An SI nerve block relieves pain from the sacroiliac (SI) joint, located in the lower back where the spine meets the pelvis. It helps with chronic lower back pain, sciatica, and discomfort in the buttocks or hip region, especially when other treatments fail.

During the procedure, a local anesthetic like lidocaine and a steroid are injected near the middle cluneal nerve, which transmits pain signals from the SI joint. Blocking these nerves can reduce inflammation and improve mobility. X-ray or ultrasound ensures precise needle placement. If successful, radiofrequency ablation (RFA)—using heat to disrupt pain signals—may offer relief for six months or more.

This procedure is done under local anesthesia, so you’ll be awake but the area will be numbed. Sedation is available if you’re anxious, but general anesthesia isn’t necessary. You may be advised to avoid eating or drinking (NPO) before the procedure based on your provider’s guidance.

You might need to stop certain medications, especially blood thinners, to reduce bleeding risks. After the procedure, rest for the day and avoid heavy lifting or strenuous activities for at least 24 hours. Some soreness is normal, and ice packs can ease discomfort.

Recovery is quick. You may feel immediate relief from the anesthetic, lasting several hours, while the steroid takes a few days to fully work. Successful procedures can provide relief for months and may be repeated every six to twelve months if necessary.

If SI joint pain is affecting your mobility, a nerve block may be a step toward relief. Consult your medical team about this treatment or other options like RFA or advanced pain management techniques.