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How Bones Work


The Breaks: Bone Fractures
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arm fracture
©iStockphoto.com/muratseyit
What happens when your sibling shoves you off the top bunk

­Although bone is very strong material, it can break in a number of ways with enough force pushing, pulling or twisting it. Here are some of the more common breaks:

  • Stress fracture. This type of fracture is the result of sustained force on a bone, such as that created by running or jumping. Most stress fractures occur in the lower body, due to the accumulated weight that the bones in our legs and feet must support. It's possible to have a stress fracture without feeling any pain.

  • Open fracture. Unlike closed fractures in which all portions of the broken bone remain within the skin, open fractures result in a piece of bone puncturing and piercing the skin.

  • Complete fracture. This is when the bone breaks neatly into two pieces.

  • Single fracture. This identifies a break in which the bone has only one damaged area.

  • Comminuted fracture. Also known as "More painkillers, please," comminuted fractures are bones that have been crushed or broken into more than two fragments.

  • Greenstick fracture. With this type of fracture, the bone has cracked on one side, but not all the way through. These breaks normally occur in children.

  • Pathologic fractures. These fractures may be caused by external forces, but the underlying cause is a bone that has been weakened by disease or infection, such as bone cancer.

  • Displaced fractures. The two broken ends of the bone don't line up and require repositioning before they're set in place.

  • Simple transverse. This type of fracture is an even, perpendicular break to the bone. (Imagine if someone chopped your femur bone in half by neatly striking it from the side at a right angle.)

  • Oblique fracture. An oblique fracture would be a diagonal fracture running lengthwise along the bone. (Think greenstick fracture, but all the way through the bone.)

  • Spiral fracture. Spiral fractures occur when the bone has been twisted past its maximum point of resistance.

Here are a few of the more common break locations:

  • Colles' fracture is just a fancy name for a broken wrist. It's also the most common type of fracture.

  • Hip fractures. More than half the fractures seen in older people are hip fractures [source: FDA]. Hip fractures are actually a break in the femur bone, right below the joint that connects the upper portion of the femur to the pelvis.

  • Compression fractures. This is a fracture that affects the spine. Bad falls are usually responsible for compression fractures, in which one or more vertebrae are essentially crushed.

Now that we know how bones break, let's see how they're mended.


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