Your ankle joint is where the 2 long bones in your lower leg meet the small bones at the top of your foot. A break in any of these bones can be considered a broken ankle. But doctors usually say "broken ankle" when you've broken one of the long bones. All broken bones are considered fractures. For more information, see Overview of Broken Bones.
You may need physical therapy after the splint or cast comes off.
If the bones stay in place, the ankle usually heals well. If the bones come out of position, you may get arthritis and have a higher chance of getting another ankle fracture.