Transarterial Embolization Versus Sham Procedure in Adults With Treatment-Resistant Inflammatory Arthritis of a Single Large Joint

The goal of this clinical trial is to learn whether transarterial embolization (TAE) can relieve pain and improve well-being in adults with inflammatory arthritis that remains active in only one large joint (wrist, elbow, shoulder, ankle, knee or hip) despite anti-inflammatory drugs, joint injections and physiotherapy. The researchers expect that more people treated with TAE than with a sham (simulated) procedure will reach low pain and a good overall assessment of their health one month after the procedure. The main questions it aims to answer are: * Does TAE increase the proportion of participants who reach low pain and a good overall assessment of their health one month after the procedure, compared with a sham procedure? * Is TAE safe, and does it improve quality of life and reduce the need for medication over three months? TAE is a minimally invasive procedure. A thin catheter is guided through an artery in the groin or wrist to the small vessels that feed the inflamed lining of the joint, and tiny resorbable gelatin particles are injected to temporarily reduce the abnormal blood flow that sustains inflammation and pain. Researchers will compare TAE with a sham procedure to find out whether any benefit comes from the embolization itself rather than from the experience of undergoing a procedure. Participants will: * Be randomly assigned (like flipping a coin) to TAE or to the sham procedure. Neither the participants nor the doctor who evaluates them will know which procedure they received. * Undergo the procedure in the angiography room with light sedation. The sham procedure takes place in the same room, with the same team, sedation and duration, but without any puncture of the artery, contrast medium or X-rays. * Attend visits before the procedure and 1 week, 1 month and 3 months after it, answer questionnaires on pain and quality of life, and keep a diary of symptoms and medicines for 7 days after the procedure. After 3 months, participants who received the sham procedure will be offered TAE.