Fig. 2From: Comparison of smith-petersen osteotomy, pedicular subtraction osteotomy, and poly-segmental wedge osteotomy in treating rigid thoracolumbar kyphotic deformity in ankylosing spondylitis a systematic review and meta-analysisComparison of three types of osteotomy on kyphosis correction among SPO, PSO and PWO. Information: Both PSO and PWO had bigger correction angle than SPOBack to article page