THORAX AND IDIOPATHIC SCOLIOSIS

Abstract

This review is related to the role of thorax in scoliogenesis. The embryology, the prenatal and the postnatal growth of the rib cage of (RC) and the lungs are briefly described. The development of normal RC, the frontal and sagittal diameters of it, the values of mid-thoracic diameters, the thoracic index, the biomechanical contribution of the RC to thoracic stability, the increase in frontal and sagittal thoracic diameter during breathing are defined. The infancy, childhood, puberty (ICP) model of growth is used in both the segmental thoracic ratios (TR) and the Segmental Rib-vertebra angles (RVA) in order to assess the normal and deformed RC in Early Onset (EOS) and Late Onset Scoliosis (LOS). The neuromuscular mechanisms as possible factors causing age-related RVAs changes are discussed. Then the posterior truncal/thoracic asymmetries are reviewed related to school scoliosis screening (SSS) referrals. Next, the development of RC is analyzed in resolving and progressive infantile idiopathic scoliosis (IIS), and in adolescent idiopathic scoliosis (AIS). The menarche and laterality of thoracic scoliotic curves, congenitally fused ribs and pulmonary function in children with idiopathic scoliosis (IS) is also discussed. The pathogenesis of IS according to the Nottingham concept and RC, the thorax and pelvis complex during gait and rotational inertia, the Double Rib Contour Sign (DRCS) and Rib Index (RI), the effect of growth on the relationship of spinal and thoracic deformity are explained. The postoperative fate of IS hump deformity in relation to the RI and the aetiological implications for IS are then stated. The role of the rib-sternum complex is mentioned. John Sevastiks thoracospinal concept of aetiopathogenesis of AIS and his research about IS are described, namely experiments on ribs, correction of experimentally produced scoliosis, suggested surgical intervention on the ribs, experiments on nerves, vascular changes in the chest wall after unilateral resection of the intercostal nerves, and breast asymmetries in female suffering AIS. A biomechanical model using different Cobb angle and rib hump (RH) correction is mentioned. The issue of thoracic kyphosis and hypokyphosis and the impact of the lateral spinal profile (LSP), that is the sagittal plane, is discussed. Finally, IS and evolution of thoracic shape as a scar of evolution are pointed out.