INTRODUCTION Lumbar radiculopathy is a common neurological pain condition caused by irritation or compression of one or more lumbar or sacral nerve roots. It typically presents with low back pain radiating into the lower limb in a dermatomal distribution and may be accompanied by numbness, paraesthesia, muscle weakness, diminished reflexes and functional limitation. Intervertebral disc herniation and degenerative lumbar spinal changes, including foraminal or lateral recess stenosis, are the principal causes. The condition can considerably restrict mobility, activities of daily living, sleep and occupational performance and may consequently impair quality of life.[1] Initial management generally includes activity modification, pharmacological treatment, physiotherapy and structured exercise. However, a proportion of patients continue to experience disabling radicular pain despite adequate conservative treatment. Although surgical decompression may be required for progressive neurological deficits or persistent severe symptoms, image-guided epidural interventions provide an important minimally invasive treatment option for appropriately selected patients.[2] Epidural corticosteroid injections are intended to reduce inflammation surrounding the affected nerve root. Corticosteroids inhibit inflammatory mediators, decrease vascular permeability and reduce ectopic neuronal discharge, while the accompanying local anaesthetic may provide immediate pain relief and facilitate rehabilitation. Epidural injections may be administered through caudal, interlaminar or transforaminal approaches. The transforaminal epidural steroid injection (TFESI) route allows targeted delivery of medication into the neural foramen adjacent to the clinically and radiologically involved nerve root. This selective delivery may produce a higher local drug concentration at the site of pathology while using a relatively small injectate volume.[3]Available evidence indicates that TFESI can provide meaningful short-term pain reduction and functional improvement, particularly in patients with radiculopathy caused by lumbar disc herniation.[4] Nevertheless, treatment response varies according to the underlying pathology, duration and severity of symptoms, degree of nerve-root compression, injection technique and outcome definition. Statistical improvement in mean pain scores may not necessarily reflect a benefit that patients consider clinically worthwhile. Therefore, treatment effectiveness should be assessed using clinically interpretable outcomes, such as at least 50% reduction in the Numeric Rating Scale (NRS) score and a clinically important improvement in the Oswestry Disability Index (ODI). The subsequent requirement for lumbar spine surgery may also provide an indication of the longer-term clinical course. Although TFESI is generally considered minimally invasive, careful patient selection, image guidance, contrast confirmation and adherence to safety precautions are necessary because infection, bleeding, intravascular injection, nerve injury and rare serious neurological complications have been reported.[5] The present study was therefore undertaken to evaluate pain relief and functional recovery following single-level unilateral TFESI and to determine the proportions of patients attaining clinically meaningful improvement and avoiding lumbar spine surgery. AIM To evaluate the effectiveness of single-level unilateral transforaminal epidural steroid injection in achieving clinically meaningful pain relief and functional recovery among patients with lumbar radiculopathy. OBJECTIVES 1. To compare NRS pain scores and ODI functional disability scores at baseline, one week and four weeks following TFESI. 2. To determine the proportion of patients achieving at least a 50% reduction in NRS score and/or at least a 10-point improvement in ODI score at four weeks. 3. To determine the proportion of patients who avoided lumbar spine surgery during the 12 months following TFESI.

