Sacroiliac joint dysfunction refers to pain in the sacroiliac joint region that is caused by inflammation of the sacroiliac joint.
Sacroiliac joint dysfunction causes low back which can radiate to leg also not dissimilar to lumbar radiculopathy.
It is also sacroiliac joint disorder, sacroiliac joint disease, sacroiliac joint syndrome or sacroiliac syndrome, or sacroiliac instability.
Sacroiliac joint has been shown to be a source of pain in 10-27% of suspected cases of chronic low back pain.
Pathophysiology of Sacroiliac Joint Pain
The sacroiliac joint is formed between auricular surfaces of sacrum and ilium. There are two sacroiliac joints – left and right. These are diarthrodial joints.
The sacroiliac joints are very strong, reinforced by strong ligaments that surround it and does not have much motion.
Important ligaments of sacroiliac joints are
- Posterior sacroiliac ligament
- Interosseous ligaments
- Sacrotuberous ligament
- Dorsal sacroiliac ligament
They function to transmit the forces of the upper body to the pelvis and also act as a shock-absorbing structure
In this joint, hyaline cartilage on the sacral side moves against fibrocartilage on the iliac side. The sacroiliac joint contains numerous ridges and depressions that function instability.
Though it is not clear, an alteration in the normal joint motion is thought to cause the sacroiliac joint pain.
The pain is often attributed to hypomobility or hypermobility of the joint.
Hypermobility or instability usually results in the pain typically felt in the lower back and may also radiate to the groin area.
Ligamentous insufficiency is mainly responsible for hypermobility. The joint itself is structurally normal and healthy and would not show degenerative changes
Trauma, hormonal imbalances as in pregnancy, biomechanical or muscle length imbalances could cause hypermobility.
Hypomobility or less movement results in pain that is felt on one side of the low back or buttocks. The pain can also radiate to the leg [ usually remains above the knee, but can extend to the ankle or foot just like radiculopathy]
This type is more common in young and middle-aged women.
Hypomobility could mean a totally fused joint or a significantly rigid joint. While the former is irreversible, the latter could respond to treatment.
Causes of Sacroiliac Joint pain
Conditions, where sacroiliac joints can be involved, are
- Rheumatoid arthritis
- Marie-Strumpell Disease
- Ankylosing spondylitis
- Congenital deformity
- Pregnancy [Relaxin hormone causes excess motion at the SI joint]
- Leg length discrepancy can also develop SI joint pain.
- Prior spinal surgery
The patient may present with lower back pain, buttocks pain, sciatic leg pain, groin pain, hip pain are common symptoms.
Symptoms may worsen with prolonged or sustained positions like sitting, standing or lying.
Movements, like bending forward, hill climbing, stair climbing and rising from a seated position, can also provoke pain.
Clinical Tests for Sacroiliac joints
These tests do not offer any value individually but three positive tests increase the odds of the pain being caused by the sacroiliac joint.
This test is performed with the patient in the standing position and assesses the motion at the sacroiliac joint.
While keeping stance on one leg, the patient flexes the opposite hip and knee into the chest. The motion of the sacroiliac joint is assessed by placing one thumb under the posterior superior iliac spine on the side of hip flexion, with the other thumb in the midline at the S2 level.
In normal situations, the thumb under the posterior superior iliac spine drops inferiorly and laterally when the hip is flexed.
The motion is compared to the normal side and a decrease in motion is indicated by the lesser movement of the thumb.
Fortin Finger test
The patient is asked to point to the site of pain with one finger. If the site of pain is within 1 cm of the posterior superior iliac spine, the test is considered positive.
Patrick/ Faber Test
This involves flexion, abduction, and external rotation of the hip.
The patient lies supine. The affected limb is flexed, adducted and externally rotated so that the heel is placed on the opposite knee.
Then, downward pressure is applied to the medial knee stressing both the hip and sacroiliac joint
The test is considered positive if there is a pain in the sacroiliac joint.
This pain provocation test applies torsion to the joint.
The patient is supine. The affected hip and knee are maximally flexed toward the trunk, and the opposite leg is extended. [This can be achieved by allowing the leg to dangle off the edge of the table. Application of pressure downward on the leg would achieve hip extension and stress the sacroiliac joint
Pressure is applied to the flexed extremity. The finding is positive if the pain is felt across the sacroiliac joint.
The patient lies on one side. The examiner applies pressure on one pelvic brim in the direction of the other. A positive result is a pain across the sacroiliac joint.
Van Durson standing flexion test
The patient stands with the examiner behind him. The examiner’s places thumbs just below each posterior superior iliac spine.
The patient is asked to flex the trunk forward without bending the knees. An asymmetric motion indicates a positive sign.
Piedallu seated flexion test
The patient is seated and the examiner stands behind him. The examiner’s thumbs are placed just below the posterior inferior iliac spine. An asymmetry of the motion is considered positive.
Iliac Gapping Test
Distraction can be performed to the anterior sacroiliac ligaments by applying pressure to the anterior superior iliac spine.
Diagnosis of Sacroiliac Dysfunction
X-ray, CT scan, or MRI, do not usually reveal abnormalities and therefore are not reliable for diagnosis.
Diagnostic sacroiliac joint block under fluoroscopy or CT-guidance is the current gold standard for diagnosing sacroiliac dysfunction.
75 percent change in relief of pain on two separate visits, in most likelihood, suggests the sacroiliac origin of pain.
Treatment of Sacroiliac Joint Dysfunction
Drugs, education, and physical therapy are initial management options.
Failure of initial therapy calls for diagnostic sacroiliac injections after 1–2 weeks.
Sacroiliac joint injection for treatment may then follow.
Surgery, a last resort, involves fixation of the joint with screws.
Treatment options are discussed below.
Ice or cold packs, applied in 15 to 20-minute intervals to reduce inflammation in the area, along with rest to reduce irritation. On reduction of pain, gradual return to normal activities may be done.
Following drugs could be used
- Anti-inflammatory medications
- Muscle relaxants
- Local painkiller gels
Supports or braces
Lumbosacral corset or braces can sometimes be very helpful when the joint is inflamed or painful. When it calms down, the orthotic can be weaned away.
Physical therapy and exercise
physical therapy helps to strengthen the muscles around the sacroiliac joint and increase the flow of blood to the area, which in turn stimulates a healing response.
Sacroiliac joint injections
This involves the application of anesthetic and corticosteroid to help reduce inflammation around the joint, which in turn will help relieve the pain.
The relief can help the patient start with a physical therapy program and return to normal activity levels.
Sacroiliac Joint Fusion
Surgery is a possible option if the patient does not improve in spite of continued treatment with the above means for weeks together.
The surgery involves fixation across the sacroiliac joints to achieve fusion. Fusion eliminates abnormal motion and thus cause of pain.