PREOPERATIVE SPINAL-CANAL INVESTIGATION IN ADOLESCENT IDIOPATHIC SCOLIOSIS CURVES GREATER-THAN-OR-EQUAL-TO-70-DEGREES

Study Design. This is a prospective evaluation of a consecutive series of patients with adolescent idiopathic scoliosis (AIS) with curves greater-than-or-equal-to 70-degrees. Objective. The authors investigated the possibility that large curve size may constitute an atypical presentation of idiopathic scoliosis suggestive of underlying neurologic pathology, which would warrant preoperative investigation. Summary of Background Data. The potential for intraspinal pathology to cause scoliosis is well accepted. The incidence of spinal canal abnormalities in congenital or atypical scoliosis may be as high as 30-60%. Identification of clinical neurologic deficits, congenital abnormalities, or atypical features of scoliosis are often helpful in identifying the subpopulation of scoliosis patients at risk for spinal canal pathology. Methods. Thirty-three consecutive patients with large (greater-than-or-equal-to 70-degrees) adolescent idiopathic scoliosis (AIS) and without evidence of neurologic or congenital abnormalities, were evaluated with either computed tomography/myelogram (n = 3) or magnetic resonance imaging (n 30) to assess the entire spinal canal. Results. None of the studies revealed any pathology of the neuraxis, and all 33 patients were treated with surgery without any neurologic sequelae. Conclusions. Preoperative investigation of the central neuraxis is not mandatory in large (greater-than-or-equal-to 70-degrees) but otherwise typical AIS curves. These large curves do not appear to suggest associated spinal canal anomalies.