Genicular Artery Embolization Using Rapidly Resorbable Gelatin-based Microspheres for Osteoarthritis-related Knee Pain.

Background Genicular artery embolization (GAE) is an emerging minimally invasive therapy for osteoarthritis (OA)-related knee pain. Traditional embolic agents such as imipenem-cilastatin and permanent microspheres have distinct limitations. Rapidly resorbable gelatin-based microspheres (RRGMs), designed specifically for GAE, may offer a promising alternative. Purpose To evaluate the safety and clinical outcomes of GAE using RRGMs in participants with OA-related knee pain. Materials and Methods This prospective, single-center observational study included consecutive participants with OA-related knee pain refractory to conservative treatment who underwent GAE using RRGMs between July and November 2024. Safety, the numeric rating scale (NRS) score (range, 0-10), and the Knee Injury and Osteoarthritis Outcome Score (KOOS) (range, 0-100) were assessed at 6 weeks and 3, 6, and 12 months after treatment. Clinical benefits were evaluated using the minimum clinically important difference (MCID). Descriptive statistics were used, and changes over time were assessed with the Friedman nonparametric repeated-measures test. Results A total of 194 participants (median age, 69 years; IQR, 60.5-75 years; 114 female) underwent 239 GAE procedures using RRGMs. The follow-up rates were 94% at 6 weeks (183 of 194 participants), 89% at 3 months (172 of 194 participants), 89% at 6 months (171 of 194 participants), and 79% at 12 months (154 of 194 participants). All the procedures (239 of 239) were technically successful. Transient skin discoloration occurred after 15 procedures (6.3%), and one participant developed a superficial groin hematoma (0.4%), all of which resolved without sequelae. No moderate or severe adverse events were observed. The median NRS pain score decreased from 7 (IQR, 6-8) at baseline to 3 (IQR, 2-5) at 12 months (P < .001), corresponding to a median reduction of 4 points (95% CI: 3.5, 4.0). At 12 months, 55%-80% of participants achieved improvements exceeding the MCID across all KOOS subscores. Conclusion GAE using RRGMs is safe and is associated with clinically meaningful improvement in participants with OA-related knee pain. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license.