Leg ulcer. Coloured X-ray of gross bone erosion in the lower leg due to long-standing ulceration. The large bone on the left is the tibia. The lower portion of this has disintegrated where disease has spread into the bone. The thinner bone in the middle is the fibula. Leg ulcers are open sores that fail to heal or heal very slowly. They are particularly common in the elderly and are usually caused by impaired blood supply in the leg (due to varicose veins, for example). The main treatment for leg ulcers is preventive. This patient's ulcer has caused unusually extensive damage and was thought to have become malignant.