Strategies and Safety in Iliosacral Screw Placement

Background L5 nerve radiculopathy is a serious complication associated with iliosacral (IS) screw fixation, a procedure often performed to stabilize pelvic fractures. The proximity of the L5 nerve root to the S1 sacral segment introduces significant risk, particularly when sacral dysmorphism or complex anatomy is involved. Despite advances in surgical techniques, the potential for nerve injury remains a critical concern during IS screw placement. Purpose/Hypothesis This study aims to evaluate the risks associated with L5 nerve injury during IS screw fixation and identify factors that increase the likelihood of complications, particularly in cases involving sacral dysmorphism. The hypothesis is that proper preoperative planning, sacral anatomy assessment, and improved surgical techniques can minimize the risk of L5 nerve injury during IS screw fixation.  Study/Design This is a systematic review of cohort studies, methodology papers, reviews, and cadaver studies from SCOPUS and PubMed that investigate the relationship between sacral anatomy and L5 nerve root injury during IS screw fixation. Methods A comprehensive search was conducted using the keywords “L5 nerve radiculopathy” and “Iliosacral Screw Fixation.” Studies published within the last 15 years were included. Papers involving animal models or published in languages other than English were excluded. A total of 122 studies were identified, of which 15 were selected for detailed review based on their relevance to L5 nerve injury during IS screw fixation. The studies were analyzed for sacral anatomy variations, surgical techniques, and complications. Results The studies identified key factors that increase the risk of L5 nerve injury, including sacral dysmorphism, sacral morphology, and improper preoperative planning. Malpositioning of screws in the S1 sacral segment was associated with the highest risk of L5 nerve injury, particularly in cases involving dysmorphic sacra. Cadaver studies revealed that L5 nerve root proximity to the S1 segment significantly limits the margin for error, while imaging studies highlighted the importance of preoperative identification of osseous corridors. Improved techniques, such as the use of guidewires and triangulation methods, were found to enhance the accuracy of IS screw placement. Conclusion L5 nerve root injury is a major risk during IS screw fixation, particularly in cases with complex sacral anatomy. Preoperative planning that accounts for sacral morphology, along with the adoption of advanced surgical techniques such as the triangulation method by Zheng and Zao and guidewire use, is essential to minimize the risk of nerve injury. Further research should focus on improving intraoperative navigation and refining surgical techniques to enhance patient outcomes in sacral fixation procedures.