Cast Care Introduction
- The function of a cast is to rigidly protect an injured bone or joint. It serves to hold the broken bone in proper alignment to prevent it from moving while it heals.
- Casts may also be used to help rest a bone or joint to relieve pain that is caused by moving it (such as when a severe sprain occurs, but no broken bones).
- Different types of casts and splints are available, depending on the reason for the immobilization and/or the type of fracture.
- Casts are usually made of either plaster or fiberglass material.
Plaster cast or backslab care instructions
Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.
This fact sheet explains how to care for your child in a cast at home. Please read the following instructions carefully.
If you have any questions or problems, please see your GP or go to the Emergency Department of your nearest hospital.
Care of the affected arm or leg
- During the first 24 hours try to keep your child's limb elevated above the level of their heart and encourage them to move their fingers or toes as much as possible. This will help reduce any swelling.
- FOR ARMS - Use a sling (if provided) to elevate your child's arm and rest it on pillows when sitting or lying down. Ensure your child is wearing the sling as instructed by their doctor or physiotherapist.
- FOR LEGS - Elevate your child's leg on pillows when resting and use crutches or walking aids as instructed by the physiotherapist.
Check for any of the following:
- Excessive swelling of the fingers or toes.
- Blueness or whiteness of the fingers or toes (compare this to the uninjured hand or foot).
- Pins and needles, tingling or burning.
- Numbness or loss of feeling.
- Inability to move fingers or toes.
- Severe or increasing pain under the plaster.
- A grizzly child that cannot be settled.
- Pain that is unrelieved by analgesia.
If any of the above occur, elevate the limb for 20 minutes and encourage finger / toe movement. If the symptoms are not relieved, report immediately to the Emergency Department of your nearest hospital.
Itchy Plaster Cast Remedy
There's nothing worse than an ITCHY CAST you can't take off!
But here's some things you can try to Remedy the Itch
- Remember never to wet your cast.
- Raise the leg or arm up for an hour to reduce swelling inside the cast.
- Try an oral antihistamine from your Pharmacist.
- Don't use anything to reach down into your cast and scratch with that can abrade your skin - these micro-cuts will make the itching worse. This can also push down the protective layers under the cast putting you at risk of being cut when the cast is removed.
- For fibreglass casts applying a vibratory massage machine to the area works very well - but this is not to be done with plaster casts as it will shatter them.
- Pour some baby powder between the cast and your itchy skin.
- If you really can't stand it, go back to your doctor and let them take off and put on a new cast.
MLA Citation for School Reports, Links, and Presentations: Types of Fractures / Broken BonesFracture / Broken Bone SymptomsFracture / Broken Bone FixationFracture / Broken Bone ManipulationColles FracturePlaster Cast CareItchy Cast Remedy
How Casts Are Applied
Many different sizes and shapes of casts are available depending on what body part needs to be protected. A doctor decides which type and shape is best for each person.
- Cast application
- Before casting material is applied (plaster or fiberglass), a "stockinette" is usually placed on the skin where the cast begins and ends (at the hand and near the elbow for a wrist cast). This stockinette protects the skin from the casting material.
- After the stockinette is placed, soft cotton batting material (also called cast padding or Webril) is rolled on. This cotton batting layer provides both additional padding to protect the skin and elastic pressure to the fracture to aid in healing.
- Next, the plaster or fiberglass cast material is rolled on while it is still wet.
- The cast will usually begin to feel hard about 10-15 minutes after it is put on, but it takes much longer to be fully dry and hard.
- Be especially careful with the cast for the first 1-2 days because it can easily crack or break while it is drying and hardening. It can take up to 24-48 hours for the cast to completely harden.
- Plaster casts
- A plaster cast is made from rolls or pieces of dry muslin that have starch or dextrose and calcium sulfate added.
- When the plaster gets wet, a chemical reaction happens (between the water and the calcium sulfate) that produces heat and eventually causes the plaster to set, or get hard, when it dries.
- A person can usually feel the cast getting warm on the skin from this chemical reaction as it sets.
