Spinal and pelvic ligament weakness as a cause of Sacroiliac joint dysfunction

Ross Hauser, MD; Danielle Matias, PA-C; Demi Foster, APRN

We are going to start this article with a March 2022 paper in the journal Spine Surgery and Related Research. (1) What is being said in the research is that despite six months of conservative care and ultimately surgery, the treatments failed the patient. Why? It was a ligament injury not a disc problem. Let’s read the research.

“Most sacroiliac joint disorders are conservatively treated; however, patients with severe pain occasionally require SIJ arthrodesis (fusion) after the failure of continuous conservative management for more than 6 months.”

What the researchers here focused on was ligaments, the tough bands of connective tissue that hold bones in place.

“(The researchers) investigated the incidences of preoperative tenderness in the sacrotuberous ligament (the ligament that connects the bones of the pelvis to lumbar vertebras) and postoperative lower-buttock pain originating from the sacrotuberous ligament to determine the best way to manage these symptoms to achieve good outcomes.”

Post-surgical pain is something we see frequently in patients. In many cases that we treat, there is almost always a ligament problem that went undetected through the entire conservative care-surgical process and was then revealed after the surgery when the surgical procedure corrected all the problems on MRI. The problem is that micro or small tear damage may not be picked up on MRI. Please see our article Is your MRI or CT Scan sending you to a back surgery you do not need? for an expanded discussion on this topic.

In this study, the researchers examined the records of 33 patients (14 men and 19 women) with an average age of 47.7 years (range: 25-79 years) who underwent SIJ fusion for severe pain. Here are the outcome observations.

In many patients, significant pain relief was acquired after surgery.
Before the surgery, tenderness of the sacrotuberous ligament was identified in 21 of 33 patients (63.6%).
- The sacrotuberous ligament tenderness resolved after surgery in 12 of these 21 patients (57.1%); however, it persisted in nine patients (42.9%), all of whom were women.
- Of the 12 patients who did not have preoperative sacrotuberous ligament tenderness, 4 (33.3%) developed lower-buttock pain and had sacrotuberous ligament tenderness.
- In total, 9 (27.3%) of the 33 patients whose progress could be followed up after SIJ arthrodesis (fusion) had pain originating from the sacrotuberous ligament; the sacrotuberous ligament pain in 8 of the 9 patients was relieved after the sacrotuberous ligament injections and physical therapy.

Here is the conclusion of this paper: “The sacrotuberous ligament pain can occur pre- and postoperatively, and management of both persisting and new-onset sacrotuberous ligament pain after SIJ arthrodesis (fusion) should be considered to achieve better outcomes.”

Let’s take a moment to review the conclusion. Many patients achieve successful surgeries. Some people do not. In people without successful surgical outcomes, a problem with the sacrotuberous ligament (the ligament that connects the bones of the pelvis to the lumbar vertebras) has been identified. Managing sacrotuberous ligament pain origins, those that continued from before surgery, and new pain attributable to occurring post-surgery. The pain of the patient and the success of the treatment depends on ligament treatments.

Ligaments are bands of fibrous tissue that connect bones to each other, like the vertebrae to each other and the sacrum to the pelvis.

Ligaments are bands of fibrous tissue that connect bones to each other, like the vertebrae to each other and the sacrum to the pelvis. The sacrum is the part of the spine below the fifth and last lumbar vertebrae and above the coccyx. The uppermost portion of our pelvis is called the ilium. The area that connects these structures is the sacroiliac joint (SI): Sacro from the sacrum, and iliac from the ilium.

In a December 2019 study, (2) doctors made these observations concerning Prolotherapy and Platelet Rich Plasma (PRP) Injections. Platelet Rich Plasma (PRP) Injections are considered a type of Prolotherapy when applied in a similar manner. These injections are explained further below.

