What is a Sacroiliac Joint Injection?

A sacroiliac joint injection is an injection of an anesthetic with a long lasting steroid (similar to cortisone) in the sacroiliac joint between the sacrum (tailbone) and the ileum (part of the pelvis). The sacroiliac joints are located in the back where the lumbosacral spine of the lower back joins the pelvis. They are paired (right and left) and are surrounded by a joint capsule like the finger joints. 

What is the purpose of it? 

The steroid injected reduces the inflammation in the joint space. This can reduce pain, and other symptoms caused by inflammation. 

For more information: