With a transforaminal epidural steroid injection (ESI), often referred to as a 'nerve block', the needle is placed alongside the nerve as it exits the spine, and medication is placed into the 'nerve sleeve'. The medication then travels up the sleeve and into the epidural space from the side. This allows for a more concentrated delivery of steroid into one affected area (usually one segment and one side). Transforaminal ESIs can also be modified slightly to allow for more specific coverage of a single nerve and can provide diagnostic benefit, in addition to improved pain and function.
The procedure requires only local anesthesia. $800 is added to the price if general anesthesia is needed.