Spine Deform. 2026 Apr 30. doi: 10.1007/s43390-026-01383-1. Online ahead of print.
ABSTRACT
PURPOSE: To evaluate pelvic incidence (PI) as a reliable parameter for analysing sagittal profiles in patients with adolescent idiopathic scoliosis (AIS).
METHODS: This retrospective cohort study included 100 patients with AIS (aged 12-17 years) who underwent posterior spinal deformity correction and had a 2-year follow-up. Radiographic parameters-Pelvic Incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), sagittal vertical axis (SVA), and T1 pelvic angle (TPA)-were evaluated preoperatively, at 6 months, and at 2 years postoperatively. Sagittal profiles were classified using the theoretical Roussouly system. Statistical analysis used repeated-measures ANOVA with Tukey HSD post hoc testing to assess temporal variability and Pearson correlation coefficients to assess associations between pelvic and spinal parameters.
RESULTS: The mean age was 13.3 years, with females comprising 66% of the cohort; Lenke type 5 was the most common curve type. Roussouly type 3 predominated at all time points. Pelvic parameters (PI and SS) remained stable (p > 0.1), whereas spinal parameters showed significant changes in LL (p = 0.000) and TK (p = 0.001). Global alignment shifted in SVA (p = 0.014), while TPA remained unchanged (p > 0.3). PI consistently correlated with PT (r = 0.60), SS (r = 0.64), and LL (r = – 0.55) across intervals.
CONCLUSION: PI showed minimal temporal variability, confirming its reliability as a morphological parameter in AIS. These findings support the role of PI in sagittal alignment assessment and reinforce the applicability of the Roussouly classification in AIS patients.
PMID:42062673 | DOI:10.1007/s43390-026-01383-1
