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Sacroiliac Joint Pain Fact Sheet



Up to 85% of all people have lower back pain at some point in life.1 Low back pain is second only to upper respiratory problems as a reason for visits to a physician,2 generating 15 million office visits annually.3 It is the fifth-ranking cause of admission to hospital and the third most common cause of surgical procedures.3,4,5 In 2005, annual direct and indirect costs for treatment of low back pain has reach $86 Billion.6 

What is the sacroiliac joint? 

The sacroiliac joint forms the lowest segment of the spine and distributes the force delivered from the upper body. Sacroiliac joints are located on either side of the sacrum, which is in the low back and the pelvic areas. The sacroiliac joint connects the sacrum, the triangular bone at the bottom of the spine, with the pelvis iliac crest. 

What is the function of the sacroiliac joint? 

The function of the sacroiliac joint is to transfer weight and forces due to movement from your upper body through the pelvis to your legs and vice versa. The pelvis acts as a central base through which large forces are transferred and dissipated. The primary role of the sacroiliac joint is to provide stability for the pelvis, and to bear the load of the upper body. 

Why does the sacroiliac joint start having problems? 

Potential causes of sacroiliac joint problems include degenerative disease, history of trauma, pregnancy/ childbirth, and other unknown reasons. The sacroiliac joint may be disrupted due to lack of joint continuity (injury, traumatic event or repetitive trauma to the joint) or may suffer from sacroiliitis (swelling) resulting from a variety of causes. 

How does the sacroiliac joint cause pain? 

The sacroiliac joint is a synovial joint and has a nerve supply that originates from multiple lumbosacral root levels with partial innervation from L2 (anterior joint) to S3 (posterior joint). Strong ligaments encase each joint and allow for approximately two to four millimeters of movement during weight-bearing and forward flexion. When these ligaments become damaged either due to normal wear and tear or by injury, they may have excessive motion. This excessive motion may inflame and disrupt the joint and surrounding nerves. When this happens, people can feel pain in their back or buttocks, especially with lifting, running or even walking. 

How common are sacroiliac joint problems? 

It is commonly reported in clinical literature that up to 25% of all low back pain is caused by the sacroiliac joint.7 In addition, the incidence of sacroiliac joint degeneration in post-lumbar fusion patients is 75% at 5 years post-surgery.8 

How is low back pain due to the sacroiliac joint manifested? 

Many people have low back pain associated with the sacroiliac joint that begins spontaneously. However, in just as many reported cases, sacroiliac joint pathology can be related to a specific event, often an injury. It is difficult to directly relate any specific functioning difficulty (including walking, sitting, standing, sleeping on the affected side, job activity, bowel movements, cough, sneeze, etc.) to the sacroiliac joint as a source of pain. One key indication is the specific location of the pain in the lowest back and buttock region. 

Who is at risk for sacroiliac joint problems? 

Injury from accidents, including falling, is a predisposing factor for sacroiliac joint pain. Women may be at increased risk for sacroiliac joint problems because of their broader pelvises, the greater curve of their necks, and shorter limb lengths. Pregnancy often leads to stretching of the pelvis, specifically in the sacroiliac ligaments. In addition, clinical literature has also documented the incidence of sacroiliac joint degeneration in post-lumbar fusion surgery is 75% at 5 years post-surgery.8 

Is the sacroiliac joint part of a low back pain differential diagnosis? 

Most published differential diagnosis for low back pain fail to consider sacroiliac joint as a source of lower back pain.9, 10 Underscoring the need for proper diagnosis is the fact that pain caused by sacroiliac joint dysfunction can mimic discogenic or radicular low back pain potentially leading to the wrong diagnosis and treatment such as lumbar spine surgery.11 

Clinical References: 

1. Frymoyer JW (1988) Back pain and sciatica. N Engl J Med 318:291ñ300 

2. Anderson GBJ. Epidemiologic features of chronic low-back pain. Lancet 1999; 354:581-5. 

3. Hart, et al. Physician office visits for low back pain. Frequency, clinical evaluation, and treatment patterns from a U.S. national survey. Spine. 1995;20(1):11-9. 

4. Praemer A, Furnes S, Rice DP. Musculoskeletal conditions in the United States. Rosemont: AAUS, 1992: 1ñ99. 

5. Taylor, et al. Low-back pain hospitalization: recent United States trends and regional variations. Spin 1994; 19: 1207ñ13. 

