I talked to the dr. and he explained the hyaluronic acid vs. PRP vs steroids. The PRP, if it works for you, lasts the longest- usually up to a year while the acid is not as long lasting. Of course the $ consideration makes it difficult for some as the acid injection is paid through private insurance and Medicare while the PRP is self pay. The one that has the most success is the PRP. 80-90 % experience relief. The Hyaluronic acid works about 50% of the time. The steroid injection is also covered under insurance but it can lead to more damage to the joint. I decided on the PRP and the injection was done within a half hour. I left the office with the paperwork that warned me not to do any thing that would stress my knee out too much for the next week and not to submerge my leg in water for 24 hours. That is all reasonable. Now, I will just wait to see if it works. Meanwhile, my son told me to look at Ray Peat's info about avoiding tissue damage by using a hormone cream so I am going to try it on my other knee to see whether I can avoid another out of pocket expense. Ray Peat is the person who mentioned that people with hypothyroidism are prone to osteoparthritis because their hormones are disrupted by the thyroid issue.