I had arthroscopic meniscus surgery on my left knee a year and a half ago. Prior to meeting with the surgeon, I went to an orthopedic doctor who didn't do any surgery, only non-surgical treatments. Based on X-ray and MRI he said that there wasn't any good non-surgical option for long-term success. My meniscus had a small tear, and it was the flap that was causing pain. The surgery went well, and I've had full recovery.
I now have the same pain in my right knee, and again went to the non-surgical orthopedic doctor to get it diagnosed, since I wasn't 100% sure that it was the same issue. Again, after the images, he said surgery is the only option so I've seen the surgeon, and will do the surgery. The surgeon said that it's not uncommon at all for both the meniscus's to be a problem if one of them is. In fact, he said that it's pretty predictable for that situation to occur.
The non-surgical orthopedic doctor did say that if there's arthritis in the knee that some surgeons won't operate, since some recent studies seem to indicate that arthritis may be accelerated after meniscus surgery. Fortunately, neither of my knees show signs of arthritis (although I had both arthritic hips replaced five years ago). I'm 63.