Ankle question no stupid anwsers?

How can you make your ankle straight if you have a healed ankle but the tendion hasn't return to normal or is it scar tissue it hasn't gone back to It's original length would I have to have surgrey to fix it and if I did how many weeks would I be in a boot for and what kind of bit would I have would I have one that goes up to the knee or one that stops by the shin