Sacroiliac joint injection

How many treatments of acupuncture have you had at this point? Unless you have something significant happening (i.e. a bad rupture, stenosis, etc.) you should be fine within 3-5 treatments - 7-10 at the absolute most. Certainly well enough to drive anywhere for an hour.

The downsides of the injection is you are essentially degrading tissue. So if you have a strong degenerative process, bad herniation, etc. you can temporarily make things better but potentially making your long term outcome worse. And that is besides the normal risks of poor reactions to the steroids, damage to nerves in the area, etc. And if it does help, it’s usually not for very long. There are, however, cases where people get an injection, have a great response and it cuts the inflammation long enough for some of the internals to heal - so I’m not entirely against the idea. An all too often outcome, however, is next to nothing.

Back pain is generally extremely easy to treat with acupuncture and generally responds very well and quickly even in more serious cases. Ideally (my bias), you should be seeing an acupuncturist who also practices tuina (Chinese medical massage) and who does cupping as well. You will likely get the best response from that combination.

But the easy answer to your question, is except for any unforseen side effect, no a steroid injection will not get in the way of your acupuncture treatment, but it is very likely it is completely unnecessary with proper treatment.