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 gr eater-than-or-equal-to 70-degrees. Objective. The authors investigated the possibility that large curve size may constitute an atypical pres entation of idiopathic scoliosis suggestive of underlying neurologic p athology, which would warrant preoperative investigation. Summary of B ackground Data. The potential for intraspinal pathology to cause scoli osis is well accepted. The incidence of spinal canal abnormalities in congenital or atypical scoliosis may be as high as 30-60%. Identificat ion of clinical neurologic deficits, congenital abnormalities, or atyp ical features of scoliosis are often helpful in identifying the subpop ulation of scoliosis patients at risk for spinal canal pathology. Meth ods. Thirty-three consecutive patients with large (greater-than-or-equ al-to 70-degrees) adolescent idiopathic scoliosis (AIS) and without ev idence of neurologic or congenital abnormalities, were evaluated with either computed tomography/myelogram (n = 3) or magnetic resonance ima ging (n 30) to assess the entire spinal canal. Results. None of the st udies revealed any pathology of the neuraxis, and all 33 patients were treated with surgery without any neurologic sequelae. Conclusions. Pr eoperative investigation of the central neuraxis is not mandatory in l arge (greater-than-or-equal-to 70-degrees) but otherwise typical AIS c urves. These large curves do not appear to suggest associated spinal c anal anomalies.