I think IMO it depends on how much pain/disability the problem is giving him and what else he has tried first.
If the decision is left to him then there is information that he should ask for in order to be able to make a reasoned decision.
I would ask what the rate of improvement is from the treatment, that is to say out of everyone who has it, how many get benefit and how much benefit and what the rate of people who get the risk side effect(s) is.
What risk factors are there for getting a risk side effect (who is more/less likely to suffer) how are the side effect problem treated, what is the clear up rate and how many people end up worse off after the injections.
How many procedures does the hospital/doctor carry out in a year and what is his/her failure rate?
There is loads of useful info on the net. My Dh is currently having medical procedures that carry some risk and what I got from Google was very useful BUT when looking at side effects, remember that all the folk who have the procedure, get great results and no problems are only going to figure as statistics, not detailed reports.
Good luck in whatever he (and you) decide.