Is the ultrasound of the treatment kind (physio) or diagnostic (test) kind?
Sometimes ultrasound shows up things that don't show on X-rays. I've had it done a few times and it showed that I have calcified tendons everywhere and also arthritis in my fingers. My rheumy actually does this herself.
There's also ultrasound done during physio. It has never helped me much but I believe it can.
I've had the physio kind of ultrasound twice I had weekly treatments after my hip replacement, and also when I was recovering from a broken ankle. I think it helped reduce the amount of scar tissue from my surgery, not sure it made a difference to my ankle recovery.
It it's for treatment, I hope it helps you feel better!