Medial Meniscus Tear, Cyst, and Chondromalacia Patella- Surgery vs. Therapy

I am a 23 year old female, 5'5" 110-115lbs, in good health and I have been suffering from knee pain (both knees) for years. I first got an MRI scan of my left knee when I was about 15 years old, 8 years ago, and the result was a torn meniscus (physical therapy was recommended, but I only went a few times). I don't actually recall how bad the pain was then, or when it hurt, but for the past few years my knees have mainly hurt after sitting for a long time. I sometimes feel pain when I walk or go up stairs, but that pain isn't nearly as consistent as it is when sitting.
I finally got another MRI scan a couple of weeks ago (of just my left knee, since insurance wouldn't cover a scan of both), and here are the findings:

Capsular surface tear of the body of the medial meniscus is evident decompressing to a 0.7 x 0.8 x 1.4 m parameniscal cyst...Mild softening of the patellar cartilage is evident. A very small joint effusion is identified.

The doctor told me my options were physical therapy or arthroscopic surgery. I don't really have the time for therapy, so I initially thought surgery was the better option, but after reading about CMP, I think that my knee pain (which is mostly from sitting) has more to do with that. I always thought that my knee pain may just be associated with my low muscle mass, especially in my thighs, but I never wanted to do much exercise and exacerbate the problem if it was just due to a torn meniscus. But after reading that a treatment for CMP is low-resistance exercise for the quads, is it worth trying that, or is it just better to try surgery, considering the other two issues (meniscus tear and cyst)?

Any insight would be much appreciated!

[sara_eagle]

You need to have an arthoscopy to take care of the meniscal tear.  Therapy will not help with that!