Skeletally Immature Patients With Adolescent Idiopathic Scoliosis Curves 15°–24° Are at High Risk for Progression

Study Design: Retrospective review. Objectives: To evaluate the incidence of adolescent idiopathic scoliosis (AIS) curve progression and brace prescription in skeletally immature patients (Risser 0 to Risser 1) with curves 15°–24°. Summary of Background Data: Many skeletally immature patients with mild AIS ask about the likelihood of curve progression. No studies have answered these questions. Methods: The charts and radiographs of 302 consecutive patients with curves 15°–24° at initial visit, Risser 0 to Risser 1, were reviewed until skeletal maturity (≥Risser 4) or surgery. Curves averaged 19.1° ± 2.9° at initial visit. The Risser grade was 0 in 247 patients (82%) and 1 in 55 patients (18%). Patients who were Risser 0 were compared with those who were Risser 1, curves 15°–19° were compared with curves 20°–24°. Results: The majority of patients demonstrated curve progression ≥5° (65%). Patients who were Risser 0 did not progress significantly more than patients who were Risser 1 (10° vs. 8°) (p = .22). Patients with curves 20°–24° did not progress significantly more than patients with curves 15°–19° (10° vs. 9°) (p = .65). Conclusions: Curve progression for small curves (15°–19°) is similar to curves between 20° and 24°. Close observation or perhaps early intervention for these patients is necessary. These data may suggest a paradigm shift to earlier brace initiation and call for early treatment in small curves. Level of Evidence: Level II.