Sacroiliac Joint Dysfunction
Pain from the joint linking the spine and pelvis
Quick Facts
- Type: Musculoskeletal (joint) condition
- Location: Lower back and buttock
- Common in: Pregnancy, after injury, arthritis
- Treatment: Physical therapy, medication, injections
Overview
The sacroiliac (SI) joints are two strong joints that connect the triangular bone at the base of the spine (the sacrum) to the pelvis (the ilium), one on each side. They transfer weight between the upper body and the legs and normally move only a small amount. Sacroiliac joint dysfunction is a term for pain and problems arising from these joints, whether from too much movement, too little movement, or inflammation.
SI joint dysfunction is a common but often overlooked cause of lower back and buttock pain. Because its symptoms overlap with other back problems such as a herniated disc or hip arthritis, it can be tricky to pin down. The good news is that most cases improve with non-surgical treatment.
Symptoms
The main symptom is pain, usually on one side, that may include:
- Pain in the lower back and buttock
- Pain that can spread into the hip, groin, or down the back of the thigh, often not below the knee
- Discomfort that worsens with standing for long periods, climbing stairs, or rising from sitting
- Pain when putting weight on the affected leg
- A feeling of stiffness or instability in the pelvis
Symptoms can resemble sciatica or hip problems. Pain is often worse with prolonged standing or with movements that stress the joint, such as getting in and out of a car.
Causes
Sacroiliac joint dysfunction can result from the joint moving too much, too little, or becoming inflamed. Contributing causes include:
- Injury: A fall, car accident, or sudden impact that jolts the joint.
- Pregnancy: Hormones loosen the pelvic ligaments and the changing posture and weight stress the joints.
- Arthritis: Wear-and-tear osteoarthritis or inflammatory conditions such as ankylosing spondylitis.
- Uneven movement: A difference in leg length, an altered gait, or stress on one side after hip or spine surgery.
- Repetitive strain: Heavy lifting or repeated stress on the joint.
Risk Factors
- Pregnancy and recent childbirth
- Previous lower back, pelvic, or hip injury
- Osteoarthritis or inflammatory arthritis such as ankylosing spondylitis
- A difference in leg length or an abnormal walking pattern
- Previous spinal fusion surgery, which can stress the SI joints
- Activities involving repeated heavy lifting or impact
Diagnosis
Diagnosing SI joint dysfunction can be challenging because its symptoms overlap with other conditions. Doctors use:
- History and physical exam: Asking about the pain and performing maneuvers that stress the SI joint to see if they reproduce the pain.
- Ruling out other causes: Checking for hip arthritis, a herniated disc, or nerve problems.
- Imaging: X-rays, CT, or MRI to look for arthritis, inflammation, or other problems, though imaging is often normal.
- Diagnostic injection: Injecting a numbing medication into the joint; significant relief supports the diagnosis.
Treatment
Most people improve with non-surgical care aimed at reducing pain and restoring normal joint movement.
- Physical therapy: Exercises to strengthen the muscles around the pelvis and core, improve posture, and stabilize the joint.
- Pain relief: Anti-inflammatory medications and, for short periods, heat or ice.
- Activity changes: Modifying movements that aggravate the joint and improving body mechanics.
- Supportive devices: A pelvic belt may help in some cases, including during pregnancy.
- Injections: Corticosteroid injections into the joint can reduce inflammation and pain.
- Procedures or surgery: Rarely, nerve treatments or joint fusion are considered for persistent, severe cases that do not respond to other care.
Prevention
You can reduce the chance of SI joint pain or recurrences with a few habits:
- Keep your core and hip muscles strong with regular exercise
- Use good posture and safe lifting techniques
- Maintain a healthy weight to reduce stress on the pelvis
- Warm up before sports and avoid sudden overexertion
- Address leg-length differences or gait problems with your doctor or a physical therapist
When to See a Doctor
See a doctor if you have persistent lower back or buttock pain that does not improve with rest and self-care, or that interferes with daily activities. Seek prompt care if your back or buttock pain is accompanied by:
- Numbness, tingling, or weakness in the legs
- Loss of bladder or bowel control
- Fever, unexplained weight loss, or pain following a significant injury
These features can point to a more serious problem that needs urgent evaluation.
Frequently Asked Questions
Where is sacroiliac joint pain felt?
SI joint pain is usually felt on one side in the lower back and buttock, and it can spread into the hip, groin, or the back of the thigh, often not below the knee. It tends to worsen with standing, climbing stairs, or rising from a seated position.
What causes sacroiliac joint dysfunction?
It can result from the joint moving too much or too little, or from inflammation. Common causes include injury, the ligament loosening and posture changes of pregnancy, arthritis, a leg-length difference, and stress after spinal fusion surgery.
How is sacroiliac joint dysfunction diagnosed?
Doctors use the history, a physical exam with maneuvers that stress the joint, and tests to rule out other causes such as a disc problem or hip arthritis. Imaging is often normal, so a numbing injection into the joint is sometimes used to confirm it.
How is SI joint dysfunction treated?
Most people improve with physical therapy, anti-inflammatory medication, activity changes, and sometimes a pelvic support belt. Corticosteroid injections can reduce pain, and surgery such as joint fusion is reserved for severe cases that do not respond to other care.
Can pregnancy cause SI joint pain?
Yes. During pregnancy, hormones loosen the pelvic ligaments and the changing weight and posture put extra stress on the sacroiliac joints, which commonly causes lower back and buttock pain. It often improves after delivery, and physical therapy can help.
References
- MedlinePlus, U.S. National Library of Medicine. Sacroiliac joint pain.
- American Academy of Orthopaedic Surgeons (AAOS).
- Mayo Clinic. Back pain — Symptoms and causes.
- Arthritis Foundation. Ankylosing Spondylitis and the SI Joints.