Sacroiliac (SI) Joint Dysfunction | What is it?

Experiencing frustrating lower back, hip or groin pain? The source could be arising from your sacroiliac (SI) joint. Sacroiliac joint dysfunction is an all too common culprit of lower back, hip or groin pain, responsible for approximately 15-30% of lower back pain cases. Properly understanding the intricacies surrounding what causes this debilitating condition and how it’s accurately diagnosed is the key to hopefully finding lasting relief.

Let’s closely explore the anatomy, causes, symptoms, diagnosis and treatment options for SI joint dysfunction.

Understanding Your SI Joint Anatomy

The sacroiliac (SI) joints provide an important connection between your lower spine and pelvis. Learning some basics about SI joint anatomy will help you understand where your pain may be coming from and why certain treatments are recommended.

First, picture your spine. The SI joints sit just above your tailbone, attaching your sacrum to your hip bones. Your triangular sacrum forms the base of your spine, with one SI joint connecting each side to your inner hip sockets. So you have two SI joints total, one on the left and one on the right, spanning the lower part of your back on each side of your sacrum.

Now let’s examine the joint structure. The hipbone side is covered with sturdy fibrocartilage while the sacrum side contains slippery hyaline cartilage, allowing subtle movements to absorb impact. A fibrous ligament network crisscrosses each joint, limiting excessive mobility to avoid instability.

The ligaments of the SI Joint include the following:

• Anterior sacroiliac: Connects the front pelvis to the sacrum
• Posterior sacroiliac: Connects the back pelvis to the sacrum
• Interosseous: Surrounds the sacrum side, attaching it firmly to the pelvis
• Sacrotuberous: Stabilizes the back of the pelvis and sacrum
• Sacrospinous: Spans from the sacrum to pelvic spine for added support

Numerous nerves also supply sensation. The SI region is actually densely packed with nerve endings, which is why dysfunction can cause such severe pain.

What Exactly Causes SI Joint Pain?

There are a few key mechanisms that produce pain in the SI region:

Hypermobility

• Excess motion severely strains ligaments
• Creates pelvic instability
• Very common in pregnancy

Hypomobility

• Restricted movement
• Muscle tension and stiffness
• Degenerative changes like arthritis

Inflammation

• Infection
• Autoimmune disease
• Can cause considerable swelling/pain

Trauma

• Falls, fractures, accidents
• Whiplash injuries
• Can overstretch or partially tear ligaments

In pregnancy, the hormone relaxin intentionally loosens ligaments and extra weight gain strains joints. Inflammation doesn’t always cause observable damage but small tears or bone spurs can irritate nerves. Let’s closely explore the most common symptoms so you can determine if your pain fits the pattern.

Major Signs of SI Joint Dysfunction

Subtle rocking movements enable shock absorption but excessive strain can cause piercing pain. Women are especially vulnerable during pregnancy when extra weight gain and hormones deliberately loosen ligaments.

• Lower back pain just above the tailbone is classic
• Pain on one side of the lower back/buttocks
• Groin pain when walking
• Pain severely shooting down legs
• Pain when standing up from sitting
• Activities like walking up stairs or changing sitting positions
• Morning stiffness
• No numbness/tingling indicating nerve damage

The tricky aspect is that SI pain often radiates, mimicking sciatica from a herniated disc. But the quality of nerve-related pain differs – your doctor should thoroughly investigate all possibilities.

Diagnosing the Cause

Since many conditions cause lower back/pelvic pain, accurately diagnosing the root cause takes some attentive sleuthing and persistence. Your doctor will:

• Take a detailed medical history – ask about past injuries, pregnancy, etc.
• Thoroughly palpate the lower back & pelvic area
• Perform several provocative tests moving your legs to assess pain response
• Order imaging exams – x-rays, CT or MRI scans
• Potentially inject numbing medicine into the joint itself

Based on your wide-ranging symptoms and very precise exam findings, your doctor can determine the likelihood of SI joint involvement. A wide variety of other potential causes like discs, spinal stenosis or hip arthritis must be thoroughly investigated before finally landing on an accurate diagnosis.

Genuine Hope for Healing

The encouraging news is there are many conservative treatment options before considering risky surgery:

• Physical therapy – manipulations, targeted exercises to stabilize
• Over-the-counter pain relievers
• Custom braces to properly compress & support the joint
• Steroid injections greatly reduce swelling
• Radiofrequency ablation intentionally disables nerve fibers transmitting chronic pain signals

Minimally invasive fusion surgery is sometimes absolutely necessary if all other reasonable measures fail over an extended length of time. This uses small incisions to place implants leading to intentional bone growth across the SI joint, essentially immobilizing the painfully moving parts.

Getting to the root cause of sacroiliac joint pain can be a long and frustrating journey. However, an accurate diagnosis is key to finding effective treatment and relief. While each case is unique, there are tried and true conservative therapies like physical therapy, medication, braces and injections that can help stabilize the joint and reduce inflammation. If more aggressive treatments like ablation or surgery are needed to allow you to function, discuss it with your doctor.