@cccs from what I was told, about 18 months. Well, I am on my 18th month and I can say, on a good day, my pain has gone from a 10 to a 3 on average; some days lower and others a bit higher. I just feel it is slowly getting better and the last thing I want is a full reoccurrence and I fear another infusion of any medication can and more than likely will cause additional or continuous pain all over again.