Posterior of vertebral column decancellation for ankylosing spondylitis patients with rigid thoracolumbar kyphotic deformity

Objective To introduce and evaluate the efficacy and safety of a new vertebral osteotomy method: vertebral column decancellation (VCD) for patients with rigid thoracolumbar kyphosis deformity secondary to ankylosing spondylitis (AS). Methods From June 2009 to May 2012, 36 AS patients who underwent VCD for correction of thoracolumbar kyphosis were included in this retrospective study.The diagnosis of AS with rigid thoracolumbar kyphosis was made on the basis of radiographic features, laboratory tests, and clinical features according to New York standards.The technique of VCD was administrated at single osteotomy vertebrae in thoracolumbar region of AS kyphosis patients according to classification of AS kyphosis.Intraoperative bleeding and perioperative complications were recorded.Pre-and postoperative chin-brow vertical angle (CBVA), sagittal vertical axis (SVA), sagittal Cobb angle in thoracolumbar region were recorded and analyzed.Scoliosis Research Society-22 (SRS-22) was used to evaluate the pre-and postoperative life quality of these patients. Results All surgeries were completed successfully and no major acute complications such as complete paralysis or death occurred.Compared with preoperative CBVA, SVA and thoracolumbar sagittal Cobb angle, postoperative CBVA, SVA and thoracolumbar sagittal Cobb angle improved significantly 45°(13°-60°) vs 10°(4°-17°), 22.4 (14.3-29.5) cm vs 7.9 (2.6-12.5) cm, 42°(25°-63°) vs 5°(0°-16°), P< 0.05.Compared with preoperative, the SRS-22 score increased significantly at 6 months after operation (2.42±0.54) vs (4.25±0.48), (2.15±0.48) vs (4.18±0.50), P< 0.05. Conclusion The technique of vertebral column decancellation (VCD) is a new, safe and effective option for correction of rigid thoracolumbar sagittal deformities caused by AS.In the meantime, VCD can avoid the complications such as excessive shortening and injury of spinal cord in the correction of deformity and sagittal imbalance.