Pathophysiology of spinal deformities in neurofibromatosis. An analysis of seventy-one patients who had curves associated with dystrophic changes.

The findings in seventy-one patients who had previously untreated spinal deformities associated with dystrophic changes and who had neurofibromatosis were reviewed to identify the risk factors for progression of the curve as well as the natural history of the dystrophic changes and curve patterns. Four different types of curves were evaluated. Two of them had the most severe progression: (1) kyphoscoliosis with angular kyphosis (gibbus) and marked dystrophic changes and (2) so-called kyphosing scoliosis (a scoliosis that has so much rotation [90 degrees] that progression is evident only on the lateral roentgenogram) with a round kyphosis. Risk factors for substantial progression of the curve were an early age of onset, a high Cobb angle at the first examination, an abnormal kyphosis, vertebral scalloping, severe rotation at the apex of the curve, location of the apex of the curve in the middle to caudal thoracic area, penciling of one rib or more on the concave side or on both sides of the curve, and penciling of four ribs or more.