Clinical and Radiographic Results After Posterior Wedge Osteotomy for Thoracolumbar Kyphosis Secondary to Ankylosing Spondylitis: Comparison of Long and Short Segment

To compare the efficacy of long and short segment instrumentation after pedicle subtraction osteotomy (PSO) for thoracolumbar kyphosis caused by ankylosing spondylitis (AS). Sixty-four consecutive AS patients were analyzed and divided into groups according to length of instrumentation. We defined short segment instrumentation (SSI) as construct length <7 levels (≤3 levels above and below the osteotomy) (n = 17). By contrast, long segment...