I hate to read you are suffering. A knee replacement is suppose to improve your function and it does not sound like that has been your experience. Have you talked to your doctor about your symptoms? Has he/she given you any feedback?
I have not had a knee replaced but hope someone here who has will write to you. You might also post in the orthopedics forum as I know they talk about joint replacements there as well.
I had my left knee replaced at the age of 42, Feb 09. I have not at anytime had relief from the pain either. I have seen a different ortho. doc and he said that it is paoosible that the replacement is not in correctly or it may be the wrong size. He said that if that was the case it would have to come out and redone. I got so scared I didn't go back. I am now developing lower back and hip problems because I walk with a limp. I made a appt with yet another dr. I need to feel I have no other options. I can tell you that I have pretty much the same symptoms that you have. I also break out in a rash that looks like little blisters. I have an appt. on the 8th of Feb. I will let you know what the dr. says.
I had my rt knee replaced in July of 2006 and like you suffered from pain and unbearable stiffness. 2 months later surgeon did an arthroscopoy to remove huge amount of scar tissue. Loads of phys. therapy later, still could not straighten or bend knee more than about 75 deg. Had partial revision the following year in summer of 2007 when still more scar tissue was removed.....not much improvement as more formed almost immediately. Now 3 years later my knee has not gotten any better and every step I take is uncomfortable. The stinging you refer to is due to the nerve endings. It takes a long time for that to go away. I am unable to stand, sit or walk for any length of time either. I was just 60 when I had the surgery and am now coming up to 65. I hate the thought of living like this for the rest of my life. I hate the thought of MORE surgery but may be forced to have them try to remove scar tissue yet again. We cannot give up. Keep trying to find a surgeon who will try to give you options. good luck.