A Randomized, Placebo-Controlled Trial of Transdiscal Radiofrequency, Biacuplasty for Treatment of Discogenic Lower Back Pain

Placebo Control and Blinding in Randomized Trials of Procedural Interventions: A Systematic Review and Meta-Regression

Importance

Unlike medications, procedural interventions are rarely trialed against placebo prior to becoming accepted in clinical practice. When placebo-controlled trials are eventually conducted, procedural interventions may be less effective than previously believed.

Objective

To investigate the importance of including a placebo arm in trials of surgical and interventional procedures by comparing effect sizes from trials of the same procedure that do and do not include a placebo arm.

Data Sources

Searches of MEDLINE and Embase identified all placebo-controlled trials for procedural interventions in any specialty of medicine and surgery from inception to March 31, 2019. A secondary search identified randomized clinical trials assessing the same intervention, condition, and end point but without a placebo arm for paired comparison.

Study Selection

Placebo-controlled trials of anatomically site-specific procedures requiring skin incision or endoscopic techniques were eligible for inclusion; these were then matched to trials without placebo control that fell within prespecified limits of heterogeneity.

Data Extraction and Synthesis

Random-effects meta-regression, with placebo and blinding as a fixed effect and intervention and end point grouping as random effects, was used to calculate the impact of placebo control for each end point. Data were analyzed from March 2019 to March 2020.

Main Outcomes and Measures

End points were examined in prespecified subgroups: patient-reported or health care professional-assessed outcomes, quality of life, pain, blood pressure, exercise-related outcomes, recurrent bleeding, and all-cause mortality.

Results

Ninety-seven end points were matched from 72 blinded, placebo-controlled trials (hereafter, blinded) and 55 unblinded trials without placebo control (hereafter, unblinded), including 111 500 individual patient end points. Unblinded trials had larger standardized effect sizes than blinded trials for exercise-related outcomes (standardized mean difference [SMD], 0.59; 95% CI, 0.29 to 0.89; P < .001) and quality-of-life (SMD, 0.32; 95% CI, 0.11 to 0.53; P = .003) and health care professional-assessed end points (SMD, 0.40; 95% CI, 0.18 to 0.61; P < .001). The placebo effect accounted for 88.1%, 55.2%, and 61.3% of the observed unblinded effect size for these end points, respectively. There was no significant difference between unblinded and blinded trials for patient-reported end points (SMD, 0.31; 95% CI, -0.02 to 0.64; P = .07), blood pressure (SMD, 0.26; 95% CI, -0.10 to 0.62; P = .15), all-cause mortality (odds ratio [OR], 0.23; 95% CI, -0.26 to 0.72; P = .36), pain (SMD, 0.03; 95% CI, -0.52 to 0.57; P = .91), or recurrent bleeding events (OR, -0.12; 95% CI, -1.11 to 0.88; P = .88).

Conclusions and Relevance

The magnitude of the placebo effect found in this systematic review and meta-regression was dependent on the end point. Placebo control in trials of procedural interventions had the greatest impact on exercise-related, quality-of-life, and health care professional-assessed end points. Randomized clinical trials of procedural interventions may consider placebo control accordingly.

Nonsurgical Interventional Spine Pain Procedures: Outcomes and Complications

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Nonsurgical interventional spine pain procedures provide an additional treatment option for lower back pain at the traditional bifurcation of conversative vs. operative management.

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Transforaminal epidural steroid injections, radiofrequency ablations, intrathecal drug delivery, and spinal cord stimulation were found to be effective and safe techniques when applied to their specific indication.

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Thermal annuloplasty and minimally invasive lumbar decompression showed mixed support.

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Discography, sacroiliac joint injections, and spinous process spacers lacked sufficient evidence to support efficacy.

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Medial branch blocks and facet joint injections were found to be useful diagnostic tools.

An Updated Overview of Low Back Pain Management

We aimed to determine the recommendation level for the treatment of acute and chronic low back pain (LBP). A systematic review (SR) of the literature was performed and all English-language articles that discuss acute and chronic LBP, including MEDLINE and the Cochrane Database of Systematic Reviews, were searched. Of the 873 searched literature reports, 259 articles, including 131 clinical trials, 115 SRs, nine meta-analyses, and four clinical guidelines were analyzed. In these articles, high-quality randomized controlled trials, SRs, and used well-written clinical guidelines were reviewed. The results indicated multiple acute and chronic LBP treatment methods in the literature, and these reports when reviewed included general behavior, pharmacological therapy, psychological therapy, specific exercise, active rehabilitation and educational interventions, manual therapy, physical modalities, and invasive procedures. The Trial conclusions and SRs were classified into four categories of A, B, C, and D. If there were not enough high-quality articles, it was designated as "I" (insufficient). This review and summary of guidelines may be beneficial for physicians to better understand and make recommendations in primary care.

The Effectiveness of Intraosseous Basivertebral Nerve Radiofrequency Ablation for the Treatment of Vertebrogenic Low Back Pain: An Updated Systematic Review with Single-Arm Meta-analysis

OBJECTIVE

To provide an estimate of the effectiveness of basivertebral nerve (BVN) radiofrequency ablation (RFA) to treat vertebrogenic low back pain (LBP).

DESIGN

Systematic review with single-arm meta-analysis.

POPULATION

Persons ≥18 years of age with chronic LBP associated with type 1 or 2 Modic changes.

INTERVENTION

Intraosseous BVN RFA.

COMPARISON

Sham, placebo procedure, active standard care treatment, or none.

OUTCOMES

The proportion of patients treated with BVN RFA who reported ≥50% pain score improvement on a visual analog scale or numeric rating scale. The main secondary outcome was ≥15-point improvement in Oswestry Disability Index score.

METHODS

Three reviewers independently assessed articles published before December 6, 2021, in MEDLINE and Embase. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework was used to evaluate the overall quality of evidence.

RESULTS

Of the 856 unique records screened, 12 publications met the inclusion criteria, representing six unique study populations, with 414 participants allocated to receive BVN RFA. Single-arm meta-analysis showed a success rate of 65% (95% confidence interval [CI] 51-78%) and 64% (95% CI 43-82%) for ≥50% pain relief at 6 and 12 months, respectively. Rates of ≥15-point Oswestry Disability Index score improvement were 75% (95% CI 63-86%) and 75% (95% CI 63-85%) at 6 and 12 months, respectively.

CONCLUSION

According to GRADE, there is moderate-quality evidence that BVN RFA effectively reduces pain and disability in most patients with vertebrogenic LBP. Further high-quality studies will likely improve our understanding of the effectiveness of this procedure.

The association of payer type and opioid use on functional improvement at short-term follow-up after lumbosacral transforaminal epidural steroid injection: Results of a large registry study

Background

Lumbosacral transforaminal epidural steroid injection (LTFESI) is a commonly performed intervention for treating radicular pain. While factors that predict pain improvement after LTFESI have been evaluated, minimal literature exists regarding predictors of functional improvement.

Purpose

To identify factors that are associated with functional improvement at short-term follow-up after LTFESI.

Study design

Retrospective review of prospectively collected registry data.

Patient sample

Patients undergoing LTFESI at an academic spine center who completed an Oswestry Disability Index (ODI) questionnaire both pre-procedure and one to three weeks post-procedure.

Outcome measures

The outcomes of interest were the proportions of patients who experienced a minimal clinically important difference (MCID) in function defined as ​≥ ​30% improvement in ODI score, as well as ​≥ ​10-point and ≥15-point improvement in ODI score.

Methods

Logistic regression analysis was performed to examine the associations of predictor variables to the ODI responder/non-responder outcome variable. The predictor variables for the analysis included: age, baseline ODI score, Charleston Comorbidity Index (CCI), payer type, prior lumbosacral spine surgery, pre-injection opioid use, two-level injections, bilateral injections, repeat injection, trainee presence during injection, immediate numerical rating scale (NRS) change post-injection. An odds ratio (OR) and its 95% confidence intervals (CIs) were calculated.

