Pulsed radiofrequency of lumbar dorsal root ganglion for lumbar radicular pain: A systematic review and meta-analysis

BACKGROUND

Pulsed radiofrequency (PRF) of the lumbar dorsal root ganglion (DRG) has been widely used as a method to relieve lumbar radicular pain (LRP). However, the value of PRF application in LRP patients remains uncertain. This systematic review aimed to compare the effects of PRF of lumbar DRG and LEI in patients with LRP.

METHODS

A literature search was performed using well-known databases for articles published up to May 2023. We included randomized controlled trials (RCTs) that evaluated the effects of PRF compared to LEI with or without steroids. We screened articles, extracted data, and assessed risk of bias in duplicate. The pain scores and Oswestry Disability Index (ODI) scores at 1, 3, and 6 months after procedures were obtained. A random-effects meta-analysis model was applied for outcomes. We evaluated evidence certainty for each outcome using the GRADE scoring system. This review was registered in the PROSPERO (ID: CRD42021253628).

RESULTS

A total of 10 RCTs were included and data of 613 patients were retrieved. We assessed the overall quality of the evidence as very low to moderate. PRF showed no difference in pain scores at 1 (mean difference [MD] -0.80, 95% confidence interval [CI] -1.59 to 0.00, low certainty) and 6 months (MD -2.37, 95% CI -4.79 to 0.05, very low certainty), and significantly improved pain scores at 3 months (MD -1.31, 95% CI -2.29 to -0.33, low certainty). There was no significant difference in ODI score at any interval (very low to low certainty). In the subgroup who underwent a diagnostic block, did not use steroids, and PRF duration greater than 360 s, PRF significantly reduced pain scores at 3 months after procedures.

CONCLUSIONS

We found low quality of the evidence supporting adjuvant PRF to the lumbar DRG has a greater analgesic effect at 3 months after procedures in patients with LRP than LEI. We identified no convincing evidence to show that this treatment improves function. High-quality evidence is lacking, and data were largely derived from short-term effects. Given these limitations, high-quality trials with data on long-term effects are needed.

The Kumar Technique: A Novel and Effective Approach to Transforaminal Epidural Steroid Injections

Background Transforaminal epidural steroid injections (TFESIs) are widely used as a minimally invasive treatment for lumbar radicular pain. This study presents an alternative approach for lumbar TFESI, the Kumar Technique, which utilizes a more lateral and inferior needle starting point to better align the trajectory of the needle with the neural foramen. We hypothesize the Kumar Technique will result in safer and more effective outcomes than the traditional approach to TFESI. This article was previously presented as a poster at the 2023 University of Florida College of Medicine Celebration of Research on February 27-28, 2023, and as an abstract and poster at the 2023 University of Florida Department of Anesthesiology Celebration of Research on March 29, 2023. Methods The charts for 1,424 patients who received lumbar TFESIs were retrospectively reviewed, and patients were stratified into groups receiving either the traditional approach or the Kumar Technique. Outcomes measures included numerical pain scores, measures of functional status and activity limitations, duration of pain relief, and procedural complications. Results Compared to the group undergoing the traditional approach, patients receiving the Kumar Technique reported a significantly greater decrease in average pain (-2.3 (95% CI: -3.0 to -1.6) vs -1.1 (95% CI: -1.4 to -0.7)) and maximum pain (-2.4 (95% CI: -3.2 to -1.6) vs -1.3 (95% CI: -1.8 to -0.9)). Patients receiving the Kumar Technique had a significantly greater likelihood of reporting any pain relief (OR: 2.10, 95% CI:1.59 to 2.79) compared to those undergoing the traditional approach. In addition, a greater percentage of patients receiving the Kumar Technique experienced at least one month of pain relief compared to the traditional approach (54% vs 40%; z = 3.85, p < 0.001). The occurrence of complications did not significantly vary between the modified (4.1%) and the traditional (3.0%) approaches. Conclusions The Kumar Technique is a modified TFESI approach that allows for improved access to the nerve roots through a more lateral and inferior needle entry point. The analysis supports the benefits of the Kumar Technique with patients experiencing a greater reduction in pain and longer durations of pain relief without increasing the risk of complications.

A New Role for Epidurography: A Simple Method for Assessing the Adequacy of Decompression during Percutaneous Plasma Disc Decompression

Percutaneous plasma disc decompression (PPDD) is a minimally invasive treatment for discogenic low back pain and herniated disc-related symptoms. However, there are no known outcome predictive variables during the procedure. The purpose of this study was to evaluate and validate epidurography as an intra-procedure outcome predictor. We retrospectively enrolled 60 consecutive patients who did not respond to conventional treatments. In the next stage of treatment, PPDD was performed, and the epidurography was conducted before and after the PPDD. We analyzed the relationship between epidurographic improvement and the success rate. The Numerical Rating Scale and the Oswestry Disability Index were used to assess pain and functional capacity, respectively, before the procedure and 1 month after the procedure. The pain reduction and the success rate in the epidurographic improvement group were significantly higher than in the epidurographic non-improvement group. Both the Numerical Rating Scale and the Oswestry Disability Index scores were significantly reduced in both groups, but there was no significant difference in Oswestry Disability Index scores. This study's results showed that PPDD is an effective treatment method. We also suggested that epidurography may be a potential outcome predictor for ensuring successful outcomes and determining the endpoint of the procedure.

