Prospective comparison of flexibility radiographs in adolescent idiopathic scoliosis.

STUDY DESIGN

A prospective evaluation of radiographs in patients undergoing anterior spinal fusion or posterior spinal fusion for adolescent idiopathic scoliosis.

OBJECTIVE

To determine the most effective preoperative radiographic method for evaluating coronal plane flexibility by comparing preoperative and postoperative correction.

SUMMARY OF BACKGROUND DATA

Curve flexibility is traditionally evaluated with side-bending radiographs. Recently, the fulcrum-bending radiograph was shown to provide better correction of thoracic curves undergoing posterior spinal fusion but was not evaluated in thoracolumbar/lumbar curves or in patients undergoing anterior spinal fusion.

METHODS

Preoperative coronal radiographs of 46 consecutive patients undergoing spinal fusion for adolescent idiopathic scoliosis obtained while standing, lying supine, side-bending (maximally bending while supine), push-prone (padded bolsters applied to chest wall while prone), and fulcrum-bending (curve apex suspended over a radiolucent fulcrum while lateral) were compared with standing postoperative radiographs. Cobb angles were determined and evaluated for statistical significance.

RESULTS

The fulcrum-bending radiograph demonstrated statistically better correction than other preoperative methods for main thoracic curves (P < 0.01) but fell short of demonstrating the correction obtained surgically. There was no statistical difference between side-bending, fulcrum-bending, or postoperative correction for thoracolumbar/lumbar curves (all P values > 0.07). The left side-bending was the most effective method for reducing upper thoracic curves (P < 0.001). There was no difference in the results obtained for curves corrected by anterior spinal fusion or anterior spinal fusion.

CONCLUSION

To achieve maximal preoperative correction, thoracic fulcrum-bending radiographs should be obtained for evaluating main thoracic curves, whereas side-bending radiographs should continue to be used for evaluating both upper thoracic and thoracolumbar/lumbar curves.