Lilly - How Do You Keep a Lab/Collie Calm?

Think my dog, Lilly, tore her ACL again. Doesn't even have the stitches out from the first surgery yet. She can barley walk again. Not sure how I'll pay for it. How do you keep a lab/collie from tearing around the house as soon as she feels better? Another surgery will be $1,000 again. Goodbye savings. I'm sure the vet will let me make payments this second time around (hopefully) but the real question is how do I prevent her from tearing it a third time? It may be time to kennel her when we're not home. At least until she heals up. Poor girl. We've never done that before. She's going to think she's being punished.