“SI joint pain can be generated from extra-articular elements including ligaments and capsules. (The SI joint pain does not necessarily have to come from the joint itself). Prolotherapy involves the injection of hyperosmolar dextrose or Platelet-Rich Plasma (PRP) into the area where repairing and strengthening are thought to be needed. The application of Prolotherapy for SI joint pain consists of injections in the periarticular and intra-articular areas to treat pain and sacral ligament laxity. Some studies reported the positive clinical outcomes of Prolotherapy for SI joint pain and even a superior effect and longer duration for relief of SI joint pain compared to the injection of a steroid into the joint. In recent studies, a significant reduction in the pain scores of SI joint pain was observed in patients receiving intra-articular PRP injections compared to those receiving steroid injections.

No one is looking at the ligaments of the Sacroiliac Joint – that is why “nothing is working.”

When patients talk to us, the reason they are sitting on our exam table is that they have had many treatments and they report “nothing is working.” Some have had the surgeries, denervation, physical therapy, and cortisone mentioned above. Part of the reason nothing is working is that the treatment plan they have been given is not addressing the correct problem. This is evident because they have continued pain. As mentioned, the treatment and diagnosis of sacroiliac joint dysfunction are complex and confusing. This is why there is no gold standard of treatment. However, there is no gold standard of treatment if you are hunting disc disease as the problem because of failure to identify the true source of low back pain as sacroiliac (SI) joint dysfunction.

We are going to start presenting evidence in this article that many people can have their sacroiliac joint dysfunction healed if the focus of their treatment turns from looking at disc disease to looking at spinal ligament damage and weakness causing sacroiliac (SI) joint instability, weakness, and pain. Further, we will discuss new and archival research that shows Prolotherapy injections to be a “high-value” treatment.

Failed Sacroiliac Joint Dysfunction treatments may have failed because of the focus on discs, not ligaments.

In the next section, we are going to discuss the spinal ligaments that may be impacting your continued pain. First, In this video Prolotherapist Danielle Matias, MMS, PA-C discusses a pretty common scenario of patients who are diagnosed with sacroiliac joint dysfunction but whose MRI is normal and they try some physical therapy but it doesn’t resolve the issue. The reason for this is most frequently underlying ligament laxity in the region causing SI joint instability.

Having an MRI that shows nothing “that can be fixed” while still having back pain can be incredibly frustrating for patients. These people are suffering from all this pain and they have this negative MRI meaning treatments to help them will be limited. Their doctors may send them to physical therapy to see if that helps. In cases of SI joint dysfunction physical therapy can potentially be very beneficial assuming that the ligaments of the SI joint are intact and they have a lot of integrity. (They can hold the SI joint in place).

Patients who have suffered an injury to the ligaments (acute injury or degenerative wear and tear) of the SI joint, these people can have inherent instability and their MRI is still normal or shows negative or no findings. When they go to physical therapy, it will fail them and now these people lose hope. You can’t build muscles around your SI joint if you don’t have strong ligaments. Physical therapy may help a little bit, but it may not be able to resolve your pain if you’re suffering from underlying ligament instability.

The problems with ligaments after physical therapy after sacroiliac joint treatment are noted in a September 2021 paper in the Journal of Physical Therapy Science. (3) After physical therapy, the incidence of residual sacrotuberous ligament pain in the persisting lower-buttock pain was 57.9%.

Radiating pain

People can also have low back pain that radiates into the butt or the back of the leg and again nothing might show up on MRI but what could be happening is intermittent pressure caused by the weak or damaged ligaments allowing the SI joint to become hypermobile and press on the sciatica nerve and give you temporary sciatic symptoms.

SI joint dysfunction is defined as spinal instability from deficient ligament strength in the posterior elements of the SI joint.

We are now presenting our own 2016 medical research published in Clinical Medicine Insights, Arthritis, and Musculoskeletal Disorders. (4) In this research, Danielle Steilen-Matias, PA-C described the source of low back and buttock pain as related to the sacroiliac (SI) joint is present in as many as 15%–30% of back pain patients, and perhaps up to 40% in patients who have had a previous lumbar fusion. We also discuss dextrose Prolotherapy injections as a viable treatment option.