Results

A total of 606 patients were included in the analysis. More than half of the patients (56.8%) reported a ≥7.1% improvement in ODI score, and about 30% reported a ≥30% improvement in ODI score. Approximately 36% and 20% of the patients reported ≥10-point and ≥15-point reductions in ODI score, respectively. Medicaid and Medicare payer type and pre-injection opioid use were significantly associated with a lower likelihood of ≥30%, and ≥15-point improvements in ODI, after adjusting for the other factors (p ​< ​0.05).

Conclusions

When using various common definitions of MCID for ODI score improvement, Medicaid, Medicare, and pre-injection opioid use were identified as factors that are negatively associated with functional improvement at short-term follow-up after LTFESIs.

Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) causes a variety of signs and symptoms, such as low back pain (LBP), intervertebral disc herniation, and spinal stenosis, which contribute to high social and economic costs. IDD results from many factors, including genetic factors, aging, mechanical injury, malnutrition, and so on. The pathological changes of IDD are mainly composed of the senescence and apoptosis of nucleus pulposus cells (NPCs), the progressive degeneration of extracellular matrix (ECM), the fibrosis of annulus fibrosus (AF), and the inflammatory response. At present, IDD can be treated by conservative treatment and surgical treatment based on patients' symptoms. However, all of these can only release the pain but cannot reverse IDD and reconstruct the mechanical function of the spine. The latest research is moving towards the field of biotherapy. Mesenchymal stem cells (MSCs) are regard as the potential therapy of IDD because of their ability to self-renew and differentiate into a variety of tissues. Moreover, the non-coding RNAs (ncRNAs) are found to regulate many vital processes in IDD. There have been many successes in the in vitro and animal studies of using biotherapy to treat IDD, but how to transform the experimental data to real therapy which can apply to humans is still a challenge. This article mainly reviews the treatment strategies and research progress of IDD and indicates that there are many problems that need to be solved if the new biotherapy is to be applied to clinical treatment of IDD. This will provide reference and guidance for clinical treatment and research direction of IDD.

Comparison of ultrasound guided pulsed radiofrequency of genicular nerve with local anesthetic and steroid block for management of osteoarthritis knee pain

Background

To compare ultrasound-guided pulsed radiofrequency (PRF) of the genicular nerve with the genicular nerve block using local anesthetic and steroid for management of osteoarthritis (OA) knee pain.

Methods

Thirty patients with OA knee were randomly allocated to receive either ultrasound-guided PRF of the genicular nerve (PRF group) or nerve block with bupivacaine and methylprednisolone acetate (local anesthetic steroid [LAS] group). Verbal numeric rating scale (VNRS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) scores were measured at pre-procedure and 1-, 4-, and 12-weeks post-procedure.

Results

VNRS scores decreased significantly (P < 0.001) in both the groups at 12 weeks and other follow up times compared to baseline. Seventy-three percent of patients in the PRF group and 66% in the LAS group achieved effective pain relief (≥ 50% pain reduction) at 12 weeks (P > 0.999). There was also a statistically significant (P < 0.001) improvement in WOMAC scores in both groups at all follow up times. However, there was no intergroup difference in VNRS (P = 0.893) and WOMAC scores (P = 0.983). No complications were reported.

Conclusions

Both ultrasound-guided PRF of the genicular nerve and blocks of genicular nerve with local anesthetic and a steroid provided comparable pain relief without any complications. However, PRF of the genicular nerve is a procedure that takes much more time and equipment than the genicular nerve block.

Efficacy of Radiofrequency as Therapy and Diagnostic Support in the Management of Musculoskeletal Pain: A Systematic Review and Meta-Analysis

Radiofrequency (RF) is a minimally invasive procedure used to interrupt or alter nociceptive pathways for treating musculoskeletal pain. It seems a useful tool to relieve chronic pain syndromes, even if, to date, solid evidence is still needed about the effectiveness of this therapy. By this systematic review and meta-analysis, we aimed to evaluate the efficacy of RF in treating musculoskeletal pain. PubMed, Medline, Cochrane, and PEDro databases were searched to identify randomized controlled trials (RCTs) presenting the following: patients with chronic musculoskeletal pain as participants; RF as intervention; placebo, anesthetic injection, corticosteroid injection, prolotherapy, conservative treatment, physiotherapy, and transcutaneous electrical nerve stimulation as comparisons; and pain and functioning as outcomes. Continuous random-effect models with standardized mean difference (SMD) were used to compare the clinical outcomes. Overall, 26 RCTs were eligible and included in the systematic review. All of them analyzed the efficacy of RF in four different regions: cervical and lumbar spine, knee, sacroiliac (SI) joint, shoulder. The outcomes measures were pain, disability, and quality of life. A medium and large effect in favor of the RF treatment group (SMD < 0) was found for the shoulder according to the Visual Analogical Scale and for the SI joint according to the Oswestry Disability Index. A small effect in favor of the RF treatment group (SMD > 0) was found for the spine according to the 36-item Short Form Survey. Non-significant SMD was found for the other outcomes. RF represents a promising therapy for the treatment of chronic musculoskeletal pain, especially when other approaches are ineffective or not practicable. Further studies are warranted to better deepen the effectiveness of RF for pain and joint function for each anatomical region of common application.

Prospective, randomized, multicenter study of intraosseous basivertebral nerve ablation for the treatment of chronic low back pain: 24-Month treatment arm results

BACKGROUND

Vertebral endplates, innervated by the basivertebral nerve, can be a source of vertebrogenic low back pain when damaged with inflammation, visible as types 1 or 2 Modic changes. A randomized controlled trial (RCT) compared basivertebral nerve ablation (BVNA) to standard care (SC) showed significant differences between arms at 3 and 6-months. At 12-months, significant improvements were sustained for BVNA. We report results of the BVNA arm at 24-months.

METHODS

Prospective, open label, single-arm follow-up of the BVNA treatment arm of a RCT in 20 US sites with visits at 6-weeks, and 3, 6, 9, 12 and 24-months. Paired comparisons to baseline were made for the BVNA arm at each timepoint for Oswestry Disability Index (ODI), Visual Analog Scale (VAS), Short Form Health Survey (SF-36), EQ-5D-5L, and responder rates.

RESULTS

140 patients were randomized, 66 to BVNA. In the 58 BVNA patients completing a 24-month visit, 67% had back pain for >5 years, 36% were actively taking opioids at baseline, 50% had prior epidural steroid injections, and 12% had prior low back surgery. Improvements in ODI, VAS, SF-36 PCS, and EQ-5D-5L were statistically significant at all timepoints through 2 years. At 24 months, ODI and VAS improved 28.5±16.2 points (from baseline 44.5; p < 0.001) and 4.1±2.7 cm (from baseline 6.6; p < 0.001), respectively. A combined responder rate of ODI≥15 and VAS≥2 was 73.7%. A ≥50% reduction in pain was reported in 72.4% of patients and 31.0% were pain-free at 2 years. At 24 months, only 3(5%) of patients had BVNA-level steroid injections, and 62% fewer patients were actively taking opioids. There were no serious device or device-procedure related adverse events reported through 24 months.

CONCLUSION

Intraosseous BVNA demonstrates an excellent safety profile and significant improvements in pain, function, and quality of life that are sustained through 24 months in patients with chronic vertebrogenic low back pain.

Placebo Effect of Sham Spine Procedures in Chronic Low Back Pain: A Systematic Review

Background

The literature lacks information about the characteristics of the placebo effect following sham spine procedures for chronic low back pain. We aim to evaluate the effect using pain score data from the sham arms of published trials.

Methods

Relevant trials were selected and reviewed. Baseline and post-procedure pain scores were collected. Each follow up pain score was considered an episode and compared to its baseline for significance. Patients and episodes were pooled and analyzed using three parameters: patient reported outcome measures (PROMs) (Oswestry Disability Index [ODI], Visual Analog Scale [VAS], Numerical Rating Scale [NRS] and Short Form-36 [SF]), anatomical targets (disc, facet, sacroiliac joint [SIJ], ramus communicans nerve [RCN], basivertebral nerve [BVN], and caudal) and follow up periods (early: 0–2, intermediate: >2–4 and late: >4–6) in months. The percentage of pooled patients in the episodes that had significant reduction in pain scores was termed placebo effect. The outcome was defining the magnitude of the placebo effect and determining if it was influenced by the three parameters.

