Limb is another name for the arms or legs. Limb differences are when an arm or leg is not shaped in the usual way. For example, a child’s legs may be curved or one might be shorter than the other. Or, a bone in the arm may be short or missing. A limb difference that a child is born with is called congenital. A limb difference that happens after birth is called acquired. To amputate something is to cut it off. An operation where a doctor has to cut off a body part because of a severe injury or infection is called an amputation. Some body parts that might get amputated include a finger, foot, or leg.