Looking after your plaster cast

A cast is a hard shell made of plaster of Paris, fibreglass or polyester which goes around your arm or leg (or another part of your body). This page from Great Ormond Street Hospital explains about your cast, how to look after it and how we remove it.A cast will stabilise and hold the bones and joints in place following a break or surgery until healed. A cast is also applied to improve the position of joints and muscles.
There are usually several layers to a cast:

  1. A stretchy stocking or dressing next to your skin.
  2. Padding which is a bit like cotton wool but not as fluffy.
  3. The outer layer can either be plaster of Paris, fibreglass or polyester – ask us if we have your favourite colour.

Did you know?

Casts date back to the Ancient Egyptians - they used flour, eggs and animal fat to make a hardened cast – that must have been smelly! A more modern cast was developed by Ambroise Pare in the 16th century - this was made of wax, cloth and cardboard. Plaster casts, made from gypsum plaster (known as plaster of Paris) were first used in the 19th century in hospitals. In the last 30 to 40 years new materials have been developed, such as fibreglass, polyester, and rubber - these are lighter, stronger, and also come in different colours!

Different types of cast

The type of cast will depend on your surgery or injury.

What to look out for

If you notice any of these, call us immediately on the numbers at the end of this page:

  • your fingers or toes feel cold and look white or blue – which does not improve when you wriggle them
  • the cast feels too tight and becomes painful
  • your fingers or toes swell up and do not improve when you raise your arm or leg above your heart
  • you have pins and needles or numbness
  • there is any oozing or wetness coming through the cast as this may indicate a wound infection or pressure ulcer
  • there is an unexplained smell
  • the cast is rubbing or digging into your skin, or you can feel a burning sensation, as this may indicate a pressure ulcer
  • the cast is becoming loose and slipping
  • the toes start to disappear inside the cast
  • the cast cracks, breaks, becomes soft and crumbles

Dos and don’ts


  • keep your cast dry
  • elevate your arm or leg higher than your heart when it feels sore – this will help with swelling and pain
  • remember to use and move the parts of your body that are not in the cast.
  • always use a cast shoe if you are allowed to put weight through the cast. this will protect the cast and prevent you slipping.

Do not:

  • get your cast wet
  • use a hair dryer to dry it if it does get splashed
  • put anything inside the cast
  • use any talcum powder or creams inside the cast
  • trim the cast yourself

Removing the cast

We will arrange an appointment for your cast to be removed. We use three different tools to take it off:

  • an oscillating saw
  • cast spreader
  • bandage scissors

The process

  1. The oscillating saw works with a side-to-side movement and not in a circular motion so it feels more like a vibration while grinding through the outer part of your cast. It is very noisy so you might want to wear headphones.
  2. We use bandage scissors to cut through the padding and stretchy stocking – the scissors have blunt ends so they won’t cut your skin.
  3. We use a cast spreader to widen the opening in the cast made by the oscillating saw.
  4. We will show you the tools before we start to remove your cast – you may be able to help remove the cast.

Any questions?

Just ask us if you have any questions or concerns – we are here to help! Monday to Friday from 9am to 5pm – call the Orthopaedic Practitioner 07795646101. Or e-mail us on- plasterteam.orthopaedics@gosh.nhs.uk

You can also call the Orthopaedic Clinical Nurse Specialists 020 7813 8132 or 020 7762 7904.

Out of hours, call Sky Ward on 020 7829 8807 or 020 7829 8806.

If you are very concerned, take your child to the nearest Accident and Emergency (A&E) department.

Compiled by:
The Orthopaedic Practitioner in collaboration with the Child and Family Information Group
Last review date:
October 2018