I use my pressure cooker to make bone broth. Upside - it doesn't take 24 hours, so the house doesn't smell like cooking bones for a whole day. Downside - unless you get an electric one with automatic shut off, you have to be near it for a few hours.
How I do it:
All the bones into the strainer part of the pressure cooker. Two tablespoons of unfiltered apple cider vinegar. (It's an 8 quart pressure cooker). I don't add salt until I eat it.
I use the largest knuckle bone as a guide. So, fill to Max line, cook at pressure for an hour. Depressurize and check. It's never done at this point, so fill with filtered water back up to the Max line. Cook for another hour at pressure. It's rarely done at this point. Fill to Max line (last time). Cook at pressure for about 40-45 minutes. Depressurize and check. There shouldn't be any gelatinous substance on the largest knuckle bone at all, and some of the smaller bones may be splitting. It's done. It becomes pure wiggly goodness when it cools/is refrigerated.
Remove strainer with bones; let broth cool. Ladle it into jars or ice cube trays. Put in freezer and/or fridge. Be happy. I add salt when I eat it, and also often add a half sheet of nori torn or cut into small pieces.
I don't know what nutritionists say about bone broth, but I always get a jolt of energy and my face gets warm when I eat it, so it must be doing something.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine