The prevalence of intraspinal pathology associated with scoliosis
has been reported to be as high as 26% in some series1, and, on the basis of this finding,
preoperative magnetic resonance imaging is used in the screening
of patients with adolescent idiopathic scoliosis. However, this
practice continues to be highly controversial. In order to better
resolve this issue, we performed what we believe to be the largest
prospective study to evaluate the need for preoperative magnetic
resonance imaging in patients with adolescent idiopathic scoliosis
requiring arthrodesis of the spine.
A total of 327 consecutive patients with adolescent idiopathic
scoliosis were evaluated between December 1991 and March 1999. All
patients in the study presented with an adolescent idiopathic scoliosis
curve pattern and had a complete physical and neurologic examination.
Magnetic resonance imaging of the brain and the spinal cord were
performed as part of their preoperative work-up.
Seven patients had an abnormality noted on magnetic resonance
imaging. These abnormalities included a spinal cord syrinx in two
patients (0.6%) and an Arnold-Chiari type-I malformation
in four (1.2%). One patient had an abnormal fatty infiltration
of the tenth thoracic vertebral body. No patient required neurosurgical
intervention or additional work-up. All patients who underwent spinal
arthrodesis with segmental instrumentation tolerated the surgery
without any immediate or delayed neurologic sequelae.
The fact that magnetic resonance imaging did not detect any important
pathology in the large number of patients in this study strongly
suggests that magnetic resonance imaging is not indicated prior
to arthrodesis of the spine in patients with an adolescent idiopathic
scoliosis curve pattern and a normal physical and neurologic examination.