A new minimally invasive procedure called genicular artery embolization (GAE) using fast-dissolving microspheres reduced knee osteoarthritis pain by 57% in patients who hadn't responded to traditional treatments. The findings, published in the peer-reviewed journal Radiology, represent the largest prospective study to date evaluating this approach for knee pain relief.

What Is This New Knee Pain Treatment?

Genicular artery embolization is a minimally invasive procedure that targets the small blood vessels feeding the knee joint. Researchers at Charité, a top-ranked hospital in Berlin, tested a new embolic agent called Nexsphere-F, which is made from fast-resorbable gelatin-based microspheres. Unlike older embolic materials that remain permanently in the body, these microspheres dissolve over time, potentially reducing long-term side effects.

The study enrolled 194 patients with knee osteoarthritis who had already tried conventional treatments without success, including corticosteroid injections and hyaluronic acid injections. Across 239 procedures, the treatment achieved a 100% technical success rate, meaning the procedure was completed as intended in every case.

How Significant Were the Pain Improvements?

Patients reported dramatic pain relief. Before the procedure, their pain scores averaged 7 on a 10-point scale. After 12 months, pain scores dropped to 3, representing a 57% reduction. Beyond pain relief, approximately 80% of patients achieved what researchers call a "minimum clinically important difference," meaning their improvement was substantial enough to meaningfully affect daily life.

Patients

Knee function and quality of life also improved significantly across all measures tested. The study used the Knee Injury and Osteoarthritis Outcome Score (KOOS) to track these improvements, a validated tool that assesses how well patients can walk, climb stairs, and perform other daily activities.

How Does This Compare to Existing Treatments?

The safety profile of Nexsphere-F appears superior to older embolic materials. Permanent microspheres and another older agent called imipenem-cilastatin have been associated with skin discoloration rates as high as 65% and 18%, respectively, in previous studies. Some patients using permanent particles even experienced skin ulceration. By contrast, Nexsphere-F caused only transient skin discoloration in 6.3% of procedures, and this discoloration resolved within 24 hours.

No moderate or severe procedure-related adverse events were reported in the study, suggesting the treatment is well-tolerated overall.

What Are the Next Steps for This Treatment?

The publication in Radiology, a leading peer-reviewed journal with an impact factor of 17.6, reflects strong international recognition of the treatment's potential. In the United States, a clinical trial called RESORB is currently underway to support FDA approval. The company behind Nexsphere-F expects this clinical data to support expansion into the European market, where the device already holds CE marking approval, and to help establish insurance reimbursement and wider adoption among hospitals and clinics.

Steps to Understanding Your Treatment Options for Knee Osteoarthritis

• Exhaust Conservative Options First: The study enrolled patients who had already tried corticosteroid injections and hyaluronic acid injections without adequate relief, suggesting these should be attempted before considering more invasive procedures.
• Ask Your Doctor About Minimally Invasive Alternatives: Genicular artery embolization is less invasive than joint replacement surgery and may be worth discussing if traditional injections haven't worked.
• Understand the Evidence Level: This is a prospective study, which provides stronger evidence than retrospective analyses, and the results were published in a top-tier peer-reviewed journal, indicating rigorous scientific review.
• Monitor FDA Approval Status: The RESORB clinical trial in the United States is ongoing, so this treatment may become more widely available in coming years as regulatory approval progresses.

For patients with moderate to severe knee osteoarthritis who haven't found relief through injections, this emerging treatment offers a new option backed by solid clinical evidence. The 57% pain reduction and high rate of meaningful functional improvement suggest that genicular artery embolization with Nexsphere-F could help many people avoid or delay knee replacement surgery.