Minimally Invasive Embolization Procedure Reduces Knee Osteoarthritis Pain

Many patients fail conservative therapy yet are not ready for arthroplasty, leaving a treatment gap that affects function and quality of life. Interventional options that reduce pain while preserving the joint are needed in ambulatory and perioperative care. To help address this challenge, clinicians have introduced genicular artery embolization as a minimally invasive alternative for select patients.

At the University of Colorado Anschutz School of Medicine (Aurora, CO, USA), vascular interventional radiology teams perform genicular artery embolization (GAE) as an outpatient procedure and are leading clinical trials on its effects. The approach is intended for individuals with knee osteoarthritis who have not benefited from medications, physical therapy, or injections. It is currently positioned for patients with mild to moderate disease, with durability reported to be less robust in severe cases.

GAE decreases synovial inflammation by reducing arterial inflow to pathologic periarticular vessels. Under conscious sedation, clinicians create a small incision in the leg crease and advance a microcatheter from the femoral artery using fluoroscopic guidance and contrast. Embolic microspheres are then delivered into the genicular arteries supplying abnormal vessels identified in the patient’s pain map. After several hours of observation, patients are discharged the same day with short activity restrictions.

Early outcomes described by treating clinicians indicate that most patients experience marked pain reductions and improved activity. Approximately 70% of patients reportedly halve their pain scores, and a subset achieves complete pain relief following the procedure. The U.S. Food and Drug Administration has granted breakthrough device status to multiple embolic technologies used for GAE since 2021, reflecting growing regulatory support for this indication.

Evidence continues to accrue internationally and in the U.S. Four-year follow-up data from Japan indicate durable pain relief after a single outpatient GAE, while U.S. two-year data suggest sustained benefit among responders. Ongoing studies at CU Anschutz are evaluating changes in intra-articular fluid after GAE and assessing a temporary arterial treatment device, Nexsphere-F. Although presently focused on knees, clinicians report expansion of embolization strategies to other pain syndromes, including frozen shoulder, tennis elbow, and plantar fasciitis.

“GAE is a promising minimally invasive procedure that may fill that spot for people who have failed conservative treatments but are not yet ready to have a major surgery,” said Leigh Casadaban, MD, MS, assistant professor of radiology at the University of Colorado Anschutz School of Medicine.

“The theory is that GAE reduces inflammation inside the knee joint, and symptom relief can last years. Four-year data published in Japan shows that if you have one outpatient procedure, your pain relief can last for those four years. In the U.S., we now have two-year data, which shows that if you have a good response, pain relief can last two years. That really speaks to the theory that we’re hopefully modifying something in the joint,” said Casadaban.

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University of Colorado Anschutz School of Medicine