A cast holds a broken bone in place as it heals. Casts also help prevent or decrease muscle contractions, and are effective at providing immobilization, especially after surgery.
Casts immobilize the joint above and the joint below the area that is to be kept straight and without motion. For example, a child with a forearm fracture will have a long arm cast to immobilize the wrist and elbow joints.
The outside, or hard part of the cast, is made from two different kinds of casting materials.
Plaster (white in color)
Fiberglass (comes in a variety of colors, patterns, and designs)
Cotton and other synthetic materials are used to line the inside of the cast to make it soft and to provide padding around bony areas, such as the wrist or elbow.
Special waterproof cast liners may be used under a fiberglass cast, allowing the child to get the cast wet. Talk with your child's healthcare provider for special cast care instructions for this type of cast.
Below is a description of the various types of casts, the location of the body they are applied, and their general function.
Type of cast
Short arm cast
Applied below the elbow to the hand.
Forearm or wrist fractures. Also used to hold the forearm or wrist muscles and tendons in place after surgery.
Long arm cast
Applied from the upper arm to the hand.
Upper arm, elbow, or forearm fractures. Also used to hold the arm or elbow muscles and tendons in place after surgery.
Arm cylinder cast
Applied from the upper arm to the wrist.
To hold the elbow muscles and tendons in place after a dislocation or surgery.
Shoulder spica cast
Applied around the trunk of the body to the shoulder, arm, and hand.
Shoulder dislocations or after surgery on the shoulder area.
Applied around the neck and trunk of the body.
After surgery on the neck or upper back area.
Short leg cast
Applied to the area below the knee to the foot.
Lower leg fractures, severe ankle sprains and strains, or fractures. Also used to hold the leg or foot muscles and tendons in place after surgery to allow healing.
Leg cylinder cast
Applied from the upper thigh to the ankle.
Knee, or lower leg fractures, knee dislocations, or after surgery on the leg or knee area.
Unilateral hip spica cast
Applied from the chest to the foot on one leg.
Thigh fractures. Also used to hold the hip or thigh muscles and tendons in place after surgery to allow healing.
One and one-half hip spica cast
Applied from the chest to the foot on one leg to the knee of the other leg. A bar is placed between both legs to keep the hips and legs immobilized.
Thigh fracture. Also used to hold the hip or thigh muscles and tendons in place after surgery to allow healing.
Bilateral long leg hip spica cast
Applied from the chest to the feet. A bar is placed between both legs to keep the hips and legs immobilized.
Pelvis, hip, or thigh fractures. Also used to hold the hip or thigh muscles and tendons in place after surgery to allow healing.
Short leg hip spica cast
Applied from the chest to the thighs or knees.
To hold the hip muscles and tendons in place after surgery to allow healing.
Abduction boot cast
Applied from the upper thighs to the feet. A bar is placed between both legs to keep the hips and legs immobilized.
Assistive devices for children with casts include:
Keep the cast clean and dry.
Check for cracks or breaks in the cast.
Pad rough edges to protect the skin from scratches.
Don't scratch the skin under the cast by putting objects inside the cast.
Use a hairdryer placed on a cool setting to blow air under the cast and cool down the hot, itchy skin. Never blow warm or hot air into the cast.
Don't put powders or lotion inside the cast.
Cover the cast while your child is eating to prevent food spills and crumbs from entering the cast.
Prevent small toys or objects from being put inside the cast.
Raise the cast above heart level to decrease swelling.
Encourage your child to move his or her fingers or toes to promote circulation.
Don't use the abduction bar on the cast to lift or carry the child.
Older children with body casts may need to use a bedpan or urinal to go to the bathroom. Tips to keep body casts clean and dry and prevent skin irritation around the genital area include the following:
Use a diaper or sanitary napkin around the genital area to prevent leakage or splashing of urine.
Place toilet paper inside the bedpan to prevent urine from splashing onto the cast or bed.
Keep the genital area as clean and dry as possible to prevent skin irritation.
Contact your child's healthcare provider if your child has any of these symptoms:
Fever (see Fever and children, below)
Increased swelling above or below the cast
Decreased ability to move toes or fingers
Complaints of numbness or tingling
Drainage or bad odor from the cast
Cool or cold fingers or toes
The cast becomes wet or dirty
Blister, sores, or a rash develop under the cast
Use a digital thermometer to check your child’s temperature. Don’t use a mercury thermometer. There are different kinds and uses of digital thermometers. They include:
Rectal. For children younger than 3 years, a rectal temperature is the most accurate.
Forehead (temporal). This works for children age 3 months and older. If a child under 3 months old has signs of illness, this can be used for a first pass. The provider may want to confirm with a rectal temperature.
Ear (tympanic). Ear temperatures are accurate after 6 months of age, but not before.
Armpit (axillary). This is the least reliable but may be used for a first pass to check a child of any age with signs of illness. The provider may want to confirm with a rectal temperature.
Mouth (oral). Don’t use a thermometer in your child’s mouth until he or she is at least 4 years old.
Use the rectal thermometer with care. Follow the product maker’s directions for correct use. Insert it gently. Label it and make sure it’s not used in the mouth. It may pass on germs from the stool. If you don’t feel OK using a rectal thermometer, ask the healthcare provider what type to use instead. When you talk with any healthcare provider about your child’s fever, tell him or her which type you used.
Below are guidelines to know if your young child has a fever. Your child’s healthcare provider may give you different numbers for your child. Follow your provider’s specific instructions.
Fever readings for a baby under 3 months old:
First, ask your child’s healthcare provider how you should take the temperature.
Rectal or forehead: 100.4°F (38°C) or higher
Armpit: 99°F (37.2°C) or higher
Fever readings for a child age 3 months to 36 months (3 years):
Rectal, forehead, or ear: 102°F (38.9°C) or higher
Armpit: 101°F (38.3°C) or higher
Call the healthcare provider in these cases:
Repeated temperature of 104°F (40°C) or higher in a child of any age
Fever of 100.4° F (38° C) or higher in baby younger than 3 months
Fever that lasts more than 24 hours in a child under age 2
Fever that lasts for 3 days in a child age 2 or older