Embolization of abnormal blood vessels using rapidly resorbable gelatin-based microspheres is safe and provides significant, lasting pain relief and functional improvement for patients with osteoarthritis-related knee pain, according to a study published on June 16 in Radiology, a journal of the Radiological Society of North America.
Osteoarthritis is the most common form of arthritis, causing inflammation, stiffness, reduced mobility and sensory nerve pain. The World Health Organization reports that knee osteoarthritis affects over 365 million adults worldwide and is one of the leading contributors to disability. Genicular artery embolization (GAE) is an emerging minimally invasive treatment that targets abnormal blood vessels around the joint using superselective embolization. In this procedure, an interventional radiologist guides a thin catheter directly to each affected vessel and injects tiny particles to block it, reducing inflammation and easing pain without surgery.
Researchers hypothesized that GAE using rapidly resorbable gelatin-based microspheres could combine the favorable characteristics of temporary embolic agents and permanent microspheres while eliminating their limitations. These size-calibrated spherical particles are designed to dissolve within hours. Dr. Fleckenstein said, "GAE is a whole new treatment regimen that targets abnormal hypervascularity around the joint and, in turn, modulates the pathological neurovascular environment. By reducing both inflammation and pain, GAE with resorbable microspheres may be the first procedure that alters the course of the disease, slowing its progression."
The prospective single-center study included 114 women and 80 men with osteoarthritis-related knee pain who did not respond to at least three months of conservative treatment such as physiotherapy or anti-inflammatory drugs. All participants underwent GAE between July and November 2024; some received two procedures for bilateral symptoms within four weeks apart. In total, there were 239 procedures performed under image guidance with no moderate or severe adverse events reported.
Outcomes were analyzed at baseline as well as six weeks, three, six, and twelve months following treatment. Follow-up rates ranged from 94% at six weeks to 79% at twelve months post-procedure. Dr. Fleckenstein said, "In our cohort we saw a significant drop in pain and a significant increase in function including sports and recreation and daily activity... Most importantly their quality of life significantly increased." Median Numeric Rating Scale scores dropped from seven at baseline to four at six weeks then three at both six- and twelve-month follow-ups—a sustained reduction maintained throughout one year.
At twelve months after treatment, eighty percent achieved improvements exceeding minimum clinically important differences based on Numeric Rating Scale scores alone. Dr. Fleckenstein concluded, "Our study demonstrates that GAE using rapidly resorbable gelatin-based microspheres is a safe minimally invasive therapy that provides meaningful pain relief... By embolizing pathological vessels we're able to normalize vessel structure—and in turn—the neuronal structure of the knee." He also noted this represents the largest body of evidence yet for this approach.
