Introduction: This study investigated preop AIS pts with right thoracic curves to determine which clinical and radiographic findings correlate with neural axis abnormalities on MRI, and which do not.
Methods: 529 AIS patients with Lenke 1–4 right thoracic curve patterns had MRI evaluation preoperatively. Thirty‐six of these patients (6.8%) had abnormal MRIs (syrinx, chiari malformation, diastematomyelia, and/ or tethered cord). To differentiate between those with normal MRIs (n=493) and those with abnormal MRIs (n=36), the following preop clinical parameters were evaluated: age, height, weight, asymmetric abdominal reflexes, thoracic rotation (scoliometer), coronal decompensation, trunk shift, shoulder elevation, and SRS‐30 questionnaire. Radiographically, thoracic curve magnitude, thoracic rotation (Nash‐Moe), coronal decompensation, trunk shift, length of thoracic curve, location of curve apex, sagittal balance, thoracic kyphosis (T2‐T12), and lumbar lordosis were evaluated.
Results: Those with abnormal MRI findings were shorter in height by a mean difference 4.0 cm [p=0.04], had greater clinical thoracic rotation by a mean diff 2.40 [p=0.01], and had greater radiographic thoracic kyphosis by a mean diff 5.90 [p=0.04]. There was a trend for more asymmetric abdominal reflexes in the abnormal MRI group (6.1%) than in the normal MRI group (3.5%). There were no significant differences in: age (14.9 yrs vs 14.7 yrs), coronal decompensation (clinical or radiographic), trunk shift (clinical or radiographic), shoulder elevation, thoracic curve magnitude (61.40 normal MRI group vs 63.60 abnormal group), length of thoracic curves (7.0 segments normal group vs 7.2 segments abnormal group), location of curve apices, radiographic sagittal balance, or any domains of the preop SRS‐30 questionnaire.
Conclusion: 6.8% of preop AIS pts with right thoracic curves had neural axis abnormalities on MRI. Patients with short stature, increased clinical rotation and/or increased kyphosis are at higher risk for neural axis abnormality. Surgeons should utilize this information when contemplating whether a preop MRI is indicated in those with right thoracic AIS curve patterns. This information is not intended to be representative of the juvenile idiopathic scoliosis population.