Traction radiography performed under general anesthetic: A new technique for assessing idiopathic scoliosis curves

Study Design. A prospective review of 24 patients with late-onset idiopathic scoliosis. Objectives. To compare curve flexibility measured using supine bending radiography and traction radiography; to examine the correlation of each technique with postoperative correction; and to determine the influence of each technique on the decision to perform concomitant anterior release surgery with posterior instrumentation. Summary of Background Data. Assessment of curve flexibility is important in decision making before surgical correction of scoliosis. Supine bending radiographs are presently the gold standard technique by which flexibility is assessed, but their reliability has been questioned. No literature has shown a conclusively superior role for traction radiography in assessing idiopathic scoliosis curves. Methods. Each patient had erect anteroposterior radiographs and supine bending radiographs. On the day of surgery, traction radiography was performed under general anesthetic. The correction obtained in the Cobb angle between the bending and traction radiographs was compared. The influence of the traction radiography on the decision for anterior release surgery and its correlation with postoperative result was examined. Results. Traction radiography demonstrated significantly greater curve flexibility than supine bending radiographs (P < 0.001). Eleven of 13 patients planned for anterior release surgery and posterior instrumentation avoided anterior release after review of the traction radiography. No significant difference was demonstrated between the traction radiography and postoperative correction (P = 0.13). Conclusion. Traction radiography is superior to supine bending radiography in assessing curve mobility before surgery. This method benefits patients by allowing them to avoid anterior release surgery and helps predict postoperative correction.