How can I make my Grandmother go to the hospital?

So this is a really bad situation. My grandmother (76) is a shut in and hasn't left the house in ten years. My grandfather does everything for her, but over the past few years, her health has really declined. She refused to go the doctor's or hospital. Over the past year, she has stopped bathing and has had a few falls. She refused nursing care and really any help at all.

Yesterday she had another fall and I am sure she broke her hip. She is in so much pain, but she will not go to the hospital. I know she is afraid to go and even with all of her pain, she will not even consider it. I tried to be really sensitive and kind when I told her about 100 times today that she needs to go. The more I pushed it, the more she yelled no.

I don't know the rules, because I've never been in this situation before. I don't know if she is allowed to refuse to go (which she will do if I call for an ambulance). I am sure she will scream and put up a fight, even with her pain (I don't know if cops need to be there). I also feel like I would be betraying her, but she needs help.

She is in so much pain, but just won't go. What do I do? Beyond that, I think she knows that if she does go to the hospital, she will never come back home (that's how bad her condition is). On top of that, she is probably an Alcoholic, which makes it so much harder. I just don't know what to do.