Comparison of two surgeries in treatment of severe kyphotic deformity caused by ankylosing spondylitis: Transpedicular bivertebrae wedge osteotomy versus one-stage interrupted two-level transpedicular wedge osteotomy

• The simple and effective surgery used for ankylosing spondylitis was explored.
• Two surgeries in treatment of patients with ankylosing spondylitis were compared.
• One-stage interrupted two-level transpedicular wedge osteotomy can be used in future.

ObjectiveTo explore a simple and effective surgery for correcting severe kyphotic deformity caused by ankylosing spondylitis (AS).Materials and methodsFrom January 2003 to December 2009, we respectively reviewed 32 patients with severe spinal kyphosis caused by AS with at least 2-year follow-up. Patients were divided into two groups, according to surgical methods: transpedicular bivertebrae wedge osteotomy (Group A) or one-stage interrupted two-level transpedicular wedge osteotomy (Group B). We recorded operating time and blood loss. Variation between pre- and post-operative sagittal imbalance, global spinal alignments (Cobb angle of T1 and L5, TLKA), lumbar lordosis, chin-brow vertical angle, thoracolumbar kyphosis angle in both groups were analyzed.ResultsThe average operating time was 236 ± 39 min and the average blood loss was 2200 ± 712 ml in Group A, and 252 ± 43 min, 2202 ± 737 ml respectively in Group B. There were no significant differences in operating time and blood loss. Variation between pre- and post-operative sagittal imbalance, global spinal alignments, lumbar lordosis and chin-brow vertical angle (CBVA) were comparable between the two groups. The variation of thoracolumbar kyphosis angle was significantly greater in Group B compared with Group A. SRS-22 scores were similar in the two groups at the 2-year follow-up and significantly improved compared with preoperative.ConclusionsFor correcting severe kyphosis in patients with AS, the one-stage interrupted two-level transpedicular wedge osteotomy is a safe and effective technique which can significantly improve the thoracolumbar kyphosis angle.