Yagi M, et al. - The aim of authors was to elucidate the role of bone strength for developing proximal junctional failure (PJF) following corrective surgery for adult spinal deformity (ASD). For PJF, low bone-mineral density (BMD) was noted to be a significant risk factor in this propensity-matched cohort (odds ratio 6.4). While correcting ASD in patients with low BMD, surgeons ought to consider prophylactic treatments.