The Difference Between Sciatica and SI Joint Dysfunction

Sciatica vs. SI Joint Dysfunction

When trying to determine whether you are dealing with sciatica or SI joint dysfunction, it may be helpful to recognize what each condition is and where the pain originates.

What Is SI Joint Dysfunction?

The SI joint is located where the spine meets the pelvis and provides shock absorption for the upper body. However, when the SI joint is not working correctly, you may experience lower back and leg pain similar to sciatica.

What Is Sciatica?

Sciatica is defined as pain that radiates along the sciatic nerve path. The sciatic nerve is the longest nerve in the body and branches from your lower back through your hips and buttocks and down each leg. Like SI joint dysfunction, sciatica tends to affect one side of your body at a time and may vary in intensity. 

The Causes of Sciatica vs. SI Joint Dysfunction

Understanding the difference between the cause of sciatica and SI joint dysfunction starts with understanding the root of each condition. By figuring out the source of your discomfort, your pain may become easier to diagnose and treat.

What Causes Sciatica?

Sciatica is often caused by a herniated disc, bone spur, or narrowing of the spinal canal, otherwise known as spinal stenosis. When a nerve in your lower back becomes compressed, irritated, or inflamed, it may cause radiating pain along the sciatic nerve, thus causing sciatica. 

What Causes SI Joint Dysfunction?

Unlike sciatica, SI joint dysfunction is not caused by nerve compression. Instead, this condition can be brought on by several different factors, including:

• A traumatic injury
• Osteoarthritis
• Ankylosing spondylitis
• Infections of the sacroiliac joints

Pregnancy may also lead to SI joint dysfunction due to the release of the hormone relaxin. In addition, the extra weight brought on by pregnancy may lead to instability, stress, and abnormal wear to the SI joint.

The Symptoms of Sciatica vs. SI Joint Dysfunction

While sciatica and SI joint dysfunction have similar symptoms, there are a few key ways to tell them apart. One distinguishable factor between the two conditions is the pattern of pain.

SI joint pain often affects the lower back and is off to one side. Sacroiliac joint pain is usually easy to pinpoint. On the other hand, sciatica tends to start in the lower back and radiate down the sciatic nerve path. As a result, this pain may be more difficult to localize.  

Symptoms of Sciatica

The symptoms of sciatica may vary in intensity. For some, the pain is manageable and only causes mild discomfort. However, others may experience more severe pain that interferes with their daily activities.

Symptoms of sciatica include:

• Numbness in the lower back, buttocks, legs, or feet
• Sharp pain that radiates from the lower back and down the legs
• Difficulty walking
• Muscle weakness
• Burning or tingling sensations

Symptoms of SI Joint Dysfunction

Like sciatica, SI joint dysfunction may cause pain in the lower back, buttocks, and legs. Additionally, you may also experience:

• Instability in the pelvis
• Reduced range of motion in the lower back, pelvis, and hips
• Increased pain when running or putting weight on one side
• Sharp, stabbing pain in the buttocks and back of thighs

While SI joint dysfunction may produce sciatica-like symptoms, it rarely goes beyond the knee. 

Diagnostic Testing for SI Joint Pain

Because SI joint dysfunction and sciatica symptoms are similar, it may be challenging to determine which condition you are experiencing. Therefore, your doctor may conduct a diagnostic test such as the Fortin finger test to help determine whether you are dealing with SI joint dysfunction or sciatica.

Your doctor may also use a combination of a physical examination, medical history, and imaging tests to diagnose your condition.

How Is the Fortin Finger Test Conducted?

During the Fortin finger test, you will either sit or stand and be asked to pinpoint where you are experiencing pain. Your doctor will then ask you to identify your area of pain again, but this time with your eyes closed.

If you are able to identify the pain within 1 cm of the posterior superior iliac spine (PSIS) twice in a row, you are likely dealing with SI joint dysfunction. The PSIS is the section of the hip where the major ligaments of the hip attach. 

If you have difficulty pinpointing the pain or your pain moves around, it is likely that you are dealing with sciatica or another condition.

Treatments for Sciatica and SI Joint Dysfunction

If you think you may be experiencing either sciatica or SI joint dysfunction, it is important to see a medical professional. Visiting a doctor is the best way to diagnose your condition and find an appropriate treatment plan.

Treatment Options for Sciatica

For some, home remedies may be enough to relieve sciatic nerve pain. While resting for a few days may be necessary, too much rest may worsen your pain. 

Other at-home treatments may include:

• Using cold packs or heat pads
• Stretching
• Over-the-counter pain medication such as ibuprofen

If home remedies do not provide relief, your doctor may recommend:

• Medications such as anti-inflammatories and muscle relaxants
• Physical therapy
• Corticosteroid injections
• Acupuncture
• Chiropractic care

Surgery is a last resort and is only recommended if other treatment options have been unsuccessful. 

Treatment for SI Joint Dysfunction

Treating SI joint dysfunction often starts with home remedies such as ice, heat, exercise, and over-the-counter pain medication. Like sciatica, rest for a day or two may be advised. However, too much rest may worsen your pain.

If at-home treatments do not provide relief, your doctor may recommend:

• Physical therapy
• Supportive braces
• Sacroiliac joint injections
• Chiropractic care

The LinQ Stabilization System

If home remedies, physical therapy, and other nonsurgical treatments do not provide relief from SI joint dysfunction, the LinQ SI Joint Stabilization System may be able to help. This treatment provides patients with a minimally invasive option that may help them get long-term relief from SI joint pain.

This innovative procedure uses a small bone allograft implant designed to stabilize the dysfunctional SI joint. After the procedure, most patients are able to leave the hospital the same day and return to most of their normal activities within a few weeks.

Discover How LinQ May Help Your Low Back Pain

If you are dealing with low back pain or SI joint dysfunction and would like to find a LinQ provider near you, contact PainTEQ today. We would be happy to connect you with a doctor who can answer your questions and help you get started on the path to finding relief.