I heard a mention of that bit about being upright and arthritis this morning, and I also heard a comment which was that exercise and physiotherapy can help to compensate. I'm going to put the next part in bold:
I can give a personal proof that exercises, done consistently and properly, and directed by a good physio, can obviate the need for a replacement hip, even when one has had for years an 'advanced degenerative condition resulting in complete loss of hip joint space'. Prior to this being triggered again by enforced rest following the accident, I had only occasional, minor difficulty, but now I am, I think, stronger than I was before. Please, please tell anyone you know who wants to avoid major surgery to follow this plan.