Straightening the facts: early versus late adolescent surgery in idiopathic scoliosis

This study aimed to investigate how age at surgery influences outcomes in teenage patients with adolescent idiopathic scoliosis (AIS), addressing the gap in comparative analysis within the adolescent years.In this retrospective cohort study, patients with AIS who underwent posterior spinal fusion were divided into two groups: less than 14 years (Y-14) and greater than or equal to 14 years (O-14). Inclusion criteria were Lenke Type 1A curve, scoliosis 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 identified factors associated with curve correction.The study included 168 patients (Y-14, n = 37; O-14, n = 131). The Y-14 group demonstrated significantly larger preoperative main thoracic curves (59.7 vs. 53.3°) and greater flexibility (52.9 vs. 46.4%). The Y-14 group achieved higher correction rates both immediately after surgery (83.3 vs. 77.5%) and at 2-year follow-up (82.3 vs. 75.6%), maintaining more favorable main thoracic curve correction over time (final follow-up: 10.2 vs. 12.9°). SRS-22 scores showed no significant differences between groups. In univariable analysis, age, height, weight, main thoracic bending, and flexibility were significantly associated with main thoracic curve correction. Multivariable analysis identified age as an independent predictor of correction.Patients who underwent AIS surgery before age 14 demonstrated superior radiographic outcomes and maintained better correction over time than those who underwent the surgery at 14 years or older, while SRS-22 clinical outcomes were similar between the groups. These findings suggest that surgical timing within adolescence influences radiographic correction in AIS. LEVEL OF EVIDENCE: Level III.