Results

Seventeen studies that reported 535 patients and 55 pain scoring episodes were considered eligible. Significant reduction in pain scores was reported in 21 episodes. The overall placebo effect among the patients during the studied period was 53.2%. The rate ranged according to PROMs from 42.4% to 72.1%, anatomical targets from 11.1% to 100% and follow up periods from 47.9% to 59%. The placebo effect differed significantly between the various domains in the three parameters.

Conclusion

Placebo effect was observed in nearly half of the patients during the first 6 months following a sham spine procedure. The effect was influenced by utilized PROMs, anatomical target and follow up period. The findings should be considered in the design of new sham spine procedure trials. Further research is required to delineate the effect of bias on the findings.

The Effectiveness of Intraosseous Basivertebral Nerve Radiofrequency Neurotomy for the Treatment of Chronic Low Back Pain in Patients with Modic Changes: A Systematic Review

OBJECTIVE

Determine the effectiveness of intraosseous basivertebral nerve radiofrequency neurotomy for the treatment of chronic low back pain with type 1 or 2 Modic changes.

DESIGN

Systematic review.

POPULATION

Persons aged ≥18 years with chronic low back pain with type 1 or 2 Modic changes.

INTERVENTION

Intraosseous basivertebral nerve radiofrequency neurotomy.

COMPARISON

Sham, placebo procedure, active standard care treatment, or none.

OUTCOMES

The primary outcome of interest was the proportion of individuals with ≥50% pain reduction. Secondary outcomes included ≥10-point improvement in function as measured by Oswestry Disability Index as well as ≥2-point reduction in pain score on the Visual Analog Scale or Numeric Rating Scale, and decreased use of pain medication.

METHODS

Three reviewers independently assessed publications before May 15, 2020, in MEDLINE and Embase and the quality of evidence was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation framework.

RESULTS

Of the 725 publications screened, seven publications with 321 participants were ultimately included. The reported 3-month success rate for ≥50% pain reduction ranged from 45% to 63%. Rates of functional improvement (≥10-point Oswestry Disability Index improvement threshold) ranged from 75% to 93%. For comparison to sham treatment, the relative risk of treatment success defined by ≥50% pain reduction and ≥10-point Oswestry Disability Index improvement was 1.25 (95% confidence interval [CI]: .88-1.77) and 1.38 (95% CI: 1.10-1.73), respectively. For comparison to continued standard care treatment the relative risk of treatment success defined by ≥50% pain reduction and ≥10-point Oswestry Disability Index improvement was 4.16 (95% CI: 2.12-8.14) and 2.32 (95% CI: 1.52-3.55), respectively.

CONCLUSIONS

There is moderate-quality evidence that suggests this procedure is effective in reducing pain and disability in patients with chronic low back pain who are selected based on type 1 or 2 Modic changes, among other inclusion and exclusion criteria used in the published literature to date. Success of the procedure appears to be dependent on effective targeting of the BVN. Non-industry funded high-quality, large prospective studies are needed to confirm these findings.

Invasive Treatments for Low Back Disorders

OBJECTIVE

This abbreviated version of the American College of Occupational and Environmental Medicine's Low Back Disorders guideline reviews the evidence and recommendations developed for invasive treatments used to manage low back disorders.

METHODS

Comprehensive systematic literature reviews were accomplished with article abstraction, critiquing, grading, evidence table compilation, and guideline finalization by a multidisciplinary expert panel and extensive peer-review to develop evidence-based guidance. Consensus recommendations were formulated when evidence was lacking and often relied on analogy to other disorders for which evidence exists. A total of 47 high-quality and 321 moderate-quality trials were identified for invasive management of low back disorders.

RESULTS

Guidance has been developed for the invasive management of acute, subacute, and chronic low back disorders and rehabilitation. This includes 49 specific recommendations.

CONCLUSION

Quality evidence should guide invasive treatment for all phases of managing low back disorders.

Prospective analysis of radiofrequency denervation in patients with chronic low back pain

BACKGROUND

To analyse the effectiveness of lumbar rhizolysis in patients with facet joint-related chronic low back pain and to study the influence of various variables on the results. Facet joints are thought to be responsible for up to 15% of all cases of chronic low back pain. Although radiofrequency denervation of these joints is a common procedure, there is currently no solid evidence to allow the selection of patients who may be candidates for this technique to be selected or the effectiveness and safety thereof to be demonstrated.

METHODS

A prospective analytical study of 100 patients treated with lumbar rhizolysis at the Hospital Universitario de Cabueñes (Gijón, Spain) between 2016 and 2019. Various demographic variables, the evolution of the visual analogue scale (VAS), the Oswestry Disability Index (ODI) and consumption of analgesics pre- and postoperatively was analysed at 2, 6, 12 and 24 months.

RESULTS

The mean age of our sample was 57.8 years (27.0-85.5), with a BMI of 27.09 (16.14-46.22), and 63.8% of subjects were female. The mean duration of the symptoms prior to the intervention was 8.7 years, with 28.7% of subjects having a history of spinal surgery. The intervention resulted in a significant reduction in analgesics consumption. Moreover, a statistically significant reduction in pure low back pain, radiating pain and in the ODI in the short to medium term was observed with respect to baseline. We found that being female, having a history of prior low back surgery, the time to progression and the analgesic level consumed by the patient were related to a greater disability.

CONCLUSIONS

Lumbar rhizolysis results in a significant reduction in pain and functional disability in patients with chronic low back pain in both the short- and medium-term, and reduces the need for analgesics consumption.

A prospective, single arm study of intraosseous basivertebral nerve ablation for the treatment of chronic low back pain: 12-month results

Background

The basivertebral nerve (BVN) has been a recently discovered target as a potential source for vertebrogenic chronic low back pain (CLBP). Prior randomized controlled trials have demonstrated safety and efficacy of BVN ablation for vertebrogenic CLBP, but minimal data exists regarding BVN ablation’s clinical effectiveness with broader application outside of strict trial inclusion criteria.

Methods

Prospective, single arm, open label effectiveness trial of 48 patients from community spine and pain practices treated with BVN ablation. Inclusion criteria required more than 6 months of CLBP and type 1 or 2 Modic changes on MRI to be enrolled. Patients were followed post procedure for 12 months using ODI, VAS, EQ-5D-5L and SF-36 patient reported outcome metrics.Results: 47 patients successfully received BVN ablation and 45 patients completed 12 months of follow up. Mean reduction in ODI at 12 months was 32.31 +/- 14.07 (p<0.001) with 88.89% (40/45) patients reporting a ≥15 point ODI decrease at 12 months. Mean VAS pain score decrease was 4.31+/-2.51 at 12 months (p<0.001) and more than 69% reported a 50% reduction in VAS pain scale. Similarly, SF-36 and EQ-5D-5L scores improved 26.27+/-17.19 and 0.22+/-0.15 (each p<0.001).

Conclusions

This data supports the clinical effectiveness of BVN ablation in the community practice setting, with similar 12 month improvements in patient reported outcomes as seen in previously published randomized control trials.

Radiofrequency denervation for chronic back pain: a systematic review and meta-analysis

OBJECTIVES

To assess the effectiveness of radiofrequency denervation (RD) of lumbosacral anatomical targets for the management of chronic back pain.

DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

METHODS

A database search (Medline, Medline in Process, Embase, CINHAL and the Cochrane library) was conducted from January 2014 to April 2019 for placebo or no-treatment controlled trials of RD for the management of chronic back pain. Included trials were quality assessed using the Cochrane Risk-of-Bias Tool and the quality of outcomes assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Meta-analysis was conducted to calculate mean difference (MD) in post-treatment Pain Score.

RESULTS

Nineteen RCTs were included in the review. There appears to be short-term pain relief (1-3 months) provided by RD of the sacroiliac joint (five trials, MD -1.53, CI -2.62 to 0.45) and intervertebral discs (four trials, MD -0.98, CI -1.84 to 0.12), but the placebo effect is large and additional intervention effect size is small (<1 on an 11 point (0-10) Pain Scale). Longer-term effectiveness (>6 months) is uncertain.

