HQ Team
June 23, 2026: A minimally invasive procedure that blocks the small blood vessels supplying an arthritic knee can reduce pain by about half and improve movement.
The procedure, genicular artery embolization (GAE), improved function among nearly 200 people with knee arthritis, according to a report published in the journal Radiology.
It followed 194 patients for one year and found the improvements lasted throughout that time with minimal side effects.
Osteoarthritis of the knee, the most common form of joint disease, is caused by the gradual breakdown of cartilage — the cushioning tissue between the bones, leading to pain, stiffness and reduced function. According to a 2023 analysis in The Lancet Rheumatology, osteoarthritis affected more than 595 million people globally in 2020 and is projected to worsen as populations age and obesity rates rise. In India alone, it is estimated to affect roughly 15 per cent of adults, making it one of the most common causes of disability in the country.
What is genicular artery embolization, and how does it work?
In the procedure genicular artery embolization or GAE, genicular refers to the blood vessels that supply the knee joint. In an arthritic knee, these vessels proliferate abnormally (a process called neovascularization), creating a dense network of new, leaky blood vessels and nerves that contribute directly to pain and inflammation. GAE works by blocking these overactive vessels, essentially cutting off the abnormal blood supply that drives pain.
This study tested a new generation of embolic agents, the tiny particles injected to block the vessels, called rapidly resorbable gelatin-based microspheres (microspheres are microscopic beads that lodge in and block blood vessels). What makes these particles different is that they dissolve within hours of being injected, unlike earlier permanent microspheres that remain in the body indefinitely. Researchers hypothesised that this temporary blockade could deliver the same pain relief as permanent particles while avoiding the longer-term risks associated with them.
What the study found
The study, conducted at Charité University Hospital in Berlin, enrolled 194 patients with a median age of 69 years, all of whom had knee osteoarthritis that had not responded to at least three months of conventional treatment, including physiotherapy, corticosteroid injections and anti-inflammatory drugs. A total of 239 procedures were performed, since 45 patients had both knees treated.
On a standard pain scale running from 0 to 10, the median pain score before treatment was 7 — indicating severe pain. At 12 months, it had dropped to 3. That is a reduction of 4 points, which is double the threshold considered clinically meaningful (a 2-point reduction) by standard medical benchmarks.
Functional outcomes, measured using a validated tool called the Knee Injury and Osteoarthritis Outcome Score (KOOS), also improved significantly across all categories, such as daily activity, sports and recreation, symptoms, pain and quality of life, all reaching statistical significance (P < .001). Between 55 and 80 per cent of patients met or exceeded the minimum threshold for meaningful clinical improvement across all these measures at the 12-month mark.
The safety picture
The safety profile was reassuring. The only notable side effect was temporary skin discolouration over the treated area, which occurred in 6.3 per cent of procedures (15 out of 239) and resolved on its own within 24 hours in every case. One patient developed a mild bruise at the groin where the catheter was inserted. No moderate or severe adverse events were recorded across any of the 239 procedures.
By comparison, earlier studies using permanent microspheres have reported skin discolouration rates as high as 65 per cent, and there is also concern about their long-term effects on surrounding tissues. The resorbable microspheres in this study appear to offer a cleaner side-effect profile, likely because they dissolve before causing prolonged tissue reactions.
How the procedure is done
The procedure is performed under local anaesthesia. A thin tube called a catheter is inserted into the femoral artery at the groin and guided by X-ray imaging to the blood vessels supplying the knee. Once the overactive vessels are identified; typically by an abnormal blush of blood flow visible on imaging, the microspheres are injected to block them. Patients stay overnight and are discharged the following day.
What this means for patients
For the roughly 595 million people worldwide living with knee osteoarthritis — a figure from the Global Burden of Disease study — the treatment options beyond painkillers and knee replacement surgery have historically been limited. GAE sits in the gap: less invasive than surgery, but potentially more effective for longer than corticosteroid injections.
The authors caution that the study was conducted at a single centre without a comparison group, meaning the contribution of placebo effect cannot be fully separated from the true treatment effect. Larger, randomised controlled trials are needed to confirm these findings before the procedure becomes standard of care.
