Medical casts are used especially for the treatment of fractures. The broken bones are fixed from outside by a cast. This is called a conservative treatment in contrast to a fixing of the bones inside by artificial parts during an operation.
Beside the treatment of fractures, casts are used to relieve pain for example after strains or contusions, after surgery or during inflammations. In the case of infections caused by bacteria a cast supports the defence reaction of the immune system. Furthermore, casts are important after surgical restoration of ligaments and tendons.