A fracture is a broken bone, the same as a crack or a break. A bone may be completely fractured or partially fractured in any number of ways (crosswise, lengthwise, in multiple pieces).

Althouh bones are rigid, they do bend, or give, somewhat when an outside force is applied. However, if the force is too great, bones will break, just as a plastic ruler breaks when it is bent too far.

The severity of a fracture usually depends on the force that caused the break. If the bone's breaking point has been exceeded only slightly, the bone may crack rather than break all the way through. If the force is extreme, such as that caused by an automobile crash or gunshot, the bone may shatter.

If the bone breaks in such a way that bone fragments stick out through the skin, or a wound penetrates down to the broken bone, the fracture is called an open fracture. This type of fracture is particularly serious because once the skin is broken, infection in both the wound and the bone can occur.

Common types of fractures include:

• Stable fracture. The broken ends of the bone line up and are barely out of place.
• Open (compound) fracture. The skin may be pierced by the bone or by a blow that breaks the skin at the time of the fracture. The bone may or may not be visible in the wound.
• Transverse fracture. This type of fracture has a horizontal fracture line.
• Oblique fracture. This type of fracture has an angled pattern.
• Comminuted fracture. In this type of fracture, the bone shatters into three or more pieces.