Patient guide
Genicular artery embolization (GAE) for knee osteoarthritis: who it may help and what the evidence shows
What genicular artery embolization is, how it eases knee osteoarthritis pain, who may be suitable, what pooled studies and sham-controlled trials show, recovery, risks and how it compares with injections and knee replacement.
GAE at a glance
- No incisionA thin catheter through a puncture
- Walk out the same dayDay-care procedure
- Local anaestheticWith light sedation if needed
- About 1 hourFor most procedures
- Mostly minor effectsBruising or skin discolouration
- Evidence emergingChosen case by case
Knee osteoarthritis and the usual treatment
Knee osteoarthritis is the wearing of the cartilage and the inflammation of the joint lining, causing pain on walking, stairs and standing, stiffness and swelling. The usual first steps are exercise and physiotherapy, weight loss, walking aids, anti-inflammatory medicines and injections into the joint (steroid, hyaluronic acid or similar). When the joint is badly worn and pain is severe, knee replacement is the definitive treatment. GAE is considered for people in between: pain that is real and limiting, but not yet at the stage for replacement, or who cannot or do not wish to have it.
What GAE does
In osteoarthritis, the lining of the joint (synovium) becomes inflamed and grows abnormal small vessels fed by the genicular arteries, the small branches that supply the knee. GAE passes a catheter to these branches and closes them with tiny microspheres or a temporary agent, reducing the blood flow that keeps the lining inflamed. The treatment does not regrow cartilage. Its aim is to reduce pain, so that you can move and exercise more [1, 2].
How the procedure is done
GAE takes about an hour and is done as day-care.
- X-ray and sometimes MRI confirm osteoarthritis as the cause of your pain, and kidney function is checked.
- Under local anaesthetic, a catheter enters an artery at the groin or wrist and is guided to the genicular arteries around the knee under X-ray.
- Contrast dye shows a blush around the joint lining. Tiny particles are injected into the arteries feeding it until the blush fades.
- The catheter is removed and a dressing is placed. After observation, you walk out the same day.
What the studies show
A 2026 meta-analysis pooled 45 studies with 2,205 patients, mostly uncontrolled. Pain scores fell by about 37.5 points on a 100-point scale at 1 month and 37.1 points at 12 months, and function and pain scores also improved by amounts larger than the usual clinically important thresholds. The commonest side effects were temporary skin discolouration (11%) and haematoma (3%). The certainty of this evidence was rated very low to low, because most studies had no control group [1].
The sham-controlled trials give a more cautious picture. A systematic review of three such trials with 138 patients found short-term pain relief, with one trial showing a large difference at 1 month, but other pain and function scores were not clearly better than sham, there were no serious adverse events, and the authors called for larger trials with longer follow-up [2].
Amin et al., Cardiovasc Intervent Radiol 2026, 45 studies, 2,205 patients [1]. Certainty of evidence: very low to low.
Who may be considered, and who is not suitable
GAE is a selective treatment, and these are the usual points.
- Knee osteoarthritis confirmed on X-ray or MRI, usually mild to moderate.
- Pain that limits daily life and has not improved after at least three months of exercise, medicines and injections.
- Not suitable: active infection, inflammatory arthritis as the main cause, serious contrast allergy, poor kidney function, pregnancy, or severe artery disease in the leg.
- Advanced, bone-on-bone disease with severe deformity usually needs knee replacement rather than GAE.
Options compared
No single option is right for everyone, and they are often combined.
| Exercise and medicines | Joint injections | GAE | Knee replacement | |
|---|---|---|---|---|
| What it is | Physiotherapy, weight loss, tablets | Steroid or other injections into the knee | Embolization of small knee arteries | Surgery to replace the joint |
| Invasiveness | None | A needle in the joint | A small arterial puncture | Major surgery |
| Best for | Everyone, as the foundation | Flares, short-term relief | Mild to moderate disease with refractory pain | Advanced, severe disease |
| Evidence strength | Strong | Established, short-term | Emerging | Strong, long-term |
Recovery and risks
Most people walk out the same day, with some soreness or a bruise at the puncture site. A skin discolouration or mild pain around the knee for a few days or weeks can occur. Avoid strenuous activity for the period you are advised and continue your exercise programme, since it supports the result. Complications are uncommon, and pooled data reported temporary skin discolouration in about 11% and haematoma in about 3% [1]. Rare problems include closure of a non-target artery or skin changes.
Cost and insurance
The cost depends on the procedure, the embolic material used and the day-care facility, and is explained after consultation and a review of your scans. Because these treatments are newer, insurance cover varies between policies and is checked before the procedure, and it is never assumed. Please ask the team for the specifics of your policy.
Frequently asked questions
- Does genicular artery embolization cure knee osteoarthritis?
- No. It does not regrow cartilage. It aims to reduce pain by closing the small arteries that feed an inflamed joint lining [1].
- Does GAE work better than a placebo?
- Sham-controlled trials are small and short, and some showed a clear early benefit while others showed no clear difference in some scores. Larger trials are needed [2].
- Can GAE help me avoid knee replacement?
- In some people with mild to moderate disease, it may reduce pain enough to postpone surgery, but it is not a substitute for replacement in advanced disease.
- How long does it take to see an effect?
- In pooled studies, improvement was seen by 1 month and maintained at 12 months in uncontrolled studies [1]. Individual results vary.
- Is the procedure safe?
- It is generally well tolerated, with temporary skin discolouration and bruising the commonest effects. Rare serious problems are possible, and your doctor will explain them [1].
References
- Amin AT, Safar IEM, Trujillo RB, et al. Outcome and safety of genicular artery embolization for knee osteoarthritis: a systematic review and meta-analysis. Cardiovasc Intervent Radiol. 2026;49:1682-1697. Read the source
- Milhem F, Takhman M, Elgendy MS, et al. Genicular artery embolization for knee osteoarthritis: a systematic review of sham-controlled randomized trials. J Orthop. 2025;67:361-368. Read the source
Want to discuss your options?
Speak with the Clinic Seven team.