An Overview of Sacroiliac Joint Pain

Man with back pain trying to exercise
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You are likely acutely aware of your low back pain, but what you may not realize is exactly why it's occurring. Issues related to the sacroiliac (SI) joints are common, yet somewhat under-recognized causes. SI joints (there are two) are located on either side of your lower back between the sacrum—a triangle-shaped bone that sits beneath the lumbar spine and above the tailbone—and the pelvic bones. SI joints, like any other, can become irritated, dysfunctional (they move too much or not enough), or injured, all of which can lead to pain.

Given that your sacroiliac joints serves two purposes—to act as a shock absorber, decreasing stress on the pelvis and spine, and to appropriately transfer the load from your upper body to your lower body when standing or walking—it's easy to see how they can become compromised.

Causes

The "why" behind SI joint pain commonly stems from repetitive use. For example, the continued pounding pressure from an exercise like running may be a cause. Other causes or factors that increase a person's risk for developing SP joint pain include:

  • An injury or trauma to the ligaments that surround the SI joint
  • Previous spine surgery
  • Pregnancy (though the pain is temporary)
  • Uneven leg length that disrupts walking patterns

Since the sacroiliac joint is a synovial joint, it can also be affected by whole-body conditions that result in joint inflammation. For example, ankylosing spondylitis is a type of inflammatory arthritis that causes pain and stiffness in the SI joint and spine joints. Gout is another form of inflammatory arthritis that results from the uric acid buildup in various joints, including the SI joint.

Symptoms

The primary symptom of sacroiliac joint pain, as its name suggests, is pain, often reported as sharp, stabbing, or dull and located in the lower back or the back of the hip area. Sometimes the pain is felt in the groin, thigh, below the knee, or in the buttocks. Movements or positions that stress the joint can worsen the pain, such as standing up from a sitting position, walking up stairs, turning in bed, or bending/twisting.

Keep in mind, depending on the cause, other symptoms (both musculoskeletal and non-musculoskeletal) may arise. For instance, with ankylosing spondylitis, a person classically experiences back stiffness that is worse in the morning and improves with activity. Other potential symptoms of ankylosing spondylitis include pain in the hip or shoulders, fatigue, and non-joint related symptoms like eye pain and blurry vision.

Diagnosis

Diagnosing SI joint dysfunction can be particularly tricky. This is because it can be challenging to locate the SI joint on a physical exam. Moreover, tenderness over the SI joint is not a slam-dunk test for confirming a diagnosis. This is because other conditions can refer pain to the sacroiliac joint, such as a herniated disc in the lower spine, spinal stenosis, or osteoarthritis or bursitis of the hip.

Furthermore, while imaging tests, like an X-ray, computed tomography (CT) scan, or magnetic resonance imaging (MRI), may be helpful in the diagnostic process, they can also appear "normal," despite a true SI problem being present.

Although still debated, some experts consider an image-guided injection of anesthetic (a numbing agent) into the joint as the "gold standard" diagnostic test for SI joint dysfunction. If a person experiences at least a 75 percent improvement in pain, the test is considered "positive."

The upside of this test is that following the anesthetic (if pain relief is achieved), a corticosteroid can be injected into the SI joint to provide longer-lasting relief.

Treatment

Besides a corticosteroid injection into the sacroiliac joint, there are a variety of other therapies used to treat SI joint pain. In fact, prior to (or in addition to) recommending an injection into the joint, a doctor will likely recommend physical therapy exercises and nonsteroidal anti-inflammatory drugs (NSAIDs) to ease pain and inflammation.

A physical therapist will closely examine your SI joint, as well as your spine, hips, pelvis, and leg muscles. He will also ask you several questions related to your pain and devise a treatment plan based on your evaluation.

Some specific therapies recommended for SI joint pain include:

  • Massage and techniques to correct the SI joint alignment
  • Stretching and strengthening exercises
  • Hot and cold treatments to relax the muscles and ease the pain
  • Wearing a sacroiliac belt to support the joint (this is commonly recommended for pregnant women with SI joint pain)

If these conservative therapies do not provide relief, the last resort option is surgery to fuse the sacroiliac joints.

Lastly, for SI joint pain due to inflammatory arthritis, whole-body therapies may be recommended. For instance, anti-TNF drugs may be indicated for ankylosing spondylitis to prevent the disease from getting worse.

A Word From Verywell

Sacroiliac joint pain can be debilitating and intrusive to your daily life, but the upside is that it can often be treated with simple, conservative measures, as well as a little time and patience. If you are finding that your current treatment plan is not working, talk with your primary care doctor. You may benefit from seeing a doctor who specializes in SI joint pain, such as a sports medicine doctor or a physiatrist.

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