Genicular Artery Embolization Using Resorbable Gelatin Microspheres for Refractory Knee Pain: Technique, Safety and Clinical Outcome

Abstract Purpose: To evaluate the safety, technique and clinical outcome of genicular artery embolization (GAE) using resorbable gelatin microspheres (RGM) in patients with knee osteoarthritis (OA) or persistent pain after total knee replacement (TKR). Material and Methods: In this prospective observational study, 45 patients with knee OA (Kellgren–Lawrence 1–4, n = 35) or post-TKR pain (n = 10) were included. GAE was performed using 100–300 µm RGM. Embolic volume and treated vessels were documented. Clinical outcome was evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Numeric Rating Scale (NRS) at baseline, 6 weeks, 3 and 6 months. Psychological comorbidities were screened using the Hospital Anxiety and Depression Scale (HADS). Adverse events were recorded. Results: At 6 months, mean NRS improved by 35% and KOOS subscale pain by 55% (p < 0.001) with no significant differences between OA grades and post-TKR. A median of 3 (2–6) vessels were embolized with a mean total embolic volume of 6.5 mL (2.1–18.0 mL) per session. Patients with a HADS score ≥ 8 showed less improvements in the KOOS (up to 2.2 points less per HADS point increase; p < 0.05). Total embolic volume was significantly higher in advanced OA and post-TKR, averaging at 2.7 mL more per OA grade (p < 0.0001). No major complications were observed. Conclusion: GAE using RGM in doses higher than 2 mL is safe and demonstrates short-term clinical efficacy across all OA grades and in post-TKR pain. Patients with severe OA and post-TKR pain received higher embolic volumes. A HADS score ≥ 8 is associated with reduced clinical benefit. Graphic Abstract