Quantec raster stereography has been recognized as an accurate and reliable tool for evaluating back contour and posterior truncal rotation in patients with scoliosis. In this prospective study, 35 patients with adolescent idiopathic scoliosis underwent both spinal radiography and Quantec three-dimensional evaluation of their idiopathic scoliosis before and after surgical intervention, consisting of anterior and/or posterior spinal fusion, with or without thoracoplasty. Comparison of established key parameters showed significant improvement in thoracic and thoracolumbar Cobb angle, as well as Quantec Q-angle. Thoracic rotation, Suzuki rib hump sum, and posterior trunk asymmetry also improved due to spinal fusion.