I have arthroscopic surgery scheduled on my right knee tomorrow. Opinions appreciated!?

I am 53 and tore my meniscus (small complex tear of posterior horn of medial meniscus) presumably after starting a workout regime including sprinting about 9 weeks ago. The right leg was hurting for about 7 weeks after that, than the pain started to lessen to the point where it is gone or virtually gone after nine weeks. And now I have surgery tomorrow (Friday, April 16)! The kicker is that now my left knee is the one that hurts (maybe by compensating for the right knee the past weeks?). So am wondering if I should go through with the surgery, and even if still needed if I should have an MRI on the left knee and if needed have arthroscopic surgery on both knees at that same time? Also anesthesia is general without intubation. Anyone know why no intubation? Does that mean no chance of stopping breathing? Advice on any or all issues greatly appreciated!!