CONCLUSIONS

RD of selected lumbosacral targets appears to have a small, short-term, positive effect for the management of patients with chronic back pain. However, the quality of evidence for the majority of outcomes is low or very low quality and there is still a degree of uncertainty, particularly around the duration of effect.

A technological overview of cooled radiofrequency ablation and its effectiveness in the management of chronic knee pain

Knee osteoarthritis (OA) is a painful and sometimes debilitating condition affecting an estimated 14 million people in the USA alone. Management of knee OA begins with conservative medical treatments and progresses to total knee arthroplasty. Managing pain until a patient is eligible for arthroplasty remains a key part of the treatment algorithm for knee OA. Cooled radiofrequency ablation has shown clinical effectiveness in managing knee OA pain, with a majority of patients experiencing upwards of 12 months of analgesic effect. Herein is presented an overview of the technology of cooled radiofrequency ablation and a summary of current clinical trials demonstrating the treatments effectiveness.

Guidelines for Composing and Assessing a Paper on the Treatment of Pain: A Practical Application of Evidence-Based Medicine Principles to the Mint Randomized Clinical Trials

Objective

To perform a thorough assessment of the recently published Mint Trials in order to illustrate how to read and analyze a study critically, according to principles of evidence-based medicine.

Design

Narrative review.

Method

We have applied the recently published guidelines for composing and assessing studies on the treatment of pain to a recently published article describing a large study that claimed its "findings do not support the use of radiofrequency denervation to treat chronic low back pain." These guidelines describe the critical components of a high-quality manuscript that allows communication of all relevant information from authors to readers.

Results

Application of evidence-based medicine principles to the publication describing the Mint Trials reveals significant issues with the methodology and conclusions drawn by the authors. A thorough assessment demonstrates issues with inclusion/exclusion criteria, diagnostic block protocols, radiofrequency neurotomy technique, co-interventions, outcome measurement, power analysis, study sample characteristics, data analysis, and loss to follow-up. A failure to definitively establish a diagnosis, combined with use of an inadequate technique for radiofrequency neurotomy and numerous other methodological flaws, leaves the reader unable to draw meaningful conclusions from the study data.

Conclusions

Critical analysis, rooted in principles of evidence-based medicine, must be employed by writers and readers alike in order to encourage transparency and ensure that appropriate conclusions are drawn from study data.

Current Concepts in Intradiscal Percutaneous Minimally Invasive Procedures for Chronic Low Back Pain

STUDY DESIGN

A systemic review of thermal annular procedures (TAPs) and percutaneous disk decompression procedures (PDDPs) for the treatment of discogenic chronic low back pain (CLBP) was conducted.

OBJECTIVE

The objective of this review is to evaluate and to compare the effectiveness of TAPs and PDDPs in treating discogenic CLBP and to assess the frequency of complications associated with those procedures.

MATERIALS AND METHODS

English-language journal articles were identified through computerized searches of the PubMed database and bibliographies of identified articles and review papers. Articles were selected for inclusion if percutaneous minimally invasive procedures were the treatment options for patients with CLBP and if follow-up outcome data included evaluations of back pain severity, functional improvement, and/or incidence of complications. For this review, 27 studies were included.

RESULTS

Intradiscal electrothermal therapy (IDET) procedure in properly selected patients may eliminate or delay the need for surgical intervention for an extended period, whereas few adverse effects have been reported. In contrast to IDET, there is far less literature on the effectiveness of radiofrequency annuloplasty and intradiscal biacuplasty procedures. Nucleoplasty is a potentially effective treatment option for patients with contained disc herniation, while the procedure is well tolerated. Increased success rates have been found for percutaneous laser disc decompression and automated percutaneous lumbar discectomy in strictly selected patients.

CONCLUSIONS

These procedures can be effective and may obviate the need for surgery completely. Further prospective randomized sham-controlled trials with higher quality of evidence are necessary to confirm the efficacy of these procedures.

Discogenic low back pain: interventional treatment

Low back pain (LBP) is one of the most common causes of disability in the adult population. A significant place in its genesis is occupied by a degenerative-dystrophic diseases of intervertebral discs. The article highlights the classification and mechanism of discogenic pain origin. Various types of interventions aredescribed for this pathology: indications, specificities of carrying out manipulations and therapeutic effects, efficiency and possible complications of procedures.

The response to radiofrequency neurotomy of medial branches including a bipolar system for thoracic facet joints

Background and aims The evidence for interventional treatment of thoracic facet joint pain remains limited. This is partly due to inconsistency of the path of thoracic medial branches and a lower incidence of thoracic facet pain among spine pain patients. The purpose of this study is to evaluate the efficacy of bipolar radiofrequency (RF) neurotomy of medial branches for treating chronic thoracic facet joint pain. Methods This is a retrospective record review of all patients diagnosed to have thoracic facet pain with diagnostic block and subsequently treated with bipolar RF neurotomy of medial branch between January 2012 and December 2015. The outcome measures were mean changes in Numeral Rating Scale (NRS) and Pain Disability Index (PDI). Results There were 71 patients with complete data available for analysis. The mean age of the patients was 57.9±11.2 years. The mean duration of pain was 23±10.5 months. The majority of patients (82%) had pain reduction of more than 50% at 12 months after bipolar RF neurotomy. The NRS decreased significantly from baseline of 7.75±1.25 to 2.86±1.53 at 3 months and 2.82±1.29 at 12 months post-procedure (p<0.001. p<0.001, respectively). The PDI improved significantly from 40.92±12.22 to 24.15±9.79, p<0.05). There were no serious adverse effects or complications of the procedure reported in this study. Conclusions Bipolar RF neurotomy of thoracic medial branch is associated with a significant reduction in thoracic facet joint pain. The promising findings from this case series merit further assessment with prospective, randomized controlled trial which will produce a more reliable and accurate finding for its clinical applications.

Prospective, Multicenter, Randomized, Crossover Clinical Trial Comparing the Safety and Effectiveness of Cooled Radiofrequency Ablation With Corticosteroid Injection in the Management of Knee Pain From Osteoarthritis

BACKGROUND AND OBJECTIVES

Osteoarthritis (OA) of the knee affects the aging population and has an associated influence on the health care system. Rigorous studies evaluating radiofrequency ablation for OA-related knee pain are lacking. This study compared long-term clinical safety and effectiveness of cooled radiofrequency ablation (CRFA) with intra-articular steroid (IAS) injection in managing OA-related knee pain.

METHODS

This is a prospective, multicenter, randomized trial with 151 subjects with chronic (≥6 months) knee pain that was unresponsive to conservative modalities. Knee pain (Numeric Rating Scale [NRS]), Oxford Knee Score, overall treatment effect (Global Perceived Effect), analgesic drug use, and adverse events were compared between CRFA and IAS cohorts at 1, 3, and 6 months after intervention.

RESULTS

There were no differences in demographics between study groups. At 6 months, the CRFA group had more favorable outcomes in NRS: pain reduction 50% or greater: 74.1% versus 16.2%, P < 0.0001 (25.9% and 83.8% of these study cohorts, respectively, were nonresponders). Mean NRS score reduction was 4.9 ± 2.4 versus 1.3 ± 2.2, P < 0.0001; mean Oxford Knee Score was 35.7 ± 8.8 vs 22.4 ± 8.5, P < 0.0001; mean improved Global Perceived Effect was 91.4% vs 23.9%, P < 0.0001; and mean change in nonopioid medication use was CRFA > IAS (P = 0.02). There were no procedure-related serious adverse events.

CONCLUSIONS

This study demonstrates that CRFA is an effective long-term therapeutic option for managing pain and improving physical function and quality of life for patients with painful knee OA when compared with IAS injection.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT02343003).

Unique aspects of clinical trials of invasive therapies for chronic pain

Nearly all who review the literature conclude that the role of invasive procedures to treat chronic pain is poorly characterized because of the lack of “definitive” studies. The overt nature of invasive treatments, along with the risks, technical skills, and costs involved create challenges to study them. However, these challenges do not completely preclude evaluating invasive procedure effectiveness and safety using well-designed methods. This article reviews the challenges of studying outcomes of invasive therapies to treat pain and discuss possible solutions. Although the following discussion can apply to most invasive therapies to treat chronic pain, it is beyond the scope of the article to individually cover every invasive therapy used. Therefore, most of the examples focus on injection therapies to treat spine pain, spinal cord stimulation, and intrathecal drug therapies.

