Young scoliosis patients do not need routine MRI scanning before spinal surgery

Most patients with scoliosis (curved spine) developing after age ten don't need routine magnetic resonance imaging (MRI) scanning before spine-straightening surgery, suggests a study in the April 14 issue of Spine. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

In young scoliosis patients without symptoms of neurological abnormalities, preoperative MRI scanning adds costs while detecting few abnormalities and adding little information for surgical planning, according to research led by Dr. Mohammad Diab of University of California San Francisco.

MRI Scans May Not Be Helpful—or Cost-Effective
The researchers analyzed data on 2,206 patients with adolescent idiopathic scoliosis, drawn from a larger study of scoliosis surgery in children. Adolescent idiopathic scoliosis is the most common type of scoliosis, generally developing after age ten. These children have no identifiable cause of their spinal curvature—idiopathic means "unknown cause." The patients were 1,812 girls and 394 boys; average age at scoliosis surgery was 14 years, 3 months.

Forty-two percent of the patients underwent MRI scanning before surgery. Preoperative MRI is sometimes recommended to check for accompanying conditions that may affect the surgical plan—especially neurological conditions causing damage to the spinal cord itself. None of the children in the study had any signs of neurological problems before surgery.

The MRI scans detected other abnormalities in about ten percent of children screened, or about four percent overall. The most common abnormalities were congenital malformations (syringes and Chiari malformations) with the potential to cause spinal cord damage. Patients with these neurological abnormalities need neurosurgery, in addition to straightening of the spinal curve.

Two factors—more severe curvature of the middle spine and juvenile scoliosis (developing before age ten)—were associated with a higher rate of MRI abnormalities. These factors might be helpful in identifying which children should undergo preoperative MRI scanning. There were no differences in complication rates between patients with normal versus abnormal MRI scans.

The study provides spinal surgeons with new guidance on using MRI for preoperative assessment of patients with adolescent idiopathic scoliosis. The results suggest that MRI is currently "over-requested"—it's performed in a relatively high number of patients, most of whom have no abnormality. In this situation, performing MRI not only adds unnecessary costs, but may potentially lead to increased risks.

Although the study may stir debate among surgeons, Dr. Diab and co-authors believe that most patients with adolescent idiopathic scoliosis—as long as they have no symptoms indicating neurological abnormalities—don't need MRI scanning before surgery. They conclude, "Our data question the routine use of MRI as a screening tool for adolescent idiopathic scoliosis."