I am not sure why people would say that injections do not work.
I am the vet who had it injected into his back.
In July of 2016, I made the mistake of allowing a friend drive my car. I was in the passenger seat, and he made an error in judgment by deciding to see if the car could fly. We hit two tree's, I had to be cut out of my own car. The end result was a broken back. My L1 and L2 were disintegrated.
Long story short, I did not end up having surgery like my buddy who was driving my car did. He had a 13 hour surgery, and lost most of the use of his left leg. My Neuro said that because of all of the core training I do via BJJ/MMA/Muay Thai, enabled the bone fragments to stay in place more or less; as I understand it.
The treatment modality I tried was simple. Once I was able to move again, and raise my arms above my head, I simply did hangs from a pull up bar for as long as I was able. I've always been very flexible, so I stretched every day; and I especially did bridges using a swiss ball every day, at least twice a day. Once in the morning and once in the evening for about 15 minutes minimum.
Above and beyond all of that: I had the opportunity to give stem cells a shot. And it absolutely worked. Not only did it work, my back, right now, is in better shape now, than it was prior to my accident. I had a curvature in my spine thanks to wear and tear that I earned while I was in the Army. I was an Infantryman, and did a good portion of my time in a LRSD; and the gear carried was above and beyond a "regular" Infantry load. So now, the curvature is no longer, my back is stronger than ever.
As a matter of fact, the treatment was so effective, was back in the gym by December doing squats and deads. I was back on the mats by the end of January.
$3000 was what it cost, right into my back.
I cannot recommend it highly enough!