Knee surgery recovery: What to expect?

Hey everyone! I couldn't find a thread quite like this one, so I'm hoping you all might be able to help me out with some info. My grandmother (she's 78) needs to go in for knee surgery—a total joint replacement, I think that's the term they use—so if anyone here has gone through the exact same thing or just knows a bit more about the process, could you please share? I'm looking for the lowdown on what the actual surgery is like, how the recovery goes, physical therapy, and all that good stuff. Thanks so much in advance!

P.S. I totally meant to put "knees" in the title—my bad, just a quick typo 🙂