My doctor says he should do an arthoscopy on my knee but i read this doesn't help knee pain in most cases.?

Depends: The diagnosis is key to your expectations. If your diagnosis is arthritis alone, then you may not get a long-term benefit.

Arthroscopy?: Arthroscopy should never be done for diagnosis. Most are done after an MRI shows a lesion that can be treated surgically, and not before. It is expensive, requires anesthesia, and leaves you (if diagnositic) telling you that you have inflammation. If your preoperarative diagnosis is not surgical, do not have it done!

Good 4 meniscus tear: If you have a meniscus tear, a scar band called a plica, a cartilage flap, a loose body, bad synovitis, or an acl tear, an arthroscopy can give excellent pain relief and functional improvement. So the procedure is very good when done for the correct reason.

I thoroughly disagre: I thoroughly disagree ! i stand by my statement ! there is no such justification for " diagnostic" arthroscopy! this is 2012, not 1992. References available. If I have a pt who needs arthroscopy, they are referred. My favorite quote : give a man a hammer and he will look for a nail!