Source of Data Data were obtained from the medical records, pain-clinic records, procedure documentation and follow-up records of patients who had undergone single-level unilateral TFESI for lumbar radiculopathy at P.D. Hinduja National Hospital and Medical Research Centre, Mahim, Mumbai. Information regarding baseline clinical characteristics, MRI findings, injected nerve-root level, baseline and follow-up outcome scores and lumbar spine surgery during follow-up was retrieved. Study Design This was a hospital-based retrospective descriptive and longitudinal observational study. Study Location The study was conducted in the Department of Anaesthesiology and Pain Medicine, P.D. Hinduja National Hospital and Medical Research Centre, Mahim, Mumbai, Maharashtra, India. Study Duration Records of eligible patients who had undergone TFESI between July 2021 and June 2025 were reviewed. Each patient’s available clinical follow-up was examined at one week and four weeks for pain and functional outcomes and for up to 12 months to determine whether lumbar spine surgery had been performed. Sample Size The study included 90 patients. Because this was a retrospective record-based study, all consecutive patients fulfilling the eligibility criteria during the predefined study period were included until the final sample of 90 eligible records was obtained. Inclusion Criteria 1. Patients aged 18 years or older. 2. Patients with unilateral, single-level lumbar radiculopathy involving the L3, L4, L5 or S1 nerve root. 3. Radiculopathy established on clinical examination and confirmed by MRI of the lumbosacral spine. 4. Patients who had undergone a single-level unilateral TFESI using a local anaesthetic and corticosteroid. 5. Patients with documented baseline NRS and ODI assessments and available post-procedure follow-up information. Exclusion Criteria 1. Patients with symptomatic multilevel lumbar disc disease or multilevel radiculopathy. 2. Patients with a history of lumbar spine surgery. 3. Patients who had undergone bilateral or multilevel epidural injections during the index procedure. 4. Patients with incomplete procedure documentation. 5. Patients whose records lacked essential baseline or follow-up outcome data. Procedure and Methodology After obtaining the necessary institutional permission, eligible records were identified from the pain-clinic and hospital databases. The patients’ demographic characteristics, including age and sex, were recorded. Clinical and radiological information included the affected side, vertebral disc level and involved lumbar or sacral nerve root. TFESI had been performed under standard aseptic precautions and image guidance. The patient had been appropriately positioned, and the target neural foramen was identified. After local infiltration of the skin, a spinal needle had been advanced toward the target foramen under imaging guidance. Needle placement had been verified in appropriate views, and contrast medium had been administered to confirm epidural/periradicular spread and exclude intravascular placement. A mixture of corticosteroid and local anaesthetic had subsequently been injected according to the departmental protocol. Patients had been monitored after the procedure for immediate complications and had been discharged with appropriate instructions when clinically stable. Pain intensity was assessed using the 11-point NRS, ranging from 0, indicating “no pain,” to 10, indicating the “worst imaginable pain.” Functional disability was assessed using the ODI. Baseline NRS and ODI scores recorded before TFESI were compared with the corresponding scores documented at one week and four weeks after the procedure. The primary outcome measures were changes in NRS and ODI scores at one and four weeks. A reduction of at least 50% from the baseline NRS score was considered clinically meaningful pain relief. An improvement of at least 10 points in the ODI score was considered clinically meaningful functional recovery. Records were also reviewed to identify whether the patient had undergone lumbar spine surgery within 12 months following TFESI. All eligible information was entered into a structured data-collection form and subsequently compiled into a master chart. Sample Processing No blood, tissue or other biological samples were collected or processed because the study was based entirely on retrospective clinical records. The collected data were screened for completeness, checked for consistency, coded and entered into an electronic database. Direct patient identifiers were removed from the analytical dataset, and each participant was assigned a unique study identification number. Data Collection Data were collected using a predesigned structured data-extraction form. The variables included age, sex, affected spinal level, involved nerve root, side of radiculopathy, MRI-confirmed pathology, date of TFESI, baseline NRS, NRS at one and four weeks, baseline ODI, ODI at one and four weeks, achievement of at least 50% pain reduction, achievement of at least a 10-point ODI improvement and performance of lumbar spine surgery within 12 months. The extracted data were cross-checked against the source records before analysis. Missing observations were reported for the relevant variables, and no unrecorded clinical value was assumed or fabricated. Statistical Methods Data were analysed using MedCalc version 23.4 and R version 4.5. Continuous variables were assessed for distribution and presented as mean with standard deviation when approximately normally distributed or median with interquartile range when skewed. Categorical variables were expressed as frequencies and percentages.Changes in NRS and ODI scores across baseline, one-week and four-week assessments were evaluated using repeated-measures analysis of variance when parametric assumptions were satisfied or the Friedman test when the data were non-normally distributed. Pairwise comparisons between baseline and follow-up measurements were performed using the paired-samples t-test or Wilcoxon signed-rank test, as appropriate, with adjustment for multiple comparisons. The proportions achieving at least 50% NRS reduction, at least a 10-point ODI improvement and avoidance of surgery were reported with 95% confidence intervals. Associations between categorical variables were examined using the chi-square test or Fisher’s exact test. Where appropriate, logistic regression analysis was used to identify factors associated with clinically meaningful response or subsequent surgery. All tests were two-tailed, and a p value below 0.05 was considered statistically significant.

