Fig. 2

Segmental sagittal (A–C) and coronal (D–F) Cobb angles measured using CT-MPR. Despite the significantly smaller preoperative sagittal Cobb angles in the PAP group compared with the AP group (A), postoperative sagittal Cobb angle at the level of L4/5 was significantly larger in the PAP group than in the AP group (B). The postoperative changes in the sagittal segmental Cobb angles were significantly larger in the two-stage PAP group than in the single-stage AP group at all intervertebral levels (C). The change in the coronal segmental Cobb angle at the level of L4/5 was also significantly larger in the PAP group than in the AP group (F). *P < 0.05, **P < 0.01