First, observations:

Low back pain patients who remain symptomatic despite tailored physiotherapy are believed to possess deficient ligament strength in the posterior elements of the SI joint, resulting in insufficient stability to permit effective muscle recruiting strategies.
Experimental studies have found Prolotherapy effective in stimulating the production of collagen fibers, thus strengthening ligaments.

Before we continue with the research on Prolotherapy for sacroiliac joint dysfunction, we would like to reinforce the argument that we need to shift focus away from the problems of the discs to problems of the ligaments in treating Sacroiliac joint dysfunction.

In this video, Ross Hauser, MD gives an introduction to our treatment philosophies in the diagnosis and treatment of Sacroiliac Joint Dysfunction

Here is a summary of this video:

People will come into our office with MRIs that show a herniated disc, disc protrusion, or degenerative disc disease, and think that is the cause of their problem. There has been no discussion with the patient of the pain culprit possibly coming from the sacroiliac joint. When we ask patients if they had their sacroiliac joint examined, they often tell us that they do not even know what the sacroiliac joint is.
When most people injure their back, they usually do it from a bending and twisting motion. When they come into our office they describe their back pain as the lower left side of the lower right side. They rarely say it is right down the middle.
The sacroiliac joint is a very large joint that sits in a sea of spinal and pelvic ligaments, the tough connective tissue that holds bone to bone. In the illustration below the white bands of tissue that hold the sacroiliac joint are the ligaments. They sit on the left and right sides of the spine.
In our office, we offer Prolotherapy injections. This treatment can stimulate the repair of the spinal ligaments and bring pain-free stability back to the lower back. pelvic, and sacroiliac joint.

What are we seeing in this image?

In this illustration, white bands of tissue that hold the sacroiliac joint are the ligaments. They sit on the left and right sides of the spine. In this image, arrows signify points of irritation to the sciatic nerve caused by excessive movement and instability in the Sacroiliac Joint. This can cause various symptoms in the patient including low back and leg pain, numbness down the leg, and general instability and weakness from the spine to the toes.

Sacroiliac instability. In this image arrows signify points of irritation to the sciatic nerve caused by excessive movement and instability in the Sacroiliac Joint. This can cause various symptoms in the patient including low back and leg pain, numbness down the leg and general instability and weakness from spine to toes.

Spinal ligaments identified as a point of interest in treating Sacroiliac joint dysfunction treatment

The opening statement of a 2015 research article from doctors at the Mayo Clinic (5) brings all these concerns together when the researchers state: “Understanding spinal kinematics (the movement of the spine) is essential for distinguishing between pathological conditions of spine disorders, which ultimately lead to low back pain.

It is of high importance to understand how changes in mechanical properties affect the response of the lumbar spine, specifically in an effort to differentiate those associated with disc degeneration from ligamentous changes (problems of the spinal ligaments), allowing for more precise treatment strategies.”

Doctors from the Low Back Pain and Sacroiliac Joint Center, Sendai Shakaihoken Hospital in Japan wrote of their findings in the European Spine Journal, (6) that said referred pain from the sacroiliac joint can be isolated to the anterior ligament sacroiliac joint region, and that by treating the ligaments pain can be alleviated.

This is an interesting study in that it discusses referral pain patterns. It has been well established that an injury in one part of the body can affect other, distant body parts, especially in regard to a ligament injury.

Here the Japanese doctors speculated that the sacroiliac joint may be the cause of pain in other parts of the pelvic region and that these pain origins may be centralized to the joint’s posterior ligamentous region.

