When I've been in a similar situation, I've done it the old fashioned way, ie, filled my freezer with plenty of homemade microwaveable meals. That way I know exactly what's in the meals too, so I don't need to worry about hidden carbs.

Just FYI, here are are some previous threads discussing Atkins frozen foods:
http://forum.lowcarber.org/showthread.php?t=448333
http://forum.lowcarber.org/showthread.php?t=448967
http://forum.lowcarber.org/showthread.php?t=455893

I'm certainly not saying don't bother with them (if you find them somewhere), but maybe only keep one or two on hand, and fill the freezer with your own food?

One thing I have also done is to have several packages of cooked chicken, all ready to be turned into various easy dinners such as simmer a few spices, add the chicken, then some cream or coconut cream. Or this can be done before freezing. I have also had plenty of mince/ground beef in frozen in separate serves that can easily be turned into a load of different dinners. Mince can also be turned into meatballs and/or meatloaf prior to freezing. There are just so many ideas!

And you have my very best wishes that your knee surgery goes well.