A greenstick fracture is a type of bone injury that occurs when a bone bends and partially breaks, similar to how a young twig bends and splinters. This type of fracture is most common in children because their bones are softer and more flexible than those of adults. In a greenstick fracture, the bone may crack on one side while remaining intact on the other, making it different from a complete fracture. Treatment typically involves immobilization with a cast or splint to allow the bone to heal properly, and it usually heals faster than more severe fractures.