Pinned elbow fracture. X-ray showing metal pins and plates (bright white) immobilising a fracture at the elbow joint. The elbow joint is where the humerus (upper-arm bone, upper centre) meets the two smaller bones of the forearm, the radius and ulna (lower centre). The metal plates, inserted between the joint and beside the humerus at upper left, have been screwed in place with pins. Metal staples (small loops) have been used to suture the long surgical incision made to insert the plates. Most fractures are due to sudden injury, in this case from a fall. Broken bones must be aligned and immobilised to allow the injury to heal properly.