From the Research
A L4/5 retrodiscal transforaminal epidural steroid injection primarily addresses the L5 nerve root. This injection targets the area where the L5 nerve root exits the spinal canal through the L4/5 neural foramen. The procedure involves delivering anti-inflammatory corticosteroid medication directly to the inflamed nerve root as it emerges from below the L4/5 disc. The anatomical reasoning behind this is that spinal nerve roots exit below the pedicle of their corresponding numbered vertebra. Therefore, at the L4/5 disc level, the L5 nerve root is the one traversing this space and potentially being compressed or irritated by disc pathology. The injection helps reduce inflammation and pain by delivering medication directly to the affected nerve root, providing targeted relief for patients experiencing radicular symptoms in the L5 nerve distribution, which typically includes the lateral leg and dorsum of the foot. The procedure is performed under fluoroscopic guidance to ensure accurate needle placement and medication delivery to the intended nerve root.
Some key points to consider when performing this procedure include:
- The contrast spreading patterns in retrodiscal transforaminal epidural steroid injections, as observed in a study published in 2012 1, which found that contrast spread over the L4 nerve root in 27 cases and the L4 and L5 nerve roots in 3 cases in the L4-5 RD group.
- The effectiveness of preganglionic epidural steroid injection through the translateral recess approach, as described in a 2019 study 2, which found this approach to be effective and safe for lumbosacral radiculopathy.
- The comparison of the effect of single lumbar transforaminal epidural steroid injections for the treatment of L4-5 and L5-S1 paramedian disc herniation, as reported in a 2019 study 3, which found that transforaminal epidural steroid injections for L4-5 paramedian disc herniation were more effective than those for L5-S1 paramedian disc herniation.
Overall, the goal of a L4/5 retrodiscal transforaminal epidural steroid injection is to provide relief from radicular symptoms by reducing inflammation and pain in the L5 nerve root, and this procedure has been shown to be effective in achieving this goal, as supported by the evidence from studies such as those published in 2012 1 and 2019 3.