What is sacroiliac joint pain/dysfunction?
The sacroiliac joint (SI joint) is the joint connecting the sacrum which is the lowest portion of the spine to the ilium which is the hip bone. The human body has two sacroiliac joints, one on the left and one on the right, and they are located just over the medial aspect of the upper buttock region. Sacroiliac joint dysfunction refers to pain in the SI joint region that is caused by abnormal motion in the sacroiliac joint, either too much motion or too little motion and typically resulting in inflammation within the joint. Pain from the sacroiliac joint is a common cause of low back pain, estimated to be responsible for 15% to 30% of lower back pain cases. SI joint pain and dysfunction has multiple causes including direct injury or trauma (fall, motor vehicle accident), scoliosis and leg length discrepancy placing uneven pressure on one side of the pelvis, pregnancy causing ligaments in the SI joints to relax and pelvic changes associated with child birth, and previous back fusion surgery which can displace added pressure to the SI joints.
How is sacroiliac joint pain diagnosed?
Sacroiliac joint pain should be suspected if the pain localizes or begins in the upper buttock area. Pain from the SI joint can also be referred into the leg including the groin, thigh, and calf which can make it difficult to differentiate between sciatic pain from a pinched nerve in the spine. The pain can cause the patient to favor and lean to the opposite side when sitting or walking. There are several physical maneuvers of the hip and leg that are performed in the office that suggest SI joint pathology. Imaging studies such as X-ray, CAT scan, and MRI are not reliable for detecting SI joint problems but are more helpful to rule out other causes such as herniated disc or facet joint arthritis. The most reliable test for diagnosing SI joint as the pain source is by injecting a steroid/numbing medication into the joint and obtaining relief of pain. Other causes of back and leg pain coming from the spine or hip must be ruled out.
What is the treatment for SI joint pain/dysfunction?
The treatment for SI joint pain involves a combination of anti-inflammatory medications and physical therapy or chiropractic manipulation. For persistent pain, SI joint injections can provide both therapeutic pain relief and help confirm the diagnosis. An effective joint injection should provide the patient with 3-6 months of pain reduction. Another procedure that may provide relief is known as radiofrequency ablation. The technique involves use of specialized needles and heat to inactivate painful nerves supplying the sacroiliac joint thereby interrupting pain signals to the brain. If injections and radiofrequency ablation fail to provide long lasting relief then surgery may be a good option. The surgery known as sacroiliac joint fusion involves a minimally invasive approach to stabilize the joint typically by inserting three titanium implants across the joint. The surgery has been shown to provide significant, long lasting pain relief for greater than 80% of patients.