A minimally invasive procedure targeting abnormal knee blood vessels offers lasting osteoarthritis pain relief without surgery, according to new findings. The technique achieved meaningful improvements in mobility and pain reduction for 80% of patients assessed at a one-year follow-up.
Osteoarthritis involves cartilage deterioration and joint inflammation. When physical therapy, anti-inflammatory medications, and injections into the knee fail, patients often face joint replacement surgery.
Doctors Inject Gelatin Particles to Reduce Knee Inflammation
- The Procedure: Doctors thread a microscopic catheter through an artery to inject rapidly dissolving gelatin particles into abnormal blood vessels around the knee.
- The Mechanism: This targets abnormal blood vessel growth to reduce localized inflammation and calm pain-signaling nerves without open surgery.
- The Results: Clinical data show sustained pain reduction and functional improvement for up to 12 months in the majority of treated patients.
Evaluating Resorbable Microspheres in Genicular Artery Embolization
The investigated technique, known as genicular artery embolization (GAE), approaches knee arthritis by addressing the vascular environment surrounding the joint. Rather than replacing damaged cartilage, doctors use fluoroscopy—real-time X-ray imaging—to guide a thin catheter into specific small arteries. They then deliver tiny, rapidly resorbable gelatin-based microspheres engineered to dissolve within hours. This embolization reduces blood flow through pathological vessels while preserving normal circulation.
Florian Nima Fleckenstein, M.D., deputy head of Interventional Radiology Campus Mitte at Charité – Universitätsmedizin Berlin, noted that the treatment fills a distinct therapeutic gap. “For many patients with knee osteoarthritis, there is a real treatment gap today,” Fleckenstein said.
The study, conducted between July and November 2024, evaluated 194 patients with a median age of 69 years and a median body mass index of 28.4. Forty-five participants received treatments in both knees, totaling 239 procedures. All interventions were technically successful. Mild, temporary complications occurred in 6.7% of procedures, including brief skin discoloration and one superficial blood collection near the insertion site, with no moderate or severe adverse events recorded.
Patients Show Sustained Pain Reduction and Improved Mobility
Researchers monitored patient outcomes at six weeks, three months, six months, and 12 months. Substantial reductions in knee pain and improvements in mobility and quality of life were observed, with benefits persisting through the 12-month follow-up.
Functional metrics showed corresponding improvements across daily activities, sports, and overall quality of life. At the one-year mark, 80% of participants assessed exceeded the minimum clinically important difference. Fleckenstein emphasized the real-world utility of the trial, stating that the cohort mirrors patients physicians encounter daily.
Despite these promising functional outcomes, questions remain regarding disease modification. While the procedure successfully modulates the neurovascular environment, the study did not demonstrate that GAE prevents cartilage deterioration or reverses existing joint damage.
The findings build upon a growing body of literature examining vascular embolization for knee osteoarthritis, though results across published studies vary. A randomized study published in Clinical Radiology in 2026 reported superior pain reduction in patients receiving GAE combined with standard care compared to standard care alone after one year, though that trial utilized polyvinyl alcohol particles and lacked a sham control.
Conversely, a randomized, sham-controlled study published in European Radiology in April 2026 followed 58 patients for 12 months and found no statistically significant difference in pain reduction between the GAE and sham treatment groups, nor did MRI examinations show significant reductions in joint inflammation. A September 2026 analysis in the European Journal of Radiology examining 22 studies and a separate June 2026 review of 45 studies both documented improvements in pain and function but rated the overall certainty of available evidence as low or very low.
| Study / Analysis Metric | Patient Cohort Size | Key Finding / Outcome |
|---|---|---|
| Fleckenstein et al. | 194 patients (239 procedures) | 80% of patients assessed at one-year follow-up reported clinically meaningful pain relief. |
| Clinical Radiology Trial (2026) | 50 patients | Pain scores improved by 72.7% in the GAE group compared to 24.2% in standard care. |
| European Radiology Trial (April 2026) | 58 patients | Sham-controlled study found no statistically significant difference in pain reduction between GAE and sham groups. |
References
- Clinical Radiology – Comparative trials evaluating genicular artery embolization versus standard care.
- European Radiology – Sham-controlled trials investigating vascular interventions in osteoarthritis.
- European Journal of Radiology – Systematic analyses of clinical data and evidence certainty in knee embolization.
