Longer Screws Can Reduce the Stress on the Upper Instrumented Vertebra With Long Spinal Fusion Surgery: A Finite Element Analysis Study

A finite element analysis study.Of proximal junctional failure, upper instrumented vertebra (UIV) fracture can causes severe spinal cord injury. Previously, we reported that higher occupancy rate of pedicle screw (ORPS) at UIV prevented UIV fracture in adult spinal deformity surgery; we had not yet tested this finding using a biomechanical study. The purpose of present study was to measure the differences in loads on the UIV according to the...