In the US they call this Mesotherapy. A form at the bottom of the link here:
Mesotherapy for Pain Management & Sports Medicine
allows you to search for a practitioner.
I don't know how it would work in the US, but in France, the procedures can be done either by a doctor, or a nurse who has been trained and certified in the protocol and who takes the prescription from a DR and does the job, or accepts patients on her own.
It would be nice if that was the way it works (or could work) in the US because a number of nurses could be trained and open their own practice; I think they would have plenty of patients!
The US is also using it a lot for cosmetic applications:
Mesotherapy Specialist
The thing is, it is really easy to do with a little training, and theoretically, a husband or wife could do the basic treatment on their partner. They would just need to have the right equipment which consists of the ampoules of isotonic Quinton, the precise kind of disposable needles and disposable syringes. I've heard that insulin syringes with their tiny needles work in a pinch.
Pain relief is pretty quick, sometimes after the first treatment, or at least by the third (depends on type of pain and cause). And this comes from just injecting something like 2 ml/cc of Quinton at each site producing a "button" that looks like a bug bite or something. Well, they do a string of these "buttons" along the spine on both sides of it, close to it, and sometimes, if there is enough flesh, right on it. But since the tiny (4 mm) needle can't go any deeper than about right in the mid layer of the skin, it can't hurt anything.
I've been told that there is an upper limit of how many buttons you ought to have at a given session, something like a maximum of 250 ml of Quinton. But when I go for the drip treatment, I get over 500 ml of solution dripped in over an hour, so don't know about that 250 ml thing. Probably a useful precaution, though. 250 at 2 ml per site would be 125 injection sites!!! That's a lot. But if you do along the spine about 2 to 3 inches apart, you can get quite a few buttons on there! And they often go right up into the hairline at the top of the neck. The therapist has even put buttons all over my sacrum!
The really weird thing is that SOME sites along the spine (and elsewhere) are like wood and don't want to accept the injection. Our therapist actually has calluses on her fingers from so often having to really push the syringe plunger hard to get the water to go in! And usually, those are the places that need it most. And she is always careful to not push hard on the skin, but to make the force go between the plunger and the little handles of the syringe by squeezing. In this way, she is able to get the water in, though it goes slowly.
From my own experience, I'm convinced that treatment along the spine also helps the organ systems of the body that are fed by the nerves that exit the spine in the locations being treated so it might be a good idea to just do the whole spine for systemic issues maybe once a year or something.
I guess from the above, you can figure out that the reason the therapy is not widely promoted is because, in the end, it is so cheap. If a person buys the hypertonic solution and dilutes it with distilled water to make isotonic, has their own disposable needles and syringes, they could get cured of a whole host of pains and miseries for really cheap! Surgeons would be out of business!