Straightening the Facts: Early versus Late Adolescent Surgery in Idiopathic Scoliosis

Abstract Purpose: This study aimed to investigate how age at surgery influences outcomes in teenage patients with AIS, addressing the gap in comparative analysis within the adolescent years. Methods: In this retrospective cohort study, patients with AIS who underwent posterior spinal fusion were divided into two groups: <14 years (Y-14) and ≥14 years (O-14). Inclusion criteria were Lenke Type 1A curve, Cobb angle between 45° and 80°, and minimum 2-year follow-up. Radiographic parameters, correction rates, and Scoliosis Research Society-22 (SRS-22) scores were compared. Univariable and multivariable regression analyses were performed to identify factors associated with curve correction rates. Results: The study included 168 patients (Y-14, n=37; O-14, n=131). The Y-14 group demonstrated significantly larger preoperative main thoracic (MT) curves (59.65° vs. 53.29°) and greater curve flexibility (52.88% vs. 46.35%) than the O-14 group. The Y-14 group achieved higher correction rates both immediately after surgery (83.25% vs. 77.49%) and at two-year follow-up (82.28% vs. 75.61%), maintaining more favorable MT curve correction over time (Final follow-up: 10.18° vs. 12.91°). The SRS-22 scores showed no significant differences between groups. In univariable analysis, age, height, weight, MT bending, and flexibility were significantly associated with MT curve correction. Multivariable analysis confirmed age as an independent predictor of correction. Conclusion:Patients who underwent AIS surgery before the age of 14 years demonstrated superior radiographic outcomes and maintained better correction over time than those who underwent the surgery at 14 years or older, while clinical outcomes measured using the SRS-22 scores were similar between the groups.