Musculoskeletal Joint Injections
Sacroiliac Joint Injection
What is the sacroiliac (SI) joint?
The sacrum lies at the lower end of the spine, just below the lumbar spine. The sacroiliac (SI) joints sit between the sacrum and the iliac bone (also called the ilium), connecting the upper body to the lower body. In order to withstand the high pressures of walking, standing, and sitting, the SI joints have a puzzle-shaped design held together by several ligaments, and therefore do not normally move well. When these ligaments are injured or become loose, the joints can become hypermobile and ‘stretch’ too much. Because SI joints were not designed to accommodate such movement, the result is severe and disabling pain.
Pain caused by SI joint dysfunction or inflammation is usually in the lower back (left or right side) and radiates to the buttock, posterior thigh, groin, and occasionally the lower leg. There is often tenderness over the back surface of the SI joint, but this is not reliable for diagnosis. Pain is often worse after long periods of sitting or standing, turning in bed, or stepping up on the affected leg. This makes it difficult to differentiate from other causes of low back pain, such as pain from a herniated disc or arthritic/strained facet joint.
A sacroiliac joint block can accurately diagnose SI joint pain
If back pain is not relieved with non-steroidal anti-inflammatory (NSAID) drugs, reduced activity, weight loss, back supports/bracing and physical therapy, diagnosis of SI joint pain can be made using a sacroiliac joint block, which is an injection of local anesthetic into the joint using X-ray guidance for accuracy.
These blocks may be diagnostic (test only) and/or therapeutic (with cortisone or prolotherapy).
One of three things may happen:
- The pain does not go away – which means that the pain is probably not coming from the SI joint.
- The pain goes away and stays away for a few hours, but the original pain comes back and does not get better again. This would mean the block was also of diagnostic value. The pain is probably coming from the joint, but the steroid was not of benefit.
- The pain goes away after the block. The pain may come back later that day, but then the pain gets better again over the next few days. This means that the block was of therapeutic value – the steroid had a long-lasting effect on the pain.
If you get good, lasting benefit from the injections, the block may be repeated 1 or 2 times. If you experience a good but short-term benefit, other lasting procedures (Radiofrequency neurotomy or Prolotherapy) may be discussed. Repetitive use of steroids around the SI joint may cause cartilage breakdown and further restriction and pain.
What are steroids?
Corticosteroids are a class of medications that are related to cortisone. Cortisone is a naturally-occurring corticosteroid hormone produced by your adrenal glands.
How do cortisone injections work?
After injection, cortisone works to reduce inflammation in and around the joint. As a result, you should feel less pain, swelling, stiffness, and warmth, and be able to function a little easier.
How long does it take for a cortisone injection to work, and how long will it last?
Most injections typically take 24-48 hours to take full effect. If local anesthetic was given with the steroid injection, you may feel improvement relatively quickly. The duration of Improvement varies. Some patients report months of relief, whereas others only find a few days of relief.
How often can I have repeat cortisone injections?
If a significant benefit is achieved after the first injection, then repeat injections may be used. There is some controversy that too many injections may weaken tendons and ligaments, and accelerate the loss of cartilage, but other studies have found the opposite – that injections can slow joint damage and help preserve the joint. Occasionally a trial of three steroid injections may be needed to determine if they work for you, usually one month apart.
What should I do after a cortisone injection?
If possible, it is best to rest the joint for 24-48 hours. Studies have shown this may improve the effect of the injection.
Can I drive afterwards?
Depending on what you had done, yes, as long as you feel you can safely control the vehicle. It is probably better not to rush straight off after the injection, but to sit and relax for 10-15 minutes. That way you can be sure you will be able to manage on the road.
What are the possible side effects of a cortisone injection?
Most joint injections result in no side effects. Side effects which rarely occur include: injury to the joint or tendon, loss of the fat layer below the skin, loss of skin colour, calcification around the joint, and joint infection. The joint may also ‘flare up’ transiently after an injection. Long term use of steroids exceeding 560 mg of triamcinolone or its equivalent per year may lead to bone loss (osteoporosis), but your clinical team will keep a close eye on the use of steroids. Very rarely, steroid use may lead to acute hip problems, increase in blood pressure, pressure inside the eye, and an increase in blood sugar.
When should I call my physician or seek medical attention?
If the injected joint becomes very painful, red, or swollen, seek medical attention immediately as the joint may be infected. If the joint is infected, it is very important to seek medical attention as soon as possible.
For people with diabetes
Cortisone injections may increase blood sugar levels. Patients with diabetes may develop high sugar levels for up to 14 days. Please contact your diabetes physician if blood sugar rises above 14 mmol/L. If your blood sugar levels go above 20 mmol/L, go directly to the emergency room. If you use insulin, you may need a larger dose during this time. It is important to check your blood sugar using a glucometer and test strips more often after you receive a cortisone injection.