Cast

A Cast is a sedative bandage that is used as an alternative to normal plaster bandages. He is also called Cast Association or Plastic plaster designated.

What is a cast?

In contrast to the "normal" bandage, a cast bandage is not made of plaster but of plastic.

Like plaster casts, casts are also used to treat broken bones.

In some cases, plaster casts are combined with cast casts.

Shapes, types & types

A cast bandage usually consists of a stretchable carrier fabric. This carrier fabric is made of fiberglass or polyester. The stretchable carrier fabric is coated with a plastic resin for stability. This plastic resin is activated and hardens when it is immersed in water. The hardening process varies depending on the water temperature and the immersion time. The colder the water, the less time there is to model.

In another variant, the cast bandage can also be applied dry. To do this, the elastic base material is wrapped around the affected extremity. The plastic resin coating is then activated by misting with water. Usually, casts are cured within half an hour. A fully hardened cast bandage is also fully resilient.

In conservative bone fracture treatment, the patient is usually first put on a conventional plaster cast. These conventional plaster casts enable longitudinal splitting immediately after hardening. This enables the affected extremity to swell further. This would not be possible with the circular cast association. A cast bandage can only be applied when the extremity has swollen again. Therefore they are sometimes also referred to as Secondary associations.

Structure & functionality

The cast bandage is applied to the affected extremity. It then serves the mechanical fixation of the broken bone. As a rule, cast bandages are mainly used for uncomplicated and stable bone fractures. Before applying the bandage, the fracture must first be brought back into its anatomical position. This process is also known as repositioning.

The bandage is then used to stabilize and immobilize the affected extremity. With the help of the cast, the body should be given the opportunity for tissue healing and rehabilitation. The bandage restricts movements that are not beneficial for healing. Only in this way is new bone formation possible.

Cast and plaster casts are often used on children. Typical fractures that are treated with casts are fractures of the forearm, the radius, the scaphoid bone of the hand, lower leg fractures in children, uncomplicated outer ankle fractures and metatarsal and tarsal fractures. For fractures that are treated surgically, casts are usually used for temporary immobilization before the operation. They can also be used postoperatively.

Medical & health benefits

Casts offer several advantages over plaster casts. For example, they are much lighter than plaster bandages. Bandages in particular, which patients have to wear for a long time, can be stressful due to their heavy weight and delay healing.

Despite the low weight, the casts have a higher strength. They also harden faster than plaster casts. In this way, full load capacity can be achieved very early on. Plaster casts are sensitive to water. Casts are insensitive to water. There is also a special upholstery and underlay material that enables showering or bathing with the cast bandage. The cast bandages are available in many colors and even with a motif print. This promotes acceptance, especially with children.

But casting associations do not only have advantages. They are significantly more expensive than plaster of paris. The higher costs are usually too high for associations that have to be renewed frequently. Casts are also expensive for bandages that are only worn for a few days. The cast bandages are also not very permeable to water vapor or air. Patients therefore sweat more under this bandage.

Due to the rough surface of the bandages, there is also the risk of clothing being damaged. The disposal of the cast bandages is also more problematic. There is also a suspicion that the cast bandages may contain allergenic substances.

In terms of medical effectiveness, there are no real differences between the two types of plaster. The complications of the cast bandages are the same as with plaster casts. Insufficient padding can lead to pressure sores.

If the casts are placed too tightly or the affected extremity swells afterwards, it can lead to a complete or partial disturbance of the blood circulation. If this circulatory disorder is not recognized, a Volkmann contracture could result. In a Volkmann contracture, the muscles of the forearm are shortened due to insufficient blood flow. Nerves can also be damaged by the insufficient blood flow. A so-called claw hand is typical of Volkmann's contracture.

The pressure of the upper edge of a lower leg cast on the fibula head can also cause pressure damage to nerves. Peroneal paralysis is typical. The long immobilization can also lead to muscle atrophy. Deep vein thrombosis is also a known risk from therapies associated with long immobilization. A feared consequence of deep vein thrombosis is life-threatening pulmonary embolism.