Narrowed leg arteries. Coloured angiogram of the legs of a 52-year-old patient. The femur (thigh bone) runs down from the top and the tibia (shin bone) runs from the knee down. The patient's left leg (right) has been amputated below the knee. There are irregular narrowings (stenosis) in the patient's right leg arteries seen at left, which are usually caused by atheroma (fatty deposits on the inner wall). Treatment is often a surgical procedure known as an angioplasty, where a stent (wire mesh tube) is inserted into the narrowed region and expanded, which reopens the artery to ensure normal blood flow.