Two-Level Spinal Osteotomy for Severe Thoracolumbar Kyphosis in Ankylosing Spondylitis: Experience With 48 Patients

Study Design. A retrospective study. Objective. To report surgical results for severe thoracolumbar kyphosis secondary to ankylosing spondylitis (AS) corrected with 2-level spinal osteotomy. Summary of Background Data. Transpedicular osteotomy in the lumbar spine is the major approach to correct kyphosis in AS. Most surgical procedures were performed at 1 level and only few literature report 2-level osteotomy in 1 patient. Methods. From January 2003 to June 2011, we reviewed 48 patients experiencing AS with severe thoracolumbar kyphosis who underwent stage 2-level spinal osteotomy in our hospital. The osteotomies were performed at T12 and L2 or L1 and L3, according to the apex of kyphosis. Preoperative and postoperative height, chin-brow vertical angle, sagittal balance, and the sagittal Cobb angle of the vertebral osteotomy segment were documented. Intraoperative, postoperative, and general complications were recorded. Results. The chin-brow vertical angle improved from 65.0° ± 28.0° to 5.0°± 10.0° (P = 0.000) and the sagittal imbalance distance improved from 26.9 ± 10.4 cm to 10.6 ± 5.6 cm (P = 0.000). The mean amount of correction was 24.9° at the superior site of the osteotomy and 38.1° at the inferior site of the osteotomy. Postoperatively, all patients could walk with horizontal vision and lie on their backs. No major acute complications such as death or complete paralysis occurred. Five patients experienced complications such as infections (n = 1) and cerebrospinal fluid leaks (n = 4). Both Oswestry Disability Index and Scoliosis Research Society scores improved largely. Fusion at the osteotomy site was achieved in each patient, and no implant failures were noted. Conclusion. Single-stage 2-level osteotomy can effectively and safely correct kyphotic deformities of the thoracolumbar spine caused by AS. Level of Evidence: 3