The doctors divided the posterior sacroiliac joint into four sections

upper = section 1,
middle = section 2,
lower = section 3,
and other (the cranial portion of the ilium outside the SIJ – in the illustration above that would be the leftmost white band in the left side panel) = section 0.
- Referred pain from SIJ section 0 was mainly located in the upper buttock along the iliac crest;
- Referred pain from section 1, around the posterosuperior iliac spine; (the low back area of the iliac)
- Referred pain from section 2, in the middle buttock area;
- Referred pain from section 3, in the lower buttock.
- In all, 22 (44.0 %) patients complained of groin pain, which was slightly relieved by lidocaine injection into SIJ sections 1 and 0.

The research team concluded: “Dysfunctional upper sections of the sacroiliac joint are associated with pain in the upper buttock and lower sections with pain in the lower buttock. Groin pain might be referred from the upper SIJ sections.”

There is so much to discuss here.

Foremost, the patients in this study had pain from the ligaments of the sacroiliac joint region.
What if they were sent to traditional treatment, that is a spinal fusion surgery?
Will fusion help or hurt these patients?
If anything the surgery will damage already damaged ligaments and create a high risk for Failed Back Surgery Syndrome.

Spinal ligaments are identified as a point of interest in treating groin pain related to sacroiliac joint dysfunction.

The investigation expanded. In a paper from October 2017, the same Japanese research team publishing in the medical journal Clinical Neurology and Neurosurgery (7) looked to identify the prevalence of groin pain in patients with sacroiliac joint dysfunction, lumbar spinal canal stenosis, and lumbar disc herniation who did not have hip disorders.

They looked at:

127 patients (57 men, 70 women, average age 55 years) with sacroiliac joint dysfunction

Then they looked at

the pain areas in the buttocks and back; including pain increase while in positions such as sitting, lying supine, and side-lying; a sacroiliac joint dysfunction shear test (manual physical examination of the range of motion); and four tender points composed of the posterior superior iliac spine (PSIS), long posterior sacroiliac ligament (LPSL), sacrotuberous ligament (STL), and iliac muscle.

RESULTS:

Fifty-nine (46.5%) patients with sacroiliac joint dysfunction had groin pain, In these patients, pain provoked by the sacroiliac joint dysfunction shear test and the tenderness of the posterior superior iliac spine and long posterior sacroiliac ligament were significant physical signs that differentiated sacroiliac joint dysfunction from lumbar stenosis and lumbar disc herniation.

Conclusion:

The prevalence of groin pain in patients with sacroiliac joint dysfunction was higher than in those with lumbar stenosis and lumbar disc herniation.
When patients who do not have hip disorders complain of groin and lumbogluteal pain, not only lumbar disorders but also sacroiliac joint dysfunction should be considered.

In other words, there was a link between groin pain and low back pain.

There are several diagnostic clues that low back pain (and referral pain into the buttock or leg) is related to the sacroiliac joint and the ligaments.

The preferred diagnostic method of a skilled Prolotherapist has always been palpitation – gently press down with your thumb to reproduce pain. “X” then makes that spot. See our article on the Accuracy of MRI for assessing treatment.

There are several diagnostic clues that low back pain (and referral pain into the buttock or leg) is related to the sacroiliac joint:

When asked to pick the spot from which pain emulates, people almost always point to the top of the sacroiliac joint.
When asked what makes the pain worse, patients usually mention positions that increase the force on the sacroiliac joint, such as sitting.
When asked which positions make the pain better, patients will describe positions that decrease the force on the sacroiliac joint, such as lying down with the knees bent or on their sides with a pillow between the legs.
When describing their pain, it is mostly in the lower back, off midline, and in a sacroiliac ligament referral pattern that is almost always very low in the back and involves the buttocks. The pain pattern involves a numb feeling but no true numbness, and it skips the knee. True nerve entrapment involving the sciatic nerve from a herniated disc or a pinched nerve from a bone spur characteristically is most severe down the leg, involving the knee and going into the foot, and the patient has some true loss or decreases in feeling (sensation).
Physical examination of stressor maneuvers on the sacroiliac joint.
Plain radiographs show sclerosis on one (or both) of the sacroiliac joints, indicating increased force on the subchondral bone there.