What is a plaster of paris

plaster cast

What is a plaster cast?

A plaster cast consists of a so-called underlay (usually made of a cotton material), padding, a hard layer of plaster and a cover. Plaster of paris is one of the conservative treatment methods for bone fractures, torn tendons and ligaments and for the correction of misalignments. With the help of the plaster cast, the doctor immobilizes the affected body parts - the body's own healing is supported in this way. Depending on the form of the association, a distinction is made between different types:

  • Closed or circular plaster of paris (round plaster of paris) - the plaster of paris surrounds the entire circumference of the extremity
  • Split plaster (split plaster) - a closed plaster of paris is cut lengthways after hardening
  • Plaster splint - the plaster cast only covers part of the limb
  • Plaster of paris corset (torso plaster) - the plaster of paris extends from the chest to the pelvis and stabilizes the spine

The classic plaster cast consists of lime plaster, but is now also being replaced by modern plastic plasters, which weigh less and harden faster. Both the doctor and appropriately trained nursing staff can put on a plaster cast.

When do you put a plaster cast?

Plaster of paris bandages are an aid in conservative treatment and are used for the following clinical pictures:

  • Uncomplicated broken bones (fractures) - the break point is not shifted, stable and there are no splinters
  • Strains
  • Torn tendons and ligaments
  • Inflammatory bone and joint processes
  • Curvature of the spine (scoliosis)
  • Clubfeet (so-called redression cast)

How do you put on a plaster cast?

Before the plaster cast is put on, the doctor checks the skin for infections or pressure points, cleans it and applies cream. Your doctor will also ask you if you have ever had an allergic reaction to a cast. Depending on the clinical picture, the affected part of the body is held at a certain angle when the plaster cast is put on.

First, a protective layer is placed directly on the skin. It consists of an underlay made of elastic cotton material and an overlying layer of upholstery wadding. Areas that have to withstand a lot of pressure can be padded with an additional layer of cotton wool. A layer of crepe paper compresses the underlay and cotton wool and prevents the plaster of paris from coming into contact with the skin.

Before putting them on, the plaster bandages are briefly dipped in cold water and squeezed out. Then the doctor wraps the arm or leg from far away from the body (distal) to close to the body (proximal) and without tension. He smooths out every plaster bandage after it has been put on so that the individual layers nestle against each other and against the extremity and no wrinkles arise. In addition, so-called longuettes can be integrated - multi-layer bandage strips that support like a splint and give the plaster cast additional stability. The ends of the joist and the upholstery are not wrapped, but turned over at the end and fixed with another plaster of paris bandage. This creates a padded edge. Overall, the plaster of paris cast can be reworked and corrected for about five to ten minutes.

If the cast is put on immediately after an injury or an operation, it is important to cut (split) the cast lengthways so that swelling does not damage it. The finish is a cover that protects the plaster cast from dirt.

If the cast has dried after about two days, the doctor will examine the extremity for skin color, temperature and swelling and ask about pain, numbness and mobility.

What are the risks of a plaster cast?

When properly applied, a plaster cast stabilizes the affected part of the body and prevents its mobility. As a result, the muscles can shrink, the muscle mass decreases (muscle atrophy) and the joints also become increasingly stiff. The pressure of the bandage slows the blood flow underneath and increases the risk of thrombosis - that is, blood clots can develop. By elevating the extremity and moving it regularly, you can prevent thrombosis.

If the cast was wrapped too tightly or if the pressure increases due to swelling, pressure damage can occur. Typical symptoms are pain, blue or white coloring of the skin or tingling, circulatory and sensory disorders and loss of movement. If a thrombosis or pressure damage is suspected, the bandage is removed immediately.

What do I have to consider after a plaster cast?

If you feel pain immediately after applying the plaster cast or later, if the extremity is throbbing, tingling or feeling numb, you should inform your doctor. Increasing restricted mobility or cold, blue or pale skin are also warning signals that you should inform your doctor about. Also, let your doctor show you where to feel your pulse.

If the plaster cast is no longer needed, the doctor cuts it open using a plaster burr. This special milling machine cannot cause any injuries due to its shaking movements. You may feel heat build up on your skin. The plaster of paris is spread with a plaster spreader and the individual layers are cut open with bandage scissors. Now the plaster cast carefully removed and the skin cleaned and creamed. The doctor will often check the healed fracture with an X-ray. He may prescribe physiotherapy exercises to restore full mobility to the affected part of the body.

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