Table 1: Overall effectiveness of single-level unilateral TFESI in lumbar radiculopathy Outcome Before TFESI, Mean (SD) or n (%) After TFESI, Mean (SD) or n (%) Effect estimate (95% CI) Test of significance P value NRS pain score at 1 week (n=90) 8.46 (0.86) 3.81 (1.42) Mean reduction: 4.65 points Wilcoxon signed-rank, |Z|≥3.89 <0.001* NRS pain score at 4 weeks (n=83) 8.45 (0.87) 3.42 (1.56) Mean reduction: 5.02 points Wilcoxon signed-rank, |Z|≥3.89 <0.001* ODI score at 1 week (n=79) 15.33 (8.73) 10.80 (8.09) Mean improvement: 4.53 points Wilcoxon signed-rank, |Z|≥3.89 <0.001* ODI score at 4 weeks (n=83) 15.88 (8.57) 7.17 (6.44) Mean improvement: 8.71 points Wilcoxon signed-rank, |Z|≥3.89 <0.001* ≥50% reduction in NRS at 4 weeks (n=83) 65 (78.3%) 68.3%-85.8% One-sample χ²=26.61 <0.001* ≥10-point ODI improvement at 4 weeks (n=81) 46 (56.8%) 45.9%-67.0% One-sample χ²=1.49 0.222 Avoided surgery among patients with known 12-month status (n=67) 55 (82.1%) 71.3%-89.4% One-sample χ²=27.60 <0.001* Table 1 presents the overall effectiveness of single-level unilateral TFESI in patients with lumbar radiculopathy. The mean NRS pain score decreased from 8.46 (0.86) before TFESI to 3.81 (1.42) at one week, representing a mean reduction of 4.65 points. At four weeks, the mean NRS score decreased from 8.45 (0.87) to 3.42 (1.56), with a mean reduction of 5.02 points. Both reductions were statistically significant (Wilcoxon signed-rank test, |Z|≥3.89; p<0.001). Functional disability also improved significantly. The mean ODI score decreased from 15.33 (8.73) to 10.80 (8.09) at one week, corresponding to an improvement of 4.53 points, and from 15.88 (8.57) to 7.17 (6.44) at four weeks, corresponding to an improvement of 8.71 points (p<0.001 for both comparisons). At four weeks, 65 of 83 evaluable patients (78.3%; 95% CI: 68.3%-85.8%) achieved at least a 50% reduction in NRS score, which was statistically significant (χ²=26.61; p<0.001). A clinically meaningful ODI improvement of at least 10 points was observed in 46 of 81 patients (56.8%; 95% CI: 45.9%-67.0%); however, this proportion was not significantly different from 50% (χ²=1.49; p=0.222). Among the 67 patients with known 12-month outcomes, 55 (82.1%; 95% CI: 71.3%-89.4%) avoided lumbar spine surgery (χ²=27.60; p<0.001). Table 2: Comparison of NRS and ODI scores at baseline, one week and four weeks following TFESI Outcome comparison Baseline, Mean (SD) [95% CI] 1 week, Mean (SD) [95% CI] 4 weeks, Mean (SD) [95% CI] Mean change Test of significance P value NRS: baseline vs 1 week (n=90) 8.46 (0.86) [8.28-8.63] 3.81 (1.42) [3.52-4.10] −4.65 Wilcoxon signed-rank, |Z|≥3.89 <0.001* NRS: baseline vs 4 weeks (n=83) 8.45 (0.87) [8.26-8.63] 3.42 (1.56) [3.09-3.76] −5.02 Wilcoxon signed-rank, |Z|≥3.89 <0.001* NRS: 1 week vs 4 weeks (n=83) 3.78 (1.46) [3.47-4.10] 3.42 (1.56) [3.09-3.76] −0.36 Wilcoxon signed-rank, Z≈−1.52 0.129 ODI: baseline vs 1 week (n=79) 15.33 (8.73) [13.40-17.25] 10.80 (8.09) [9.01-12.58] −4.53 Wilcoxon signed-rank, |Z|≥3.89 <0.001* ODI: baseline vs 4 weeks (n=83) 15.88 (8.57) [14.04-17.72] 7.17 (6.44) [5.78-8.55] −8.71 Wilcoxon signed-rank, |Z|≥3.89 <0.001* ODI: 1 week vs 4 weeks (n=75) 11.12 (8.15) [9.28-12.96] 7.23 (6.73) [5.70-8.75] −3.89 Wilcoxon signed-rank, |Z|≥3.89 <0.001* Table 2 compares NRS pain and ODI disability scores at baseline, one week and four weeks after TFESI. Among 90 patients evaluated at one week, the mean NRS score decreased significantly from 8.46 (0.86; 95% CI: 8.28-8.63) at baseline to 3.81 (1.42; 95% CI: 3.52-4.10), giving a mean reduction of 4.65 points (|Z|≥3.89; p<0.001). Among the 83 patients evaluated at four weeks, the mean NRS score decreased from 8.45 (0.87; 95% CI: 8.26-8.63) to 3.42 (1.56; 95% CI: 3.09-3.76), representing a reduction of 5.02 points (p<0.001). The NRS score showed a further small reduction of 0.36 points between one and four weeks, from 3.78 (1.46) to 3.42 (1.56), but this additional improvement was not statistically significant (Z≈−1.52; p=0.129). The mean ODI score decreased significantly from 15.33 (8.73; 95% CI: 13.40-17.25) at baseline to 10.80 (8.09; 95% CI: 9.01-12.58) at one week, with a mean improvement of 4.53 points (p<0.001). At four weeks, the mean ODI score decreased from 15.88 (8.57; 95% CI: 14.04-17.72) to 7.17 (6.44; 95% CI: 5.78-8.55), representing an improvement of 8.71 points (p<0.001). Among 75 patients with both follow-up assessments, ODI decreased further from 11.12 (8.15) at one week to 7.23 (6.73) at four weeks, with a statistically significant mean improvement of 3.89 points (p<0.001). Table 3: Clinically meaningful pain relief and functional recovery at four weeks Clinically meaningful outcome Achieved, n (%) Not achieved, n (%) Proportion achieving outcome (95% CI) Test of significance† P value ≥50% reduction in NRS (n=83) 65 (78.3%) 18 (21.7%) 78.3% (68.3%-85.8%) χ²=26.61 <0.001* ≥10-point improvement in ODI (n=81) 46 (56.8%) 35 (43.2%) 56.8% (45.9%-67.0%) χ²=1.49 0.222 Either clinically meaningful pain relief or functional improvement Not directly estimable‡ Not directly estimable‡ †One-sample chi-square test against an expected proportion of 50%. ‡The aggregate results report NRS and ODI responders separately. The number achieving either or both outcomes requires patient-level cross-tabulation and should not be obtained by adding the two responder counts because the groups overlap. Table 3 shows the proportions of patients achieving clinically meaningful pain relief and functional recovery at four weeks. Of the 83 patients with available NRS data, 65 (78.3%; 95% CI: 68.3%-85.8%) achieved at least a 50% reduction in pain, whereas 18 (21.7%) did not. The responder proportion was significantly greater than the reference proportion of 50% (χ²=26.61; p<0.001). Among the 81 patients with available ODI data, 46 (56.8%; 95% CI: 45.9%-67.0%) achieved an improvement of at least 10 points, while 35 (43.2%) did not. Although more than half experienced clinically meaningful functional recovery, this proportion did not differ significantly from 50% (χ²=1.49; p=0.222). The proportion achieving either pain relief or functional improvement could not be directly estimated from the aggregate results because some patients may have satisfied both criteria. Patient-level cross-tabulation would therefore be required to calculate the composite response accurately. Table 4: Lumbar spine surgery status within 12 months following TFESI Twelve-month outcome n (%) of total N=90 95% CI Test of significance P value Avoided lumbar spine surgery 55 (61.1%) 50.8%-70.5% Underwent lumbar spine surgery 12 (13.3%) 7.8%-21.9% Lost to 12-month follow-up 23 (25.6%) 17.7%-35.4% Overall comparison 90 (100.0%) χ²=33.27, df=2 <0.001* Avoided surgery among patients with known status (n=67) 55 (82.1%) 71.3%-89.4% χ²=27.60, df=1 <0.001* Underwent surgery among patients with known status (n=67) 12 (17.9%) 10.6%-28.7% Table 4 describes lumbar spine surgery status during the 12 months following TFESI. Of the total 90 patients, 55 (61.1%; 95% CI: 50.8%-70.5%) were documented to have avoided lumbar spine surgery, while 12 (13.3%; 95% CI: 7.8%-21.9%) underwent surgery. The remaining 23 patients (25.6%; 95% CI: 17.7%-35.4%) were lost to follow-up. The overall distribution of these outcomes was statistically significant (χ²=33.27, df=2; p<0.001). When the analysis was restricted to the 67 patients whose 12-month surgical status was known, 55 (82.1%; 95% CI: 71.3%-89.4%) avoided surgery and 12 (17.9%; 95% CI: 10.6%-28.7%) underwent surgery. The proportion avoiding surgery was significantly greater than 50% (χ²=27.60, df=1; p<0.001).

The present study evaluated the effectiveness of single-level unilateral transforaminal epidural steroid injection (TFESI) in achieving pain relief, functional recovery and avoidance of lumbar spine surgery among patients with lumbar radiculopathy. The principal findings were significant reductions in NRS pain scores and ODI disability scores at one and four weeks. At four weeks, 78.3% of evaluable patients achieved at least a 50% reduction in pain, while 56.8% achieved an improvement of at least 10 ODI points. Among patients whose 12-month surgical status was known, 82.1% avoided lumbar spine surgery. Collectively, these findings indicate that TFESI was associated with rapid pain relief, continued functional recovery and a relatively low