2.2 patients per month over 45 months. Patient attrition was 42% after 1 year (41/98) and 52% after 2 years (51/98). Exercise group patients were significantly younger (11.6 vs 12.5 years) without differences in the baseline Cobb angle (16.2° vs 17.1°). Self-reported exercise adherence averaged 82% at 6 months and 63% at 1 year (n = 35). A significantly lower frequency of patients was braced in the Exercise group after 1 year (26% vs 55%, p = 0.03) but not after 2 years (48% vs 63%, p = 0.31). Curve magnitude changes between groups were not significant after 1 and 2 years. Conclusion: Performing a multi-site RCT for mild AIS in the United States is challenging with slow enrollment and high attrition. Young patients with small curves have difficulty adhering to the intensive demands of Schroth-based therapy. Level of evidence: II.