I thought I'd just comment. For ages I had pain in my right hip area which was waking me up every night. Once I was up and about, no pain. I went to the doctor as I was worried it about my hip bone deteriorating. After examining me, he said that in fact it was a small muscle deep in my buttock that was causing the problem - nothing skeletal. I self-referred myself to the physiotherapist at the hospital who examined me and gave me a few exercises to do at home. I'm now pain-free and just do the exercises for a few days if it seems to be reoccurring. This obviously isn't much help for those needing hip replacements, but may be useful to others.