Have any of your specialists considered using pregabalin (Lyrica)? I know some are a bit in the dark with it's use, primarily they think it will only work in neuralgia (nerve related pain) but there is a bit more evidence for the treatment of pain arrising from muscles and connective tissue ec etc. It's not cheap but may be worth a crack as it could work very well.
I only mention it as I had a patient come in with similar chronic pain issues, I suggested she discuss with her GP the possibility of a short trial with Lyrica, when she came back 2 weeks later she had an 80-90% reduction in severity, so much so she had tossed her Panadeine, Tramadol and Fentanyl Patches that she had been relying on for the past 11 years. I've never seen such a change in mood in such a brief time.