Hi Pegray & welcome to the board.
I thought I would add in my experiences with injections. In addition to having scoliosis (C4-T4), I also have hip issues due to a car accident in 2004. It damaged the socket and tore my SI joint.
After a few months of suffering, I had a SI injection that didn't help. It was merely done by feel in the doctor's office. However, a month or so later, I had a second one done under a fluoroscope. It, though, made a HUGE difference! I went from having a persistent burning spear pain in the SI to far more mild and more intermittent SI problems. While my SI does bother me here and there, that injection in particular really made a difference.
More recently, I've tried an epidural in my cervical spine. It was done at a spine hospital and was given Versed during the treatment (a short acting benzodiazepine-hypnotic). Unfortunately, that didn't make a difference for me.
However, I periodically get trigger point injections. What I found with them is that they sometimes can help with focused points of pain (along the rhomboid muscle between spine and shoulder blade). Out of the ten or so set of trigger point injections I've had, a couple have made a big difference, though most were a bust. In particular, I haven't found them to help with more diffuse pain, such as the cramping in my upper trapezius.
Let me add that you should seek out a good physical therapist in your area. I've never had any luck with chiropractors, but PTs are a different story. From them I learned some stretches that really help. Moreover, there are some PTs trained in techniques for scoliosis (one this is well known is called the Schroth method). If your scoliosis causes rhomboid issues in particular, have a look at this video:
www.youtube.com/watch?v=s41QTV1Vpeg