Fig. 3

Examples of two patients with similar thoracic coronal deformity but markedly different sagittal alignment. For the first patient with (a) thoracic curve of 19.5° at T5-T10, (b) sagittal parameters included thoracic kyphosis of 41.9°, lumbar lordosis of 66.2°, pelvic incidence of 42.3°, pelvic tilt of 14.6°, sacral slope of 37.5°, Pelvic incidence – lumbar lordosis of − 14.1°. Despite a similar (c) coronal curve magnitude (19.2° at T5-T10), there was a (d) greater negative mismatch between pelvic and spinal parameters (− 26.1°) with less thoracic kyphosis (30.2°). Other sagittal parameters included pelvic incidence of 42.9°, pelvic tilt of − 4.1°, sacral slope of 49.3°, and lumbar lordosis of 71.4°