Three-Plane Morphological Remodeling of the Rib Cage and Spine in Early-Stage Scoliogenesis in Idiopathic Scoliosis.

Understanding normal growth patterns is essential for identifying early pathological deviations such as idiopathic scoliosis (IS). School scoliosis screening programs (SSSP), alongside clinical data, provide large-scale population datasets that enable the study of anthropometric and developmental differences between healthy children and those with IS. These data contribute significantly to understanding the epidemiology, natural history, and early pathogenesis of the condition. This study focuses on early morphological changes of the rib cage, spine, and trunk prior to the clinical manifestation of IS, integrating evidence from frontal, transverse, and sagittal plane assessments. In the frontal plane, reduced rib-vertebra angles (RVA) and rib asymmetry development suggest that thoracic deformity and asymmetric muscular forces may precede spinal curvature. Observations of 12th rib asymmetry further indicate a potential role of muscular biomechanics in lumbar curve development. Additionally, congenital rib anomalies highlight the influence of thoracic structure on spinal deformity. In the transverse plane, parameters such as the Rib Index (RI) and Segmental Rib Index (SRI) reveal that thoracic asymmetry is present even in mild scoliosis and correlates with curve severity, supporting the hypothesis that rib cage deformity is a crucial factor in scoliogenesis. Early thoracic changes, detectable through signs such as the Double Rib Contour Sign, may occur before measurable spinal curvature, particularly during growth. Sagittal plane analysis demonstrates that subtle reductions in thoracic kyphosis may facilitate, but not initiate, spinal rotation, acting as a permissive factor in disease progression. Overall, the evidence supports a model in which thoracic deformity precedes and contributes to spinal curvature. Multiplanar assessment underscores the central role of rib cage asymmetry in the initiation and progression of idiopathic scoliosis, offering important implications for early detection and future predictive models and preventive strategies.