SI Joint Fixation
Surgical fixation of the sacroiliac joint (SIJ) has increased in popularity over the last few decades, especially with the recent emergence of minimally invasive techniques. The indications for this procedure are expanding and include joint dysfunction, degeneration/arthrosis, trauma, and postpartum instability, among others. With rising frequency of lumbosacral arthrodesis, interest has developed regarding the SIJ as a pain generator due to accelerated degeneration/dysfunction as an “adjacent segment” receiving more force distribution. The current body of literature suggests that a targeted history and physical examination specific to the SIJ, and provocative testing, are paramount for appropriate patient selection. A thorough understanding of the anatomy and biomechanics involving the SIJ is essential to forming a critical review of the various surgical approaches and hardware instrumentation options as they become available. The SIJ anatomy can be approached from several open corridors including ventral-ilioinguinal, posterolateral iliosacral, and posterior sacral-alar-iliac approach. Similarly, minimally invasive approaches have been developed using posterolateral iliosacral trans-articular and posterior intra-articular techniques. Multiple hardware options are available for SIJ fixation and continue to grow, including screw-plate and screw-rod constructs, trans-articular fusion rods, intra-articular cages, trans-articular threaded screws, and hollow modular anchoring screws. The epidemic nature of low back pain will likely lead to an expanding interest in SIJ fixation, and critical appraisal of the cost and efficacy of hardware and techniques will warrant greater study.
