Sacroiliac Joint Pain

Dysfunction in the sacroiliac (SI) joint can present as pain in the lower back. Sacroiliac pain often presents as sciatica-like symptoms producing buttock and leg pain. Due to this, accurate diagnosis is important to determine the source of pain.

Managing SI Joint symptoms typically involves physical therapy, stretching exercises, pain medication, and joint injections. While many people respond to non-surgical treatment, surgical options to fuse the joint and stop painful motion may be recommended.

Once considered the primary cause of lower back pain, SI joint pain evaluation has been almost entirely ignored since the 1940s.1 Recently, the SI joint has gained renewed interest due to new diagnostic techniques and treatments. It is now estimated that the sacroiliac joint is responsible for 15% to 30% of lower back pain cases.2

Where are the Sacroiliac Joints?

The sacroiliac joints are located in the last segment
of the spine and connect the sacrum to the hip bones.
The SI joints can be located below the waist where two
dimples are visible. Anatomically, this is known as the
Posterior Superior Iliac Spine (PSIS).

ANTERIOR VIEW (Front facing)

What Causes SI Joint Pain?

The SI joint can become painful due to an injury (disruption) or degeneration (arthritis). When this happens, nerves in the joint can become inflamed (known as sacroiliitis). Symptoms can present as lower back, buttock, and leg pain.

The most common causes of SI Joint pain are:
  • Injury (fall, accident, lifting, etc.)
  • Pregnancy/Childbirth
  • Degeneration (age-related arthritis, prior lumbar fusion)

Sacroiliac joint pain is more common in women than men. The primary reason is a woman’s SI joints are designed for childbirth. Women who are pregnant or have recently given birth may be more susceptible to sacroiliac joint pain.3

For most women, this pain disappears within a few months after childbirth. However, 20 percent of the women with low back and pelvic pain during pregnancy continue to have low back and pelvic pain 3 years following delivery.4

SI Joint Pain Terminology

Many terms have been used by physicians to describe SI joint pain. These include SI joint dysfunction, SI joint syndrome, SI joint strain and SI joint inflammation, and pelvic girdle pain.


If non-surgical treatments have failed to provide relief, ask your doctor if SI joint surgery with the Catamaran™ SIJ Fusion System is right for you. To learn more about the Catamaran SIJ Fusion System, click here.


  • 1. Vleeming, et al. The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. J Anat. 2012 Dec; 221(6): 537–567.
  • 2. Cohen, et al. Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment. Expert Rev Neurother. 2013 Jan; 13(1):99-116.
  • 3. McGrath C. Clinical considerations of sacroiliac joint anatomy: a review of function, motion and pain. Journal Osteopathic Medicine 2004; 7(1):16-24
  • 4. Noren L. Lumbar back and posterior pelvic pain during pregnancy: a 3-year follow-up. Eur Spine J. 2002;11;267-271.