Twelve-Month Follow-up of a Randomized Clinical Trial Comparing Intradiscal Biacuplasty to Conventional Medical Management for Discogenic Lumbar Back Pain

Objective

This report conveys 12-month outcomes of subjects treated with intradiscal biacuplasty (IDB) and conservative medical management (CMM) for chronic low back pain of discogenic origin, and results for subjects who elected to receive IDB + CMM 6 months after CMM-alone.

Methods

Sixty-three subjects were originally randomized to the IDB + CMM group (N = 29) or CMM-alone (N = 34). Six months following continuous CMM-alone treatment, participants in this study group were permitted to "cross-over" to IDB + CMM (N = 25), and followed for an additional 6 months. The original IDB + CMM study subjects were followed for a total of 12 months (N = 22).

Results

Pain reduction at 12 months was statistically significant and clinically meaningful in the original IDB + CMM group compared to baseline. Functional and disability outcomes were also improved statistically and clinically. Fifty-five percent of the IDB + CMM patients responded to treatment with a mean VAS reduction of 2.2 points at 12 months. Furthermore, 50% and 64% of subjects reported clinically significant improvements in SF36-PF and in ODI, respectively. There was a 1.7-point reduction (improvement) on a 7-point PGIC scale, and a 0.13-point increase (improvement) in the EQ-5D Health Index. Fifty-percent of cross-over subjects responded to IDB + CMM intervention. Mean outcome scores for cross-over subjects were similar to those of the originally-treated subjects, and functional and disability endpoints were improved statistically and clinically compared to respective baseline values.

Conclusions

The study demonstrated long-term clinical effectiveness of IDB + CMM for treating chronic lumbar discogenic pain. Furthermore, the cross-over study subjects experienced similar improvements in pain, function, disability, and satisfaction.

Blinding in trials of interventional procedures is possible and worthwhile

In this paper, we use evidence from our earlier review of surgical randomised controlled trials with a placebo arm to show that blinding in trials of interventional procedures is feasible. We give examples of ingenious strategies that have been used to simulate the active procedure and to make the placebo control indistinguishable from the active treatment. We discuss why it is important to blind of patients, assessors, and caregivers and what types of bias that may occur in interventional trials. Finally, we describe the benefits of blinding, from the obvious ones such as avoiding bias, as well as less evident benefits such as avoiding patient drop out in the control arm.

Magnetic Resonance Imaging Undetectable Epiduroscopic Hotspot in Chronic Diskogenic Back Pain-Does Sinuvertebral Neuropathy Actually Exist?

BACKGROUND

The causes of chronic diskogenic back pain have not yet been clearly identified. Neural ingrowth around the annulus is widely considered to be one of the possible cause. However, neuropathy around the annulus has yet to be observed visually. We report a case of a hotspot that was observed in an epiduroscopic view, but not in imaging findings.

CASE DESCRIPTION

A 46-year-old woman was admitted with pain in the back, left buttock, and posterior thigh for 2 years. A straight leg raising test was positive on the left side, and left great toe dorsiflexion was decreased to grade 3/5. The Visual Analog Scale pain score was 7/10. On the basis of her symptoms, epidural block, medial branch block, sacroiliac joint block, piriformis muscle injection, physical therapy, and medication were attempted, but no improvement in symptoms was observed. A provocation test was performed at the L3-L4, L4-L5, and L5-S1 intervertebral disks, and severe pain was induced in the L5-S1 intervertebral disk, which was not suspicious on magnetic resonance imaging. We performed transforaminal epiduroscopic laser ablation on L5-S1 and found a hotspot on L5-S1 during the procedure. During laser provocation of the hotspot, the patient complained of severe pain in her lower back and legs, and her pain decreased after ablation of hotspot with laser and improvement in motor weakness was noticed.

CONCLUSION

In this study, we observed annulus hotspots, which have not been observed in imaging studies such as computed tomography or magnetic resonance imaging in patients with chronic back pain and leg pain, and observed remarkable symptom improvement after transforaminal epiduroscopic laser ablation.

Comparison of coblation annuloplasty and radiofrequency thermocoagulation for treatment of lumbar discogenic pain

This study aimed to compare the effectiveness and safety of coblation annuloplasty and radiofrequency thermocoagulation for lumbar discogenic pain.Patients who suffered from lumbar discogenic pain and underwent coblation annuloplasty and radiofrequency thermocoagulation surgery were included. A questionnaire, including the visual analo scale (VAS), MacNab criteria, pain relief rate, and any complications due to surgery, was completed by the patients with the help of a trained volunteer who was blinded to the study. Data were collected at 1 week, and 1, 3, 6, and 12 months after surgery. Significant pain relief was defined as postoperative pain relief ≥50% compared with the preoperative state. Any complications during or after surgery were also recorded.A total of 122 patients were included; 37 patients were lost in the follow-up and 85 were evaluated. Among these, 45 patients underwent coblation annuloplasty (CA group, n = 45) and 40 underwent radiofrequency thermocoagulation procedures (RF group, n = 40).VAS pain scores were decreased at 1 week and 1, 3, 6, and 12 months postoperatively compared with preoperation in both groups (P < .05). The CA group had significantly lower VAS scores at 6 and 12 months of follow-up than did the RF group (P < .05). According to the modified MacNab criteria, the proportions of patients with excellent and/or good results at 3, 6, and 12 months of follow-up were significantly higher in the CA group compared with the RF group (P < .05).Only 2 patients reported soreness at the needle insertion site in the CA group. However, 3 patients had soreness at the needle insertion site, 3 had increased intensity of low back pain, 1 had intracranial hypotension, and 2 had new numbness in the leg and foot in the RF group. At the 1-year follow-up, this numbness was present all of the time. No major complications occurred in the CA group.Our study suggests that CA is a more effective and safe minimally invasive procedure than RF for treating lumbar discogenic pain.

Blinding in trials of interventional procedures is possible and worthwhile

In this paper, we use evidence from our earlier review of surgical randomised controlled trials with a placebo arm to show that blinding in trials of interventional procedures is feasible. We give examples of ingenious strategies that have been used to simulate the active procedure and to make the placebo control indistinguishable from the active treatment. We discuss why it is important to blind of patients, assessors, and caregivers and what types of bias that may occur in interventional trials. Finally, we describe the benefits of blinding, from the obvious ones such as avoiding bias, as well as less evident benefits such as avoiding patient drop out in the control arm.

Effect of bipolar pulsed radiofrequency on refractory chronic cervical radicular pain: A report of two cases

RATIONALE

Despite undergoing transforaminal epidural steroid injection (TFESI), many patients complain of persisting cervical radicular pain. For the management of chronic cervical radicular pain, clinicians are widely applying pulsed radiofrequency (PRF) stimulation to dorsal root ganglions (DRGs). To enhance the effect of PRF stimulation, we conducted bipolar PRF stimulation in 2 patients with chronic cervical radicular pain that was refractory to monopolar PRF and repeated TFESIs.

PATIENT CONCERNS

Patients 1 and 2 presented with a numeric rating scale (NRS) score of 7 and 6 for chronic cervical radicular pain, respectively, despite undergoing monopolar PRF and 2 TFESIs.

DIAGNOSES

On cervical magnetic resonance imaging, foraminal stenosis at the right C6-7 and right central to right foraminal disc protrusion on C6-7 were observed in patients 1 and 2, respectively. Two patients showed a positive response on diagnostic right C7 selective nerve root block with 0.5 mL of 1% lidocaine.

INTERVENTIONS

Bipolar PRF stimulation was performed under C-arm fluoroscopy. Two parallel RF cannulas (less than 1 cm apart) were used for DRG stimulation. The PRF treatment was administered at 5 Hz and a 5-ms pulsed width for 360 seconds at 45 V with the constraint that the electrode tip temperature did not exceed 42°C.

