Extreme Swelling and Pain

I had an arthroscopic surgery on my right knee in December of 2005 because of pain and swelling. During the surgery they found nothing but a little bit of arthritis behind my patella. Since the surgery the inflamation hasn't decreased at all. My knee is HUGE and it has been for the past year. I have pain on the interior side of my knee. Recently I was at the doctors and they tried to remove fluid but couldn't get anything out, since then I've had horrible pain on the front of my patella along with the previous pain on the interior side. Ive been on 4 different anit-inflamation medications and one doctor suspected I had Lyme Disease and I took an antibiotic for that which did nothing. I've been in chronic pain and discomfort for over a year and the swelling has never decreased. Has anyone ever heard of anything like this? Im desperate for any helps or hints. Thank you!