An air cast is a medical device that encases a healing body part in a cushioned casing, reducing pain and promoting healing. Typically, it consists of two basic components, an air-filled splint that is surrounded by a hardened exterior shell. Unlike traditional hard plaster or fiberglass casts, air casts may be removed for washing, and trade off total rigidity for comfort and convenience.
Air-filled casts are an option available for strain, sprain, and bone fracture recovery. They have changed little since since their inception, and are still used almost exclusively used for hand, wrist, foot, and lower leg injuries. Their inner, air-filled bladders may be inflated, by mouth or a pump, to the required level of cushioning, while the hard plastic exterior frame is tightened and typically held in place with metal or plastic Velcro® fasteners.
Like a hard cast, an air cast attempts to promote healing by reducing the shock of potential impacts, while keeping bones and joints in a specific position so they can heal properly. While not customized on a per-patient basis like a hard cast, these come in different sizes so a comfortable fit should be attainable in almost all situations. Air boots are manufactured in shoe sizes, making a correct fit that much easier to determine. Wrist casts are generally produced in small, medium, and large specifications.
In addition to added comfort, using an air cast can help avoid some of the negative side effects that come with a hard cast. Since they are not removable, extended wear of a hard cast often results in mild to moderate dermatological problems. Beyond the drying and scaling of unwashed skin, dermatitis, ulcers, and rashes are not uncommon in patients wearing a hard cast. Fiberglass and plaster casts are also quite heavy and physically cumbersome, whereas air casts, being largely hollow, save for the rigid outer shell, are much lighter and easier to move around in.
The typical prescription for wearing an air cast varies depending on the body part and the severity of the injury. Mild to moderate sprains, and even some minor bone fractures, may only need days or weeks of such restriction and protection. In more severe situations, such as when a weight-bearing bone — like the tibia — is broken, a hard cast is still necessary for an initial period. After this, an air cast can be used for the remainder of the healing process. Depending on the state of healing, patients may walk, and sometimes are even cleared to drive, while wearing an air cast.