SI Joint Dysfunction—The Great Imitator!

Authored by: Dr. Thomas Nguyen

It’s no surprise that there are many causes for lower back pain, but over the years the majority of medical professionals have only focused on the familiar, common causes for this pain. This includes discogenic pain, arthritic pain, nerve pain, and musculoskeletal pain. What many doctors fail to realize, however, is that there is another source of lower back pain that is often unrecognized and undiagnosed – sacroiliac {SI} joint dysfunction. I like to call this source of pain ‘The Great Imitator’ because it often mimics the same features as other sources of pain, including the same distribution of pain in the back and legs. SI joint dysfunction is often missed because it is difficult to diagnose properly.


The SI joint is a standard ball-and-socket joint that connects the bottom of the spine to the pelvis {hips}. It is a strong joint that is reinforced with ligaments and muscles and acts to transmit forces from the upper body to the hips and legs. The SI joint also acts as a shock absorber. Pain results in the SI joint when there is a dysfunction of normal motion and movement {i.e. too much movement or too little movement}. Inflammation of this joint can result in pain that is located in the lower back and/or radiates down the lower back and side of the thigh to as far as the foot. Symptoms can occur with little activity like prolonged sitting, worsened when trying to get up afterwards or with activity like walking or repetitive bending.


Accurate diagnosis of SI joint dysfunction is largely determined from your clinical history and a complete physical exam. The physical exam eliminates other causes of the pain, while ruling in SI joint dysfunction with certain provocative tests. The gold standard for the diagnosis of SI joint pain really occurs with a diagnostic SI joint injection via arthrogram using a numbing medication. It takes a highly skilled and experienced physician to be able to insert the needle in the correct region of the SI joint. The injection is performed under fluoroscopic (live X-ray) guidance with injection of a dye to ensure placement inside the SI joint.  A diagnosis is confirmed when the patient reports significant, almost complete relief of pain for the normal duration of the local anesthetic numbing agent.


Successful treatment of SI joint dysfunction requires a multidisciplinary approach between the spinal specialist and physical therapy to relieve pain and restore normal function.  Initial conservative treatments include rest and alternating ice and heat for up to 2 weeks, oral anti-inflammatory medications, supportive devices if indicated and physical therapy.  When the pain is too much to allow activity, an SI joint injection with a steroid medication or platelet rich plasma {PRP} is performed to take away inflammation and pain to facilitate optimal physical therapy and rehab.  The patient will then work with a qualified physical therapist to restore normal function by strengthening the SI joints that are too loose or unrestricting the SI joints that are too tight.

For intractable, severe cases of chronic SI joint pain and dysfunction that have failed conservative treatments, a patient can opt to pursue radiofrequency ablation or SI joint fusion.  Radiofrequency ablation is a noninvasive procedure that interrupts the sensory nerve supply to the SI joint through the use of thermal denervation.  This procedure can offer relief to patients for many months to years. Surgery may also be an option in treating difficult SI joint dysfunction with the goal of fusing an unstable joint to restore normal function.

If you think your pain may be a result of an SI joint dysfunction, or you are interested in learning more about treatment options for your lower back pain, contact us today!

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