I've had two surgeries on my right knee. The first one was a mess and after 10-12 years of lockups and it going out, I had another done and have had none of the problems with it collapsing on me or locking up. Now, after 23 years of bone on bone, I'm close to needing a replacement. I'm going to try supplements, which seem to be helping, and put it off for as long as I can. It ain't fun.