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

Abstract

Objective: To explore a simple and effective surgery for correcting severe kyphotic deformity caused by ankylosing spondylitis (AS).

Materials and methods: From 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.

Results: The 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.

Conclusions: For 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.

Keywords: Ankylosing spondylitis; Kyphosis; One-stage interrupted two-level transpedicular wedge osteotomy; Transpedicular bivertebrae wedge osteotomy.