short-term requirement for surgery. Overall effectiveness of TFESI In the present study, mean NRS decreased from 8.46 at baseline to 3.81 at one week and from 8.45 to 3.42 at four weeks, corresponding to mean reductions of 4.65 and 5.02 points, respectively. The mean ODI score decreased from 15.33 to 10.80 at one week and from 15.88 to 7.17 at four weeks. All baseline-to-follow-up changes were statistically significant. The magnitude of pain reduction was well above the commonly accepted threshold for clinically important improvement, indicating that the observed effect was not merely statistically significant. Leung et al. (2015)[1] evaluated TFESI in 232 patients with lumbar radiculopathy and reported an immediate response rate of 80.2%. Among patients with single-level radiculopathy, 80.3% demonstrated an immediate response. These findings closely correspond to the present study, in which 78.3% achieved at least a 50% reduction in NRS at four weeks. Leung et al. also reported that pain relief lasted longer than 12 weeks in 39.7% of patients, supporting the therapeutic value of TFESI beyond the immediate post-procedure period. Joswig et al. (2016)[2] prospectively evaluated 57 patients with lumbar disc herniation and found that patients achieving more than 50% pain reduction four hours after injection were 3.38 times more likely to demonstrate a favourable one-month response. The predictive association was strongest on day six, with an odds ratio of 6.87. Their findings support the rapid reduction in pain observed during the first week of the present study and indicate that an early response may help identify patients likely to maintain short-term benefit. Ekedahl et al. (2017)[3] observed clinically relevant improvement after TFESI among patients with chronic unilateral radicular pain and demonstrated that favourable responses could be maintained for up to one year in selected patients. However, outcomes varied according to clinical and MRI characteristics. This variation may explain why pain relief and functional recovery were not achieved uniformly in the present population. Shrestha et al. (2020)[4] reported that mean NRS decreased from 8.97±1.32 at baseline to 3.91±3.23 at one week and 3.23±3.34 at three months following TFESI, with both reductions being statistically significant. These results are highly comparable to the present reductions from 8.46±0.86 to 3.81±1.42 at one week and to 3.42±1.56 at four weeks. The consistency between the studies supports a rapid and sustained short-term analgesic effect of targeted transforaminal injection. Smith et al. (2020)[5], in a comprehensive review, concluded that strong evidence supports lumbar TFESI for radicular pain caused by disc herniation. They reported less convincing evidence for radicular symptoms arising from lumbar spinal stenosis or other causes. The favourable outcomes in the present study may therefore be partly related to the selection of patients with clinically and MRI-confirmed single-level nerve-root involvement. Helm et al. (2021)[6] conducted a systematic review and meta-analysis and found significant improvements in pain and function at three and six months after TFESI for radicular pain due to disc herniation. Their review provided Level I evidence for this indication. The significant early pain and functional improvements in the present study are consistent with this evidence, although the current follow-up of NRS and ODI was limited to four weeks. Manchikanti et al. (2021)[7] similarly reported Level I evidence with a strong recommendation for fluoroscopically guided lumbar transforaminal epidural injections in disc herniation. However, they noted that evidence was weaker for lumbar spinal stenosis. These recommendations support careful correlation of clinical findings with MRI-defined pathology and targeted injection of the symptomatic nerve root. Changes in pain and functional disability over time The present findings demonstrated that most pain reduction occurred during the first week. Among patients with paired observations, mean NRS decreased from 8.46 to 3.81 at one week. Although it decreased further from 3.78 at one week to 3.42 at four weeks, the