Is there more injections then an epidural injection for mid-back pain?

1: There are many other options besides epidural steroid injections. Depending on the source of your pain a block of the facet joint or even something as simple as a trigger point injection (an injection of local anesthetic into the muscle) may help you.

Yes: This would depend what the actual source of the pain is, it's possible that the pain you are describing is not amenable to any type of injection and some other remedy may be more appropriate. "facet" injections, "intrathecal" injections or enen trigger point injections are used for certain types of pain.

Yes: In addition to epidural injections, facet injections are sometimes also used for back pain. No injection is a fool proof cure for back pain, although they may be helpful as an adjunct.