Comparison of Smith-Petersen osteotomy and pedicle subtraction osteotomy for the correction of thoracolumbar kyphotic deformity in ankylosing spondylitis: a systematic review and meta-analysis.

Study Design. A systematic review and meta-analysis. Objective. To compare the efficacy and safety outcomes of Smith-Petersen osteotomy (SPO) and pedicle subtraction osteotomy (PSO) for patients with ankylosing spondylitis (AS) with thoracolumbar kyphotic deformity. Summary of Background Data. Both SPO and PSO are used to correct thoracolumbar kyphotic deformity due to AS. Evidence is insufficient to determine which has better efficacy and safety outcomes. Methods. A systematic literature search was performed. Studies concentrating on treating thoracolumbar kyphotic deformity due to AS with SPO and/or PSO were included. Efficacy was determined with radiographical outcomes, including sagittal vertical axis and lumbar lordosis. Safety was determined with complication rates. The data were analyzed with Review Manager and R software. Results. Twenty-three studies were included. Among them, 5 were comparative studies and were used for a meta-analysis. All 23 studies were pooled to evaluate the radiographical correction and incidence of complications. The meta-analysis of the 5 comparative studies showed no significant difference between groups in either correction of sagittal vertical axis and lumbar lordosis or incidence of complications. The pooled data also showed similar radiological correction and complication rates between SPO and PSO. SPO was found to have potential risk of aortic rupture and slightly higher risk of permanent neurological deficit without statistical significance, whereas PSO was shown longer operative time and more blood loss. Conclusion. This systematic review and meta-analysis demonstrates that both SPO and PSO are effective in correcting thoracolumbar kyphotic deformity in AS and have similar risk of most complications. Aortic rupture and related death during correction is reported in SPO and should be taken into consideration for decision making.