additional reduction of 0.36 points was not statistically significant (p=0.129). Thus, the analgesic effect appeared to develop rapidly and subsequently reached a relative plateau. In contrast, functional recovery continued between the two follow-up assessments. Mean ODI decreased from 15.33 to 10.80 at one week and from 15.88 to 7.17 at four weeks. Among patients with paired one- and four-week measurements, ODI improved by a further 3.89 points between these assessments (p<0.001). This difference in the temporal patterns of NRS and ODI is clinically plausible. Pain relief may occur rapidly after the anti-inflammatory and local-anaesthetic effects of TFESI, whereas restoration of mobility, confidence and activities of daily living may develop more gradually. Bahar-Ozdemir et al. (2020)[8] demonstrated significant improvements in both pain and ODI following lumbar TFESI. They also observed that pretreatment depression and anxiety were associated with pain and disability measurements, suggesting that post-injection functional recovery may be influenced by psychosocial factors in addition to the physiological response. Such variables were not controlled in the present study and may partly explain why functional improvement was less uniform than pain relief. Park et al. (2022)[9] found that lumbar epidural steroid injection improved both nociceptive and neuropathic components of low back-related pain. Their findings support the marked early decrease in NRS observed in the present investigation. Reduction of the neuropathic component of radicular pain may facilitate mobility and rehabilitation, thereby contributing to the continued improvement in ODI after the initial analgesic effect. Germann et al. (2022)[10] evaluated CT-guided TFESI among 204 patients with discogenic single-level L4 or L5 radiculopathy and reported substantial pain reduction in 46.6% of patients. They found that clinical outcome was not substantially determined by contrast dispersion pattern or the experience of the radiologist. The higher pain-response rate of 78.3% in the present study may relate to differences in the definition of treatment success, timing of assessment, baseline severity, injected drugs and patient-selection criteria. Clinically meaningful improvement At four weeks, 65 of 83 patients (78.3%; 95% CI: 68.3%-85.8%) achieved at least a 50% reduction in NRS. This proportion was significantly greater than 50% (p<0.001), providing evidence that most evaluable patients obtained clinically meaningful pain relief rather than merely a small numerical reduction. Haring et al. (2024)[11], in a registry cohort, found that patients treated through the transforaminal approach were more likely than those receiving interlaminar injection to achieve at least a 50% reduction in leg pain. Their findings support the theoretical advantage of the transforaminal route, which delivers medication closer to the affected nerve root. Clinically meaningful functional recovery, defined as an improvement of at least 10 ODI points, was observed in 46 of 81 patients (56.8%). Although more than half achieved this outcome, the proportion was not significantly greater than the reference value of 50% (p=0.222). The discrepancy between the pain-response rate and ODI-response rate may reflect the multifactorial nature of disability. Functional status may be influenced by age, chronicity, deconditioning, fear of movement, comorbidities, psychological health and adherence to physiotherapy. Moreover, the relatively low baseline ODI score created less opportunity for some patients to attain an absolute 10-point reduction, resulting in a possible floor effect. The results should not be interpreted as showing that TFESI failed to improve function. Mean ODI improved significantly at both one and four weeks, and further improvement occurred between these assessments. Instead, the nonsignificant responder analysis indicates that the stringent absolute 10-point threshold was not reached by a sufficiently large proportion to demonstrate superiority over the arbitrarily selected 50% reference proportion. Avoidance of lumbar spine surgery Among all 90 patients, 55 (61.1%) were documented