I have known two people now who have had their knees replaced. Both around age 55. They say it was the best thing they ever did!! One of them had the other one done too because they were so happy with the results. She also has had her shoulder done, and one hip. I think she is like 40% titanium now!!! She had some serious injuries when she was young due to an accident so now that she is getting older she has required these surgery to fix these failing areas.
I remember when I was young that my great-grandma had her knee replaced but it still caused her nothing but trouble. I think the way they do it, and the products they use now days must really be something.
I don't know how old you are, but I don't think you can be too young to have a surgery if you need it!! You recover much faster, and the risks involved are much less the younger you are. However, what do I know??? I am no doctor!!
I do hope that you require the lesser surgery, or no surgery at all!!!! And I hope they can get rid of your pain for you!!! Best wishes to you!!!!