Advice for Patients with a Plaster Cast

Due to your recent injury, a cast has been applied to your injured limb. This provides support and protection to the site of your injury whilst it heals. Depending on the type of injury, your cast may extend from your elbow or armpit to your fingers, or from your hip or knee to your toes, stopping movement above and below your injury. The type of injury also affects whether you will be able to weight bear on your limb. You will be informed of your weight bearing status during your consultation. Your cast will be made with either plaster of Paris (24 hours to set), or a polyester or fibreglass material (30 minutes to set). It will feel very heavy to begin with, but will get lighter as it dries. During this time you should take extra care of your cast and leave it uncovered to allow the cast to dry out naturally.

What is the difference between a ‘back slab’ and a ‘full cast’?

A ‘back slab’ is a slab of plaster of Paris that does not go around the entire limb. It is used to treat injuries where swelling is expected to happen. It is secured with a bandage. This type of plaster is usually temporary and will either be ‘completed’ (extra plaster applied over original) or replaced completely at your next appointment.

A ‘full cast’ is commonly made of a synthetic material which is lighter in weight and encircles the entire limb. This doesn’t require securing with a bandage. It only allows for a small amount of swelling. It is also harder wearing and usually worn for a longer period of time.

After your cast has been applied

It is important to take care of your cast and regularly do the following:

• Move your fingers or toes and all other joints not immobilised by the cast, several times every hour
• Keep the limb elevated (above heart level) when not in use, especially in the first 48-72 hours after application to help reduce the swelling
• If a sling has been provided, it should be worn when you are up and about during the early stages to help reduce swelling. Remember to remove the sling regularly and mobilize your joints as advised
• Wear the cast shoe provided if your clinician has advised you to walk on your plaster
• Use walking aids as instructed.

It is important that you take great care not to do any of the following:

• Get the cast wet, as this can cause various skin problems and reduction of your cast’s strength
• Push objects down the cast for any reason eg to scratch, as wounds and ulcers can develop
• Do not cut or adjust the cast yourself
• Attempt to dry your cast with a hairdryer, as your cast will become hot and may burn you
• Do not let the limb hang down unless it is being used, especially during the first few days. (The limb needs to be elevated at heart level to reduce the swelling)
• Remove the cast yourself
• Wear a watch, ring or jewellery on the injured limb
• Walk on your cast until it is completely dry (and then only if you have been told to do so by your clinician)

Washing and cleaning

You should never allow your cast to become wet, as this will weaken it. There are numerous companies that offer covers for protection when washing, or you can use a plastic bag to cover up the cast when you have a bath or shower. Use sticky tape or a rubber band to seal the bag to make it watertight. Always remove the bag as soon as you can to avoid causing sweating, which could also damage the cast.

Exercises

It is important to exercise all joints not immobilised in the cast and to repeat every couple of hours during the day until the cast is removed. This helps to reduce swelling, stiffness, maintain some muscle strength and improve circulation. This can be painful and difficult to start with, but should improve within the first week.

Upper limb

• Fully straighten your fingers and then bend to make a fist five times
• Circle thumb, and then touch to each finger
• Fully straighten and bend elbow
• Rotate shoulder, then lift arm above the head, followed by placing arm behind back.

Lower limb

• Wiggle your toes regularly
• Fully straighten and bend your knee (if the plaster ends below your knee)
• Gently clench the muscles in the back of your calf and thigh to improve blood flow
• Move hip.

Driving

Your insurance may not be valid whilst you are being treated in a cast. It should be stressed firmly that patients DO NOT drive whilst wearing a cast.

Flying

Many airlines require your cast to have been applied at least 48 hours prior to flying, or may require your cast to be split beforehand. Please seek advice from your airline before flying.

Plaster cast removal

When the time has come for your cast to be taken off, it will be removed either by using the vibrating plaster saw, shears or scissors, depending on which type of casting material has been used.

After your cast has been removed

Due to the long period of time that your limb has been immobilised, you may experience some of the following, so do not panic:

• You may find that your limb feels thin and strange. This is normal
• You may experience swelling, discomfort and stiffness in the affected limb. This is quite normal and may continue for several weeks. You may find it helpful to keep the limb elevated
• Your skin may be dry and itchy. Do not scratch; try using baby oil or moisturiser
• Your skin will be sensitive, so be careful if going in the sun and apply a sun block
• Physical activities eg manual labour, sport etc should be reduced or avoided during the first few weeks after cast removal.

On the day of your follow-up appointment

You may require several treatments during your visit to clinic, such as x-rays and dressings. This, along with varying numbers of patients, means that sometimes you may have to wait longer than we would like, so we apologise for any inconvenience in advance.

DVT signs and symptoms

Due to immobilisation and reduced mobility, there is a higher risk of developing a DVT (deep vein thrombosis). It is important to stay as active as possible, drink plenty of fluids and be aware of the signs and symptoms.

Please contact the plaster room or the Emergency Department immediately if you experience any of the following:

• Pain in the calf, thigh or chest
• Sudden onset of shortness of breath with no physical exertion
• Swelling of the leg
• Increased or decreased warmth of the leg
• Redness in the leg
• Bluish skin discoloration.

Pressure ulcer

A pressure ulcer (sore) is a type of injury that breaks down the skin and underlying tissue. A small number of high risk patients are at increased risk of developing a pressure sore in a brace, which reduces mobility.

• Make sure to regularly reposition your leg throughout the day so that you are not constantly resting on the same area for long periods of time (every two hours)
• If you notice any discomfort or pain under the brace, most noticeably at the edges or heel, please contact the plaster room for urgent review
  Ensure the top and bottom of the brace is not rubbing and leaving red marks
• Do not rest the leg on the heel for long periods of time and place a pillow under the leg.

Further advice and instruction

To be completed by the orthopaedic team.

Contact us if you experience any of the following

• Your fingers become painful, swollen or blue
• You are unable to move the limb or joints
• You feel “pins and needles” or numbness in the limb
• Any ‘burning’ or ‘blister-like’ pain or severe irritation under the cast
• Discharge, blood staining or wetness under the cast
• If you drop any object into the cast
• The plaster appears too tight or loose fitting
• The plaster cracks or becomes soft
• Excessive itching
• The plaster has got wet.

Please contact the plaster room where a booked appointment can be made for you to return for assessment. Arriving without a prior appointment may result in longer waits or you having to return at another time. Outside of plaster room hours, please contact your local Minor Injuries Unit or the Emergency Department if urgent.

Contact numbers

We hope that you have found this information useful. If you have any questions or are worried about anything, please speak to the following Dorset County Hospital staff:

Orthopaedic Practitioners James Vincent, Sarah Nelmes and Zara Penwell

Plaster Room: 01305 255498

About this leaflet

Authors: James Vincent, Senior Orthopaedic Practitioner and Sarah Nelmes, Orthopaedic Practitioner
Written: April 2020
Approved: September 2020
Review date: September 2023
Edition: 1

If you have feedback regarding the accuracy of the information contained in this leaflet, or if you would like a list of references used to develop this leaflet, please email patientinformation.leaflets@dchft.nhs.uk