Retrospective Comparison of Short- and Mid-Term Performance of 200-µm Polyethylene Glycol Microspheres vs Ethiodized Oil Emulsion for Genicular Artery Embolization in Symptomatic Knee Osteoarthritis

Purpose To report up to 6-month outcomes of genicular artery embolization (GAE) using polyethylene glycol microspheres vs ethiodized oil emulsion in patients with medically refractory symptomatic knee osteoarthritis (KOA). Material and Methods In this single-center retrospective study, sixty-eight patients (65 y.o, M/F (11/57)) underwent GAE from 9/2021 to 3/2025 using a permanent agent: 200-micron microspheres (HydroPearl®, n = 42), or a temporary agent: emulsion of ethiodized oil (LipioJoint, n = 46). Outcomes were assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total and Pain sub-score at baseline, 1, 3, and 6 months post-GAE. Adverse events (AEs) were reported by the CIRSE AE classification system. A descriptive statistical and multivariable analysis was performed. Results Eighty-eight knees treated with KOA severity: Kellgren–Lawrence (KL) 2: 10 vs 23%, KL 3: 57 vs 33%, KL4: 33 vs 44%, respectively (permanent vs temporary, P = 0.051). Pain sub-scale score decreased by 27 vs 44%, 25 vs 37%, and 23 vs 36% at 1, 3, and 6 months, respectively. There was higher percent WOMAC pain reduction in ethiodized oil emulsion at 1 but not at 3 and 6 months ( P = 0.020–0.119). Adverse events included: skin changes without ulceration (n = 14), knee swelling requiring prednisone (n = 5), and access site hematoma (n = 2). A lower AE rate was observed for total AEs and skin changes with ethiodized oil emulsion ( P = 0.018). Conclusion GAE shows positive short-term outcomes up to 6 months post-treatment for KOA with temporary and permanent embolic agents. Ethiodized oil may offer a better short-term efficacy and lower risk of skin discoloration compared to polyethylene glycol microspheres.