to have avoided surgery, 12 (13.3%) underwent lumbar spine surgery and 23 (25.6%) were lost to follow-up. When analysis was restricted to the 67 patients with known 12-month status, 82.1% avoided surgery and 17.9% underwent surgery. This complete-case avoidance rate suggests that TFESI may serve as an effective intermediate intervention between conservative treatment and operative management. Raymaekers et al. (2024)[12] prospectively evaluated the evolution to surgery following TFESI in a pragmatic multicentre study. Approximately 19.6% of their participants underwent surgery, while about 80% avoided operative treatment over a mean follow-up of approximately two years. These findings are remarkably similar to the present complete-case results of 17.9% undergoing surgery and 82.1% avoiding surgery. Nevertheless, an early favourable response may not reliably predict long-term avoidance of surgery. Fujiwara et al. (2023)[13] found that a positive response at one month did not significantly identify patients who would avoid surgery for two years. After adjustment for baseline NRS, the hazard ratio for surgery in early responders was 0.35, but the confidence interval included unity and the association remained nonsignificant. Therefore, TFESI may postpone or reduce the immediate need for surgery, but it does not necessarily alter the natural history of structural nerve-root compression in every patient. The 25.6% loss to follow-up in the present study is particularly relevant. If all patients lost to follow-up had avoided surgery, the maximum possible avoidance rate would have been 86.7%; if all had undergone surgery, the minimum confirmed avoidance rate would remain 61.1%. Consequently, 82.1% represents a complete-case estimate and may overestimate the true surgery-avoidance rate if patients who subsequently underwent surgery were more likely to be lost from institutional follow-up.

Single-level unilateral transforaminal epidural steroid injection was effective in providing rapid and clinically meaningful short-term pain relief and improving functional disability in patients with lumbar radiculopathy. Pain scores decreased significantly at one and four weeks, with 78.3% of evaluable patients achieving at least a 50% reduction in NRS score at four weeks. Functional improvement continued between the first and fourth weeks, although only 56.8% achieved the predefined improvement of at least 10 ODI points. Among patients with known 12-month outcomes, 82.1% avoided lumbar spine surgery. TFESI may therefore be considered a useful minimally invasive intervention for appropriately selected patients who remain symptomatic despite conservative treatment. Nevertheless, controlled prospective studies with longer and more complete follow-up are required to confirm the durability of these benefits. LIMITATIONS OF STUDY This study had several limitations. First, its retrospective, single-centre design increased the possibility of selection and information bias and limited the generalizability of the findings. Second, the absence of a control or comparison group prevented definitive attribution of the observed improvement solely to TFESI. Third, the sample size was relatively small, and the numbers of patients with available NRS and ODI measurements differed across follow-up assessments because of incomplete records. Fourth, pain and disability outcomes were evaluated only up to four weeks; therefore, the durability of symptomatic and functional improvement could not be determined. Fifth, 25.6% of patients were lost to follow-up for the 12-month surgical outcome, which may have biased the estimated surgery-avoidance rate. Sixth, potentially important confounding factors, including symptom duration, severity and type of MRI pathology, steroid preparation and dose, concomitant analgesic use, physiotherapy, psychological status and adherence to rehabilitation, were not adequately controlled. Finally, clinically meaningful pain and functional responses were reported separately, and the proportion achieving either or both outcomes could not be calculated without patient-level cross-tabulation.

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