Sacroiliac (SI) Joint Dysfunction: Causes and Advanced Treatment Options

Understanding Sacroiliac Joint Dysfunction

Lower back pain is one of the most common reasons people seek medical care, but not all back pain originates from the spine itself. In many cases, the source of discomfort may be the sacroiliac (SI) joints—two joints located where the sacrum (the triangular bone at the base of the spine) connects to the pelvis.

When these joints become inflamed, irritated, or dysfunctional, patients may experience significant pain that can affect mobility, daily activities, and overall quality of life. Fortunately, advances in diagnosis and treatment are helping many patients find relief without major surgery.

What Is the SI Joint?

The sacroiliac joints act as shock absorbers between the upper body and lower extremities. These joints transfer forces generated during walking, standing, lifting, and other movements.

Although the SI joints move only slightly, they play an important role in maintaining stability and supporting the body’s weight. Even small changes in joint function can lead to significant discomfort.

What Causes SI Joint Dysfunction?

SI joint dysfunction occurs when the joints become either too mobile (hypermobility) or too stiff (hypomobility). Both situations can trigger inflammation and pain.

Common causes include:

Arthritis

Age-related wear and tear can cause degeneration of the SI joints, similar to osteoarthritis in other joints throughout the body.

Injury or Trauma

Falls, car accidents, sports injuries, or sudden impacts can damage the ligaments and structures surrounding the SI joint.

Pregnancy and Childbirth

Hormonal changes during pregnancy loosen ligaments to prepare the body for delivery. This increased flexibility can place additional stress on the SI joints and sometimes lead to lingering pain after childbirth.

Previous Spine Surgery

Patients who have undergone lumbar fusion surgery may develop SI joint dysfunction because the altered mechanics of the spine can place greater stress on the pelvis.

Repetitive Stress

Activities involving repetitive twisting, lifting, running, or prolonged standing may contribute to SI joint irritation over time.

What Are the Symptoms of SI Joint Dysfunction?

SI joint pain can mimic several other conditions, making diagnosis challenging.

Common symptoms include:

• Pain in the lower back
• Pain on one side of the buttock
• Hip pain
• Groin discomfort
• Pain that radiates into the thigh
• Difficulty standing after sitting for long periods
• Increased pain when climbing stairs
• Pain when getting in or out of a vehicle
• Discomfort during prolonged standing or walking

Unlike lumbar nerve compression, SI joint dysfunction usually does not cause numbness, tingling, or weakness extending below the knee.

Why Is SI Joint Dysfunction Often Misdiagnosed?

Because SI joint symptoms overlap with conditions such as:

• Lumbar disc herniations
• Facet joint arthritis
• Hip disorders
• Piriformis syndrome
• Sciatica

many patients spend months or even years seeking answers before receiving an accurate diagnosis.

Research suggests that SI joint dysfunction may account for up to 15-30% of chronic lower back pain cases, yet it is frequently overlooked.

How Is SI Joint Dysfunction Diagnosed?

Medical History

Providers review symptom patterns, previous injuries, surgeries, and factors that worsen or relieve pain.

Physical Examination

Specific movement tests can help identify SI joint involvement. Patients may be asked to perform certain motions that place stress on the joint to reproduce symptoms.

Imaging Studies

X-rays, MRI scans, and CT scans may help rule out other causes of pain, although SI joint dysfunction itself is not always visible on imaging.

Diagnostic SI Joint Injection

One of the most accurate diagnostic tools involves injecting a local anesthetic directly into the SI joint using image guidance. Significant pain relief following the injection strongly suggests the SI joint is the source of symptoms.

Conservative Treatment Options for Sacroiliac Joint Dysfunction

Physical Therapy

A structured physical therapy program can help:

• Improve pelvic stability
• Strengthen supporting muscles
• Correct movement patterns
• Enhance flexibility

Activity Modification

Avoiding activities that aggravate symptoms while maintaining healthy movement can reduce irritation and promote healing.

Anti-Inflammatory Medications

NSAIDs may help decrease inflammation and provide short-term symptom relief.

SI Belts and Bracing

External support devices may improve pelvic stability, particularly in patients with ligament laxity or postpartum SI joint pain.

Advanced Interventional Treatments

Image-Guided SI Joint Injections

Corticosteroid injections performed under fluoroscopic or ultrasound guidance can reduce inflammation within the joint and provide significant pain relief.

Many patients experience symptom improvement that allows them to return to physical therapy and normal activities.

Radiofrequency Ablation (RFA)

For patients with persistent SI joint pain, radiofrequency ablation may offer longer-lasting relief.

During this minimally invasive procedure, specialized needles target the nerves responsible for transmitting pain signals from the SI joint. Heat generated by radiofrequency energy disrupts these pain pathways.

Benefits may include:

• Reduced pain
• Improved mobility
• Relief lasting six months to over a year in some patients
• Avoidance of more invasive procedures

Regenerative Medicine Treatments

Emerging regenerative therapies are becoming increasingly popular for certain patients with SI joint dysfunction.

These treatments may include:

• Platelet-Rich Plasma (PRP)
• Orthobiologic injections

The goal is to support the body’s natural healing processes and potentially improve the health of damaged ligaments and surrounding tissues.

Patients should discuss candidacy and expected outcomes with a qualified specialist, as regenerative medicine is not appropriate for every condition.

Minimally Invasive SI Joint Fusion

In severe cases where conservative and interventional treatments fail, minimally invasive SI joint fusion may be considered.

This procedure stabilizes the joint using specialized implants, reducing abnormal motion that contributes to pain.

Compared to traditional surgical techniques, modern minimally invasive approaches typically involve:

• Smaller incisions
• Reduced tissue disruption
• Faster recovery times
• Shorter hospital stays

When Should You See a Specialist?

• Lower back pain persists for several weeks
• Symptoms interfere with work or daily activities
• Conservative treatments have not helped
• Pain worsens with standing, walking, or stair climbing
• You have a history of pelvic trauma or lumbar fusion surgery

The Bottom Line

Sacroiliac joint dysfunction is a common but frequently overlooked source of lower back, buttock, and hip pain. Because its symptoms often mimic spine and hip conditions, obtaining an accurate diagnosis is critical.

Fortunately, treatment options have expanded significantly in recent years. From physical therapy and targeted injections to radiofrequency ablation, regenerative medicine, and minimally invasive SI joint fusion, patients now have more opportunities than ever to find lasting relief.

If chronic lower back or pelvic pain has not responded to traditional treatments, the SI joint may be worth investigating as a potential source of symptoms.