Usually spinal epidural injections are given in a series of 2 or 3 injections over a 9 week period of time.
Each "series" is really one injection of steroid and one injection of lidocaine or whatever numbing anesthetic the doctor is using. Therefore it is called a "series.
Each injection is done with about a 3 week interval in between each one.
The immediate relief of pain is from the numbing anesthetic used as it take about 2-3 days for the full affect of the steroid to kick in.
If the first injection provides partial relief, then a second 'series" of injections will be done in about 3 weeks and usually the doctor will attempt a slightly different location but very close to the first attempted area to relieve the pain.
If total relief is not obtained with the 2nd "series" of injections, a third may be attempted in the area that provided better relif.
If a second injection provided total relief, then the 3rd injection is held off and saved for a later time, as most doctors will only give 3 steroid spinal injections over a period of 12 months.
If there is no relief with the first injection after a weeks time, accept for the initial numbing injection, then usually a second "series" of injections may or may not be attempted and they doctor would attempt to locate the steroid in a different location to help alleviate the pain.
That's the procedure that my Pain Management doctor uses and the only way I have ever heard of it done.
I have no knowledge of only giving one injection for the pain and then waiting till it wears off to have another one, like you have Rich.
I mentioned it once to my PM doc and he never heard of doing it that way either.
I guess if it works, Rich, I wouldn't worry about it being different than what other doctors use. It may be that he uses a larger dose of the Kenalog at one time than other docs do, or you are just lucky that all you need is one to get you through for many months.
I say the "if it ain't broke, don't fix" holds for how you have your injections done. Be glad that they work and you can still go without surgery.
Fran