Guide To Understanding Cast Care

There are four different types of casts your health care practitioner may apply:

• Plaster
• Synthetic fiberglass
• Synthetic non-fiberglass material
• Waterproof Casts

You will see these types all in rolls and once applied to your injury, the material hardens quite quickly to form the cast. All four types of casts keep broken bones and surrounding tissue rigidly immobile. Synthetic casts also have the property of enabling X–rays to be taken if needed, so that the physician can see how well the healing process is taking place. Although all four types provide similar medical benefits, there are advantages and disadvantages to each type. You will be caring for your cast, so you should review the differences as follows:

1. Plaster cast

This cast consists of open−weave cotton rolls or strips impregnated with dry calcium sulfate (a chalky white powder made from gypsum crystals.)

Advantages
• It’s easy to mold.
• It rarely causes skin irritations or an allergic reaction.
• Plaster cast material is inexpensive.

Disadvantages
• It’s messy to apply.
• It’s heavy and bulky, which can cause problems for children and the elderly.
• It’s easily weakened by moisture.
• It dries more slowly than the other two types of casts.
• Not radiolucent—the cast has to be removed for X-rays to be taken and then reapplied.

2. Synthetic Fiberglass casts

This cast is formed from open–weave fiberglass tape impregnated with a chemical substance called polyurethane resin.

Advantages
• It is both lightweight and durable.
• It is porous, therefore it allows the skin to breathe.
• Resists weakening from moisture.
• After initial application, this cast dries quickly, within 4 to 5 minutes: it can bear body weight 20 minutes after its application.
• Less chance of a breakdown.
• Radiolucent—X-rays can be taken without removing the cast.

Disadvantages
• If not molded properly, edges can be abrasive.
• There are different molding techniques compared to plaster.
• Possibly not covered by health care plan.

3. Synthetic non-fiber casts

This cast consists of polyester and cotton open-weave tape impregnated with water-activated polyurethane.

Advantages
This cast dries in 7 minutes and it can bear body weight after 20 minutes.
• It is both lightweight and durable.
• It is porous, thereby reducing itching.
• It conforms well to body contours.
• It is radiolucent—allowing X-rays to be taken without removing the cast.

Disadvantages
• There are different molding techniques compared to plaster.
• Possibly not covered by health care plan.

Find this information useful? Get the Dr. Guide Book on Cast Care for a more comprehensive guide on the best way to manage and care for your cast.