Back Dominant Pain Has Equal Outcomes to Radicular Dominant Pain Following Posterior Lumbar Fusion in Adult Isthmic Spondylolisthesis: A CSORN Study

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

This study aimed to determine how the surgeon-determined and patient-rated location of predominant pain influences patient-rated outcomes at 1-year after posterior lumbar fusion in adult isthmic spondylolisthesis.

METHODS

We retrospectively reviewed consecutive patients prospectively enrolled in the Canadian Spine Outcomes and Research Network national registry between 2009 and 2017 that underwent posterior lumbar fusion for isthmic spondylolisthesis. Using longitudinal mixed-model repeated-measures analysis the change from baseline in patient-reported outcome measures (PROMs) at 1 year after surgery was compared between surgeon-determined groups (back vs. radicular) and between patient-rated pain groups (back, leg, and equal) derived from preoperative pain scores on the numerical rating scale (NRS).

RESULTS

83/252 (33%) patients had a surgeon-determined chief complaint of back pain, while 103 (41%) patients rated their back pain as the predominant pain location, and 78 (31%) rated their back and leg pain to be equal. At baseline patients in the surgeon-determined radicular group had worse NRS-leg pain than those in the back-pain group but equal NRS-back pain. At baseline patients in the patient-rated equal pain group had similar back pain compared to the patient-rated back pain group and similar leg pain compared to the patient-rated leg pain group. All PROMs improved post-operatively and were not different between the 2 groups at 1 year.

CONCLUSIONS

Our study found no difference in outcome, irrespective of whether a surgeon determines the patient's primary pain complaint back or radicular dominant, or the patient rates pain in one location greater than another.

Evidence for the BUAS-test ability to diagnose lumbar radicular pain

BACKGROUND

Differential diagnosis of low back pain (LBP) is complex and a prominent issue at all health-care levels; guidance may come from patients' history cues and clinical examination signs. Human and animal studies report that diagnosis of lumbar radicular pain (LRP) may come from evaluating subjective responses of injured lumbar nerves to a strain applied at the buttock. The Buttock Applied Strain (BUAS-test) test may guide the differential diagnosis of LBP. Following an ex-adiuvantibus criterion, clinical improvement of LRP, diagnosed with the BUAS-test and congruently treated, may support this test diagnostic ability.

METHODS

Among 258 LRP patients, who, upon first visit (V1), tested positive on the BUAS-test (with/without positive Straight Leg Raising Test, SLRT), the effect of gabapentin prescription on painDETECT (PD) questionnaire and Brief Pain Inventory (BPI) outcomes was quantified in the follow-up visit (V2). To support BUAS-test diagnostic ability, we hypothesized that, at V2, >50% of the sample would present negative PD outcome, significant (t-test) and ⩾2 points V2-V1 differences for each of the BPI-item's score. We used multinomial logistic regression (MLR) and χ² analyses to evaluate the PD-V2 outcomes' dependence upon independent variables.

RESULTS

Of the sample, 77% reported a negative PD-V2 outcome. V2-V1 differences of all BPI items were significant and >2 points. PD-V2 outcomes showed significant associations with SLRT-V1 and PD-V1, respectively, but not with gender, age group or pain site. MLR showed a significant relationship between SLRT-V1 and PD-V2 outcomes.

CONCLUSION

Among LRP patients, diagnosed by the BUAS-test and treated with gabapentin, all prespecified endpoints were reached. These results may be considered a piece of ex-adiuvantibus evidence for the BUAS-test ability to diagnose LRP. While positive BUAS-test implies potential LRP, the co-presence with positive SLRT may imply a severer LRP condition. Further prospective research, in different settings and direct clinical measures, is needed.

Recommendations for Diagnosis and Treatment of Lumbosacral Radicular Pain: A Systematic Review of Clinical Practice Guidelines

The management of patients with lumbosacral radicular pain (LRP) is of primary importance to healthcare professionals. This study aimed to: identify international clinical practice guidelines on LRP, assess their methodological quality, and summarize their diagnostic and therapeutic recommendations. A systematic search was performed (August 2019) in MEDLINE, PEDro, National Guideline Clearinghouse, National Institute for Health and Clinical Excellence (NICE), New Zealand Guidelines Group (NZGG), International Guideline Library, Guideline central, and Google Scholar. Guidelines presenting recommendations on diagnosis and/or treatment of adult patients with LRP were included. Two independent reviewers selected eligible guidelines, evaluated quality with Appraisal of Guidelines Research & Evaluation (AGREE) II, and extracted recommendations. Recommendations were classified into 'should do', 'could do', 'do not do', or 'uncertain'; their consistency was labelled as 'consistent', 'common', or 'inconsistent'. Twenty-three guidelines of varying quality (AGREE II overall assessment ranging from 17% to 92%) were included. Consistent recommendations regarding diagnosis are ('should do'): Straight leg raise (SLR) test, crossed SLR test, mapping pain distribution, gait assessment, congruence of signs and symptoms. Routine use of imaging is consistently not recommended. The following therapeutic options are consistently recommended ('should do'): educational care, physical activity, discectomy under specific circumstances (e.g., failure of conservative treatment). Referral to a specialist is recommended when conservative therapy fails or when steppage gait is present. These recommendations provide a clear overview of the management options in patients with LRP.

