Arthritis in the sacroiliac joint is a common cause of severe aching pain in the lower back or buttocks. The pain can make sitting, standing, or even walking unbearable. Fortunately, there is an effective interventional treatment that offers reduced inflammation and pain. But what so many patients do not understand is that it could take up to a week for that relief to truly kick in.
Known as a sacroiliac (SI) joint injection, the procedure is offered by Weatherford, TX-based Lone Star Pain Medicine. It represents one of the most effective means of calming inflammation in the joint. Given the prevalence of sacroiliac joint arthritis, this is a good thing.
What It Is and How It Works
The sacroiliac is a joint that connects the base of the spine to the hip bone. That means we have two, one on each side. Sacroiliac joints act as shock absorbers when we walk, run, or even stand. They can become arthritic just like any other joint in the human body.
As for an SI joint injection, it is a quick, image-guided outpatient procedure. A doctor uses fluoroscopy to find the exact location at which to inject the medicine. In most cases, injections involve two types of medications:
- Local Anesthetic – A local anesthetic, usually lidocaine or bupivacaine, offers immediate and short-term pain relief. The relief confirms that the SI joint is truly the source of a patient’s pain.
- Corticosteroid – A corticosteroid is a potent, long-acting anti-inflammatory medication. It is designed to provide extended relief by reducing inflammation and keeping it under control.
As you might expect, the local anesthetic tends to wear off as quickly as it kicks in. So while it may offer temporary pain relief, the relief tends to last only a few hours. Patients must then wait for the corticosteroid to do its thing.
Why Steroids Can Take Up to a Week to Start Working
It is not unusual to experience a bit of soreness at the injection site after the local anesthetic wears off. In addition, the actual joint pain is not necessarily relieved right away. This causes so many patients to ask, “Why does it take up to a week for steroids to start working?”
The delay is directly related to how corticosteroids interact with the human body:
- Reducing Inflammatory Proteins – Corticosteroids reduce inflammation by altering the production of inflammatory proteins. Slowing down production limits inflammation over long periods of time.
- Gradual Reduction – The corticosteroid crystals injected during an SI procedure do not break down quickly. They gradually reduce, delivering continuous anti-inflammatory action rather than a quick burst of action.
- Fluid Absorption – The impacted joint capsule must absorb pre-existing inflammatory fluid in order for swelling to go down. This takes time as well.
In essence, reducing inflammation with a corticosteroid is a gradual biological process. Some patients start noticing significant relief in a day or two. Others don’t start feeling good until about a week later.
Why It Matters
A good pain management doctor will thoroughly discuss the potential week-long delay before recommending SI joint injections. Why? Because patients need to know ahead of time what they are getting into. The seven-day window matters for two reasons:
- Doctors don’t want patients to be prematurely discouraged.
- Knowing that the joint is still inflamed has implications for the patient’s daily activity.
Doctors tend to wait a full two weeks before making a final assessment. If a patient doesn’t experience meaningful pain relief, it’s time to move on to other treatments. If the procedure does work, a doctor might recommend repeat injections a couple of times per year.