Definition

Sacroiliac (SI) joint pain is felt in the low back and may spread to the groin and legs. There is one joint on the right side of the spine and one on the left. They are held together with strong bands of fiber called ligaments. The joints help reduce impact on the spine during things like walking.

Sacroiliac Joint Copyright © Nucleus Medical Media, Inc.

Causes

Damage to bones or ligaments of the joint can cause swelling and pain. This can irritate nearby nerves. This leads to more pain.

Inflammation of the joints may be caused by:

• Problems in the bones of the joint such as:
  • Osteoarthritis
  • Infection of the joint
  • Ankylosing spondylitis
  • Stress fractures
• Injuries to the ligaments from:
  • Regular high-impact activities such as jogging
  • Trauma such as a motor vehicle accident or a fall
  • Falling or taking awkward steps off a curb or step
• Changes during pregnancy that allow the joints to move more than they should

Risk Factors

Things that may raise the risk of this problem are:

• Weak muscles
• Improper lifting
• Inflammatory conditions, such as ankylosing spondylitis or psoriatic arthritis
• High-impact sports or activities

Symptoms

SI joint pain will differ based on the exact cause. The low back pain may be dull or sharp. It may also be mild to severe. Other problems may be:

• Pain in the buttocks
• Pain that seems deep in the pelvis
• Pain in the hip, groin, or back of the thigh
• Pain that spreads down the leg on the affected side
• Stiffness of the lower spine

Pain may increase with certain activities, such as walking, twisting, rising to stand, or bending.

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done. It will focus on the back. This is often enough to make the diagnosis.

Pictures of the back may be taken if there are severe symptoms. This can be done with:

• X-rays
• CT scan

The doctor may also use a nerve block to make sure the pain is coming from the SI joint. Medicine that blocks pain is injected near the SI joint. If pain stops, then the joint is confirmed as the cause.

Treatment

Underlying causes will be treated. The goal of treatment is to manage symptoms and give the joints time to heal. Choices are:

• Initial care, such as resting the back and using cold or warm packs
• Medicine to ease pain and swelling, such as:
  • Over the counter pain relievers, such as ibuprofen
  • Prescription pain relievers
  • Muscle relaxants
  • Steroid injections into the sacroiliac joint
• Physical therapy to improve strength and range of motion

Prevention

Decreasing stress on the back will lower the chance of SI joint pain. This may be done through:

• Exercising regularly to keep muscles strong
• Using proper techniques for bending, lifting, or playing sports