Kambin's Triangle Approach versus Traditional Safe Triangle Approach for Percutaneous Transforaminal Epidural Adhesiolysis Using an Inflatable Balloon Catheter: A Pilot Study

Spinal stenosis is a common condition in elderly individuals. Many patients are unresponsive to the conventional treatment. If the transforaminal epidural block does not exert a sufficient treatment effect, percutaneous transforaminal epidural adhesiolysis (PTFA) through the safe-triangle approach using an inflatable balloon catheter can reduce the patients’ pain and improve their functional capacity. We aimed to evaluate the safety and efficacy of the Kambin’s-triangle approach for PTFA using an inflatable balloon catheter and compare this approach to the traditional safe-triangle approach. Thirty patients with chronic unilateral L5 radiculopathy were divided into two groups: the safe-triangle-approach and Kambin’s-triangle-approach groups, with 15 patients each. The success rate of the procedure was assessed. Pain and dysfunction were assessed using the Numerical Rating Scale and Oswestry Disability Index, respectively, before the procedure and at 1 and 3 months after the procedure. The success rate of the procedure was high in both the groups, with no significant difference between the groups. The Numerical Rating Scale and Oswestry Disability Index scores significantly decreased 3 months after the procedure in both the groups, with no significant difference between the groups. For patients in whom the safe-triangle approach for PTFA is difficult, the Kambin’s-triangle approach could be an alternative.

Factors Associated with Successful Response to Balloon Decompressive Adhesiolysis Neuroplasty in Patients with Chronic Lumbar Foraminal Stenosis

Epidural neuroplasty, often called percutaneous epidural adhesiolysis, is often performed in refractory patients with chronic lumbar radiculopathy or neurogenic claudication. Recent studies have showed that decompressive adhesiolysis with an inflatable balloon catheter (balloon neuroplasty) is efficient in patients who experience refractory pain from epidural steroid injection or even epidural neuroplasty with a balloon-less catheter. However, exact indications or predictive factors for epidural balloon neuroplasty have not been fully evaluated. Therefore, to assess associated factors that could affect a favorable outcome, we analyzed a prospectively collected multicenter cohort of patients with chronic refractory lumbar foraminal stenosis after balloon neuroplasty. At the 6-month point in follow-up, 92 (44.4%) patients among 207 subjects were classified as successful responders according to a robust combination of outcome measures. Multivariate logistic regression analysis also showed that mild grade lumbar foraminal stenosis may be an independent factor associated with a successful response 6 months after balloon neuroplasty (odds ratio = 2.829; 95% confidence interval = 1.351–5.923; p = 0.006). However, we found that there were 29.4% and 24.6% successful responders with moderate and severe foraminal stenosis, respectively. Attempting balloon neuroplasty in refractory lumbar foraminal stenosis, especially mild grade, may be worthwhile.

Relationship of Success Rate for Balloon Adhesiolysis with Clinical Outcomes in Chronic Intractable Lumbar Radicular Pain: A Multicenter Prospective Study

Combined balloon decompression and epidural adhesiolysis has been reported to be effective in refractory lumbar spinal stenosis. Many cases of intractable stenosis have symptom-related multiple target sites for interventional treatment. In this situation it may not be possible to perform balloon adhesiolysis, or even only epidural adhesiolysis, for all target sites. Therefore, this multicenter prospective observational study aimed to evaluate the relationship of successful ballooning rate for multiple target sites with clinical outcome. Based on the ballooning success rate of multiple target sites, the patients were divided into three groups: below 50%, 50–85%, and above 85% ballooning. A greater ballooning success rate for multiple target sites provided a more decreased pain intensity and improved functional status in patients with chronic refractory lumbar spinal stenosis, and the improvement was maintained for 6 months. The estimated proportions of successful responders according to a multidimensional approach in the below 50%, 50–85%, and above 85% balloon success groups at 6 months after the procedure were 0.292, 0.468, and 0.507, respectively (p = 0.038). Our study suggests the more successful balloon adhesiolysis procedures for multiple target lesions are performed, the better clinical outcome can be expected at least 6 months after treatment.

Clinical management of radicular pain

This review provides an overview of the diagnosis and treatment strategies for the management of radicular pain. While it is not as common as axial spinal pain, radicular pain combines the advantage of leveraging appropriate diagnostic strategies and definitive treatments with well-informed outcome measures. Multiple diagnostic measures include not only history and physical examination, but also imaging. The treatment modalities include pharmacologic management, physical and rehabilitation measures, interventional techniques and surgical treatments. Here, the authors describe the prevalence and pathophysiology of radicular pain, risk factors, diagnostic strategies, treatment modalities and the evidence for these management strategies. Finally, the authors show the efficacy of conservative management, despite surgical management being the gold standard.