The sacroiliac, or SI, joint is located where the bones at base of the spine join the bones of the pelvis. It is formed by the sacrum, which is located right above the tail bone and the ilium or the top portion of the girdle shaped pelvis. The SI joint also contains muscles, tendons and ligaments. There are two SI joints, one on each side of the body. This area is a common place for injuries, including inflammatory conditions. The first step in treatment is to determine the cause of SI joint inflammation or sacroiliitis, so that treatment and preventative measures can begin.
Arthritis
One of the many inflammatory forms of arthritis can contribute to the development of sacroiliitis, claims the OhioHealth website. This includes forms of arthritis called spondyloarthropathies, such as ankylosing spondylitis, reactive arthritis and psoriatic arthritis. The joint inflammation can also be secondary to inflammatory bowel disease or enteropathic arthritis. All of these conditions, can cause inflammation in any area of the body, but they tend to be worse in the spine.
Other forms of arthritis, such as degenerative disc disease and osteoarthritis, can also cause changes in the lower spine that leads to inflammation of the SI joints. The first step in treatment is to address the specific form of arthritis present.
Infections
While rare, an infection can cause inflammation of the SI joints, warns a report in the Journal of Bone and Joint Surgery. Since an infection is rarely the cause, diagnosis and treatment may be delayed. A wide variety of types of bacteria can cause this condition. It may begin as an infection somewhere else in the body such as tonsillitis, an infection in the intestines or other disease, which then spreads to SI joint. Bed rest and weeks of antibiotic therapy are usually required to resolve the symptoms.
Accidents
A direct blow to the SI joint can lead to inflammation, states the Internet Society of Orthopaedic Surgery and Trauma webpage. This includes automobile accidents or a direct blow to the hip from a fall or sporting event. Since an inflammation of the SI joint can cause back pain, this condition is often misdiagnosed as a herniated disk or other back-related problem. However, scans can be ordered to help rule out other causes.
Pregnancy
During pregnancy, many changes happen to the body. There is extra pressure on the back and pelvis from the size and weight of the fetus. A woman may walk or move differently to accommodate the changes. In addition, during this time the body releases various hormones, some of which can cause the ligaments in the SI joint to loosen, to make delivery easier. According to the Mayo Clinic, all of the above can contribute to SI joint pain and inflammation.
