This is something most chiropractors cannot fix. I personally would not even let them try, far too dangerous to apply force at this spot, I would only go to an osteopath who got an additional atlantotec schooling and can safely do it. Osteopaths without additional atlantotec schooling cannot do it.Most people who have chronic back pain have a misaligned atlas, see http://www.atlantotec.com/en

Deeper reason is, women give birth while laying, usually on this idiotic "medicinal" birth stool, which is very unnatural, this reduces the birth canal by 20 - 30%, this forces doctors/nurses to apply too much force or use suction cups during birth, this can shift the atlas as the babies bones are still soft, they later harden and then you have a misaligned atlas life long. So, there you got it, another epic failure of medicine. Correct birth posture is squatting see http://www.naturesplatform.com

===
If the atlas is not misaligned:
Sometimes, there is "just" the vertebral fluid depleted, drinking Quintons sea water ampullas (by Rene Quinton) is supposed to be able to replenish it, drinking is enough, so you do not have to inject it (like certain doctors offer for quite some money).

Also try an inversion table.

Check mattress, slatted frame and pillow.

Get your bed tested for water veins and other natural radiation fields (dowser, diviner). Get your bed tested for technical radiation fields (construction biologist).

Try a kneeling chair like varier variable balance.

Incline your bed http://www.inclinedbedtherapy.com

Try sleeping head north, south, or east. If you can prefer north or south.