I have to have a mri on my left knee as soon as the right is healed. I wouldn't get both done at the same time. I have bone spurs in that knee too, so I'm praying it won't be too bad. I know I will be immobile for a bit after the surgery, but I'm not scared!!
If your surgeon removes the torn piece instead of trying to repair it, you won't be immobile for long. When I had my meniscus surgery in 2010, I was using a walker (I can't use crutches) the same day as my surgery. I was even putting part of my weight onto my bad leg. I used the walker for about a week and a half.
I had the same surgery in late june 2012 and have not recovered well. I wish I never would have had the surgery. I ended up with femur patella disease from it. My kneecap is basically shifted to the side, which I was told could happen, but didnt think it would happen to me. I hope all goes well with your surgery.