Your child's arm plaster

Your child's arm plaster

Plasters (also called casts or plaster casts) and splints allow the broken bone time to rest and heal.

Key points to remember

  • children with fractures have plasters and splints to prevent the bones from moving and to allow the fracture time to rest and heal
  • it is very important that your child returns for their follow-up appointments

What is the purpose of a plaster or splint?

Children with fractures have plasters (also called casts or plaster casts) and splints to prevent the bones from moving. This allows the fracture (broken bone) time to rest and heal.

Waiting for the plaster to dry

Photo of young girl with an plaster cast on her arm

An arm plaster cast takes 24 to 48 hours to dry.

While your child is waiting for their plaster to dry, it's a good idea to rest their arm on something soft, such as a pillow or in a sling. Hard surfaces may damage your child's plaster.

The following DOs and DON'Ts are some guidelines to help you care for your child while they have their plaster on.

Some DOs

  • rest the plaster on something soft until dry - use a pillow when sitting or lying down or support the arm in a sling, especially for the first 24-48 hours, to prevent swelling
  • make sure your child moves their fingers often 
  • encourage your child to gently move the joint above the plaster (their elbow or shoulder) to avoid stiffness
  • check the colour of your child's fingers - they should be pink, and if you squeeze the fingernails and then let go, they should quickly return to pink
  • watch for swelling - compare it to the other hand - are they about the same size?
  • keep the cast clean and dry
  • check around the plaster for any smells - plasters do have a slight smell but should not be unpleasant
  • ring the emergency department or contact your medical team if you are worried

Some DON'Ts

  • don't use hairdryers or other drying equipment to dry the plaster - they may burn your child or crack the plaster - let the plaster dry naturally
  • don't press on the plaster for 24-48 hours until dry - pressing on it will dent it
  • don't write on the plaster until it is dry
  • don't get it wet
  • don't poke anything, such as knitting needles or other sharp objects, down the plaster - they may damage your child's skin and lead to infection
  • don't put lotions, creams or powder inside the plaster or around the edges
  • don't cut or remove the plaster - ring the hospital if it is uncomfortable
  • don't knock or bump the plaster
  • don't keep the sling on longer than instructed

What about bathing?

  • wrap a towel around the plaster
  • place the arm in a plastic bag large enough to cover it completely
  • secure the end with tape (such as sellotape)
  • don't put the arm in the bath - rest it on the edge of the bath
  • don't aim the shower head at the affected limb

When should I seek help?

After going home, you should take your child back to the emergency department or contact your medical team urgently if your child:

  • complains of pain that is getting worse even with pain relief and raising the fractured arm 
  • has a hand that is going cold, pale or blue or becoming more swollen
  • complains of fuzziness, numbness, pins and needles or tingling in the fractured arm or in their fingers
  • cannot move their fingers

If your child's plaster becomes cracked, broken, soft or loose, or it is rubbing, contact your medical team. 

Follow-up appointments

It is very important that your child goes to all their follow-up appointments.

Your child will usually have a fracture clinic appointment 5 to 14 days after leaving hospital. At this appointment, your child will have another x-ray to make sure the bone is healing and is in place. Your child will usually need to go to several more appointments at fracture clinic to make sure the break is healing.

Ask your nurse or doctor for instructions for your child's follow-up before you leave hospital.

Saying goodbye to the plaster

Photo of young girl having her arm plaster cast removed

When your child's injury has healed, their plaster will be removed with specially designed plaster shears or saw that will cut through the plaster but cannot cut the skin.

Plaster removal is a fast and painless process.

Back to normal

Your doctor will tell you how much physical activity your child can do while their injury heals. After the plaster comes off, your doctor will probably let your child gradually go back to regular activities, as long as they do not cause pain. 

Orthopaedic Services. Canterbury District Health Board. 2005. Care of your cast: Patient information.

Starship Children’s Health. 2005. Plaster care: Patient and family information.

Waikato District Health Board. You and your arm plaster.

Starship Foundation and the Paediatric Society of New Zealand acknowledge the cooperation of Starship Children's Health, Auckland District Health Board. The content on this page has been produced in collaboration with the Starship Orthopaedic Service.

This page last reviewed 22 November 2017.
Email us your feedback


On this page