Who is your doctor? My doc said 80% success too. It's something they all say, although I know many people who had MF fail. The people who had successful MF are probably not online though, looking for info about how to make their ankle better.
In my case, MF made my ankle worse. In retrospect I should not have got the surgery, but its a risk I took.
I'm going to forego any more surgeries and go for stem cell injections next.
MF can work, it really depends on the individual I think. Generally, younger people are said to have greater success rates. Also, if your OCD condition is moderate to severely bad, the MF is unlikely to work in my opinion. I think MF works OK with smallish sized OCDs