Sacroiliac Joint Injections

The anatomy of the sacroiliac joint

The sacroiliac joints are found beside the spine and connect the hip to the sacrum on both sides of the body. A sacroiliac joint injection, also known as an SI joint injection can be used to identify the source of an individual’s pain, while also providing therapeutic relief to the sacroiliac joint strain, dysfunction or inflammation.

Causes of sacroiliac joint pain

Causes of sacroiliac joint pain

There are several causes of sacroiliac joint pain. The joint could become inflamed through injury, wear and tear(aging) or through a problem developed through an activity which an individual undertakes regularly, such as forms of physical exercise or manual work.

Damage to the ligaments of the sacroiliac joint is another possible reason for the joint dysfunction, while a type of arthritis known as ankylosing spondylitis can damage the sacroiliac joint.

Pregnant women can suffer from sacroiliac joint pain due to the release of hormones which have the ability to alter joint movement and cause pain. It has also been found that an uneven leg length can disrupt the rhythm of strides while walking and lead to sacroiliac joint pain.

Sacroiliac joint injection procedure

Sacroiliac Joint Injection Procedure

The sacroiliac joint procedure is typically performed in a dedicated theatre as a day case procedure. It is performed using fluoroscopy (live X-ray) to help guide the needle accurately and avoid any nerve injury. The procedure will take place in theatre under full aseptic conditions with the patient on his or her stomach. A small needle in the back of your hand can be used to administer sedation or in case of an emergency. The skin is well cleaned before a small amount of local anaesthetic is applied in order to numb the injection area. The physician then directs a small needle into the joint. A small mixture of steroid (anti-inflammatory medication) and anaesthetic is then injected into the joint.

Patients are then monitored in a recovery area before transfer to the ward and discharge home. Patients may experience a numb feeling for a few hours. It is advisable to rest for 24 hours and resume stretches and exercises when the pain eases. Pain and spasms at the injection site may increase for five or more days. This window of pain relief should be utilised for performance of strengthening exercises and rehabilitation physiotherapy.



There is a variable response to injection treatment. It is important to discuss both the benefits and risks of the procedure with your doctor before any agreement to undergo the procedure is reached. Although the chance of any complications is generally low, as with all surgical procedures, there is an element of risk involved with sacroiliac joint injections including failure to get benefit or pain aggravation. There may be an allergic reaction to the steroid or any of the medications, or that the injection causes an infection or bleeding. Paralysis or nerve damage is extremely rare.