Although some broken bones do not need immobilization, most have to be returned to their correct position (reduction) and held in place so that the fractured ends are able to heal and join together properly. The method of immobilization chosen for a particular fracture depends on the type, location, and severity of the fracture.
The simplest form of immobilization is a cast, a rigid casing that is applied to a limb and left in position for several weeks to hold the fractured bone ends together and prevent movement. Casts are usually made from plaster, plastic, or resin. They are removed using an electric saw, which cuts through the cast.
Bones that are severely fractured may need metal plates, screws, nails, wires, or rods to be inserted surgically to hold the broken bone ends together. A cast may not be required. Internal fixation is often used for fractures at the ends of bones.
A specialized technique known as external fixation is often required to repair bones that are fractured in several places. In this technique, pins are inserted through the skin into the bone fragments. The pins are held in place by an external metal frame, which allows the affected limb to be used normally within a few days. The frame and pins are removed when the bone has healed.
Traction is used for the temporary immobilization of a fracture until further treatment of the injury can be carried out. The technique is often used for fractures in the shaft of the femur (thighbone). Weights are used to maintain alignment because the powerful muscles in the thigh would normally pull on the ends of the broken bone, forcing them out of alignment.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.