I broke and dislocated my ankle exactly a week ago today. It was very badly dislocated, and also I had a bad fracture on the fibula. I got surgery and have a cast on. When I have my foot elevated, or even parallel to the ground it is normal. But when I have my foot down my toes swell up and turn a blue/purple colour. As soon as I elevate my foot the toes go back to normal. Is this due to my cast being too tight and cutting off circulation, or is this quite normal?