The management of nerve root entrapment syndromes associated with the collapsing scoliosis of idiopathic lumbar and thoracolumbar curves.

From 1969 through 1978, 30 adults presented with painful idiopathic scoliosis and associated radicular symptoms. Fifteen had major thoracolumbar curves and 15 had major lumbar curves. Ten (33%) had physical findings of the nerve root entrapment, 4 having two roots entrapped. Root entrapments in the sciatic distribution were most common and arose on the side opposite the major curve, coming from the concavity of compensatory lumbosacral curves (7 of 9 patients). Root entrapment in a femoral nerve distribution came from the concavity of the major curve (1 patient). Whether in a major or compensatory curve, entrapments usually arise in the concavity (8 of 10 patients). Mechanisms of root entrapment vary, but foraminal compression and pedicular kinking were most common. When major deforming curves are corrected fairly completely, most nerve root entrapments are relieved; sciatic entrapments are decompressed by spontaneous straightening of the lumbosacral curve. Dwyer instrumentation and fusion has been the most effective method of surgical management in carefully selected cases.