The Nuances of Pedicle Subtraction Osteotomies.

In adult spinal deformity, the pedicle subtraction osteotomy is a useful technique to provide correction, especially in rigid, previously fused spines. However, it is not without its complications. In an effort to prevent pseudoarthrosis, a new technique using 4 rods has been pioneered to decrease stress on the 2 long rods while allowing for maintenance of correction with 2 smaller rods. One should also use careful neuromonitoring, especially during closure, to be able to make adjustments in time to prevent the development of neurologic deficits. Nevertheless, significant correction can be achieved and patients' functional outcomes can be greatly improved.