I read an interesting research article in the January 2018 of The Spine Journal . This paper was looking at a time period of 5 years after the last injection of steroid to the intervertebral foramen (IVF) to assess the lasting effects of decreasing leg pain. The IVF is an area of the spine where the nerve exits to go throughout the body and is often a source of pain.
The criteria for this study were people 18 years or older, the presence of a single level disc herniation as identified by MRI, radiating single leg pain for less than 6 months, a pain rating of equal to or greater than 4 out of 10 and having completed a program of conservative treatment.
The study followed 78 subjects. Of which, 58 received injections only, 14 underwent surgery only and 6 were not able to be contacted.
The overall results for both groups showed that most had excellent decrease in pain for about 6 months. However, recurrent episodes of the pain after 6 months were present for most of the subjects, regardless of the getting surgery or steroid injection. For the recurrences, subjects chose opioids, additional injections or surgery.
The authors of the study concluded that the initial effects of the the steroids are active several days yet the benefits continue for months. They conclude that the recurrences are not due to the lack of effectiveness of the steroids. Instead, factors are particular to each individual such as varied rates of degenerative changes of the disc, lifestyle activities and biomechanical factors of the subjects.
On a practical basis, if faced with this situation, an important question to ask yourself is, “Should you have surgery or injection?” Both appear to have the same long term outcome. The risk verses benefits is an important point to discuss and evaluate with your provider.
 Kennedy, D. J., Zheng, P. Z., Smuck, M., McCormick, Z.L., Huynh, L., & Schneider, B.J. (2017). A minimum of 5-year follow-up after lumbar transforaminal epidural
steroid injections in patients with lumbar radicular pain due to intervertebral disc herniation. The Spine Journal, 18. 29-35.