X-Rays, Fractures, and Casts

Objectives:

• Understand what bones are made of, what a fracture is, and how bones heal
• Make a model of a cast
• Learn about the role of an X-Ray Technician

What Do I Do All Day?

Materials Needed:

• Doll (i.e. American Girl Doll) or stuffed animal (an old one if possible, as it will be messy, but washable is ok) or another participant’s (i.e parent’s or sibling’s) fingers
• 1 foot of plastic wrap, cut into strips
• Strips of newspaper, about ¼ inch wide by 3 or 4 inches long
• A bowl or Tupperware with 1pt glue 1pt water mixture
• A pretend “camera” or really anything that can stand in for one, i.e a toilet paper tube or a shoebox
• Recommended: covering for the workspace (this one is a little messy!), extra paper towels
• Optional: if you have gauze or plaster strips around, they can be added to the cast in strips in a similar method as the newspaper

Background:

1. Bones give humans their structure and shape and protect our vital organs.
2. Bones are made up of calcium, phosphorus, sodium and other minerals, as well as collagen
3. With tendons, ligaments and muscles, bones allow us to move.
4. Bones essential parts:
   1. Outermost surface “periosteum” – thin, dense membrane that contains nerves and blood vessels
   2. Hard outside shell “cortical” bone – responsible for support and structure and releasing calcium to form new bone (80% of body)
   3. Spongy “cancellous” bone – found at end of long bones and in ribs, it’s more porous and easier to break (still strong!); contains red bone marrow (production of red blood cells)
   4. Marrow – soft, fatty substance, kind of like jelly, in bone cavities that contains stem cells that produce blood cells and fat, cartilage and bone
5. A baby is born with ~300 bones at birth. Eventually they start to fuse together.
6. Babies have a lot of cartilage that eventually grows and is replaced by bones. Cartilage is soft and flexible tissue (not bone).
7. When a bone breaks, it’s called a fracture. Fractures are more common among kids because the bones are still developing. While you might think of a broken bone that has a crack in it, there’s actually a lot of different types of fractures:
   1. A greenstick fracture: a break on one side of the bone only
   2. A buckle or torus fracture: an outward bend on one side of the bone without breaking the other side
   3. An avulsion fracture: when a tendon or ligament pulls off of a tiny piece of bone
   4. A growth plate fracture: a break in the area of a child or teen’s growing bone
   5. A stress fracture: a tiny crack in the bone
   6. A comminuted fracture: a bone breaks into more than two pieces
   7. A compression fracture: a collapsing of the bone
8. Doctors usually can treat fractures by putting on a splint or cast. These stabilize the bones so that they can heal, make sure there is no movement, and protect the injured area.
9. Sometimes a patient may need surgery where the doctor might need to move the injured bones closer to each other or add hardware to help out.
10. Did you know that when a bone breaks, blood comes out of it? The inside of bones – the bone marrow- is what makes red blood cells! So when there’s a break, our bodies form a clot around the broken part of the bone to protect and it deliver the special healing cellsit needs to recover. When all of this is happening, and all those extra cells are being called, the area gets swollen – that’s the bone beginning the healing process.
11. First, the special healing cells make a soft callous. The callous is a soft bridge between the broken parts of the bone, and it is the start of the healing process. It takes about one week for this soft callous to fully form. Just like the name says, a “soft” callous is not real strong bone.
12. So, once the soft callous is in place, osteoblasts (which are cells that act like the construction workers of the body to build up bone) get to work and start putting calcium and other minerals into the callous, which turns it into real hard bone. This is a slow process. It can take three weeks to six months for the body to change the soft callous to strong bone. You generally need to wear a cast or splint until this new hard bone has replaced the soft callous.

This information and more from Denver Health.

Activity:

1. Connect to prior knowledge:
   • Ask: have you ever broken a bone?
   • Explain: If you ever break a bone, when you go to the doctor, you’ll probably have to get an X-Ray so the doctor can see where the break is and exactly what it looks like. Then they might put a cast on it to make sure the bones line up properly so they can heal!
   • Explain: Today we will be X-Ray technicians and bone doctors to assess and treat a broken bone.
2. Using a doll, stuffed animal, or parent’s fingers, take an “X-Ray” of the injured area. This can be using a pretend camera, a toilet paper roll, really whatever you have that can be a camera. Then you can show pictures of the “x-ray” and discuss the breaks.
3. Next, clean the injury with a damp paper towel
4. Wrap the injury in a few layers of plastic wrap
5. Dip strips of newspaper into the bath of water/glue. Pull the strip out and run it between two fingers to get any excess of the mixture off. Carefully start laying the strips around the plastic wrap.
6. Continue this until it has a few layers. The cast will harden overnight and can always be decorated the following day (note: not recommended to leave on a person overnight – carefully slide off fingers and let dry. If you are worried about it coming off a person or a doll, you can also apply Vaseline prior to the plastic wrap)

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