Once positioned appropriately by your doctor, a fluoroscope (X-ray guided machine) assists in identifying the specific area to be injected. The area is then cleansed and the skin is numbed. The needle is inserted under X-ray guidance into the epidural space (the small space surrounding the nerves inside the spinal canal). A special X-ray dye will be used to verify that the needle has been correctly placed and that the medication will be delivered to the appropriate site. A long-acting anti-inflammatory steroid and local anesthetic are usually administered and the needle is removed.
Epidural steroid injections are commonly prescribed for patients with a disc injury or spinal arthritis causing nerve irritation, and generally consist of local anesthetic (numbing medication such as lidocaine) and cortisone (a steroid that reduces inflammation and pain). Lidocaine is often injected initially so patients experience minimal, if any, pain during the procedure. The injection may be performed by placing the needle posteriorly between the spine bones (Translaminar or interlaminar) and injecting the medicine into the space around the spinal nerves. A transforaminal ESI means the injection is placed slightly to one side of the spine, and the medicine is injected near the ruptured disc and inflamed spinal nerve. A caudal ESI is performed by placing the needle near the tailbone, and injecting the medicine into the region of the sacral nerves and lower lumbar spinal nerves. Epidural steroid injections, as well as most spinal injections, are performed using a special x-ray guidance system called fluoroscopy. This allows the doctor to immediately see an x-ray image on a television screen and inject the medicine precisely into the right spot. The procedure time is often less than 10-15 minutes.