My wife and I both have bad knees, I mean replacement type. Here is the good part. She first had PRP platelets (hers) injected in one of her knees oh 3 months ago. It has been an amazing result. So I have now done both of mine, last one 2 weeks ago it again is amazing impact. I was in a lot of pain looking at replacement. We will see how long this lasts Doc thinks maybe 4-5 years or more. It can be redone. Can be done in other joints as well. It is not covered by insurance runs about $1800 per. Happy walking.