Your Child's Leg Plaster

Your Child's Leg Plaster

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


Key points about your child's leg plaster

  • 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 does a plaster or splint do?

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.

See the KidsHealth page on fractures for more information

How long will it take for my child's leg plaster to dry?

A leg plaster cast takes 24 to 48 hours to dry completely.

In the first hour or two, while your child is waiting for their plaster to harden, it's a good idea to rest their leg on something soft, such as a pillow. Hard surfaces may damage your child's plaster.

What can I do to help while my child has a leg 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

  • keep the plaster raised on pillows especially for the first 24 to 48 hours, to prevent swelling 
  • rest the plaster on something soft until dry - use a pillow to rest your child's leg on
  • make sure your child moves their toes often 
  • check the colour of your child's toes - they should be pink, and if you squeeze the toenails and then let go, they should quickly return to pink
  • watch for swelling - when your child hangs their leg down there will be some swelling - they should rest their leg on a chair for a couple of hours - compare it to the other leg - are they the same?
  • keep the cast clean and dry
  • remember to bring your child's crutches to the fracture clinic, even if your child is not using them at the time
  • check around the plaster for any smells - plasters do have a slight smell but have it checked if you are worried
  • ring the emergency department or contact your doctor 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 to 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, down the plaster - it may damage your child's skin
  • don't let your child walk on their plaster unless the doctor says they can
  • don't let your child walk on their plaster without using crutches
  • 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

How can my child bathe with their leg plaster?

If your child's plaster is a below knee plaster:

  • wrap a towel around the plaster
  • place the leg in a plastic bag large enough to cover it completely
  • secure the end with tape (such as sellotape)
  • there are also some special coverings for plasters - ask your doctor about these
  • either get your child to put their foot on the edge of the bath or on a stool just outside the shower

If your child's plaster is an above knee plaster:

  • just get your child to have a good wash all over with a cloth - do not have a bath or shower

When should I seek help for my child's plaster?

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

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

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

Will my child need follow-up appointments for their plaster?

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

Your child will usually need a fracture clinic appointment 5 to 14 days after leaving hospital. At this appointment, your child may 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 a 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.

How will my child's leg plaster be 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.

When can my child return to physical activity after their leg plaster comes off?

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 guide you about when your child should go back to various activities. 

Please remember to return your child's crutches.


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 leg plaster.


Starship Foundation and the Paediatric Society of New Zealand acknowledge the cooperation of Starship Children's Health, Auckland District Health Board.  This information was produced in collaboration with the Starship Orthopaedic Service.

This page last reviewed 14 June 2021.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it