I went through four rounds of Prolotherapy treatments over ten years ago, for torn spinal ligaments. I can vouch for the effectiveness of this treatment.
I was left with a bit of a bulge on my back where the injections did their work, but that is a small price to pay to be able to ride a bike and carry a backpack up a trail again.
If you are suffering from chronic back pain, I highly recommend looking into it. It's not effective for every type of injury, but for some it can be very effective.