Analysis of the outcome of bi-vertebral transpedicular wedge osteotomy for correcting severe kyphotic deformity in ankylosing spondylitis.

To study the outcomes of bi-vertebral transpedicular wedge osteotomy in correcting severe kyphotic deformity in ankylosing spondylitis (AS). This retrospective study focused on all the patients who underwent thoracic and lumbar bi-vertebra transpedicular wedge osteotomy with pedicle screw internal fixation to treat their severe thoracolumbar kyphotic deformity of AS in our hospital from January 2014 to January 2020. The perioperative and operative data of each patient were collected and analyzed. A total of 21 male AS patients with severe kyphotic deformity were studied with a mean age of 42.2 ± 9.2 years. Intraoperatively, the mean operating time is 5.8 ± 1.6 hour with a mean blood loss of 725.5 ± 140.6 mL. The average postoperative correction of kyphosis reached 60.8o at 1 week after the surgery, which is significantly improved from preoperative presentation (P < .05), and stayed no significant change over the time during longer period of follow-ups (12-24 months) with the overall correction rate of 72.2%. Moreover, the postoperative changes in thoracic kyphosis (TK) angle, thoracolumbar kyphosis (TLK) angle, lumbar lordosis (LL) angle, maxilla-brow angle, as well as C2SVA and C7SVA sagittal balance were also significant, all of which enabled the patients to walk in upright position and sleep in the supine position with the improvements in other clinical symptoms. Bi-vertebral transpedicular wedge osteotomy of thoracic and lumbar vertebrae is a safe and effective method to restore the physiological curvature of the sagittal position of the spine and correct severe ankylosing deformity.