A greenstick fracture is exactly what it sounds like – picture a soft twig from a tree. If you bend the twig, it will likely only break partially, leaving the outside of the bend broken, but the inner part still intact. That’s what happens with long bones in a child as they are still soft enough to bend somewhat.
This type of fracture still needs to be set and casted or braced. The chances of complications are small and the majority of greenstick fractures heal well, without any problems.