Hey kath, I can relate to much of your pain. I have degenerative disc disease, spinal stenosis in the lumbar area, and occasionally the sciatica flares up with a vengeance. Epidurals have helped a lot over the years in knocking out the sciatica.
If you don't want surgery, then talk to the neurosurgeon. Ask him if he would explain the correlation between your back and the hip pain.
If you're not satisfied, would seeking a second opinion be an option?
I've learned to be proactive in my health care. I am not afraid to ask questions or get a second opinion.
I hope you stick around and post updates when you can.