@uisge The ganglion impar is a bundle of nerves near the tailbone. With the muscle pain I also have rectal pain & tight perenium. This treats the ganglion impar nerves to settle that area down. I don't think it repairs anything just treats the nerves. I think it could be referred pain as well.
As far as the hip injection I'm sure it would be cortisone. What I don't understand is why docs would perscribe that if it would do more harm. I think with all of my injections they don't know if it will help but let's try it. The SI joint injection & the piriformis injection that didn't work were said to be diagnostic as well as theraputic but the theraputic didn't happen.