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· DOS Abstracts
Neural axis abnormalities in patients with adolescent
idiopathic scoliosis - the role of MRI
Sidsel Fruergaard, Søren Ohrt-Nissen, Benny Dahl, Martin Gehrchen
Orthopedic Department, Spine Unit, Rigshospitalet; Orthopedic Department,
Spine Unit, Rigshospitalet; Orthopedic department, Texas Children’s Hospital
Background:
MRI-verified neural axis abnormalities (NAA) have been de-
scribed in adolescent idiopathic scoliosis (AIS) and several risk factors have been
associated with the presence of NAA. The clinical significance of these findings,
however, is not clear.
Purpose / Aim of Study:
The purpose of the present study was to determine
the prevalence of NAA in a large cohort of AIS patients and evaluate the clinical
significance of previously proposed risk factors.
Materials and Methods:
We prospectively included AIS patients referred to
our tertiary facility for evaluation. A full-spine MRI scan was performed on all
included patients irrespective of curve magnitude or proposed treatment mo-
dality. Clinical records and radiographs were retrospectively reviewed. MRI was
considered pathologic if syrinx, hydromyelia, Chiari malformation, diastemato-
myelia, tethered cord or other abnormalities.
Findings / Results:
The mean major curve angle was 39 degrees and 58 %
were thoracic. NAA was observed in 32 of 381 patients (9.1%). Twenty-one
patients had hydromyelia, nine patients had syringomyelia, one patient had an
arachnoid cyst and one patient had Chiari Malformation. Six patients were re-
ferred to neurosurgical evaluation but none received any neurosurgical treat-
ment. There were no statistical significant difference observed between the
NAA and no-NAA groups in terms of gender, major curve size, thoracic kypho-
sis, curve type, curve convexity, length of curve, curve progression or level of
pain (p ≥ 0.07).
Conclusions:
To our knowledge, this is the largest consecutive cohort of pa-
tients with a diagnosis of AIS undergoing MRI, and we found no association be-
tween NAA and previously proposed radiographic and clinical parameters. MRI
should not be implemented as a routine diagnostic tool in AIS evaluation, but
may be indicated in specific subgroups of patients with AIS.
Conflict of interest:
Sidsel Fruergaard: institutional grant from Medtronic
Søren Ohrt-Nissen: recived an institutional grant outside this submitted work
from K2M
Benny Dahl: institutional grant from K2M and Medtronic
Martin Gehrchen: institutional grant from K2M and Medtronic
42.