Genicular artEry embolizatioN in patiEnts with oSteoarthrItiS of the Knee (GENESIS) Using Permanent Microspheres: Interim Analysis

PURPOSE: Planned interim analysis of GENESIS; a prospective pilot study investigating the role of genicular artery embolization (GAE) in patients with mild to moderate osteoarthritis of the knee using permanent microspheres. METHODS: Thirty-eight patients, median age = 60 (45–83), attended for GAE using 100–300 μm permanent microspheres. All patients had mild to moderate knee OA, resistant to conservative treatments over 6 months. Knee MRI was performed at baseline, and 12 months, enabling semi-quantitative analysis using Whole-Organ Magnetic Resonance Imaging Score (WORMS). Knee Injury and Osteoarthritis Outcome Score (KOOS) and visual analogue scale (VAS) (0–100 mm) were completed at baseline, 6 weeks, 3 months (n = 32), and 1-year (n = 16). Adverse events were recorded prospectively. RESULTS: Technical success of accessing and embolizing the target genicular arteries was 84%. Six patients were not embolized: four due to a presumed risk of non-target embolization, and two due to a lack of hyperaemic target. Mean VAS improved from 60 (SD = 20, 95% CI 53–66) at baseline to 36 (SD = 24, 95% CI 28–44) at 3 months (p < 0.001) and 45 (SD = 30, 95% CI 30–60) at 1-year (p < 0.05). All KOOS subscales showed a significant improvement at 6-weeks, 3-months, and 1-year follow-up, except function in daily living, which reached borderline significance (p = 0.06) at 1-year. Four patients experienced mild self-limiting skin discoloration over the embolized territory. One patient experienced a small self-limiting groin haematoma. WORMS scores at 1-year follow-up showed significant improvement in synovitis (p < 0.05). There were no cases of osteonecrosis. CONCLUSION: GAE using permanent microspheres in patients with mild to moderate knee OA is safe, with potential efficacy at early follow-up.