Kim YH, Ha KH, Chang DG, et al. - The present study was undertaken to investigate the association between iliac screw (IS) loosening and proximal junctional kyphosis (PJK) after long fusion surgery for adult spinal deformity (ASD). Researchers recruited a sum of 68 ASD individuals (6 males, 62 females; mean age, 68.1 years) who underwent long fusion surgery with IS fixation. The incidence and risk factors of IS loosening were examined. They further evaluated the association between IS loosening and PJK. It was considered that postoperative sagittal malalignment should be avoided to prevent IS loosening and PJK. The iliac screw loosening happened earlier than PJK and appeared to influence the development of PJK. This association supports the hypothesis that distal stability of long constructs may raise proximal junctional stress.