The Sacroiliac Joint: An Underappreciated Pain Generator

What is the Sacroiliac Joint?

The Sacroiliac joints are located at the very bottom of the back. You have one either side of the spine. The Sacroiliac joints help make up the rear part of the pelvic girdle and sit between the sacrum (vertebrae S1-S5) and the Ilia (hip bones).

The function of the SI joints is to allow torsional or twisting movements when we move our legs. The legs act like long levers and without the sacroiliac joints and the pubic symphesis (at the front of the pelvis) which allow these small movements, the pelvis would be at higher risk of a fracture.

The concept of the SIJ causing lower back pain is now pretty well understood. However, due to the complex anatomy and movement patterns at the joints and area in general, evaluation and treatment of sacroiliac dysfunctions is still controversial.

SIJ dysfunction is a term which is commonly used when talking about sacroiliac injuries. This dysfunction refers to either hypo or hyper mobility (low or high respectively). Or in other words, the join can become 'locked' or be too mobile. This can then lead to problems with surrounding structures such as ligaments (e.g. Illiolumbar ligament) and muscles, which means SIJ problems can cause a wide range of symptoms throughout the lower back and buttocks, or even the thigh or groin.

Causes of Sacroiliac Pain

Causes of Sacroiliac joint pain can be split into four categories:

Traumatic

Biomechanical

Hormonal

Inflammatory joint disease

Traumatic

Traumatic injuries to the SIJ are caused when there is a sudden impact which 'jolts' the joint. A common example is landing on the buttocks. This kind of injury usually causes damage to the ligaments which support the joint.

Biomechanical

Pain due to biomechanical injuries will usually come on over a period of time and often with increased activity or a change in occupation/sport etc. The most common biomechanical problems include:

Leg length discrepancy

Overpronation

'Twisted pelvis'

Muscle imbalances

Hormonal

Hormonal changes, most notably during pregnancy can cause sacroiliac pain. In preparation for giving birth, the ligaments of the pelvis especially increase in laxity. Combining this with an increase in weight putting extra strain on the spine, may lead to mechanical changes which can result in pain.

Inflammatory joint disease

Spondyloarthropathies are inflammatory conditions which affect the spine. These include Ankylosing Spondolitis which is the most common inflammatory condition to cause SI joint pain.

What are the Symptoms of SI Joint Injury?

Pain located either to the left or right of your lower back. The pain can range from an ache to a sharp pain which can restrict movement.

The pain may radiate out into your buttocks and low back and will often radiate to the front into the groin.

Occasionally there may be referred pain into the lower limb which can be mistaken for Sciatica.

Classic symptoms are difficulty turning over in bed, struggling to put on shoes and socks and pain getting your legs in and out of the car.

Stiffness in the lower back when getting up after sitting for long periods and when getting up from bed in the morning.

Aching to one side of your lower back when driving long distances.

There may be tenderness on palpating the ligaments which surround the joint.

Diagnosis
History: Approximately 80% of patients with sacroiliac joint dysfunction can identify a specific episode of trauma that initiated symptoms. The trauma, however, often seems too minor to cause a persistent and severe problem. A typical injury results from lifting a heavy object with a twisting motion, such as removing a suitcase from a car trunk. Another common mechanism of injury is a slip and fall. When the history contains these or similar injuries, and symptoms remain without progressive improvement, a specific evaluation for sacroiliac joint dysfunction should be considered.

In about 20% of cases, no specific traumatic episode is recalled, and the onset of symptoms is described as insidious. When there is no history of a traumatic episode, rheumatologic disorders-such as ankylosing spondylitis-should be excluded before a diagnosis of sacroiliac joint dysfunction is entertained.

Physical examination: Patients with sacroiliac joint dysfunction can present with signs and symptoms that are very similar to those of intervertebral disc disease. Many patients have pain confined to the area of the sacroiliac joint. Others have pressure on the S1 nerve and pain following the distribution of that pressure, in a pattern known as the pseudo S1 pattern. Physicians frequently assume that a patient with this pain pattern has L5-S1 disc herniation, and they may order an MRI to confirm the diagnosis of herniation. If the MRI is negative, they may conclude that the patient has a somatoform disorder. However, the presence of a sacroiliac joint disorder should be considered.

Diffuse pain radiating to the entire lower extremity is present in approximately 25% of patients with sacroiliac joint dysfunction. In the past, this pain pattern has been thought to represent a nonorganic or hysterical pattern.

Various physical examination maneuvers have been used to identify a sacroiliac origin of pain. Patrick's test, also known as the FABER test (for flexion, abduction, and external rotation) is probably the best known. Another commonly employed maneuver is Gaenslen's test, which includes hyperextension of the hip. Recent information has shown that such screening tests are not reliable in identifying pathology of sacroiliac joint.

The single feature consistently found among patients with sacroiliac joint dysfunction is pain location; when asked to point to where the pain seems to be originating, patients point to the area immediately around the posterior superior iliac spine. Thus, dysfunction of the sacroiliac joint should be considered in any patient complaining of pain in this area, even if the various traditional physical examination maneuvers are negative.

Confirmation: Diagnosis of sacroiliac joint dysfunction can be confirmed with a diagnostic injection performed by a physician skilled in the technique. Blind injections into the area of the sacroiliac joint are inadequate. Fluoroscopy or computed tomography guidance is necessary to ensure that the injectant is administered to the correct area.

The injection should involve the placement of a small volume (1 to 3 mL) of local anesthetic into the synovial portion of the joint. Correct placement is verified by the inclusion of contrast material in the injectant, which should outline the synovial portion of the joint. Large-volume injections or injections into the ligamentous portion of the joint will extravasate into the region of the lumbosacral plexus and can produce both false-negative and false-positive results.

Treatment of SIJ Pain

What can you do to treat sacroiliac joint pain yourself?

• Rest from any activities which cause pain.
• If the surrounding muscles have tightened up, use a warm-pack to help them relax.
• Don't heat if an inflammatory condition is suspected.
• Anti-inflammatory medications may be helpful. Always check with your Doctor first.
• Try wearing a Sacroiliac back belt

Physical therapy can be very helpful. Pain in the SI joint is often related to either too much motion or not enough motion in the joint. A physical therapist can teach various stretching or stabilizing exercises that can help reduce the pain. A sacroiliac belt is a device that wraps around the hips to help stabilize the SI joints, which can also help the SI joint pain. Other options to stabilize the SI joints include yoga, manual therapy.

How can sacroiliac joint dysfunction be prevented?

Unfortunately, SI joint dysfunction is not preventable in some people. For many, it is an unfortunate part of the normal aging process. However, the severity can be reduced through treatment with medication, injections, or physical therapy. Maintaining a healthy body weight and good conditioning can reduce the chances of developing SI joint dysfunction and other forms of arthritis. By reducing the loads on the joints, there is less chance for cartilage damage and subsequent arthritis.