I can really appreciate what your friend is going through. I have severe osteoporosis and probably osteoarthritis. I have been getting water physical therapy and I am taking Prolia to try to rebuild bone density. I recently started having severe pain in the left hip and now I have it in the right hip as well. It is important to listen to our bodies BUT it is also important to try to do something to keep our bodies in working order. The longer we don't move the worse the pain will be. If your friend has not done PT he should consult his doctor and see if it would be appropriate for him/her to try very gentle physical therapy in a pool if possible. He/she might be able to try walking for a few minutes several times a day at first. Anything his doctor recommends to move. I can guarantee after a year it is going to hurt. That is why it is so important to have professional supervision. I hope he has a good doctor and good PT and insurance. This is a time when good friends might help by spending time with him, going on walks with him, exercising with him. It is boring and discouraging to do this alone and progress is necessarily slow. The more people who can rally behind him and create a network of mutual support the better. I hope this helps.