Dual S2 alar-iliac screw technique with a multirod construct across the lumbosacral junction: Obtaining adequate stability at the lumbosacral junction in spinal deformity surgery

Abstract

To illustrate the safe placement of a 5-screw/5-rod construct across the spinopelvic junction in a complex revision case utilizing 4 S2 alar-iliac (S2AI) screws as well as an iliac screw for a kickstand rod. The S2AI screws are often used for lumbosacral fixation at the base of long spinal deformity constructs. In severe spinal deformities, additional pelvic fixation beyond the standard 2 screws may help achieve and maintain correction, and also increase the rigidity of the construct. With a thorough understanding of pelvic anatomy, multiple pelvic screws, such as bilateral dual S2AI screws, may be placed safely to achieve stability and ac-commodate additional rods to perform powerful correction techniques. We illustrate the safe use of multiple rods across the lumbosacral junction in this case, by using both a hook rod construct and domino connectors – ultimately though these additional rods rely on the integrity of the pelvic fixation to provide their support. We recommend at least 3 rods across the lumbosacral junction in any adult spinal deformity case requiring pelvic fixation, and would recommend considering more than 3 rods, especially across 3-column osteotomy sites. For long spinal constructs in patients with significant adult spinal deformity, we be-lieve the use of multiple pelvic screws to a multirod construct is a safe and effective way to provide long-term correction and clinical success.