What Causes SI Joint Pain? Signs, Symptoms, and Non-Surgical Treatment Options

Lower back pain is one of the most common reasons people seek medical care, but not all lower back pain originates from the spine. For many individuals, the source of discomfort is the sacroiliac (SI) joint, a small but essential joint that connects the spine to the pelvis. SI joint dysfunction can cause pain that closely resembles sciatica, herniated discs, or hip problems, making it difficult to diagnose without a thorough evaluation.

Understanding what causes SI joint pain, recognizing its symptoms, and learning about available non-surgical treatment options can help patients find lasting relief while avoiding unnecessary procedures.

What Is the SI Joint?

The sacroiliac joints are two joints located where the sacrum, the triangular bone at the base of the spine, meets the iliac bones of the pelvis. These joints play an important role in transferring the body’s weight from the upper body to the legs while providing stability during standing, walking, lifting, and other everyday activities.

Although the SI joints allow only a small amount of movement, even minor changes in joint function can lead to significant pain and inflammation.

What Causes SI Joint Pain?

Arthritis

Osteoarthritis is one of the most common causes of SI joint pain. As cartilage gradually wears away with age, the joint surfaces become irritated, resulting in stiffness and discomfort.

Inflammatory conditions such as ankylosing spondylitis or other forms of inflammatory arthritis can also affect the SI joints.

Injury or Trauma

Falls, motor vehicle accidents, or sports injuries can damage the ligaments that stabilize the SI joint. Even if the initial injury heals, lingering instability may continue to cause chronic pain.

Pregnancy and Childbirth

Hormonal changes during pregnancy relax the ligaments surrounding the pelvis to prepare for childbirth. This increased flexibility, combined with additional body weight, places extra stress on the SI joints. While many women improve after delivery, some continue to experience persistent SI joint pain.

Repetitive Stress

Occupations or activities involving frequent bending, twisting, lifting, running, or prolonged standing can gradually strain the SI joints over time.

Previous Spine Surgery

Patients who have undergone lumbar fusion surgery may develop SI joint pain because the altered mechanics of the spine place increased stress on the joints below the fusion.

Leg Length Differences or Abnormal Walking Patterns

A difference in leg length or an abnormal gait can create uneven pressure across the pelvis, increasing stress on one SI joint and leading to chronic irritation.

What Are the Common Symptoms of SI Joint Pain?

SI joint pain often mimics other spinal conditions, making an accurate diagnosis essential. Common symptoms include:

• Pain in the lower back, especially below the waist
• Pain on one side of the buttock
• Pain that radiates into the hip, groin, or upper thigh
• Discomfort when standing after prolonged sitting
• Pain while climbing stairs
• Increased pain when walking or standing for extended periods
• Difficulty turning over in bed
• Tenderness over the SI joint
• Stiffness in the lower back or pelvis

Unlike true sciatica, SI joint pain usually does not travel below the knee, although every patient experiences symptoms differently.

How Is SI Joint Pain Diagnosed?

Diagnosing SI joint dysfunction begins with a detailed medical history and physical examination. A pain specialist will evaluate movement patterns, identify areas of tenderness, and perform specific physical tests designed to stress the SI joint.

Imaging studies such as X-rays, CT scans, or MRI may help rule out other conditions affecting the spine or hips, although they do not always confirm SI joint dysfunction.

One of the most reliable diagnostic tools is a fluoroscopically guided SI joint injection. If temporarily numbing the joint significantly reduces pain, it strongly suggests the SI joint is the primary pain source.

What Non-Surgical Treatments Are Available?

Physical Therapy

Physical therapy is often the first step in treatment. A customized exercise program can strengthen the muscles supporting the pelvis, improve flexibility, and reduce abnormal stress on the SI joints.

Activity Modification

Avoiding activities that worsen symptoms while gradually increasing movement helps prevent further irritation without promoting prolonged inactivity.

Anti-Inflammatory Medications

When appropriate, nonsteroidal anti-inflammatory medications (NSAIDs) may help reduce inflammation and improve comfort as part of a comprehensive treatment plan.

SI Joint Injections

Image-guided corticosteroid injections can reduce inflammation within the joint while providing both diagnostic information and therapeutic pain relief. Many patients experience significant improvement that allows them to participate more effectively in rehabilitation.

Radiofrequency Ablation

For patients with persistent SI joint pain, radiofrequency ablation (RFA) may provide longer-lasting relief by interrupting pain signals transmitted by the nerves surrounding the joint.

Pain relief often lasts several months or longer before the nerves gradually regenerate.

Regenerative Medicine

In carefully selected patients, regenerative medicine therapies such as platelet-rich plasma (PRP) may help support the body’s natural healing response and improve joint function. Your physician can determine whether these treatments are appropriate based on your diagnosis and overall health.

When Should You See a Pain Specialist?

Persistent lower back or buttock pain should not be ignored, especially if symptoms interfere with work, exercise, sleep, or daily activities. Because SI joint dysfunction closely resembles other spinal conditions, obtaining an accurate diagnosis is the first step toward effective treatment.

Early evaluation can help identify the true source of pain and allow patients to begin targeted therapies before symptoms become chronic.

Finding Relief from SI Joint Pain

SI joint pain is a common but often overlooked cause of lower back, hip, and buttock pain. Fortunately, advances in diagnosis and minimally invasive treatments allow many patients to find significant relief without surgery. Through personalized treatment plans that may include physical therapy, image-guided injections, radiofrequency ablation, and other non-surgical therapies, patients can reduce pain, restore mobility, and return to the activities they enjoy.

If you are experiencing persistent lower back or pelvic pain, scheduling an evaluation with an experienced interventional pain specialist can help determine whether your SI joint may be the underlying cause and identify the most appropriate treatment options for your condition.

Disclaimer: This article is intended for educational purposes only and should not be considered medical advice. Always consult a qualified healthcare provider regarding diagnosis and treatment recommendations for your specific condition.