Zhao S, et al. - Through a retrospective single-center study of individuals with ankylosing spondylitis (AS; n = 43) who underwent lumbar pedicle subtraction osteotomy (PSO) for thoracolumbar kyphosis from January 2010 to August 2016, researchers investigated the position of head in association with the global spinal alignment in AS-related thoracolumbar kyphosis. OT discordance in AS-related thoracolumbar kyphosis could be resulted because of the decreased cervical range of motion. To maintain global spinal balance, in response to the larger sagittal vertical axis (SVA) center of gravity (COG)-C7, the pelvis rotated further backward. Furthermore, the larger SVA COG-C7 could be reduced following the lumbar PSO. Nevertheless, radiographic differences between the individuals with occiput-trunk (OT) concordance and with OT discordance were discovered, there was no variation in clinical outcomes, and that larger sample size and longer follow-up are required.