- The temperature of the water used to wet the plaster affects the rate at which the cast sets. When colder water is used, it takes longer for the plaster to set, and a smaller amount of heat is produced from the chemical reaction.
- Plaster casts are usually smooth and white.
- Fiberglass casts
- Fiberglass casts are also applied starting from a roll that gets wet.
- After the roll gets wet, it is rolled on to form the cast. Fiberglass casts also get warm and harden as they dry.
- Fiberglass casts are rough on the outside and look like a weave when they dry. Some fiberglass casts may even be colored.
Care in Plaster:
Ensure your child does not scratch under the cast with sharp objects e.g. knitting needles, chopsticks or pens. Children may push objects under the plaster and this can cause a pressure ulcer on the skin. If you are suspicious that an object has been trapped inside the cast, report immediately to the Emergency Department of your nearest hospital.
Signs that there is a problem under the plaster:
- Liquid staining the plaster, i.e. yellow or green liquid oozing through.
- Foul or rotten smelling plaster.
- Do not wet, cut, heat or otherwise attempt to modify the cast at home.
- It takes about 48 hours for a plaster of paris cast to dry properly. Avoid resting the plaster on hard surfaces during this time. Allow the cast to dry naturally in circulating air. Keep it away from direct heat such as heaters, electric blankets, hot water bottles and hair dryers. Do not allow your child to walk on a leg cast.
- Younger children should bath in shallow water under supervision with the limb covered in a plastic bag and sealed with adhesive tape. Older children may be able to shower with a hand held shower hose with the limb covered in a plastic bag and sealed. Do not put your child's limb in the shower or immerse in the bath even if covered by a plastic bag.
- If the cast becomes loose, cracked, and soft or is no longer keeping the injured body part immobilised, please report to your nearest Emergency Department.
Ice and Elevation
- A doctor may want the person to use ice to help decrease the swelling of the injured body part. (Check with a physician before using ice.)
- To keep the cast from becoming wet, put ice inside a sealed plastic bag and place a towel between the cast and the bag of ice.
- Apply ice to the injury for 15 minutes each hour (while awake) for the first 24-48 hours.
- Try to keep the cast and injured body part elevated above the level of the heart, especially for the first 48 hours after the injury occurs.
- Elevation will help to decrease the swelling and pain at the site of the injury.
- Propping the cast up on several pillows may be necessary to help elevate the injured area, especially while asleep.
- Keep the cast dry. Cover the cast with a plastic bag taped securely at the top during bath and shower time and avoid placing the cast in water.
- Check for objects that may be placed inside the cast.
- Check the circulation of fingers or toes. If you are concerned, elevate the limb and wriggle fingers or toes.
- Follow the specific instructions of your child's doctor and/or the physiotherapist.
- Your child should not take part in any active play or sport.
- If you have any concerns please go to your nearest Accident & Emergency Department.
Taking Care of Your Cast
- Always keep the cast clean and dry.
- If the cast becomes very loose as the swelling goes down, call the doctor for an appointment, especially if the cast is rubbing against the skin.
- Cover the cast with a plastic bag or wrap the cast to bathe (and check the bag for holes before using the bag a second time). Some drug stores or medical suppliers have cast covers—plastic bags with Velcro straps to seal out water for protection during bathing. Avoid showers; use the bathtub and hang the covered cast or injured body part outside of the tub while you bathe. Do not lower the cast down into the water.
- If a fiberglass cast gets damp, dry it (make sure it dries completely). Because a fiberglass cast allows air through it, a hairdryer on the cool setting should do the trick (do not try to dry it using a hairdryer without a cool setting—you could burn yourself). If you have any trouble getting the cast dry, call a doctor to find out if the cast needs to be replaced.
- If the cast gets wet enough that the skin gets wet under the cast, contact the doctor. If the skin is wet for a long period of time, it may break down, and infection may occur.
- Sweating enough under the cast to make it damp may cause mold or mildew to develop. Call the doctor if mold or mildew or any other odor comes from the cast.
- Do not lean on or push on the cast because it may break.
