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.