Sacropelvic Fixation: A Comprehensive Review

Sacropelvic fixation is indicated in various clinical settings, most notably long spinal arthrodesis, reduction of high-grade spondylolisthesis, and complex sacral fractures. The sacropelvis is characterized by complex regional anatomy and poor bone quality. These factors make achieving solid fusion across the lumbosacral junction challenging. However, a better understanding of spinal biomechanics at that level has led to much higher fusion rates than those of the past. The newer fixation techniques are biomechanically superior to previous methods mainly because they achieve bony purchase anterior to the pivot point—first described by McCord et al. in 1994. Today, the two most widely used fixation techniques are iliac screws and S2-alar-iliac screws. Although these techniques are associated with very high rates of fusion, instrumentation-related pain and reoperation remain problematic. This review provides an overview of the regional anatomy and biomechanics at the lumbosacral junction, as well as a summary of fixation techniques with an emphasis on the most widely used techniques today. Level of Evidence: IV.