Transforaminal Vs Interlaminar Epidural Steroid Injection for Lumbar Radiculopathy: A Comparative Study of Pain and Function

Abstract

Background: Lumbar radiculopathy is a common cause of low back and leg pain, often managed by epidural steroid injections. Among the available routes, transforaminal and interlaminar approaches are widely used, but their relative efficacy remains debated.

Aim: To compare the efficacy of transforaminal and interlaminar epidural steroid injections in reducing pain and improving functional outcomes in patients with lumbar radiculopathy.

Methods: A prospective comparative observational study was conducted on 200 patients with clinically and MRI-confirmed lumbar radiculopathy. Participants were divided into two equal groups: Group A (n=100) received transforaminal epidural steroid injection (TFESI), and Group B (n=100) received interlaminar epidural steroid injection (ILESI). Pain and functional disability were assessed using the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) at baseline, 2, 6, and 12 weeks post-injection. Statistical analyses included t-tests, chi-square tests, and 95% confidence intervals, with p<0.05 considered significant.

Results: Baseline characteristics were comparable between groups (p>0.05). TFESI produced significantly greater pain reduction than ILESI at 2 weeks (VAS 4.1 ± 1.2 vs 4.8 ± 1.4, p<0.001), 6 weeks (3.1 ± 1.2 vs 3.8 ± 1.3, p<0.001), and 12 weeks (2.6 ± 1.1 vs 3.2 ± 1.2, p<0.001). Functional improvement was also superior in the TFESI group at 12 weeks (ODI reduction −23.8 ± 8.5 vs −21.0 ± 9.0, p=0.009). A ≥50% pain reduction at 12 weeks was achieved by 71% of TFESI patients versus 57% of ILESI patients (OR 1.79, p=0.029). Minor complications occurred in 19% and 13% of patients, respectively, with no serious adverse events.

Conclusion: Both transforaminal and interlaminar epidural steroid injections are effective for lumbar radiculopathy; however, the transforaminal approach offers earlier and more pronounced pain relief and functional recovery with a comparable safety profile.