Good question/statement. Her trouble is that either the bursa injections do not work at all, or maybe she will get a couple of months relief from the pain. But she has had so many bursa steroid injections so far, it's running her life. And the insurance won't let her get injections that are closer than maybe 3 months apart. She has a lot of arthritis (bone spurs) from her neck all the way down to her lower back to her tail bone. Tomorrow, she gets a neck injection. she can't rotate her head to the right without severe pain, But the doctor will not give her a hip injection at the same time as the neck injection no matter how painful her hip is. Twice now she has gotten the 24-injection procedure in her back to cauterize the nerve endings (they grow back) while also getting 12 steroid injections. The bursa pain is so severe she can only walk a half block before it becomes too painful to go further. Sleeping without pain is another problem too.
So, to answer your question, I don't think the pain management doctor has done any tests to determine the cause of her buritis, which is in both hips. I read one comment on the web where they have even done artificial bursa replacement. Some people just can't escape the chronic inflammation. And I don't know if medical insurance will pay for testing, they just pay for regular treatment according to their approved schedule, not according to the patient's needs. I think it is time for her to get an opinion from an orthopedic specialist.