Is my leg (fibula) going to hold up on the Appalachian Trail thru-hike??

I have always had a great desire to thru-hike the 2000+ mile Appalachian Trail, but never had the chance to get away for 7 straight months..  The timing is more than perfect right now though as I am 30 years old, a photographer and super ambitious to make a book.. EXCEPT I have one thing that is weighing down heavy on my mind and inspirations.. I broke my fibula (spiral fracture) 11 months ago during a freak accident on a fishing trip..  They inserted a plate with 7 screws last June and it seems like it is taking forever to heal. I still feel a fair amount of soreness and swelling from time to time. It's not at all bad for normal daily activities, but I'm a little worried about carrying a 50 lb. pack on my back and hiking 2000+ miles for 7 months. Do you have any suggestions on how I can exercise my ankle to prep for the journey? Is there anything that I should be concerned about as far as the swelling?