What is the key reason children are more susceptible to greenstick fractures?

Children are more susceptible to greenstick fractures primarily because their bones are softer and more flexible compared to adults. In younger children, the bone structure still has a high proportion of cartilage, which allows their bones to bend significantly under stress rather than breaking completely. This flexibility means that instead of breaking all the way through, the bone may only crack on one side, resulting in a greenstick fracture.

In contrast to other factors like bone density, involvement in sports, or growth rate, which may contribute to fracture risk in various ways, the inherent mechanical properties of children's bones directly explain the occurrence of greenstick fractures. The softer and more pliable nature of these developing bones allows them to bend but not necessarily break completely, leading to this unique type of fracture.