Avascular necrosis

Avascular necrosis is a big word that means a part of your bones is dying because it's not getting enough blood. Imagine your bones are like a big building with lots of floors. But inside the building, there are tiny roads or pathways in the walls that help bring important stuff to all the floors. This stuff is called blood, and it carries important things like oxygen and nutrients to keep your bones healthy.

Sometimes, a problem can happen with these tiny roads or pathways called blood vessels. This problem might happen if you get hurt or if a different kind of health problem happens. When this problem happens, the important stuff can't get to the floors of your building (your bones). As a result, parts of your bones can start to die.

This can be pretty painful and cause swelling. If not addressed, it can lead to problems like arthritis, or even the complete collapse of the affected bone. So, if you ever have some pain in your bones, it's important to talk to a grown-up who can take you to the doctor to get checked out.