CT-guided Pulsed Radiofrequency Combined with Steroid Injection for Sciatica from Herniated Disk: A Randomized Trial

Abstract

Background Evidence regarding effective nonsurgical management of sciatica remains limited. Purpose To determine a difference in effectiveness between combined pulsed radiofrequency (PRF) and transforaminal epidural steroid injection (TFESI) treatment versus TFESI alone for sciatic pain due to lumbar disk herniation. Materials and Methods This prospective multicenter double-blind randomized clinical trial was conducted between February 2017 and September 2019 in participants with sciatica due to lumbar disk herniation lasting 12 weeks or longer that was not responsive to conservative treatment. Study participants were randomly assigned to undergo one CT-guided treatment with combined PRF and TFESI (n = 174) or TFESI alone (n = 177). The primary outcome was leg pain severity, as assessed with the numeric rating scale (NRS) (range, 0-10) at weeks 1 and 52 after treatment. Secondary outcomes included Roland-Morris Disability Questionnaire (RMDQ) score (range, 0-24) and Oswestry Disability Index (ODI) score (range, 0-100). Outcomes were analyzed according to the intention-to-treat principle via linear regression. Results Mean age of the 351 participants (223 men) was 55 years ± 16 (SD). At baseline, NRS was 8.1 ± 1.1 in the PRF and TFESI group and 7.9 ± 1.1 in the TFESI group. NRS was 3.2 ± 0.2 in the PRF and TFESI group and 5.4 ± 0.2 in the TFESI group (average treatment effect, 2.3; 95% CI: 1.9, 2.8; P < .001) at week 1 and 1.0 ± 0.2 and 3.9 ± 0.2 (average treatment effect, 3.0; 95% CI: 2.4, 3.5; P < .001), respectively, at week 52. At week 52, the average treatment effect was 11.0 (95% CI: 6.4, 15.6; P < .001) for ODI and 2.9 (95% CI: 1.6, 4.3; P < .001) for RMDQ, favoring the combined PRF and TFSEI group. Adverse events were reported in 6% (10 of 167) of participants in the PRF and TFESI group and in 3% (six of 176) of participants in the TFESI group (eight participants did not complete follow-up questionnaires). No severe adverse events occurred. Conclusion In the treatment of sciatica caused by lumbar disk herniation, pulsed radiofrequency combined with transforaminal epidural steroid injection is more effective for pain relief and disability improvement than steroid injection alone. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Jennings in this issue.

Graphical abstract

Figure 1:

Flowchart shows enrollment and randomization criteria. NRS = numeric rating scale.

Figure 2:

CT-guided pulsed radiofrequency (PRF) with transforaminal epidural steroid injection. A 62-year-old woman underwent PRF followed by transforaminal epidural steroid injection for sciatica due to left contained intraforaminal disk herniation at the L4-5 level. (A) A 22-gauge needle electrode with a 10-mm active tip was introduced and advanced using one 3-mm oblique axial unenhanced CT scan, which revealed that the needle tip was proximate to the target dorsal root ganglion with the lateral foraminal portal of entry. (B) Sensitive stimulation (50 Hz) PRF current with a threshold of no more than 0.2 V was used to confirm proper positioning by evoking tingling or electric pain in the dermatome that had to match the target dorsal root ganglion. Therapeutic PRF was then performed in one 10-minute session with E-dose functionality, maintaining temperature below the threshold for neural damage (42°C) and a constant voltage (45 V) (G4 RF Generator; Boston Scientific). Immediately after PRF administration, epidural spread of 0.3 mL of contrast material (350 mg of iodine per milliliter, Iomeron; Bracco) was confirmed using intermittent intraprocedural CT fluoroscopic imaging with no intravascular contrast material flow demonstration. A combination of steroid and anesthetic (1 mL lidocaine [ 20 mg/mL] and 2 mL dexamethasone [10 mg/mL]) was then injected without altering needle position to conclude the procedure.

Figure 3:

(A) Numeric rating scale (NRS) for leg pain, (B) Roland-Morris Disability Questionnaire (RMDQ), and (C) Oswestry Disability Index (ODI). Panels show curves of means with 95% CIs for the 52-week observation period. Follow-up scores are denoted at 1 week (for NRS only) and at 4, 12, and 52 weeks. Values on the y-axis are expressed as different outcome measures in each panel. Blue indicates the pulsed radiofrequency (PRF) and transforaminal epidural steroid injection (TFESI) treatment group, while red indicates the TFESI group. Mean and mean differences are indicated over the panels for the area under the curve analysis with the respective 95% CIs, as analyzed with the Student t test. Results show statistical significance in favor of the combined treatment protocol at all time points for the NRS and RMDQ and ODI scales.