An orthopedic cast, body cast or surgical cast, is a shell, frequently made from plaster

Plaster

Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...

, encasing a limb

Limb (anatomy)

A limb is a jointed, or prehensile , appendage of the human or other animal body....

 (or, in some cases, large portions of the body) to hold a broken bone

Bone

Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

 (or bones) in place until healing

Bone healing

Bone healing, or fracture healing, is a proliferative physiological process in which the body facilitates the repair of a bone fracture....

 is confirmed. It is similar in function to a splint

Splint (medicine)

A splint is a device used for support or immobilization of limbs or of the spine.It can be used:* By the emergency medical services or by volunteer first responders, to immobilize a fractured limb before the transportation; it is then a temporary immobilization;* By allied health professionals such...

.

Plaster bandages consist of a cotton bandage that has been impregnated with plaster of paris, which hardens after it has been made wet.