I first thought your post was misplaced, but upon reading your brief post it appears you have already tried the obvious, but...
Has physical therapy been discussed, tried?
How is you weight, are you over weight by more than a few pounds?
When you have pain do pain meds provide relief? Does the pain return even if you do not engage in physical activity?
How about you physical activity level, relates to physical therapy but doesn't necessarily involve a PT. If you are very inactive your muscles and even bones can degenerate and become weak.
Can the causes be anxiety? I await someone saying it was/is for them, otherwise I think not due to anxiety. It may, nonetheless cause anxiety.