Sacroiliac joint injection, sometimes referred to simply as ‘SI’, is an alternative therapy intended to diagnose and treat pain resulting from a sacroiliac joint condition. The condition could be the result of an injury or an underlying disease like arthritis. To improve SI accuracy, doctors tend to use imaging procedures including fluoroscopy and ultrasound.
Both fluoroscopy and ultrasound have their advantages. According to the pain doctors at Lone Star Pain Medicine, fluoroscopy and ultrasound are utilized in SI procedures to improve accuracy.
Accuracy in what, exactly? Needle placement. SI is an injection therapy. It relies on a combination of anesthetic and steroid medications to reduce pain and inflammation. But without correct needle placement, the procedure could be unsuccessful.
Utilizing Fluoroscopy
Fluoroscopy is a specialized type of X-ray that provides real-time images of the area being scanned. When deployed as part of an SI procedure, it works very well. Studies suggest that needle placement accuracy is more than 98% with the use of fluoroscopy. As such, fluoroscopy is considered the gold standard when precise needle placement is a requirement.
So why not use it for every SI procedure? One of the big downsides to fluoroscopy is radiation exposure. Remember, fluoroscopy is a type of X-ray. Radiation exposure is not a big deal for patients receiving a single treatment every few months. But doctors and nurses being exposed to the same radiation every day could be problematic.
On the other hand, fluoroscopy’s accuracy is hard to beat. When a doctor is aiming for a very small and precise area within the sacroiliac joint, fluoroscopy is the way to go.
Utilizing Ultrasound
Rather than depending on radiation, ultrasound utilizes sound waves sent through the body and then reflected back to the machine. Think of ultrasound as radar for medical purposes. Its main advantage over fluoroscopy is the absence of radiation exposure.
Some doctors prefer ultrasound for SI procedures because of the level of real-time visualization the procedure affords. In the hands of a skilled clinician, ultrasound provides clear visualizations of all sorts of soft tissue including blood vessels and nerves. Fluoroscopy is not capable of that level of visualization.
The one downside of ultrasound is that its accuracy can vary widely. Accuracy in SI procedures ranges from 40%-100% depending on the study data you are looking at. Because ultrasound’s accuracy is questionable in terms of needle placement, it is only a good option for SI when a doctor believes precision accuracy is not necessary.
More About the SI Procedure
Knowing more about the SI procedure might make it easier to understand why a doctor would choose one imaging technology over another. Sacroiliac joint injections are part of a family of alternative injection therapies designed to offer pain relief when more traditional treatments have failed.
An SI procedure relieves pain by bathing the affected area with anesthetic and steroids. The anesthetic goes to work on the pain right away. Meanwhile, the steroids reduce inflammation and keep it under control for an extended amount of time. The combination of both can offer temporary relief from all sorts of painful sacroiliac joint conditions.
Some conditions require more precise needle placement than others. For example, nerve damage tends to be isolated and found at a site of inflammation or compression. The doctor wants to place the needle as close to the nerve as possible. But in an osteoarthritis scenario, precision accuracy isn’t necessary. Getting the needle into the joint works well enough.
In any event, fluoroscopy and ultrasound make SI procedures more effective. By guiding needle placement, they guarantee medica is injected into the right spot.
