Percutaneous Intradiscal Hydrogel Implantation Versus Sham Control for Chronic Discogenic Low Back Pain: A Randomized Controlled Double-Blind Trial. - Koetsier E; Engel H; Maino P; Cianfoni A; Scascighini L; Scarone P; Kuhlen DE; Kallewaard JW; van Kuijk SMJ (Pain physician, 2026)