I feel for you, I am in the same boat. I injured my ankle fours years ago and I am still looking for answers. The two chiropractor that I have seen (one moved so I had to find another) both tell me that my ankle ligaments are very laxed and it is chronically sprained. I have had multiple MRI's, bone scans, and EMG's.
I just came across some research that said the only definite way to diagnose an ankle injury is through arthroscopic surgery. The arthroscopic surgery found problems wit the ligaments that the MRI's miss.
http://ajs.sagepub.com/content/33/5/686.short
http://ajs.sagepub.com/content/30/3/402.short
I am hoping to convince my doctor to think outside the box and either order some stress x-rays (you might want to ask for these yourself-- just google stress x-ray and you will found out more.), an arthrogram, or arthroscopic surgery.
I hope this helps,
achilles2