If you've ever broken a bone or know someone who has, chances are you're familiar with casts and splints. Doctors use them to keep bones from moving and to support injured limbs while they heal.

Casts and splints may seem like a nuisance, but they're a key part of the healing process. To keep them working as they should (and avoid a longer healing time), they need proper care.

Here are some cast facts, as well as tips on taking care of a cast until it's time to have it removed.

Types of Casts and Splints

All casts and splints serve essentially the same purpose:

• They keep broken or injured bones from moving so they can heal properly.
• They support the muscles of injured limbs to help reduce pain and swelling.

The difference between casts and splints is the material used to make them and the reasons why each is used.

Doctors use splints for minor fractures and for newly broken bones if the area around the injury is swollen. When there's swelling, splints are a better choice than casts because a cast can get too tight and affect a person's circulation.

Doctors will usually replace a splint on a broken bone with a cast after the swelling has gone down. The stronger, closed cast will provide more protection during the time it takes for a broken bone to knit back together.

Casts

Casts are sort of like big, stiff bandages with two layers. The inside layer, which rests against the skin, is made of soft cotton. The hard outer layer prevents a broken bone from moving. It's usually made from one of two materials:

• Plaster of Paris. You may have used this for school art projects. A heavy white powder is mixed with water to form a thick paste that hardens quickly. Plaster casts are heavier than fiberglass casts and can start to dissolve if they get wet.
• Fiberglass. This type of moldable plastic is available in many different colors. Fiberglass casts are lighter and cooler than plaster casts. The outer layer of a fiberglass cast is water resistant, but the inner layer is not, although it's possible to get a waterproof liner for a fiberglass cast. The doctor or technician who puts the cast on will decide if a waterproof liner is appropriate.

If a person needs a cast that goes around the foot, doctors may use a "walking cast."

Splints

A splint is like a partial cast — a section of hard material that's held in place with an elastic bandage or Velcro straps. Like casts, splints usually have a soft cotton layer inside. The outer layer of a splint can be made from the same materials as a cast or it can be a pre-made piece of stiff metal or plastic surrounded by strong fabric.

How Are Casts and Splints Put On?

If you need a cast, here's what to expect:

• First, a doctor or cast technician wraps the injured area in several layers of soft cotton. This will be the soft inner layer of the cast.
• Next, the plaster of Paris or fiberglass that will form the outer layer is soaked in water.
• The doctor or cast tech then wraps the plaster or fiberglass around the soft inner layer. The plaster or fiberglass will be wet at first, but it will quickly dry to a hard, protective covering.
• Sometimes doctors will make tiny cuts in the sides of a cast to allow room for swelling.

The process is similar for splints:

• The doctor or cast technician starts by placing a layer of cotton around the injured area.
• Next, he or she will place the splint over the cotton. The splint is already hard, so there's no drying like there is with a cast.
• The tech or doctor will wrap an elastic bandage around the splint or, if the splint is pre-made, Velcro straps will be used to hold the splint in place.
• If the doctor says it's OK to remove the splint, you and your parent will get instructions on how to do this at home.

When a cast or splint is first put on, the doctor might tell you to keep your injured limb elevated as much as possible for the first few days. This helps reduce swelling. If you're using a "walking cast" on your foot or leg, you'll need to avoid walking on it until the plaster or fiberglass used to make it is completely dry.

Taking Care of Casts and Splints

Casts and splints need to stay in good shape in order to do their jobs properly and allow bones to heal the way they should.

Follow these tips to help keep your cast or splint as strong and as comfortable as possible while you have it on:

• Keep it dry. Most casts and splints are not waterproof, so it's very important to make sure they don't get wet. This is especially true with plaster of Paris casts. Casts and splints that get wet can lose their shape and may not be able to offer an injured limb the support it needs. Wet cotton lining also can lead to a rash or infection inside the cast. For baths and showers, you may have to cover the cast or splint with a plastic bag or special waterproof sleeve. If your cast gets wet, contact the doctor right away.
• Keep foreign objects out. If the skin inside your cast starts to itch, don't try to scratch it with anything like a coat hanger or pencil. They could get stuck inside the cast. Plus, scratching the skin inside a cast can cause an infection. Don't pour any lotions or oils inside the cast either, as they will make the lining wet and could cause a rash. The best way to relieve itching is to use a blow dryer set on "cool" to blow air into the cast.
• Check for cracks. Inspect the cast regularly for any cracks or tears. If you see one, contact the doctor right away — cracks can mean a cast isn't working as well as it should. Also let a doctor know if your cast gets hit or crushed or if you notice a weak spot. In many cases, technicians can make a simple repair to the cast without having to change it.
• Keep an eye out for problems. If the cast causes your fingers or toes to tingle; lose feeling; or turn blue, white, or purple, let a parent or school nurse know so your doctor can be contacted right away. The doctor will want to change the cast if it's too tight. Also let a parent, teacher, or school nurse know if your limb starts to swell or if the skin around the edges of the cast turns red or raw.
• Don't alter the cast. It's OK to have friends and family write or draw on your cast (permanent markers work best). But don't be tempted to break off parts of the cast or pull out the cotton lining. It could affect how well your injury heals.

Signs of a Problem

Get in touch with your doctor if you notice any of these things:

• a fever
• increased pain that doesn't go away with ice, elevation, and/or pain medication
• extreme tightness that leads to a numb or tingly feeling in your hand or foot
• loss of movement in your toes or fingers
• blisters, rashes, or raw spots on the skin inside or around the cast
• an unusual smell or discharge coming from inside the cast

How Are Casts Removed?

Once your limb has healed and the doctor says it's OK, a technician or doctor will remove the cast using a special saw. The saw's blade is dull. It's the vibrations that break the cast, not the blade, so it can't hurt your skin. Never try to remove a cast on your own. You could end up re-injuring yourself (and needing a new cast just when you thought it was all over).

Your skin may look and feel a little weird when your limb comes out of the cast. It might be dry, flaky, or scaly, and the hair might look thicker and darker than usual. Your muscles might also appear smaller and thinner. This is all normal and temporary.

You'll need to take it easy and maybe do some exercises to get your limb back in shape, but before too long everything should be back to the way it used to be.

Reviewed by: Elana Pearl Ben-Joseph
Date reviewed: September 2011