Comparison of traction, side-bending and dead-hang radiographs in preoperative evaluation and postoperative correction prediction in adolescent idiopathic scoliosis: A retrospective analysis of a novel flexibility radiograph

Abstract

A retrospective study comparing traction, dead-hang, and side-bending radiographs in adolescent idiopathic scoliosis to compare the effectiveness of dead-hang radiography in structural and nonstructural curves and evaluate it in terms of postoperative correction prediction. In the surgical correction of adolescent idiopathic scoliosis, flexibility radiographs have an important role in determining fusion levels and in surgical decision-making. Supine bending radiographs are presently considered the gold standard, but their reliability, reproducibility, and standardization along with traction films, are a subject of debate. In our clinic, dead-hang radiographs are also used as an alternative flexibility film. The role of dead-hang radiography against other flexibility radiographs is unknown. A total of 33 patients with adolescent idiopathic scoliosis were evaluated with preoperative standing, lateral, supine traction, dead-hang, supine side-bending, and postoperative standing films. Flexibility and correction rates were assessed. In structural main thoracic (MT) and thoracolumbar/lumbar (TL/L) curves, dead-hang showed significantly higher flexibility compared with traction (P < .001). In MT curves > 60°, dead-hang was superior to side-bending and traction, whereas in MT curves < 50°, side-bending showed more improvement (P < .05). Side-bending showed higher flexibility in TL/L curves < 50° (P < .05). No predictive value was found in structural curves for all 3 radiographs. In nonstructural curves, side-bending films showed over-correction while traction radiographs remained below postoperative correction. Dead-hang radiographs showed very similar flexibility to postoperative correction. Dead-hang radiograph is superior to traction. In MT curves > 60°, dead hang shows greater flexibility than side-bending. Dead-hang technique, which shows equal results with side-bending except in TL/L curves < 50°, is a successful flexibility radiograph and provides predictive value for nonstructural curves in terms of postoperative correction.