Sacroiliac Joint (SI Joint) Anatomy
Sacroiliac Joint (SI Joint) Anatomy
The sacroiliac joint (SI joint) is located in the pelvis; it links the iliac bones (pelvis) to the sacrum (lowest part of the spine above the tailbone). It is an essential component for shock absorption to prevent impact forces from reaching the spine.
Do you have SI Joint Problems?
The SI joint is a significant cause of low back pain.Clinical publications have identified the SI joint as a pain generator in 15-30% of chronic low back pain patients.1-4 In addition, the SI joint is a pain generator in up to 43% of patients with continued or new onset low back pain after a lumbar fusion.5
Like any other joint in the body, the SI joint can be injured and/or become degenerative. When this happens, people can feel pain in their buttock and sometimes in the low back and legs. This is especially true while lifting, running, walking or even sleeping on the involved side.
According to scientific data, it’s common for pain from the SI joint to feel like disc or low back pain. For this reason, SI joint disorders should always be considered in low back pain diagnosis.
Do you experience one or more of the symptoms listed below?
Low back pain
Sensation of low extremity pain, numbness, tingling, weakness
Pelvis/buttock pain
Hip/groin pain
Feeling of leg instability (buckling, giving way)
Disturbed sleep patterns
Disturbed sitting patterns (unable to sit for long periods, sitting on one side)
Pain going from sitting to standing
Making a Diagnosis
A variety of tests performed during physical examination may help reveal the SI joint as the cause of your symptoms. Sometimes, X-rays, CT-scan or MRI may be helpful in the diagnosis of SI joint-related problems.
The most relied upon method to accurately determine whether the SI joint is the cause of your low back pain symptoms is to inject the SI joint with a local anesthetic. The injection will be delivered under either X-ray or CT guidance to verify accurate placement of the needle in the SI joint. If your symptoms are decreased by at least 50%, it can be concluded that the SI joint is either the source of or a major contributor to your low back pain. If the level of pain does not change after SI joint injection, it is less likely that the SI joint is the cause of your low back pain.
Treatment Options
Once the SI joint is confirmed as the cause of your symptoms, treatment can begin. Some patients respond to physical therapy, use of oral medications, or injection therapy. These treatments are often performed repetitively, and frequently symptom improvement using these therapies is temporary. At this point, you and your surgeon may consider other options, including minimally invasive surgery.
SI Joint Fusion with the iFuse Implant System®
The iFuse Implant System is designed to provide stabilization and fusion for certain SI joint disorders. This is accomplished by inserting triangular- shaped titanium implants across the sacroiliac joint to maximize post- surgical stability and weight bearing capacity. The procedure is done through a small incision and takes about an hour. Multiple published studies on iFuse have documented procedure safety and effectiveness