Minimally invasive sacroiliac joint fusion evidence gaps with biomechanics, devices, and industry influence: A narrative review

Introduction: Over the past decade, rapid growth in surgical approaches, implant designs, and industry involvement has expanded clinical adoption for minimally invasive sacroiliac joint fusion (SIJF), yet the supporting evidence remains unclear. Research question: This narrative review critically examines current literature on minimally invasive SIJF with emphasis on SIJ biomechanics, surgical approaches (lateral, posterior, and posterolateral), implant technologies, clinical outcomes, safety profiles, and market influences, while highlighting persistent evidence gaps. Material and methods: A narrative review was conducted using PubMed to evaluate studies reporting on clinical outcomes, device trends, biomechanics, and complications of minimally invasive SIJF. Results: The lateral transiliac approach is the most extensively studied and demonstrates consistent improvements in pain and function, though it carries higher reported complication rates due to proximity to neurovascular structures. Posterior and posterolateral approaches have gained popularity more recently, showing promising early clinical outcomes and lower complication rates, but are supported by fewer high-quality studies and shorter follow-up periods. Biomechanical investigations suggest that minimally invasive SIJF primarily achieves joint stabilization rather than complete arthrodesis, challenging traditional definitions of "fusion." Discussion and conclusion: Across approaches, heterogeneity in study design, outcome measures, follow-up duration, and patient selection limits direct comparison and generalizability. High-quality randomized controlled trials with long-term follow-up, standardized outcome reporting, and direct comparisons among techniques are needed. Improved integration of biomechanics, patient-specific anatomy, and implant design will be essential to guide evidence-based decision-making and optimize patient outcomes in minimally invasive SIJF.