Fig. 1
From: Modified C7 pedicle subtraction osteotomy for the correction of cervicothoracic kyphosis
a CT scan at C7 showing measurements of vertebrae dimensions on the on the middle sagittal plane. b The outline of the vertebral body is projected parallel to itself to the sagittal plane intersecting the pedicles. c Merged A and B showing the pedicles and facets on the middle sagittal plane. d-f The apex of wedge osteotomy is set at different points to simulate different types of osteotomy: the intersection point of mid-vertebral body line with anterior vertebral body wall (d), the midpoint of mid-vertebral body line (e), the anterior 1/3 point of mid-vertebral line (f). CT indicates computed tomography