At Prairie Spine and Pain Institute, we perform pain injections for two pain main reasons; one being for therapeutic (pain relieving) purposes and the second being for diagnostic (finding out the problem) reasons.
When searching for a diagnosis practitioners will use many forms of diagnostic tools to help confirm their diagnosis. Some examples in the spine world are X-rays, MRIs, EMG nerve conduction studies, CT myelograms, discograms, and injections. In this article we will focus on steroid injections.
What most patients are unaware of is that the shot they are getting is not solely being performed to make them feel better. There is extremely valuable information also obtained when performing these injections. This is where the diagnostic information comes in. In order to understand why this information becomes available, you must first know the procedure and the medications involved. When performing any injection, whether it is in the neural foramens, sacral-iliac joints, epidural space, facet joints, or any anatomic structure related to the spine, visualization is paramount. Any injections into the spine are performed with fluoroscopic guidance, allowing us to visualize directly where to put the needle to isolate the structure being injected. Once the needle finds its destination, we further confirm the spot with injection of contrast dye allowing us to be absolutely positive that the medication will enter the area suspected of pathology. The contrast dye highlights the area being injected on the fluoroscopic imaging screen. Next the medications are injected.
The two medications involved are local anesthetic and corticosteroid. The local anesthetic is key to the diagnostic portion of this procedure. The idea being, that the suspected area involved, is injected with local anesthetic (numbing medication), which begins to act almost immediately. Patients can then track their pain scores immediately after the injection. If a patient comes in with a pain score of 9 on a 1-10 pain scale, and immediately after the injection is at a 1, we can be confident that this is part if not all of the pain generator. In a simple summary; if you have pain there, we inject it there, and if the pain goes away, we have confirmed the location of the diagnosis. The downside to the immediate relief is that the numbing medication used (local anesthetic), has a very short half-life. This means it will be broken down in the body and stop working usually within 1-3 hours of the injection. This is where the second medication corticosteroid takes over. The mechanism of action of these steroids includes inhibition of phospholipase, alterations in lymphocytes, inhibition of cytokine expression and stabilization of the cellular membrane. The inhibition of phospholipids to arachidonic acid is critical to the formation of the inflammatory mediators such as; LTB-4, LTC-4, LTD-4, and LTE-4 and various prostaglandins. Although this sounds like absolute gibberish, the take-home point is that corticosteroids work by the action of an ANTI-INFLAMMATORY effect by shutting down inflammatory mediators. The steroid in the injections is the main long lasting therapeutic agent used for this procedure.
Many patients ask, “Will Corticosteroid Injections cure my condition?” This is a very tough question to answer. Ideally and hopefully yes, but it is not always the case. However, as stated previously, we do these injections for two main reasons, therapeutic and diagnostic. If the injections do not take care of the problem, we are at least able to focus further treatment based off the diagnostic information obtained. These injections are a crucial element of diagnosing and treating patients with spine conditions.
About The Author: Derek N. Morrow, PA-C is a physician assistant with Prairie Spine and Pain Institute. Derek works in the clinic setting as a health care provider seeing patients. He is also utilized in the operating room as a first assist in surgery. In the clinic setting, his key function is to diagnose new patients and conduct their initial treatment. He works directly with patients to establish customized treatment programs and to monitor their progress. He also conducts history and physical evaluations for many patients. He performs many office procedures including trigger point injections, large joint injections, and bursa injections, all with the help of ultrasound guidance. He is radiologically trained, and uses his knowledge of X-ray, Ultrasound, MRI, CT, and EMG-Nerve Conduction Studies to establish a diagnosis and determine the appropriate treatment. Derek is surgically trained and plays a vital role in the procedures we perform at Prairie Spine and Pain Institute.