Had left knee replaced a few years ago and ever since it continues to fill up with fluid and I had to have it drained several times even though I had taken Bacterin. My concern is that when I m standing or walking the leg gives out on me. Have to catch myself from falling all the time. I do also have back problems with 5 bulging discs degenerative also? I feel I have a pinched nerve or several since my feet are numb most of the time. What do you think could be the problem??