Scoliosis. Experimental and clinical studies.

The hypothesis, advanced on the basis of experimental and clinical observations, that asymmetric growth of the ribs may be the primary cause of the thoracospinal deformity at least in some cases of right convex, thoracic, idiopathic scoliosis finds further support in the results of the anthropometric studies referred to below. There is also the possibility that asymmetric growth and more pronounced vascularization of the often larger breast may stimulate enough longitudinal growth at the underlying costosternal cartilage to upset the balance of forces acting on the normal spine. Muscular and other mechanical forces might be responsible for the further development of the deformity. Whether the data and evidence in this article will ultimately support or advance the hypothesis presented above remains to be seen. However, this hypothesis and the observations reported to date would seem to be capable of explaining the main characteristics of at least some cases of thoracic idiopathic scoliosis, i.e., the predominance in girls, the occurrence in the teens, and the predominant right convexity.