Predictors of Sacroiliac Joint Intervention Following Lumbar Spine Fusion

This retrospective database study looked at over 500,000 patients who underwent 1-5 level lumbar fusion and tracked how many later needed a sacroiliac (SI) joint fusion. Only 0.73% (3718 patients) went on to SI fusion, but among those, the strongest predictor by far was having had an SI joint injection after the index lumbar surgery (OR 15.48), followed by anterior/lateral approaches (OR 1.86), posterior approaches (OR 1.36), segmental instrumentation (OR 1.29), osteoarthritis (OR 1.14), and female sex (OR 1.09); risk of SI fusion also rose with more fused levels (HR up to 1.72 for 4-level fusion).

AI summary · from the full text · reviewed by Pukhraj Gaheer, Medical Student, Queen's University before publishing

Why it mattersHelps spine surgeons identify which lumbar fusion patients (women, more levels fused, segmental instrumentation, osteoarthritis) are at higher risk of later SI joint pain requiring intervention, informing preoperative counseling.

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• ?This is a large administrative database study using ICD/CPT codes without radiographic, symptom, or surgical technique detail; how might coding inaccuracies and lack of clinical granularity (e.g., unknown levels fused, indication for SI injection) bias the identified risk factors?
• ?Given that only 0.73% of patients required SI fusion and the strongest predictor was a prior SI injection (which itself signals emerging symptoms rather than an independent risk factor), how should this information change preoperative counseling versus intraoperative decision-making about concurrent SI fixation?