A greenstick fracture occurs when a bone bends and cracks, instead of breaking completely into separate pieces. This type of broken bone most commonly occurs in children because their bones are softer and more flexible than are the bones of adults.
In some cases, a greenstick fracture can be difficult to diagnose because there may not be much pain or swelling and the child is using the limb and has full motion. Mild greenstick fractures sometimes are thought to be sprains.
Even mild greenstick fractures are usually immobilized in a cast. In addition to holding the cracked pieces of the bone together so they can heal, a cast can help prevent the bone from breaking all the way through if the child falls on it again.