Is the Story Over? Progression After Bracing in AIS

Introduction Despite successful bracing for adolescent idiopathic scoliosis (AIS), some curves progress after brace cessation. The purpose of this study was to identify the incidence, rate, and risk factors for progression after successful brace management of AIS. Materials and Methods Patients treated with orthoses for AIS were prospectively enrolled at brace initiation, followed through successful brace completion and, on average, for 33 months (range 12-95) after brace cessation. Inclusion criteria were curves 25° to 45° and Risser 0 to II at brace initiation with cessation at Risser IV with curves measuring <50°. Exclusion criteria were cessation before Risser IV or curve progression >50° during bracing. Demographics and radiographic measures were collected. Brace compliance was measured using Thermachron temperature sensor. Postbrace progressors were compared with nonprogressors using Mann-Whitney U test, Fisher exact test, and two-sample t-test. Results Eighty-five patients who completed bracing with final curves <50° were followed after brace discontinuation >1 year. Twenty-seven/85 (31.8%) progressed postbracing to surgical curve magnitude >50° (n = 12) or progressed >5° after brace cessation without progression to surgical magnitude (n = 15). There was no difference between progressors and nonprogressors in age or menarchal status at brace initiation or completion, nor was there a difference in curve magnitude or morphology at initiation. There was no difference in duration of or compliance with bracing. Patients with postbrace surgical progression completed bracing at 46° on average compared with 33° for those who did not progress to surgical magnitude (P < 0.0001). Patients who completed bracing at >45° had an incidence of postbrace surgical progression of 67%. No patients who completed bracing with curves <40° showed progression after brace cessation. Conclusions A total of 14.1% of patients successfully treated for AIS with bracing later progressed to surgical magnitude, and an additional 17.6% progressed >5° after brace completion. Findings suggest that patients with curves measuring >40° at brace completion should be followed into young adulthood. Counseling regarding the potential future need for surgery is warranted once a curve exceeds 45° in braced patients.