Transforaminal Epidural Steroid Injection for Patients with Lumbosacral Disc Herniation in the Absence of Spine Magnetic Resonance Imaging – Is Better Really the Enemy of the Best?

PURPOSE: This study aimed to evaluate the effect of transforaminal epidural steroid injection (TFESI) in patients with lumbosacral disc herniation by comparing its effect between those diagnosed by clinical evaluation and plain radiography only (X-ray group) and those by additional magnetic resonance imaging (MRI) (MRI group). Additionally, we investigated the accuracy of the preliminary clinical assumption in the X-ray group using confirmative post-injection MRI. PATIENTS AND METHODS: We retrospectively recruited 367 patients with back and radicular pain due to lumbosacral disc herniation from a single pain clinic. Among them, 201 and 166 patients were categorized into the X-ray and MRI groups, respectively. In the X-ray group, the pathological level assumed initially by clinical evaluation and plain radiography concurred with that confirmed later on post-injection MRI in 139 patients (corresponding group); the remaining 62 patients lacked this concurrence (non-corresponding group). The NRS scores and Macnab criteria results were compared between the X-ray and MRI groups as well as the corresponding and non-corresponding groups. RESULTS: Both the X-ray and MRI groups showed significant reductions in the NRS scores at 2 and 10 weeks post-injection when compared with the pretreatment scores. However, no significant difference was noted between the groups in terms of the magnitude of clinical improvement assessed by successful reduction in the NRS or Macnab scores. Furthermore, similar results were obtained in the comparison between the corresponding and non-corresponding groups of the X-ray group. CONCLUSION: TFESI guarantees favorable clinical outcomes even in the absence of confirmative MRI in patients with back and radicular pain. The preemptive application of this procedure could be prioritized and justified in patients suspected of lumbosacral disc herniation based on clinical evaluation and plain radiography only without the preceding MRI verification.