Care of your synthetic cast

What is a synthetic cast?

A synthetic cast is a synthetic bandage that is put in water and then applied to your limb.

How long does it take to dry?

The cast will set in two to three minutes but takes about 20 to 45 minutes to dry completely.

DO NOT try to speed up the process by using a hairdryer or other appliance. During this time please take extra care to protect the cast, do not rest it on a hard surface or write on it until it is dry.

The cast is becoming too tight

If this happens you may notice:

  • Swelling of your fingers/toes
  • Numbness or pins and needles in your fingers/toes
  • Pain
  • White or blue discolouration of your fingers/toes and possible coldness

Remember—if the cast is hurting it needs attention!

The first thing to do is to raise the limb.

Arm cast

Rest the cast on a pillow/cushion so that your hand is higher than your elbow.

Leg cast

Rest the cast on a pillow/cushion so that your foot is higher than your hip. If symptoms do not improve after one or two hours then please return to us or your nearest A&E Department.

DO NOT attempt to remove the cast yourself.

Wherever possible DO rest your cast in this way to avoid swelling.

The cast is becoming too loose, cracked or soft

Under normal circumstances you should NOT be able to move the cast up, down or around your limb.

It should feel comfortable. It should NOT be cracked at any point. If you do notice any of these things, and your Fracture Clinic is unable to see you, please go to your nearest A&E Department.

Important precautions

  • Never use anything to scratch under the cast. The slightest scratch could develop into a serious infection.
  • Never trim or cut down the length of the plaster yourself, or attempt to tuck in extra padding.

Can I get the cast wet?

NO! You should never allow your cast to become wet.

Can I walk on my cast?

Only if the doctor says you can and the cast is dry.

Can I drive?

NO! You must not drive wearing any type of cast. If you do your insurance will be invalid.

How long must I wear the cast?

This entirely depends on the type of injury you have. Your doctor will advise on you how long you will need to wear the cast.

Should I exercise?

Yes, you should exercise in order to avoid stiffness in unaffected joints. We recommend that you try the following gentle movements every couple of hours during the day:

Arm cast

  • Wiggle your fingers
  • Bend and straighten your elbow joint (only if cast is below elbow)
  • Rotate your shoulder very gently

Leg cast

  • Wiggle your toes
  • Bend and straighten your knee (only if the cast is below the knee)
  • Gently clench the muscles in the back of your calf and thigh to improve the blood flow.

Taking care of your cast will help your injury heal properly.

After your cast has been removed

You may find that your arm/leg is thin and feels strange. You may also feel some stiffness and discomfort. Don’t worry, this is normal and will improve as your muscles get stronger.

Your skin may be flaky, dry and itchy. A gentle wash or bath, followed by a moisturising cream, will help.

You may be asked to wear a tubigrip (elasticated stocking) to give support to your arm/leg. This also helps to prevent swelling. You need to remove this at night.

Remember to raise your arm/leg when sitting and rings should not be worn if your hand is swollen.

DO NOT play contact sports until your doctor says it is safe to do so. However, swimming is recommended in nearly all cases. Your doctor will advise you about this.

Remember—if you have a problem with your cast please call us, or your own doctor.

Risks

Patients with a cast on their leg (above or below the knee) are at risk of developing a clot in the calf known as a deep vein thrombosis.

Very rarely, these clots can detach and become lodged in the lungs—this is a serious problem which requires urgent hospital treatment and can even be fatal.

If you experience symptoms of calf pain, chest pain or shortness of breath, please attend your local A&E department immediately.

Benefits

The benefits of having a cast will have been discussed with your doctor during consultation.

The main benefit of having a cast is to immobilise your limb to prevent further damage and to promote healing.

Contact information

This leaflet has been written by staff working in the Fracture and Orthopaedic Clinic at Chelsea and Westminster Hospital. We hope it answers some of the questions you may have. If, after you have read it, you have any questions or concerns, please contact us.

Trauma and Orthopaedics Department

Chelsea and Westminster Hospital

369 Fulham Road, London, SW10 9NH

T: 020 3315 5204