@Me2, I don't know if anything additional would be seen in an MRI image than from an ultrasound. The fact that a tear or tears WERE seen on ultrasound tells a significant story. I spent a lot of time looking at my MARS MRI images, and it was clear that some of the muscles were atrophied. My orthopedist saw the tear on the gluteus medius in the images, although I couldn't see it. When he went in surgically, with an open incision (not minimally invasive), he also found the gluteus minimus tear.
I discovered my second surgeon in a very fortuitous way. I had posted about my problem in a different forum, and a woman suggested that perhaps this was my problem. I researched the anatomy of which muscles do which functions, and it certainly seemed to fit. I then did a google search for something like "gluteus medius tendon repair surgeon", and the first result to pop up was a doctor with an orthopedic practice very near where I live! I read his extensive web page, which includes papers he has written and research he has done. He has pioneered minimally invasive surgical techniques for this kind of repair. You can even see video of him performing it. Here is the link to that page on his site, although there is lots of other info on other pages, too.
http://www.benjamindombmd.com/gluteus-medius-tears.html. I know of a couple other surgeons who are experienced and highly regarded in this kind of surgery, but not anywhere near your area. Perhaps my doctor's office could refer you to a surgeon in your area.
I don't know where your orthopedist got the idea that this surgery is not usually successful, as my surgeon's results would refute this. He has a very conservative protocol for recovery, with no physical therapy for at least the first 6 - 8 weeks, depending on the individual. You must wear a brace for those first 6 - 8 weeks and do only 20 pound weight-bearing. This all allows for the best possible result in healing. Then he has a gradual program of PT that does not move forward unless you meet the requirements of no pain or increased disability.
At the same time that the tendon repair was done, he removed the trochanteric bursa and smoothed out the greater trochanter, since I also had ischiofemoral impingement. I had felt some catching before the surgery, and none afterwards. Unlike you, I didn't have much pain when just sitting and not moving around, although if I pressed on the areas, I would feel pain.
You can google MARS MRI for info. The "metal artifact reduction sequence (MARS)" reduces the distortion in the images caused by the metal parts of the implants. Looking at my images, there is still distortion in the area immediately around the implants, but the rest of the image was very clear.
Keep on looking for professionals who can help you. They are out there!