Rod Strain After Pedicle Subtraction Osteotomy: A Biomechanical Study

Pedicle subtraction osteotomy (PSO) can provide major sagittal correction for adult spinal deformity, sometimes achieving correction greater than 30°. Surgeons have reported failure rates up to 30% within 2 years, increasing to 46% after 4 to 5 years (SDC Figure 1, http://links.lww.com/BRS/B87). Revision following failure is difficult on the patient. PSO has achieved positive outcomes, but when used to correct posture in older patients with spinal deformity and fixed sagittal imbalance, rod breakage often leads to multiple surgical revisions. These complications must be avoided.