Dynamic changes of the pelvis and spine are key to predicting postoperative sagittal alignment after pedicle subtraction osteotomy: a critical analysis of preoperative planning techniques. - Smith JS; Bess S; Shaffrey CI; Burton DC; Hart RA; Hostin R; Klineberg E; International Spine Study Group; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Burton, Douglas C; et al. (Spine (03622436), 2012)