OUTCOMES

At the 2-week and 1-month follow-up, after undergoing bipolar PRF, the pain of patient 1 was completely relieved, and at 2, 3, and 6 months, the pain was scored as NRS 2. In patient 2, at the 2-week follow-up after undergoing bipolar PRF, pain severity was reduced from NRS 6 to 2. The effect of bipolar PRF on patient 2 lasted for at least 6 months. No adverse effects were observed in either patient.

LESSONS

Application of bipolar PRF to DRGs seems to be an effective and safe technique for treating refractory chronic cervical radicular pain.

Randomized sham-controlled, double-blind, multicenter clinical trial on the effect of percutaneous radiofrequency at the ramus communicans for lumbar disc pain

Background

Investigate the effect of percutaneous radiofrequency compared to a sham procedure, applied to the ramus communicans for treatment of lumbar disc pain.

Methods

Randomized sham‐controlled, double‐blind, crossover, multicenter clinical trial. Multidisciplinary pain centres of two general hospitals. Sixty patients aged 18 or more with medical history and physical examination suggestive for lumbar disc pain and a reduction of two or more on a numerical rating scale (0–10) after a diagnostic ramus communicans test block. Treatment group: percutaneous radiofrequency treatment applied to the ramus communicans; sham: same procedure except radiofrequency treatment. Primary outcome measure: pain reduction. Secondary outcome measure: Global Perceived Effect.

Results

No statistically significant difference in pain level over time between the groups, as well as in the group was found; however, the factor period yielded a statistically significant result. In the crossover group, 11 out of 16 patients experienced a reduction in NRS of 2 or more at 1 month (no significant deviation from chance). No statistically significant difference in satisfaction over time between the groups was found. The independent factors group and period also showed no statistically significant effects. The same applies to recovery: no statistically significant effects were found.

Conclusions

The null hypothesis of no difference in pain reduction and in Global Perceived Effect between the treatment and sham group cannot be rejected. Post hoc analysis revealed that none of the investigated parameters contributed to the prediction of a significant pain reduction.

Significance

Interrupting signalling through the ramus communicans may interfere with the transition of painful information from the discs to the central nervous system. Methodological differences exist in studies evaluating the efficacy of radiofrequency treatment for lumbar disc pain. A randomized, sham‐controlled, double‐blind, multicenter clinical trial on the effect of radiofrequency at the ramus communicans for lumbar disc pain was conducted. The null hypothesis of no difference in pain reduction and in Global Perceived Effect between the treatment and sham group cannot be rejected.

A comparative study of continuous versus pulsed radiofrequency discectomy for management of low backache: Prospective randomized, double-blind study

BACKGROUND

Radiofrequency (RF) is a minimally invasive target-selective technique that has been used with success for many years in the treatment of different pathologies, such as low back pain, trigeminal neuralgia, and others.

AIM

The aim of this study is to compare different mode of RF - continuous RF (CRF) versus pulsed RF (PRF) along with steroid in the management of low back pain of discogenic origin.

SETTING AND DESIGN

Prospective, randomized, double-blind trial.

MATERIALS AND METHODS

Forty patients with chronic discogenic low back pain were randomized to receive CRF plus intradiscal triamcinolone 40 mg (Group 1) or to receive PRF plus intradiscal triamcinolone 40 mg (Group 2). Outcome measured includes immediate as well as long-term pain relief using visual analog scale, the Oswestry Disability Index and straight leg raising test.

STATISTICAL ANALYSIS

The continuous variables were compared by one-way analysis of variance test. Discrete variables were compared by Fisher's exact test/Chi-square test/Student's t-test, whichever appropriate. The value of P < 0.05 was considered statistically significant.

RESULTS

There was a significant decrease in pain score after CRF without any added side effect. Pain relief after PRF was insignificant.

CONCLUSION

CRF with steroid seems to be better for treatment of chronic discogenic low back pain than PRF with steroid.

[Interventions on the intervertebral discs. Indications, techniques and evidence levels]

CLINICAL ISSUE

Over the last decades a number of different minimally invasive interventions have been proposed for the treatment of intervertebral disc herniation and degeneration. All of these interventions aim at relieving pressure from compressed nerve roots by mechanical ablation, chemical dissolution, evaporation or coagulation of disc tissue.

STANDARD TREATMENT

Microsurgical sequestrectomy with direct visualization of the spinal canal.

TREATMENT INNOVATIONS

Minimally invasive intradiscal interventions, such as chemonucleolysis, manual and automated disc decompression, laser disc decompression, nucleoplasty and thermal anular radiofrequency (RF) techniques with posterolateral access to the intervertebral disc.

PERFORMANCE

The effectiveness and safety of the different minimally invasive procedures are compared to the standard surgical procedure on the basis of a literature review.

ACHIEVEMENTS

For patients with disc herniation requiring surgery, microsurgical sequestrectomy is the treatment of choice, while discectomy is obsolete. Intradiscal procedures have a low level of evidence while long-term results are still lacking. Randomized controlled trials are required to generate evidence-based results.

PRACTICAL RECOMMENDATIONS

Indications for treatment should be established by an interdisciplinary team with the choice of treatment depending on the interventionalist's expertise and skills. In carefully selected patients scheduled for elective treatment, the different minimally invasive procedures allow adequate treatment when performed by an experienced interventionalist.

A Prospective, Randomized, Multicenter, Open-label Clinical Trial Comparing Intradiscal Biacuplasty to Conventional Medical Management for Discogenic Lumbar Back Pain

STUDY DESIGN

This study was a prospective, randomized, crossover, multicenter trial for the evaluation of comparative effectiveness of intradiscal biacuplasty (IDB) versus conventional medical management (CMM) in the treatment of lumbar discogenic pain.

OBJECTIVE

The objective was to demonstrate the superiority of IDB over CMM in the treatment of discogenic pain with respect to the primary outcome measure.

SUMMARY OF BACKGROUND DATA

Current therapeutic options for the treatment of chronic low back pain of discogenic origin are limited. CMM is often unsatisfactory with regard to the treatment of discogenic pain. IDB offers a minimally invasive treatment that has been demonstrated to be superior to placebo in the past.

METHODS

A total of 63 subjects with lumbar discogenic pain diagnosed via provocation discography were randomized to IDB + CMM (n = 29) or CMM-alone (n = 34). At 6 months, patients in the CMM-alone group were eligible for crossover if desired. The primary outcome measure was the change in visual analog scale (VAS) from baseline to 6 months. Secondary outcome measures included treatment "responders," defined as the proportion of subjects with a 2-point or 30% decrease in VAS scores. Other secondary measures included changes from baseline to 6 months in (1) short form (SF) 36-physical functioning, (2) Oswestry Disability Index, (3) Beck Depression Inventory, (4) Patient Global Impression of Change, (5) EQ-5D VAS, and (6) back pain-related medication usage.

RESULTS

In the IDB cohort, the mean VAS score reduction exceeded that in the CMM cohort (-2.4 vs. -0.56; P = 0.02), and the proportion of treatment responders was substantially greater (50% vs. 18%). Differences in secondary measures favored IDB. No differences in opioid utilization were noted between groups.

CONCLUSION

Superior performance of IDB with respect to all study outcomes suggests that it is a more effective treatment for discogenic pain than CMM-alone.

LEVEL OF EVIDENCE

2.

Percutaneous bipolar radiofrequency thermocoagulation for the treatment of lumbar disc herniation

Lumbar disc herniation is usually managed with conservative treatment or surgery. However, conservative therapy seldom yields good results, and surgery is associated with multiple complications. This study aimed to assess bipolar radiofrequency thermocoagulation for the treatment of lumbar disc herniation. A total of 168 patients with lumbar disc herniation suitable for radiofrequency thermocoagulation were enrolled and randomized to monopolar radiofrequency thermocoagulation (control group, n=84) or bipolar radiofrequency thermocoagulation (experimental group, n=84) treatment groups. Ablation sites were targeted under CT scan guidance, and consecutive radiofrequency therapy was used. One and two probes were used for monopolar and bipolar thermocoagulation, respectively. Thermocoagulation was achieved at 50°C, 60°C, and 70°C for 60s each, 80°C for 90s, and 92°C for 100s. Symptoms and complications were evaluated using the modified Macnab criteria and Visual Analog Scale at 7, 30, and 180days postoperatively. At 180days, a significantly higher efficacy rate was obtained in the experimental group compared with control patients (91.6% versus 79.7%, P<0.05). No severe complications were occurred in either group. Targeted ablation via bipolar radiofrequency thermocoagulation is efficient for lumbar disc herniation treatment, and should be further explored for broad clinical application.

