Pedicle subtraction osteotomy for postoperative flat back and sagittal imbalance

摘要

Treatment of fixed sagittal imbalance involves performing spinal osteotomies. One option is to perform multiple Smith-Petersen osteotomies (SPO). Another option is to perform a pedicle subtraction osteotomy (PSO), which usually achieves about 30 to 40 of lordosis. A variant of the latter procedure is to resect the disc space above (modified PSO). The first procedure (SPO) is indicated when the spine is flexible with partial reduction of the deformity through mobile segments (mobile intervertebral disc space); the second procedure (PSO) is performed when the spine is fused with no correction of the deformity in the recumbent position 1.