The sacroiliac joint (SIJ) is formed where your pelvic bones join to the base of spine, or sacrum. This joint can be a source of pain like any other joint, and it may cause hip, low-back or buttock pain.
Sacroiliac joint dysfunction may also be associated with radiation of pain into the groin and/or back of your thigh.
X-ray guidance is used to insert a thin needle into one or both SI joints and steroid and local anesthetic are carefully injected.
An alternate method of treating SI joint pain is to target the nerves which provide pain sensation from the joint. These nerves are called the lateral branches. X-ray is used precisely place steroid and local anesthetic onto these nerves to relieve pain. Radiofrequency can be used in cases where blocks are successful but the duration your pain relief is too short. Radiofrequency can provide pain relief for up to 12 months.
Sacroiliac joint injections usually take up to 10 to 15 minutes when both sides are injected.
Radiofrequency ablation does not permanently destroy (or “burn”) the lateral branch nerves. The nerves will slowly regenerate over time, which is why RFA may be repeated.
You will likely feel a quick relief after a sacroiliac joint injection due to injection of local anesthetic into the joint, but the effect of steroid is usually delayed 48-96 hours.
Relief after injections usually lasts up to 2 months, while relief from lateral branch RFA can last up to one year.