Radiofrequency denervation for chronic low back pain

BACKGROUND

Radiofrequency (RF) denervation, an invasive treatment for chronic low back pain (CLBP), is used most often for pain suspected to arise from facet joints, sacroiliac (SI) joints or discs. Many (uncontrolled) studies have shown substantial variation in its use between countries and continued uncertainty regarding its effectiveness.

OBJECTIVES

The objective of this review is to assess the effectiveness of RF denervation procedures for the treatment of patients with CLBP. The current review is an update of the review conducted in 2003.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, three other databases, two clinical trials registries and the reference lists of included studies from inception to May 2014 for randomised controlled trials (RCTs) fulfilling the inclusion criteria. We updated this search in June 2015, but we have not yet incorporated these results.

SELECTION CRITERIA

We included RCTs of RF denervation for patients with CLBP who had a positive response to a diagnostic block or discography. We applied no language or date restrictions.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected RCTs, extracted data and assessed risk of bias (RoB) and clinical relevance using standardised forms. We performed meta-analyses with clinically homogeneous studies and assessed the quality of evidence for each outcome using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

In total, we included 23 RCTs (N = 1309), 13 of which (56%) had low RoB. We included both men and women with a mean age of 50.6 years. We assessed the overall quality of the evidence as very low to moderate. Twelve studies examined suspected facet joint pain, five studies disc pain, two studies SI joint pain, two studies radicular CLBP, one study suspected radiating low back pain and one study CLBP with or without suspected radiation. Overall, moderate evidence suggests that facet joint RF denervation has a greater effect on pain compared with placebo over the short term (mean difference (MD) -1.47, 95% confidence interval (CI) -2.28 to -0.67). Low-quality evidence indicates that facet joint RF denervation is more effective than placebo for function over the short term (MD -5.53, 95% CI -8.66 to -2.40) and over the long term (MD -3.70, 95% CI -6.94 to -0.47). Evidence of very low to low quality shows that facet joint RF denervation is more effective for pain than steroid injections over the short (MD -2.23, 95% CI -2.38 to -2.08), intermediate (MD -2.13, 95% CI -3.45 to -0.81), and long term (MD -2.65, 95% CI -3.43 to -1.88). RF denervation used for disc pain produces conflicting results, with no effects for RF denervation compared with placebo over the short and intermediate term, and small effects for RF denervation over the long term for pain relief (MD -1.63, 95% CI -2.58 to -0.68) and improved function (MD -6.75, 95% CI -13.42 to -0.09). Lack of evidence of short-term effectiveness undermines the clinical plausibility of intermediate-term or long-term effectiveness. When RF denervation is used for SI joint pain, low-quality evidence reveals no differences from placebo in effects on pain (MD -2.12, 95% CI -5.45 to 1.21) and function (MD -14.06, 95% CI -30.42 to 2.30) over the short term, and one study shows a small effect on both pain and function over the intermediate term. RF denervation is an invasive procedure that can cause a variety of complications. The quality and size of original studies were inadequate to permit assessment of how often complications occur.

AUTHORS' CONCLUSIONS

The review authors found no high-quality evidence suggesting that RF denervation provides pain relief for patients with CLBP. Similarly, we identified no convincing evidence to show that this treatment improves function. Overall, the current evidence for RF denervation for CLBP is very low to moderate in quality; high-quality evidence is lacking. High-quality RCTs with larger patient samples are needed, as are data on long-term effects.

Interventional Therapies for Chronic Low Back Pain: A Focused Review (Efficacy and Outcomes)

Context:

Lower back pain is considered to be one of the most common complaints that brings a patient to a pain specialist. Several modalities in interventional pain management are known to be helpful to a patient with chronic low back pain. Proper diagnosis is required for appropriate intervention to provide optimal benefits. From simple trigger point injections for muscular pain to a highly complex intervention such as a spinal cord stimulator are very effective if chosen properly. The aim of this article is to provide the reader with a comprehensive reading for treatment of lower back pain using interventional modalities.

Evidence Acquisition:

Extensive search for published literature was carried out online using PubMed, Cochrane database and Embase for the material used in this manuscript. This article describes the most common modalities available to an interventional pain physician along with the most relevant current and past references for the treatment of lower back pain. All the graphics and images were prepared by and belong to the author.

Results:

This review article describes the most common modalities available to an interventional pain physician along with the most relevant current and past references for the treatment of lower back pain. All the graphics and images belong to the author. Although it is beyond the scope of this review article to include a very detailed description of each procedure along with complete references, a sincere attempt has been made to comprehensively cover this very complex and perplexing topic.

Conclusion:

Lower back pain is a major healthcare issue and this review article will help educate the pain practitioners about the current evidence based treatment options.

An update on the management of chronic lumbar discogenic pain

Lumbar degenerative disc disease without disc herniation, also known as discogenic pain, is an elusive diagnosis of chronic low back pain. Lumbar provocation discography and fusion surgery have been frequently utilized for several decades as the gold standards for the diagnosis and treatment of symptomatic lumbar discogenic pain, though controversial, based on conjecture, rather than evidence. In addition to lumbar fusion, various other operative and nonoperative modalities of treatments are available in managing chronic lumbar discogenic pain. This review provides an updated assessment of the management of chronic lumbar discogenic pain with a critical look at the many modalities of treatments that are currently available.

Interventional therapies for chronic low back pain

OBJECTIVE

Low back pain (LBP) is a highly prevalent condition and one of the leading causes of lost productivity and health-care costs. The objective of this review is to discuss the role of interventional pain procedures and evidence of their effectiveness in treatment of chronic LBP.

METHODS

This is a narrative review examining published studies on interventional procedures for LBP. The rationales, indications, technique, evidence, and complications for the interventional procedures are discussed.

RESULTS

Interventional pain procedures are used extensively in diagnosis and treatment of chronic pain. LBP is multifactorial, and while significant progress has been made in understanding its pathophysiology, this has not resulted in a proportional improvement of functional outcomes. For certain procedures, such as spinal cord stimulation, medical branch blocks and radiofrequency ablations, and epidural steroid injections for radiculopathy, safety, efficacy, and cost-effectiveness in treating LBP have been well studied. For others, such as interventions for discogenic pain, treatment successes have been modest at best.

CONCLUSIONS

Implementation of interventional pain procedures in the treatment framework of LBP has resulted in improvement of pain intensity in at least the short and medium terms, but equivocal results have been observed in functional improvement.

Efficacy, Safety, and Predictors of Intradiscal Methylene Blue Injection for Discogenic Low Back Pain: Results of a Multicenter Prospective Clinical Series

STUDY DESIGN

Prospective clinical study of intradiscal methylene blue injection for the treatment of lumbar discogenic pain.

OBJECTIVE

The objective of this study was to collect information about efficacy, safety, and acceptability of the intervention, gain and burden of outcome measures, and sample size assumptions for a potential following randomized controlled trial (RCT). If the pilot study demonstrates that this treatment is potentially effective and safe, and the methods and procedures used in this study are feasible, a RCT follows.

SUMMARY OF BACKGROUND DATA

Low back pain (LBP) is a highly common problem with a lifetime prevalence of more than 70%. A substantial part of chronic LBP is attributable to degenerative changes in the intervertebral disc. A recently published RCT assessing the treatment intradiscal injection of methylene blue for chronic discogenic LBP, showed exceptionally good results.

METHODS

Patients were selected on clinical criteria, magnetic resonance imaging, and a positive provocative discogram. The primary outcome measure was mean pain reduction at 6 months.

RESULTS

Fifteen consecutive patients with chronic lumbar discogenic pain enrolled in a multicenter prospective case series in two interventional pain treatment centers in the Netherlands. Six months after the intervention, 40% of the patients claimed at least 30% pain relief. In patients who responded, physical function improved and medication use diminished. We observed no procedural complications or adverse events. Predictors for success were Pfirrmann grading of 2 or less and higher quality of life mental component scores.

