Years have worn out the knees and recently I tore a chunk out of one of the cartilages in my knee. The surgeon is suggesting Stem cell injection to regrow the cartilage plus to grow some cartilage where its really thin. Just wondering if anyone has had any experience with this procedure, was it successful, is it worth the money. Lots of positive marketing data out there, but cannot find hard data on the procedure. The stem cell procedure will cost between 4 to 5k out of pocket as insurance will not pay for it FDA issues, its sad I can get a knee replaced for a whole lot less.