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SI Joint Pain

The low back can be debilitating making simple tasks almost impossible.  Have you ever had low back and buttock pain but your x-rays and MRI are normal?  What is the Sacroiliac Joint?   What are the symptoms of sacroiliac joint pain?  What are the treatment options for SI joint pain?  Which treatments should be avoided and why?  What regenerative treatment options are available?  Let’s dig in.

Where is Your SI Joint?

The sacroiliac (SI) joint is a very important joint in the lower back.  It is formed by the tailbone (sacrum) and waist bones (ilium) and functions as a shock absorber between the spine and legs. It is a C-shaped joint with cartilage and an extensive complex of supporting ligaments.  Each of us has two sacroiliac joints. One on the left and one on the right. SI joint pain is common with an incidence of 15-30% of patients with low back pain (1). Patients that have undergone lumbar fusions are particularly susceptible to SI joint injury.  A recent study reported that up to 75% of patients who undergo lumbar fusion will develop SI joint degeneration (2).  Other causes of SI joint injury include trauma, degeneration, inflammation,  pregnancy, ligament laxity, and muscle weakness (3).

The SI Joint: Not An Isolated Joint

SI-Joint-Instability infographic

Conceptually it is best to think of the SI Joints as a part of the pelvic ring.   What is the pelvic ring?

The pelvic ring is located in the pelvis and is compromised of the right and the left SI joints and pubic symphysis. The pelvic ring has many important functions which include transferring the weight of the upper body to the lower body while standing and walking.  It also provides important ligament and tendon attachments to stabilize the spine during activity.  An extensive number of ligaments support both the SI joint and pelvic ring.  Proper function and stability of the pelvic ring require the supporting ligaments to be intact and strong.  If the ligaments are damaged or stretched as a result of trauma, the pelvic ring can become unstable resulting in dysfunction and pain. You can do a Patrick’s test to see if you have SI joint dysfunction.

What Are the Symptoms of SI Joint Pain?

Pain is the most prominent symptom and typically involves the dimples of Venus (4). One-sided low back and buttock pain is common typically made worse with sitting and transitioning from the sitting to standing position.  If severe, the pain can radiate into the buttock, posterior thigh extending down to the calf.

What Aggravates SI Joint Pain?

The stability of the SI joint is dependent upon two very important factors:   Ligament integrity and Muscle strength.

Ligament Instability:

The biggest issue that we observe is SI Joint instability, which happens when the ligaments get stretched.   Ligaments are thick bands of connective tissue that connect bone to bone.  When the ligaments are unstable the SI joint moves too much which in turn can cause the cartilage in the joint to be injured with resultant pain.  Ligament injury can occur as a result of trauma, continued wear and tear, hormonal fluctuations such as pregnancy,  steroid injections, and genetic predisposition.

Muscle Weakness

Muscles provide the necessary support and stability for the SI joints and pelvic ring.  Muscle weakness can results in SI joint instability, dysfunction and pain.  Common causes of muscle weakness include deconditioning and low back nerve irritation from disc protrusion, disc herniation, small joint overgrowth, slipped discs, and stenosis.

Ehlers-Danlos Syndrome (EDS)

Disorders that affect and weaken the connective tissues such as tendons and ligaments. It is a hereditary disorder which means you are born with it.  EDS has many different signs and symptoms which can vary significantly depending upon the type of EDS and its severity.   It most commonly affects the skin, joints, and blood vessels.  Joints are typically hypermobile with excessive joint range of motion because of a defect in collagen formation. In most cases Ehlers-Danlos syndrome is inherited. That is to say that you are born with it. The two main ways EDS is inherited are: autosomal dominant inheritance and autosomal recessive inheritance…

Read More About Ehlers-Danlos Syndrome (EDS)

SI Joint Syndrome

The sacroiliac joints reside between the sacrum (the tailbone segment of the spinal column) and the prominent wing-like iliac bones that form the pelvic girdle. There are two SI joints, one on the left and one on the right (highlighted in red in the image above), and along with the symphysis pubis joint at the front of the structure, they are critical for transferring forces and energy back and forth between the spine and the lower limbs. There are a number of reasons that an SI joint can become painful and inflamed, leading to SI joint syndrome. Trauma, such as a fall injury to the tail bone or a forced injury from a car accident for example, obviously can create problems in the SI joint…

Read More About SI Joint Syndrome


Spondylolisthesis means that one vertebra is slipping forward or backwards on another. This causes the hole where the nerve exits (foramen) to get smaller (also called foraminal stenosis). It also causes more wear and tear on the facet joint which can lead to arthritis or what’s called “facet hypertrophy”. spondylolisthesis recovery The amount of slippage is graded 1-4, with grade 1 meaning that the one vertebra has slipped up to 25% on the other vertebra. Grade 2 means that one bone has slipped from 25-50% with higher grades indicating more slippage. The vast majority of patients are grade 1 to 2.

Read More About Spondylolisthesis

What Is the Treatment for Sacroiliac Joint Pain?

Physical therapy is the first-line treatment of choice.  For the best clinical outcome always:

  • Evaluate the stability of the SI Joint and pelvic ring
  • Evaluate muscular strength and identify and treat causes of weakness
  • Treat comprehensively with close attention to all the ligaments, tendons and muscles including to those of the symphysis pubis.

Remember that the SI Joint is not an isolated joint.

Key muscles that are often overlooked or neglected that require an evaluation and possible strengthening include :

  •  Transversus adominus, a deep abdominal muscle (5)
  • Adductors which attach to the symphysis pubis.   These are common sites of tendon irritation and pain.

