If your child has had a fracture of a bone in their arm, they will have a cast to support and protect the bone while the fracture heals. The cast may be:
- a full cast
- a partial cast held in place with bandages – this is called a backslab.
It is important to care for your child’s arm and cast correctly after you leave hospital.
This fact sheet provides information on what to do once your child has been treated in hospital for an arm fracture. If you think your child has a fracture and you are looking for first aid advice, see our fact sheet Fractures (broken bones).
Care at home
Fractures are painful. Although immobilising the arm with a cast will help to reduce the pain, additional pain relief (e.g. paracetamol) is often needed. Give the pain relief medication regularly for the first few days, following the directions on the
packet, or as directed by the doctor.
Elevate the arm
During the first one to two days it is important for your child to rest and elevate their arm above heart level to minimise swelling.
Raise your child's arm on pillows when they are sitting or lying down, and have them use a sling when they are moving around.
Make sure the fingers are above the elbow when the arm is in the sling.
Encourage your child to bend and straighten their fingers regularly, and make sure you check their fingers for movement, feeling and circulation.
Skin care
Itching under the cast is common. Make sure your child avoids scratching inside the cast as this may damage the skin and cause infection. Do not let them push any object inside the cast (e.g. don’t allow them to use a ruler to scratch inside the cast).
Never cut or attempt to modify the cast or bandage. While it may be tempting to remove the backslab for brief periods, it is recommended that you leave it in place.
You can help relieve itch by using a hair-dryer to blow cold air into the cast (do not use warm or hot air as this can burn the skin or warp the cast). Antihistamines may be useful for reducing the itch. Talk to your local pharmacist about a suitable
antihistamine medication to use.
Cast care
It is important to keep plaster clean and dry. For showering or bathing, seal the cast in a plastic bag with tape or a rubber band. Never allow your child to immerse the cast in water, even if it is in a plastic bag. For more information, see our fact
sheet
Plaster cast care.
Even though fibreglass casts are waterproof, you need to make sure the padding underneath stays dry. If your child has a fibreglass cast, treat it as though it is a plaster cast and avoid getting it wet.
When to see a doctor
Severe pain and swelling, change in the colour of the fingers (white or blue), numbness or pins and needles, or an inability to move the fingers are signs that the arm has not been elevated for long enough or that your child’s cast may be too tight. If
any of these signs occur, rest and elevate the arm above heart level for 30 minutes.
After elevating the arm for 30 minutes, take your child to the hospital emergency department immediately if:
- the fingers remain very swollen
- the fingers remain white or blue
- your child complains of pins and needles or numbness in the fingers
- your child is not able to move their fingers, or complains of pain when you move them
- your child has severe pain that is not relieved by the recommended medication at the recommended dose.
Take your child to your GP or local hospital if:
- the cast is cracked, soft, loose or tight, or has rough edges that hurt
- you are worried that an object has been pushed inside the cast
- there is a bad smell or ooze coming from the cast
- your child is in increasing pain.
Follow-up
Your child may need to have an X-ray and review one to two weeks after they injure their arm. The cast will not need to be removed for the X-ray.
The doctor will tell you when your child should have their follow-up appointment. You may be advised to arrange follow up with your local hospital or GP.
The cast will be able to be removed once the fracture is healed.
After the cast is removed
After the cast is removed, the skin may be dry and itchy. Bathe the skin with warm water and soap, and apply a plain, non-perfumed moisturiser.
After a fractured arm, children normally regain strength by using the arm for gentle activity and play. Physiotherapy is usually not needed.
Your doctor will give specific advice regarding return to sport, which in most cases may be resumed four to six weeks after the cast is removed. If your child required surgery, full contact sports should be avoided for two to three months, but you should
discuss this with your child’s doctor.
Key points to remember
- It is important to care for your child’s arm and cast correctly after you leave hospital.
- Your child should elevate their arm above heart level for the first two days after the injury.
- Always keep plaster casts clean and dry.
- Ensure your child avoids scratching inside the cast and do not let them push any object inside the cast.
- Seek urgent medical attention if after elevating the arm for 30 minutes your child still shows signs that the cast is too tight.
For more information
Common questions our doctors are asked
What happens if the cast gets wet?
If a plaster cast, or the padding underneath a cast, becomes wet, you should see your GP or local hospital within 24 hours. The cast may need to be replaced to protect the skin underneath.
Call an ambulance (000) immediately in an emergency.
Developed by The Royal Children's Hospital Orthopaedics department. We acknowledge the input of RCH consumers and carers.
Reviewed November 2018.
This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.