Hi Anne
I have had similar problems with my knees over several years. Joint injections close together with poor results and failed aspirations.
I had a debridement and meniscus repair last July. Due to being taken off Enbrel two weeks prior to op. and not being allowed to restart for several weeks I went into 'flare mode' which had a devastating affect on the newly operated on knee and everywhere else for that matter! Things did settle down eventually and my knee started to feel a little better for a while. I've been referred back to the orthopaedic consultant twice since with ongoing problems, knee locking and giving way again but he has discharged me as he doesn't feel the RA is sufficiently well stabilised for me to undergo further surgery. He would prefer me to continue with aspirations and steroid jabs into the knee to keep it 'going' for now.
Like you Anne, I felt the Enbrel was working well on other joints but less so on my knees. Apparently both knees have substantial damage but the movement is still pretty good and I may lose some of this if I go for knee replacement. In my case the answer seems to be more aspirating, injecting and pill popping! Heyho ...

... perhaps once the RA is fully controlled again things will improve!
To all three of you, from my experience (as yuck as it was!) I would still recommend the debridement and cartilage repair as it should give relief from the ongoing pain, locking and other such pleasantries. Jenni with a bit of luck you should be able to straighten your knee much better with the gunge removed. Anne, providing you get back on the Humira quickly (two weeks post op. is recommended) it should help to control the build up of the thickened synovium. Good luck Doreen, hope it's a great success and things improve for you quickly.
Lyn x