Retrospective review of three-dimensional (3D) imaging from a multicenter database of surgically treated adolescent idiopathic scoliosis (AIS) patients. To use 3D analysis software to compare Lenke 1AR and 1AL curves in the coronal, sagittal, and axial planes. The Lenke 1AR and AL curve patterns have been shown to be two distinct curve types, with 1AL curves being more likely to add on after fusion. Analysis in 3D may help define some of the intricacies of these two curves. Ninety-four AIS patients with Lenke 1A curves and upright biplanar scanned radiographs were reviewed. Analysis was performed using 3D reconstruction software to evaluate the 3D coronal, sagittal and axial plane deformities. Coronal L4 tilt was used to distinguish between the two curve patterns. The main thoracic Cobb was not significantly different between the AR (n = 43) and AL (n = 51) curves (52° ± 8° vs. 50° ± 5°; p = .25). The thoracolumbar/lumbar Cobb was significantly smaller in the AR curves (28° ± 8° vs. 32° ± 7° ; p = .02). In the sagittal plane, T5–T12 kyphosis and T12–S1 lordosis were not significantly different (p > .2); however, the T10–L2 alignment was significantly more lordotic in the AR curves (11° ±8° vs. 4° ± 10° lordosis; p