HealthInfo Waitaha Canterbury
Care of your cast
Te manaaki i tō tākai-ukutea
Your cast protects your injured bones while you heal. While it may take a few days to get used to your cast, it is important to keep it in good condition so it can keep protecting you. That will help you heal as well and as quickly as possible.
Drying the cast
Different types of cast will dry and reach their maximum strength in different amounts of time.
- A plaster of Paris arm cast takes 24 hours to dry.
- A plaster of Paris leg cast takes 48 hours to dry.
- A fibreglass cast takes 20 minutes to dry.
Do not dry the cast with a heater or hair dryer as you will burn your skin under the cast.
Do not rest a plaster of Paris cast on hard surfaces – this can cause a dent in the cast which can lead to skin problems.
Cast care
Do not walk on your leg cast unless you have been fitted with a cast shoe and your doctor says you can.
Do not chip, crush, cut or break your cast.
Do not get the cast wet (unless it is a waterproof cast). Moisture will weaken or destroy the cast and can damage your skin under the cast. When you have a bath or shower, wrap a towel around your plaster and cover it with a well-sealed plastic bag. You may be able to buy a waterproof liner.
Self-care
The cast will help to reduce the pain of your injury, but you may still need pain relief, which your doctor will prescribe. Follow the instructions you have been given.
There may be swelling for the first few days so keep your limb and cast raised above the level of your heart. If your arm or hand is in a cast, do the exercises in Care of your arm & hand while in a wrist cast. If your leg or ankle is in a cast, move your toes.
Sometimes you can get itchy under the cast. Do not insert anything under the plaster (for example, a back scratcher, knitting needle, pen or powder) to relieve the itching. Doing so can damage your skin and cause an infection. And pushing the padding further down into the cast can cause it to bunch up, resulting in pressure on your skin.
To help relieve the itching you can:
- use a hair dryer set on cool to blow cool air down the inside of the cast
- put a covered ice pack on your skin near the cast (being careful not to get a plaster cast wet).
Sometimes the cast can rub your skin and make it sore. If the pressure on the skin is not relieved, a wound called a pressure injury can develop under the plaster cast. See Pressure injuries for information about how to prevent or treat a pressure injury.
Remember to sponge clean the fingers or toes of the limb in the cast.
It is best not to play sport while you are in an arm or leg cast.
Crutches
If your leg is in a cast, bring your crutches with you to every follow-up appointment in case your plaster is changed or removed. You may need them when you first come out of a cast until your ankle loosens up and you become confident walking again without the protection of the cast.
Return your crutches to where you got them from when you no longer need them.
Getting help
Contact the place that fitted your cast as soon as possible if you have any concerns or experience any of the following problems:
- your plaster feels too tight, too loose or is rubbing
- your plaster is broken, cracked or soft
- your plaster gets wet or damp
- you drop something inside your cast
- you have prolonged numbness or tingling, like pins and needles or you cannot move your fingers or toes
- your fingers or toes go blue or white or they feel cold
- you have increased swelling or pain in the affected limb
- you have a burning sensation under the cast
- you have symptoms of infection such as a fever, unusual pain or a foul smell from the cast.
If your cast was fitted at Christchurch Hospital, contact the Orthopaedic Outpatients Department on (03) 364-0800 (Monday to Friday before 5.30 pm) or Orthopaedic Acute Care, Emergency Department on 021-628-224 after 5.30 pm and on weekends or public holidays.
If your cast was fitted at Burwood Hospital, contact the Burwood Orthopaedic Outpatients Department on (03) 383-6840 (Monday to Friday before 4.30 pm) or Orthopaedic Acute Care, Emergency Department on 021-628-224 after 4.30 pm and on weekends or public holidays.
If your cast was fitted elsewhere, contact them with any concerns or problems.
On the next page: Deep vein thrombosis and plaster casts
Written by Orthopaedic Outpatients and Physiotherapy Departments, Christchurch Hospital. Adapted by HealthInfo clinical advisers. Last reviewed February 2022.
Sources
Review key: HILWI-174362
