The sacroiliac joint (SI joint) is where the bones of the spine connect to the pelvis. There is one joint on the right side and one on the left. These joints are held together with very strong bands of fiber called ligaments.
The SI joint has very little movement. Its main job is to decrease impact to the spine during activities like walking. Problems in this area can cause pain in the lower back which may also pass into the groin or down the legs.
Damage to bones or ligaments of the joint can cause inflammation. The inflammation can cause pain and irritate nearby nerves which leads to more pain. Inflammation of the joint may be caused by:
SI joint pain may be more likely to happen with:
SI joint pain will differ based on the exact cause of the pain. The pain may be dull or sharp and may be any of the following:
Pain may increase with certain activities such as walking, twisting, rising to stand, or bending
You will be asked about your symptoms and medical history. A physical exam will be done.
The doctor will most likely make a diagnosis based on your symptoms. If there are other more serious symptoms or severe pain your doctor want to take images of the area. This can be done with x-rays or CT scan. Most will not need these tests.
If needed, the doctor may use a nerve block to make sure the pain is coming from the SI joint. Medicine that blocks pain is injected near the SI joint. If pain stops, then the joint is confirmed as the cause.
Treatment depends on the cause of the pain. Any underlying condition would receive treatment specific for that disease. For all causes, short-term rest is often the first step to allow time for the joint to heal.
Talk with your doctor about the best treatment plan for you. Options may include one or more of the following:
Medication can help manage inflammation and reduce pain while the joint heals. Medication options include
The joint may be moving too much or too little. An imbalance of muscles around the joint can also cause more problems. Physical therapy may help to speed healing and find a cause. Therapy sessions may include:
Ortho Info—Academy of Orthopaedic Surgeons
Canadian Orthopaedic Association
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Last reviewed June 2016 by Laura Lei-Rivera, PT, DPT, GCS
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.