Treatments to Avoid

Steroid injections

When PT and or conservative treatment fails to provide improvement patients are oftentimes referred for steroid injections.  Beware as these injections have significant side effects which include:

  • Damage to the cartilage
  • A weakening of the supporting ligaments
  • Injury to the bone

A recent study evaluated the effectiveness of PRP and steroid injections for SI Joint pain. PRP provided better reduction in pain for a longer time when compared to steroid injections (6).

Sacroiliac Joint Fusion

SI joint fusion is a surgical procedure where large screws or implants are placed across the joint thereby eliminating motion.  Remember that the joint is a critical shock absorber between the spine and legs and as such must be able to move. Complications are significant.  In one study that followed 469 patients for 7 years. There were significant complications which included (7).

  •  Re-operation rates after open surgery ranged from 0%-65% whereas in the minimally invasive surgery re-operation rate ranged from 0-17%.
  •  Major complications ranged from 5%-20% and in one study were found to be 56%.
  • Continued pain with the need for oral narcotics (8)
  • Adjacent Segment Disease

To better understand adjacent segment disease please click on the video below.

Regenerative Treatment Options

PRP and bone marrow concentrate are new effective treatment options for patients with SI joint pain.  PRP is rich in growth factors that can increase blood flow and facilitate healing. Bone marrow concentrate contains many powerful repair cells that can charge into ligament, tendon, and muscle cells in addition to recruiting other repair cells in the body to assist in the repair of damaged tissue.

Ligament Injections

Damaged or stretched ligaments can be successfully treated with precise ultrasound-guided injections of PRP or bone marrow concentrate.  The SI Joint and symphysis pubis are rich in supporting ligaments that are susceptible to injury.  At the Centeno-Schultz Clinic, we have extensive experience in the treatment of ligament and SI Joint injuries.  All procedures are performed under x-ray or ultrasound guidance by board-certified, fellowship-trained physicians.

SI Joint Injections

The SI Joint and its cartilage are susceptible to injury.  When injured this can be a significant cause of pain.  The SI joint can is tortuous and can be difficult to successfully inject.  At the Centeno-Schultz Clinic, we published an x-ray guided technique for successful injection of the SI Joint within 90 seconds (9).  PRP or bone marrow concentrate is commonly injected.

Injections to Treat Muscle Weakness

Muscle strength is essential for the stability of a given joint.  Weak muscles can arise from different sources.  A common cause of muscle weakness that causes SI Joint instability and pain is low back disc bulges or herniation. Steroid injections are not the solution.  At the Centeno-Schultz Clinic, we compared PRP with steroids for low sciatica-type injuries and demonstrated PRP to be safer and superior (10).

To learn more about epidural steroid injections and a safe, natural, and effective alternative please click on the video below.

In Conclusion

The SI Joint is an important joint in the lower back that can cause pain and dysfunction.  Pain is typically one-sided involving the low back and buttock but when severe can radiate down the leg.  Each of us has a right and left SI joint.  The pelvic ring consists of the two SI Joints and the symphysis pubis.  Each is rich in supporting ligaments that provide stability for the joint.  SI Joint pain is aggravated by ligament instability and muscle weakness. Physical therapy is the first line of treatment for SI Joint injuries.  For best clinical results the stability of the joint and muscle strength must be evaluated and treated.  Treatments to avoid include steroid injections and steroids.  PRP and bone marrow concentrate are natural alternatives that are effective in treating ligamental instability, joint cartilage and muscular weakness associated with SI Joint injuries and pain.


1.Grgić V. [The sacroiliac joint dysfunction: clinical manifestations, diagnostics and manual therapy]. Lijec Vjesn. 2005;127(1-2):30-5.

2.Sembrano JN, Polly DW. How often is low back pain not coming from the back. Spine. 2009;34(1):E27-32.DOI: 10.1097/BRS.0b013e31818b8882

3.Ha KY, Lee JS, Kim KW. Degeneration of sacroiliac joint after instrumented lumbar or lumbosacral fusion: a prospective cohort study over five-year follow-up. Spine. 2008;33(11):1192-8.DOI: 10.1097/BRS.0b013e318170fd35

4.Fortin JD, Falco FJ. The Fortin finger test: an indicator of sacroiliac pain. Am J Orthop. 1997;26(7):477-80.

5.) Richardson CA, Snijders CJ, Hides JA, Damen L, Pas MS, Storm J. The relation between the transversus abdominis muscles, sacroiliac joint mechanics, and low back pain. Spine (Phila Pa 1976). 2002 Feb 15;27(4):399-405.

6. Singla V, Batra YK, Bharti N, Goni VG, Marwaha N. Steroid vs. Platelet-Rich Plasma in Ultrasound-Guided Sacroiliac Joint Injection for Chronic Low Back Pain. Pain Pract. 2017;17(6):782-91.DOI: 10.1111/papr.12526.

7.Schoell K, Buser Z, Jakoi A, et al. Postoperative complications in patients undergoing minimally invasive sacroiliac fusion. Spine J. 2016;16(11):1324-32.DOI: 10.1016/j.spinee.2016.06.016

8.Duhon BS, Cher DJ, Wine KD, Kovalsky DA, Lockstadt H; SIFI Study Group. Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: A Prospective Study. Global Spine J. 2016;6(3):257–269. doi:10.1055/s-0035-1562912

9.Centeno CJ. How to obtain an SI Joint arthrogram 90% of the time in 30 seconds or less. Pain Physician. 2006;9(2):159.

10. Centeno C, Markle J, Dodson E, et al. The use of lumbar epidural injection of platelet lysate for treatment of radicular pain. J Exp Orthop. 2017;4(1):38. Published 2017 Nov 25. doi:10.1186/s40634-017-0113-5

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