Repairing a broken leg. A doctor examining a full leg cast on a patient. The cast is made from 'Deltalite'. This is a type of glass fibre commonly used for large casts due to its lightness compared to a traditional plaster cast. A full leg cast such as this is used in the treatment of fractures of the tibia and/or fibula in the lower leg. X-ray images of the patient's leg are seen on the lightbox in the background.