Waterproof Casting for Broken Bones

The Ins and Outs of Having and Caring for a Cast after Injury

by Laura Carter - Practitioner of Hand Therapy

Casts come in all shapes & sizes, depending on the injury.  Click here to view some different casts!

Casts come in all shapes & sizes, depending on the injury. Click here to view some different casts!

What is a cast?

A cast, which keeps a broken bone (fracture)  from moving while it heals, is essentially a big bandage that has two layers. The  soft inner layer rests against the skin and provides padding for the cast. The harder, outer layer provides stability to the arm and prevents the fracture from moving.

What types of casts are there?

There are 2 main types of casts commonly used for treating bone fractures. These include:

  • Plaster of Paris, and

  • Fibreglass casts

Each type of cast has different advantages and both are used for different reasons. Plaster casts can be good to apply immediately post a nasty fracture as they allow for swelling, but are generally much heavier. Fibreglass casts are much lighter, easy to apply and x-ray more easily. They are also typically stronger than plaster casts.

Can all casts get wet?!

Unfortunately, no.  If Plaster of Paris gets wet,  it will start to disintegrate and then won’t do it’s job. Fibreglass is waterproof, but often hospitals and medical practices put this over a non waterproof inner layer. If this inner layer gets wet, then the skin can break down beneath the cast.  Luckily, at AHHT we use a special waterproof liner that doesn’t damage the skin when it gets wet! This means you can take a shower or have a swim without worrying!

Do fibreglass casts come in different colours?

They sure do! We have a range of colours and patterns to pick from when applying your fibreglass cast. Purple and blue are always crowd favourites, but if you ask our therapy dog, Daisy, she’ll say the paw print pattern is the way to go!

How are fibreglass casts applied?

The casting process is fast and easy - the most painful part is having the broken bone in the first place! We start by applying a waterproof underlay directly on the skin and wrapping it around the area needing to be kept still. We then soak the fibreglass cast material in water and get to work wrapping this over the top of the underlay.

Once this is all done, the cast can take a few minutes to dry. During the drying process, the material sets and hardens.  Soon you have a strong and sturdy cast to protect the broken bone.

Can I/my child draw on their cast?

Of course you can! This is what makes getting a broken bone at least a little more bearable for kids.  Permanent marker works best as this tends not to smudge.

How long will the cast stay on for?

This all depends on the type and nature of the fracture. Fractures in children are usually quicker to heal and will require less time immobilised. We will tell you how long your child’s fracture should take to heal before we put their cast on.


What if my child has an itch in the cast?

Try blowing some air in the cast with a hair dryer — be sure to use the cool setting, though. You should never pour baby powder or oils in the cast to try to relieve itching or try to reach the itch with long, pointed object such as a pencil or ruler — these could scratch or irritate your child’s skin and can lead to an infection.

How are casts taken off?

When it comes time to remove your child’s fibreglass cast, we have a special tool that cuts the fibreglass without any pain or without hurting the skin. It can be a little noisy and this can make it a daunting for some kids. In actual fact, it can be quite ticklish to remove a cast!  Rest assured we will always provide your child with laughter and reassurance prior to the removal of their cast. When it is time to take the cast off, we will deal with it all.

What happens when the cast is removed?

Remember, your child’s limb has been immobile for a while. Sometimes bones and muscles can be weak or stiff and take a little while to warm up again. While children’s bones are usually quite resilient, we may recommend some hand therapy for your child to help get them back firing at 110%!

If you would like a thorough, personalised assessment and treatment plan let us know and we will be happy to help!