Broken Bones (continued)

Casts are typically made of either:

• plaster of paris: a heavy white powder that forms a thick paste that hardens quickly when mixed with water. Plaster of paris casts are heavier than fiberglass casts and don't hold up as well in water.
• synthetic (fiberglass) material: made out of fiberglass, a kind of moldable plastic, these casts come in many bright colors and are lighter and cooler. The covering (fiberglass) on synthetic casts is water-resistant, but the padding underneath is not. You can, however, get a waterproof liner. The doctor putting on the cast will decide whether your child should get a fiberglass cast with a waterproof lining.

Although some kids might find casts cool when they're finally on their broken parts, the process of getting them put there can be scary, especially for a child in pain. Knowing what happens in the cast room might help alleviate some worry — both yours and your child's.

For displaced fractures (in which the pieces on either side of the break are out of line), the bone will need to be set before putting on a cast. To set the bone, the doctor will put the pieces of the broken bone in the right position so they can grow back together into one bone (this is called a closed reduction). During a closed reduction, the doctor will realign the broken bone so that it heals in a straighter position. The child is given medicine, usually through an IV, when this is done to help keep the bone from hurting. A cast is then put on to keep the bone in position.

So how is a cast actually put on? First, several layers of soft cotton are wrapped around the injured area. Next, the plaster or fiberglass outer layer is soaked in water. The doctor wraps the plaster or fiberglass around the soft first layer. The outer layer is wet but will dry to a hard, protective covering. Doctors sometimes make tiny cuts in the sides of a cast to allow room for swelling.

Once the cast is on, the doctor will probably recommend that your child prop the splinted or casted area on a pillow or stool for a few days to reduce swelling. A child who has a cast on a foot or leg (called a walking cast) shouldn't walk on it until it's dry (this takes about 1 hour for a fiberglass cast and 2 or 3 days for a plaster cast).

If the cast or splint is on an arm, the doctor might give your child a sling to help support it. A sling is made of cloth and a strap that loops around the back of the neck and acts like a special sleeve to keep the arm comfortable and in place. A child with a broken leg will probably get crutches to make it a little easier to get around.

Some pain is expected for the first few days after getting a cast, but it usually isn't severe. The doctor may recommend acetaminophen or ibuprofen. However, if your child seems to be in a lot of pain, call the doctor.

If the cast is causing your child's fingers or toes to turn white, purple, or blue, the cast may be too tight and you should call the doctor right away. Also be sure to call if the skin around the edges of the cast gets red or raw — that's typically a sign that the cast is wet inside from sweat or water. Also, kids shouldn't pick at or remove the padding from the edges of fiberglass casts because the fiberglass edges can rub on the skin and cause irritation.