SACRO-ILIAC JOINT DYSFUNCTION

 The Injury

The sacro-iliac (SI) joints are located at the back of the pelvis and 

• The SI joints are comprised of the articulations between Sacrum and the two Ilium bones of the pelvis. The joint surfaces are covered with articular cartilage and the joints are reinforced by thick, strong ligaments, which give the joint great stability.

• The SI joint helps to transmit forces during weight bearing activities. There is much controversy over movements at the SI joint, but it is generally agreed that there is forward and backward, as well as rotational movement, but only by a couple of millimeters.

Several conditions can produce pain in this region.

• Traumatic incident and biomechanical mal-alignment can be described as 'mechanical' in nature. The 'self braced' position of the SI joint can be altered by these factors and the joint can lose it's stability. This changes the mechanics of the joint, putting abnormal pressures on the joint surfaces, ligaments and surrounding muscles. It is easy to see how trauma can produce this problem; when a person lands on one buttock during a fall, for example. A similar process may occur gradually if there is altered alignment or a discrepancy of length in the legs. This can lead to SI joint dysfunction and pain due to repeated stresses on the SI joint during sporting activities.

• Hormonal changes during pregnancy is also 'mechanical' in nature. It can cause generalized laxity of ligaments that can cause mechanical SI joint dysfunction. The ligaments helping to stabilize the SI joint can become lax and this, together with increased load on the spine due to the pregnancy, can cause altered SI joint mechanics and pain. For this reason, mechanical SI joint dysfunction tends to be more common in women.

• Inflammatory disorders can also produce pain in the SI joint. These disorders are classified as 'spondyloarthropathies', which simply means a disease that affects the spine. Among these conditions are ankylosing spondylitis, psoriatic arthritis, inflammatory bowel disease and Reiter's syndrome. These conditions will be identified with blood tests. Once confirmed, a referral to a Consultant Rheumatologist is required.

 Signs and Symptoms

• Mechanical SI joint dysfunction typically causes a dull ache that is located at the base of the spine on the affected side(s).

• The pain may become worse and 'sharp' in nature during activities such as sitting, bending, lifting, standing up from a seated position, or lifting the knee up to the chest during stair climbing.

• Sometimes the pain can refer to the groin, buttock or the back of the thigh although, unlike referred pain from a disc prolapse, SI joint pain rarely goes below the knee.

 Treatment

• Rest from the aggravating activities is essential during an acute episode of pain. Once the person has found a position that relieves the pain, then this should be maintained as much as possible during the first 24 hours.

• Over the counter analgesic medication normally brings some relief of symptoms. In more chronic cases pain relief is possible with a TENS unit (a battery powered device that 'blocks' pain signals by introducing a direct current to the body).

• Successful treatment is largely dependent upon addressing any underlying factors that can predispose a person to SI joint dysfunction. In the case of a woman who is suffering from SI joint dysfunction during pregnancy, it may not be possible to eradicate the problem until after the birth. Then, once ligamentous laxity is no longer such an issue, steps can be taken to restore normal SI joint mechanics. An orthopedic belt that supports the SI joint may be helpful.

• Similarly, if SI joint dysfunction is caused by biomechanical factors, such as a leg length discrepancy or altered lower limb alignment, then these causes must be addressed. Orthotics (specially made inserts that go in the sole of the shoes) can be helpful in some cases. Specific muscle strengthening or stretching exercises can also remedy postural mal-alignment which may be contributing to SI joint dysfunction. Often the Iliacus and Psoas muscles (which flex the hip) are often over active and tight.

• Passive mobilizations by a Physical Therapist can be very effective where normal SI joint movement is 'blocked'. This has the effect of gently facilitating normal SI joint movement, thus removing abnormal stresses on the ligaments which surround the joint. Once normal SI joint movement has been restored, more active rehabilitation can be undertaken. This involves specific muscle work for the 30 plus muscles whose activity can affect SI joint stability - the series of exercises is different in each individual. In a sporting individual these exercises should be progressed to functional activities which are specific to the particular sport. This helps to prevent a recurrence once the person resumes their sport.