A comprehensive model of idiopathic scoliosis (IS) progression, based on the patho-biomechanics of the deforming "three joint complex"

Results Consequently, the imposed convex-wise, asymmetrically concentrated cyclical loads on the adjacent immature vertebral end plates and posterior elements of the spine lead to asymmetrical vertebral growth. More specifically the loading on the two facet-joins asymmetrically increases during the day, as the wedged disc space narrows due to expelled water and it asymmetrically decreases during the night, as the disc space swells due to reabsorbed water. Discussion This 24 hour period of cyclic asymmetric loading leads both to asymmetric growth of the end plates and wedging of the vertebral bodies, and to similarly asymmetric growth of the pedicles and arches posteriorly as an effect of Hüeter-Volkmann law. It is well described that the pedicle in the convex side is more elongated than in the concave side and the facet joint larger respectively.