Over The Last Few Months I Have Been Having "spasms"

Over the last few months I have been having "spasms" in my left foot. I broke my left ankle about 1 1/2 years ago and have plates and screws in it, Last week as I was walking I felt like a crack in my foot like stepping on a twig, and now there is a constant dull ache and it is swollen slightly and hurts to wear shoes.