Surgical management of global sagittal deformity in ankylosing spondylitis.

Ankylosing spondylitis (AS) is an inflammatory rheumatic disease whose primary effect is on the axial skeleton, causing sagittal-plane deformity at both the thoracolumbar and cervicothoracic junctions. In the present review article the authors discuss current concepts in the preoperative planning of patients with AS. The authors also review current techniques used to treat sagittal-plane deformity, focusing on pedicle subtraction osteotomy at the thoracolumbar junction, as well as cervical extension osteotomy at the cervicothoracic junction.