The sacro-iliac joints are two paired joints connecting the lower part of the spine to the pelvis and lower half of the body. The SI joints are very rigid, stable joints due to their bony structure and design as well as their very strong supporting ligaments. Inflammation, irritation and arthritic changes in one or the other joint can occur and cause lower back pain.
A long lasting steroid (cortisone) can be injected into the sacro-iliac joint to help decrease inflammation and/or swelling of tissue in the joint space. As a result, patients may experience reduced pain caused by inflammation of the joint. The procedure involves inserting a needle through the skin and deeper tissues into the SI joint. Sacro-iliac joint injections are not always beneficial but in some patients the relief may be substantial and long lasting. If only partial relief is obtained, a repeat injection may be performed.
Sacro-iliac joint injections are performed as an outpatient procedure. Sometimes, though not always, an IV is started if medication for relaxation is to be administered. Patients are placed face down on a special x-ray table and the skin at the injection site is sterilely prepped. Numbing medication is then used to anesthetize the skin and tissue deep to the skin to make the procedure more comfortable. An x-ray machine called a fluoroscope is used to monitor placement of the needle as well as where the medicine is being delivered. SI joint injections are relatively quick, taking approximately 20 minutes. Patients are monitored for a short time before being discharged home. On the day of the injection, patients are instructed not to drive and avoid strenuous activities. Some patients may experience a slight increase in pain for several days as the numbing medication wears off and while waiting for the injected steroid to work. The day following the injection, patients may return to their normal activities.