6. Martin, et al. Trends in Health Care Expenditures, Utilization, and Health Status Among US Adults With Spine Problems, 1997-2006 Spine. 2009; 34(19):2077-2084 

7. Cohen, Steven P. Sacroiliac Joint Pain: A Comprehensive Review of Anatomy, Diagnosis, and Treatment. Anesth Analg 2005; 101:1440-1453 

8. Ha et all. Degeneration of Sacroiliac Joint After Instrumented Lumbar or Lumbosacral Fusion. Spine 2008: 33(a): 1192-1198 

9. Deyo RA, Weinstein JN, Low Back Pain, N Engl J Med 2001: 344(5): 363-370 

10. National Institute of Neurological Disorders and Stroke (NINDS). Low Back Pain Fact Sheet. Bethesda, MD: National Institute of Neurological Disorders and Stroke; 2003 

11. Weksler, et al. The role of SI joint dysfunction in the genesis of low back pain: the obvious is not always right. Archives of ortho and trauma surgery. 2007 Dec; 10(127) 858-8 


The Condition: Sacroiliac Joint Symptoms 

The sacroiliac joint is located at the base of the spine and connects the tailbone to the pelvis. This joint can become damaged either due to normal wear and tear over time, or through injury. When this happens, it can cause pain and discomfort from the lower back down to the lower buttock region and the upper leg. Such symptoms can result in debilitation and a lower quality-of-life. 

According to published scientific literature, up to 30% of all low back symptoms are sacroiliac joint in origin1 ñ but the diagnosis of a problem with the sacroiliac joint is frequently overlooked because low back pain symptoms have many causes. In fact, many patients with disabling low back pain issues go on to receive lumbar spinal treatments, though the source of their symptoms may be sacroiliac joint in origin, either in whole or in part, leaving these patients with little or, in some cases, no relief. 

Sacroiliac Joint Symptoms and Diagnostic Methods 

A variety of tests performed during physical examination may help reveal the sacroiliac joint as the cause of low back pain symptoms. In addition, X-rays, CT-scan or MRI can be helpful in the diagnosis as well. However, the most relied upon method to accurately determine whether the sacroiliac joint is the cause of low back symptoms is to inject the sacroiliac joint with a local anesthetic. The injection is delivered with either fluoroscopic or CT guidance to verify accurate placement of the needle in the sacroiliac joint. If symptoms are significantly decreased, it can be concluded that the sacroiliac joint is either the source, or a major contributor to the low back symptoms. 

SI Joint Fusion Procedure 

SI Joint fusion is a minimally invasive surgical treatment that stabilizes the sacroiliac joint by surgically inserting three small titanium implants surgically across the sacroiliac joint. The triangular implants are coated with a porous, titanium plasma spray that acts as an interference surface, designed to help decrease implant motion and provide immediate fixation and long term fusion. The implants are able to produce a much stronger construct than conventional orthopedic screws used to treat sacroiliac joint disorders. 

Potential Benefits of the minimally invasive SI Joint Fusion Procedure 

  • Less invasive than traditional open surgery 
  • Minimal soft tissue disruption 
  • Minimal incision size 
  • Minimal tendon irritation 
  • Decreased length of stay The procedure typically takes about one hour and requires an overnight hospital stay. The procedure can be done using either local or general anesthesia; the surgeon will determine the most appropriate method, based on the patientís overall condition. 

Research reported in Open Orthopaedics Journal followed 50 patients treated with the SI joint fusion found early and sustained outcomes. In this study, patients were periodically contacted after surgery to assess SI joint pain, satisfaction and work status. Significant improvements were noted in 7 out of 9 categories of daily living and 82% of patients were satisfied at 40 months and said they would undergo the same surgery again. Complication rate was low and 13 previously disabled patients were able to return to work.

The fusion procedure is intended for sacroiliac joint fusion for conditions including sacroiliac joint disruptions and degenerative sacroiliitis. Physicians should review the procedure information for a complete discussion of contraindications, warnings, precautions, and risks. Patients should discuss these risks and considerations with their physician before deciding if this treatment option is right for them. 

1. Szadek, et al. Diagnostic Validity of Criteria for Sacroiliac Joint Pain. Journal of Pain, 2009: 10(4) 354-368Deyo RA, Weinstein JN, Low Back Pain, N Engl J Med 2001: 344(5): 363-370 

2. Rudolf*, Sacroiliac Joint Arthrodesis-MIS Technique with Titanium Implants: Report of the First 50 Patients and Outcomes. The Open Orthopaedics Journal, 2012, 6, 495-502. *Dr. Rudolf is a paid consultant of SI-BONE, Inc. 


Desert Institute of Spine Care
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