What can lead to a greenstick fracture?

A greenstick fracture is a specific type of incomplete fracture that typically occurs in children due to the inherent flexibility and softer structure of their bones. In young children, the bones haven't fully matured and possess greater plasticity, meaning they can bend considerably before breaking. This characteristic allows them to sustain a fracture that doesn't completely break through the bone, resembling the way a green twig bends and partially breaks rather than shattering completely.

In contrast, a sudden impact injury would more likely result in a complete fracture, while normal aging changes or osteoporosis in adults involve bones that are more brittle and prone to complete fractures rather than greenstick fractures. Therefore, the unique flexibility of a child's bones is the key factor that leads to this type of fracture.