CONCLUSIONS

Our findings of 40% positive respondents, and no complications, give reason to set up a randomized, double-blind, placebo-controlled, trial.

Radiofrequency ablation for chronic low back pain: a systematic review of randomized controlled trials

Low back pain affects a considerable proportion of the population and can significantly decrease quality of life. Radiofrequency ablation is an emerging technique that may offer relief from pain for patients experiencing chronic low back pain. This systematic review of the procedure aimed to summarize its efficacy in the treatment of pain in different regions of the low back.

BACKGROUND:

Radiofrequency ablation (RFA), a procedure using heat to interrupt pain signals in spinal nerves, is an emerging treatment option for chronic low back pain. Its clinical efficacy has not yet been established.

OBJECTIVE:

To determine the efficacy of RFA for chronic low back pain associated with lumbar facet joints, sacroiliac joints, discogenic low back pain and the coccyx.

METHODS:

A systematic review was conducted. Medline, EMBASE, PubMed, SPORTDiscus, CINAHL and the Cochrane Library were searched up to August 2013. Abstracts and full-text articles were reviewed in duplicate. Included articles were sham-controlled randomized controlled trials (RCTs), assessed the efficacy of RFA, reported at least one month of follow-up and included participants who had experienced back pain for at least three months. Data were extracted in duplicate and quality was assessed using the Cochrane Risk of Bias tool. Due to heterogeneity, as well as a lack of reported mean differences and SDs, meta-analysis was not possible using these data.

RESULTS:

The present systematic review retrieved 1063 abstracts. Eleven sham-controlled RCTs were included: three studies involving discogenic back pain; six studies involving lumbar facet joint pain; and two studies involving sacroiliac joint pain. No studies were identified assessing the coccyx. The evidence supports RFA as an efficacious treatment for lumbar facet joint and sacroiliac joint pain, with five of six and both of the RCTs demonstrating statistically significant pain reductions, respectively. The evidence supporting RFA for the treatment of discogenic pain is mixed.

CONCLUSIONS:

While the majority of the studies focusing on lumbar facet joints and sacroiliac joints suggest that RFA significantly reduces pain in short-term follow-up, the evidence base for discogenic low back pain is mixed. There is no RCT evidence for RFA for the coccyx. Future studies should examine the clinical significance of the achieved pain reduction and the long-term efficacy of RFA.

Nonoperative management of discogenic back pain: a systematic review

STUDY DESIGN

Systematic review of the literature.

OBJECTIVE

A systematic evaluation of the literature was performed to investigate current nonoperative management of the treatment of discogenic low back pain.

SUMMARY OF BACKGROUND DATA

Back pain is a major health care concern with up to 39% being discogenic in origin according to one study. Nonoperative therapy is likely to be the initial treatment strategy for discogenic low back pain.

METHODS

PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched for clinical studies evaluating nonoperative methods of treating discogenic back pain that were published between 2000 and 2012. Only prospective randomized controlled studies that compared a nonsurgical intervention with sham or placebo therapy were included. After removal of duplicate citations, a total of 226 articles were initially identified from the search terms. From these, we identified 11 randomized controlled trials (RCTs) from which data analysis was performed.

RESULTS

The 11 RCTs investigated traction therapy, injections, and ablative techniques. Results from 5 RCTs investigating methylene blue injection, steroid injection, ramus communicans ablation, intradiscal electrothermal therapy, and biacuplasty favored intervention over sham therapy. However, results from the study on methylene blue injections have not been replicated in other RCTs. Evaluation of the selection criteria used in the studies on ramus communicans ablation and intradiscal biacuplasty and a stratified analysis of results from the RCTs on intradiscal electrothermal therapy casts doubt on whether the conclusions from these RCTs can be applied to the general patient population with discogenic pain.

CONCLUSION

There are few high-quality studies evaluating nonoperative treatments for reducing discogenic low back pain. Although conclusions from several studies favor intervention over sham, it is unclear whether these interventions confer stable long-term benefit. There is some promise in newer modalities such as biacuplasty; however, more inclusive studies need to be performed.

Failed less invasive lumbar spine surgery as a predictor of subsequent fusion outcomes

PURPOSE

It is not uncommon for patients to undergo less invasive spine surgery (LISS) prior to succumbing to lumbar fusion; however, the effect of failed LISS on subsequent fusion outcomes is relatively unknown. The aim of this study was to test the hypothesis that patients who suffered failed LISS would afford inferior subsequent fusion outcomes when compared to patients who did not have prior LISS.

METHODS

After IRB approval, registry from a spine surgeon was queried for consecutive patients who underwent fusion for intractable low back pain. The 47 qualifying patients were enrolled and split into two groups based upon a history for prior LISS: a prior surgery group (PSG) and a non-prior surgery group (nPSG).

RESULTS

Typical postoperative outcome questionnaires, which were available in 80.9% of the patients (38/47) at an average time point of 40.4 months (range, 13.5-66.1 months), were comparatively analysed and failed to demonstrate significant difference between the groups, e.g. PSG v. nPSG: ODI--14.6 ± 10.9 vs. 17.2 ± 19.4 (P = 0.60); SF12-PCS--10.9 ± 11.0 vs. 8.7 ± 12.4 (p = 0.59); bNRS--3.0 (range -2-7) vs. 2.0 (range -3-8) (p = 0.91). Patient satisfaction, return to work rates, peri-operative complications, success of fusion and rate of revision surgery were also not different.

CONCLUSIONS

Although limited by size and retrospective design, the results of this rare investigation suggest that patients who experience a failed LISS prior to undergoing fusion will not suffer inferior fusion outcomes when compared to patients who did not undergo prior LISS.

Recombinant human bone morphogenetic protein-2-augmented transforaminal lumbar interbody fusion for the treatment of chronic low back pain secondary to the homogeneous diagnosis of discogenic pain syndrome: two-year outcomes

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

To assess clinical outcomes, perioperative complications, revision surgery rates, and recombinant human bone morphogenetic protein-2 (BMP-2)-related osteolysis, heterotopic bone, and unexplained postoperative radiculitis (BMPP) in a group of patients treated with BMP-2-augmented transforaminal lumbar interbody fusion (bTLIF) for the homogeneous diagnosis of discogenic pain syndrome (DPS) and to put forth the algorithm used to make the diagnosis.

SUMMARY OF BACKGROUND DATA

There is a paucity of literature describing outcomes of TLIF for the homogeneous diagnosis of DPS, an old but controversial member of the lumbar degenerative disease family.

METHODS

The registry from a single surgeon was queried for patients who had undergone bTLIF for the homogeneous diagnosis of DPS, which was made via specific diagnostic algorithm. Clinical outcomes were determined by analyzing point improvement from typical outcome questionnaires and the data from Patient Satisfaction and Return to Work questionnaires. Independent record review was used to assess all outcomes.

RESULTS

Eighty percent of the cohort (36/45) completed preoperative and postoperative outcome questionnaires at an average follow-up of 41.9 ± 11.9 months, which demonstrated significant clinical improvement: Oswestry Disability Index = 16.4 (P < 0.0001), 12-Item Short Form Health Survey physical component summary score = 10.0 (P < 0.0001), and a Numeric Rating Scale for back pain = 2.3 (P < 0.0001). The median patient satisfaction score was 9.0 (10 = complete satisfaction), and 84.4% (27/32) of the cohort were able to return to their preoperative job, with or without modification. There were 3 perioperative complications, 4 revision surgical procedures, and 11 cases of benign BMPP. There were no incidents of the intraoperative dural tears or nerve root injury, and litigation involvement (11/36, P > 0.17), preoperative depression (15/36, P > 0.19) or prior discectomy/decompression (14/36, P < 0.37) was not a predictor of outcomes.

CONCLUSION

Although limited by retrospective design and small cohort, the results of this investigation suggest that bTLIF is a reasonable treatment option for patients who experience DPS and affords high patient satisfaction. A larger study is needed to confirm these findings.

LEVEL OF EVIDENCE

4.