Spinopelvic Fixation Procedure On The Spine And Pelvis

Description

Spinopelvic fixation hardware spans the lumbosacral junction, linking the distal lumbar vertebrae to the sacrum and iliac wings in a posterior construct. Pedicle screws seated in the lumbar pedicles connect to longitudinal rods that descend to sacral anchors and iliac screws (iliac bolts), with the screw heads and connectors clustered posterolateral to the sacral ala and posterior superior iliac spine regions. The sacrum sits inferior to L5, and the iliac fixation points extend laterally into the pelvis, widening the base of support compared with a short-segment lumbar construct. Metal instrumentation dominates the field. Adjacent bony landmarks, including the posterior elements and sacral midline crest, provide orientation for screw trajectories. Spinopelvic constructs matter when the sacrum cannot reliably bear load, as in high-grade L5 to S1 spondylolisthesis, sacral insufficiency or traumatic fractures, pelvic ring disruption, infection, or tumor resection that compromises the posterior tension band. By extending fixation into the ilium, surgeons reduce cantilever forces at S1 pedicle screws and improve resistance to pullout, a common failure mode in osteopenic bone and long deformity corrections. The posterior perspective makes the relationship between lumbar pedicle screw heads, rod contour, and iliac screw entry points easy to parse, which is exactly what trainees struggle with when translating two-dimensional radiographs to three-dimensional anatomy. Spine surgeons and educators can use this illustration in operative planning discussions, residency lectures on lumbopelvic fixation techniques (including S2 alar-iliac versus traditional iliac screws), and textbook figures covering posterior instrumentation for adult deformity, trauma, and revision fusion. It also fits patient-facing materials explaining why fixation extends into the pelvis after long thoracolumbar fusion or sacral reconstruction. Anatomical accuracy verified by SciePro's Medical Advisory Board.