A broken arm is a common injury that can happen to anyone. Adults may stumble and fall, then try to support themselves with outstretched arms. These injuries also often occur in children while playing and falling from rides, falling off a bicycle, falling from a tree, or having an accident while playing sports. Immobilizing the arm by placing a cast is important so that the arm can heal properly.
Step
Part 1 of 3: Preparing the Arm for a Cast
Step 1. Identify the broken arm
A broken arm is usually very easy to spot. If there is any suspicion that you or your child's arm is broken, go to the ER immediately so that it can be treated. Symptoms of a broken arm include:
- Incredible pain
- Swollen
- Bruises
- Dizziness or feeling like passing out right after the arm is broken
- Arms bent in an improper way
- Victim cannot move arms or fingers
- There is a snapping or crackling sound when the injury occurs
- Bleeding and pieces of bone sticking out of the skin
Step 2. Make sure the victim is as comfortable as possible on the way to the hospital
Keep in mind that if the injury is very complex, your doctor may give you anesthesia to return the pieces of bone to their original position. Do not give the victim any food or drink.
- Use an ice pack to reduce the victim's pain and swelling. Wrap a bag of ice or a bag of frozen pods in a towel. After 20 minutes, stop compressing so the skin has a chance to warm up again.
- You can use a large towel to help the victim support her arm in a sling or to support her arm. Do not move the arm so as not to cause more damage.
Step 3. Have the doctor place a splint on the arm
A splint is used to keep the arm from moving when examined. The splint is hard on one or both sides, but there is an opening in case the arm continues to swell. The splint has several layers:
- Soft cloth to protect the skin so it doesn't irritate
- Soft cushion
- Plaster or fiberglass to prevent movement
- Elastic bandage to keep the splint blades from sliding
Step 4. Let the doctor examine the arm
The doctor will examine the arm, feel it, and may order an X-ray. X-rays will produce images of the bones of the arm and help doctors decide whether the bones should be repositioned so they can recover in the correct position.
- If the arm is lightly fractured and the bones remain in the correct position, no additional procedure is needed before placing the cast.
- If the position of the bone is not in place, the doctor will give anesthesia to numb the arm or put the victim to sleep. Then the doctor will try to return the bone to its original position.
- If this is not possible, the doctor may perform surgery. This step may be necessary if the joint is broken. Surgery may also be needed if wires, plates, screws, or pins must be attached to hold the fracture in place.
Part 2 of 3: Undergoing the Cast
Step 1. Ask your doctor about the type of cast to apply
The cast may be short or long, depending on which bone is broken.
- If the wrist is broken, a short cast is usually used. The cast will be placed from the knuckles to below the elbow. (Sometimes a long cast will be used to prevent the patient from twisting the wrist and re-positioning the bone.)
- A long cast will be used if the arm or elbow is broken. The cast will be placed from the knuckles to the upper arm.
- Fractures of the humerus (upper arm bone) are treated with a splint or brace (support), but not a cast.
Step 2. Ask the doctor what materials are used to make the cast
A cast is a hard bandage that protects the bone while the bone heals. The hard outer shell is lined with soft cushioning on the inside for a more comfortable fit. There are two types of materials that are commonly used to make casts:
- Plaster. Plaster is a white powder that is mixed with water and then allowed to harden to form the outer shell of the cast. Plaster is easier to use because it will harden slowly. Thus, doctors have more time to work. In addition, the tape gives off less heat, which reduces the chance of burning the skin.
- Fiber glass. Fiber glass is a kind of plastic. Fiberglass is more durable, lighter and better than plaster if X-rays are required.
Step 3. Watch how the doctor prepares the necessary materials, including:
- Adhesive plaster
- Scissors
- Basin of water. The temperature of the water affects how quickly the plaster will harden. The plaster will harden faster with warm water. In general, to make a plaster cast requires warm water. Fiber glass requires water at room temperature or colder.
- Gloves for making a cast, if the doctor chooses to use fiberglass
- Bearing
- gypsum material; plaster or fiberglass
- Sheets of paper or pads to keep clothes clean
- Stockinette
Step 4. Let the doctor prepare your arm
He or she will attach the pads to be attached to the inside of the cast.
- The first step taken by the doctor is to correct the position of the arm so that the bone will recover properly.
- First the doctor will put a stockinette on the arm. The stockinette will be placed about 10 cm longer above the injured area where the cast will be applied. Stockinettes are usually 5-7.5 cm wide. The doctor will flatten it out to prevent wrinkles. She probably wouldn't wear stockinettes if she thought her arms would swell even more.
- The doctor will wrap the arm with pads. Each layer will cover the previous layer by about 50% resulting in a double layer around the arm after the doctor is done. The doctor may make more layers, especially on the fingers or bony areas. The pads used on the hands may be about 5 cm wide, while the pads on the arms may be about 10 cm wide. The pads should be about 6 cm longer at each end of the area to be plastered. The pads that are installed should not be too tight and impede blood flow.
Step 5. Watch as the doctor applies the cast
The doctor will apply a cast material around the arm. Each new layer will cover the previous one by about 50%, resulting in a double layer with no missing parts. Just before adding the final layer, the doctor will fold the ends of the stockinette and padding back, and add a final layer covering them. Once the cast material has hardened, the doctor will adjust its shape by manipulating it. It's important to get the tension level right:
- A cast that is too tight can block blood flow or irritate the skin.
- A cast that is too loose or has too much padding can slide, rub, and cause scratches and blisters on the arm.
Step 6. Tell the doctor if the cast feels hot
The cast gives off heat once it hardens and you will feel uncomfortable if the cast gets too hot. There are two factors that affect the amount of heat generated. The amount of heat will be:
- Inversely proportional to the time it takes for the cast to harden. This means that the longer the cast hardens, the less heat is generated at any one time.
- Directly proportional to the number of layers used. This means that the more cast material you use, the more heat it will generate.
Part 3 of 3: Caring for the Gypsum
Step 1. Watch the arm for signs of complications
How long you should wear a cast is determined by the length of time it takes the bone to heal. Children recover more quickly than adults, but the cast may have to be worn for several weeks. If you see any of the following signs of complications, go to the ER immediately to have your cast removed:
- The pain is getting worse
- shudder
- Numb
- Extreme swelling
- Pale, blue, purplish or black fingers
- Reduced blood flow
- The loss of the ability to move the fingers that was previously not problematic
- Blisters or redness of the skin under the cast
- The liquid flows from the cast
- Unpleasant smell emanating from the arm
- Fever
Step 2. Keep the cast dry
If your doctor doesn't say your cast is waterproof, you should keep it dry. Wet conditions can cause the cast to loosen or warp. This makes the cast less effective at protecting and stabilizing the bone. You can keep your cast dry by:
- Cover it with a plastic bag when taking a shower
- Wear a raincoat or use an umbrella when outside, in the pouring rain.
Step 3. Do not put anything in the cast
As the arm begins to heal, there may be itching. However, you should refrain from doing anything that could damage the cast or injure the arm. This means you may not:
- Slip something like a pen to scratch. This can damage the inside of the cast or, if you injure yourself, cause the skin to become infected.
- Use an anti-itch medication on the inside of the cast. The drugs in question include baby powder, lotion, cream, or anti-itch oil.
Step 4. Do not pull the soft lining or break any part of the cast
If the cast is damaged or broken, contact your doctor for a new cast.
- As the arm heals, the child may no longer be as careful about the cast arm as before. Check regularly to make sure there are no cracks or tears in the cast.
- If you get a cast that can be written on, ask family and friends to sign and write an encouraging message.
