Snapped plate on broken arm. Coloured X-ray of a snapped metal plate (black, lower centre) that was holding together a broken arm bone. The original bone fracture is under the plate, on the humerus (upper arm bone) near the elbow (lower centre). The plate was screwed into the humerus to immobilise it, allowing the bone to regrow in the correct position. A new metal plate will have to be surgically fitted.