- Do not put anything inside the cast. Do not try to scratch the skin under the cast with any sharp objects; it may break the skin under the cast. Do not put any powders or lotions inside the cast.
- Do not trim the cast or break off any rough edges because this may weaken or break the cast. If a fiberglass cast has a rough edge, use a metal file to smooth it. If rough places irritate the skin, call the doctor for an adjustment.
- An arm sling may be needed for support if the cast is on the hand, wrist, arm, or elbow. It is helpful to wrap a towel or cloth around the strap that goes behind the neck to protect the skin on the neck from becoming sore and irritated.
- If the cast is on the foot or leg, do not walk on or put any weight on the injured leg, unless the doctor allows it.
- If the doctor allows walking on the cast, be sure to wear the cast boot (if given one by the doctor). The boot is to keep the cast from wearing out on the bottom and has a tread to keep people in casts from falling.
- Crutches may be needed to walk if a cast is on the foot, ankle, or leg. Make sure the crutches have been adjusted properly before leaving the hospital or the doctor's office.
When to Call Your Doctor
- Check the cast and the skin around the edges of the cast everyday. Look for any damage to the cast, or any red or sore areas on the skin.
- Call the doctor immediately if any of the following happen:
- The cast gets wet, damaged, or breaks.
- Skin or nails on the fingers or toes below the cast become discolored, such as blue or gray.
- Skin, fingers, or toes below the cast are numb, tingling, or cold.
- The swelling is more than before the cast was put on.
- Bleeding, drainage, or bad smells come from the cast.
- Severe or new pain occurs.
How a Cast Is Removed
- Do not try to remove the cast.
- When it is time to remove the cast, the doctor will take it off with a cast saw and a special tool.
- A cast saw is a specialized saw made just for taking off casts. It has a flat and rounded metal blade that has teeth and vibrates back and forth at a high rate of speed.
- The cast saw is made to vibrate and cut through the cast but not to cut the skin underneath.
- After several cuts are made in the cast (usually along either side), it is then spread and opened with a special tool to lift the cast off.
- The underlying layers of cast padding and stockinette are then cut off with scissors.
- After a cast is removed, depending on how long the cast has been on, the underlying body part may look different than the other uninjured side.
- The skin may be pale or a different shade.
- The pattern and length of hair growth may also be different.
- The injured part may even look smaller or thinner than the other side because some of the muscles have weakened and have not been used since the cast was put on.
- If the cast was over a joint, the joint is likely to be stiff. It will take some time and patience before the joint regains its full range of motion.
Many potential complications are related not only to wearing a cast but also to the healing of the underlying fracture.
- Compartment syndrome
- Compartment syndrome is a very serious complication that can happen because of a tight cast or a rigid cast that restricts severe swelling.
- Compartment syndrome happens when pressure builds within a closed space that cannot be released. This elevated pressure can cause damage to the structures inside that closed space or compartment—in this case, the muscles, nerves, blood vessels, and other tissues under the cast.
- This syndrome can cause permanent and irreversible damage if it is not discovered and corrected in time.
- Signs of compartment syndrome
- Severe pain
- Numbness or tingling
- Cold, pale, or blue-colored skin
- Difficulty moving the joint or fingers and toes below the affected area.
- If any of these symptoms occur, call the doctor right away. The cast may need to be loosened or replaced.
- A pressure sore or cast sore can develop on the skin under the cast from excessive pressure by a cast that is too tight or poorly fitted.
- Healing problems
- Malunion: The fracture may heal incorrectly and leave a deformity in the bone at the site of the break. (Union is the term used to describe the healing of a fracture.)
- Nonunion: The edges of the broken bone may not come together and heal properly.
- Delayed union: The fracture may take longer to heal than is usual or expected for a particular type of fracture.
- Children are at risk for a growth disturbance if their fracture goes through a growth plate. The bone may not grow evenly, causing a deformity, or it may not grow any further, causing one limb to be shorter than the other.
- Arthritis may eventually result from fractures that involve a joint. This happens because joint surfaces are covered by cartilage, which does not heal as easily or as well as bone. Cartilage may also be permanently damaged at the time of the original injury.