Intradiscal thermal annuloplasty versus intradiscal radiofrequency ablation for the treatment of discogenic pain: a prospective matched control trial

Mesenchymal stem cells and thermal annular procedures for discogenic pain: a systematic review with pooled analysis

Aim: Compare the effectiveness of mesenchymal stem cell injection therapies (MSC) and thermal annular procedures for the treatment of discogenic lower back pain. Materials & methods: A systematic review was performed following PRISMA 2020 guidelines. Pooled analysis was performed using patients' pain scores at baseline and at 12 months post-intervention. Results: Effect sizes based on change in pain score from baseline to 12 month follow-up revealed clinically significant improvement in pain score across all interventions. Conclusion: Minimally invasive interventions provide meaningful relief in discogenic back pain, with results suggesting promise for MSC injection therapies as a treatment model.

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.

Netrin-1 mediates nerve innervation and angiogenesis leading to discogenic pain

Objective

Discogenic low back pain (LBP) is associated with nociceptive nerve fibers that grow into degenerated intervertebral discs (IVD) but the etiopathogenesis of disease is not fully understood. The purpose of this study was to clarify the role of Netrin-1 in causing discogenic LBP.

Methods

The level of nociceptive nerve innervation was examined in disc degenerative patients and rat needle-punctured models by immunohistochemistry. Nucleus pulposus (NP) cells were isolated from IVD tissues of rats and induced degeneration by interleukin-1β (IL-1β) or tumor necrosis factor α (TNFα). The candidate genes related to neuron outgrowth and migration were selected by Next-generation sequencing (NGS). CRISPR/Cas9 was used to knockdown Netrin-1 in NP cells. The impact of Netrin-1 on nerve innervation were evaluated with P2X2、NF200 staining and microfluidics assay. Meanwhile the CD31 staining and transwell assay were used to evaluate the impact of Netrin-1 in angiogenesis. The proteins and RNA extracted from NP cells related to catabolism and anabolism were examined by western blot assay and RT-qPCR experiment. ChIP and luciferase experiments were used to assess the intracellular transcriptional regulation of Netrin-1. Further, a needle-punctured rat model followed by histomorphometry and immunofluorescence histochemistry was used to explore the potential effect of Netrin-1 on LBP in vivo.

Results

The level of nerve innervation was increased in severe disc degenerative patients while the expression of Netrin-1 was upregulated. The supernatants of NP cells stimulated with IL-1β or TNFα containing more Netrin-1 could promote axon growth and vascular endothelial cells migration. Knocking down Netrin-1 or overexpressing transcription factor TCF3 as a negative regulator of Netrin-1 attenuated this effect. The needle-punctured rat model brought significant spinal hypersensitivity, nerve innervation and angiogenesis, nevertheless knocking down Netrin-1 effectively prevented disc degeneration-induced adverse impacts.

Conclusion

Discogenic LBP was induced by Netrin-1, which mediated nerve innervation and angiogenesis in disc degeneration. Knocking down Netrin-1 by CRISPR/Cas9 or negatively regulating Netrin1 by transcription factor TCF3 could alleviate spinal hypersensitivity.

The translational potential of this article

This study on Netrin-1 could provide a new target and theoretical basis for the prevention and treatment for discogenic back pain.

Image-Guided Percutaneous Treatment of Lumbar Stenosis and Disc Degeneration

Low back pain, radicular leg pain, and lumbar spinal stenosis are the most common of all chronic pain disorders. Discogenic pain is related to distress of annular fibers and tears, whereas spinal stenosis is related to reduction of the spinal canal dimensions and compression of the neural elements; radicular pain is mainly related to disc herniation and is initially managed conservatively. The percutaneous minimally invasive approach in discogenic and radicular pain is designed to reduce the volume of the nucleus pulposus in patients with failure of medical and physical treatment prolonged for at least 6 weeks.

The Chinese Association for the Study of Pain (CASP): Consensus on the Assessment and Management of Chronic Nonspecific Low Back Pain

Chronic nonspecific low back pain (CNLBP) is defined as pain or discomfort originating from the waist, which lasts for at least 12 weeks, but no radiculopathy or specific spinal diseases. CNLBP is a complicated medical problem and places a huge burden on healthcare systems. Clinical manifestation of CNLBP includes discogenic LBP, zygapophyseal joint pain, sacroiliac joint pain, and lumbar muscle strain. Further evaluation should be completed to confirm the diagnosis including auxiliary examination, functional assessment, and clinical assessment. The principle of the management is to relieve pain, restore function, and avoid recurrence. Treatment includes conservative treatment, minimally invasive treatment, and rehabilitation. Pharmacologic therapy is the first-line treatment of nonspecific LBP, and it is most widely used in clinical practice. Interventional therapy should be considered only after failure of medication and physical therapy. Multidisciplinary rehabilitation can improve physical function and alleviate short-term and long-term pain. The emphasis should be put on the prevention of NLBP and reducing relevant risk factors.

Efficacy of transforaminal laser annuloplasty versus intradiscal radiofrequency annuloplasty for discogenic low back pain

Background

Discogenic pain is a common cause of disability and is assumed to be a major cause of nonspecific low back pain. Various treatment methods have been used for the treatment of discogenic pain. This study was conducted to compare the therapeutic success of radiofrequency (an intradiscal procedure) and laser annuloplasty (both an intradiscal and extradiscal procedure).

Methods

This single-center study included 80 patients and followed them for 6 months. Transforaminal laser annuloplasty (TFLA, 37 patients) or intradiscal radiofrequency annuloplasty (IDRA, 43 patients) was performed. The main outcomes included pain scores, determined by the numeric rating scale (NRS), and Oswestry disability index (ODI), at pre-treatment and at post-treatment months 1 and 6.

Results

The patients were grouped according to procedure. In all procedures, NRS and ODI scores were significantly decreased over time. Mean post-treatment pain scores at months 1 and 6 were significantly lower (P < 0.01) in both groups, and between-group differences were not significant. The ODI score was also significantly decreased compared with baseline. Among patients undergoing TFLA, 70.3% (n = 26) reported pain relief (NRS scores < 50% of baseline) at post-treatment 6 months, vs. 58.1% (n = 25) of those undergoing IDRA. There were no statistically significant differences between the groups in ODI reduction of > 40%.

Conclusions

Our results indicate that annuloplasty is a reasonable treatment option for carefully selected patients with lower back and radicular pain of discogenic origin, and TFLA might be superior to IDRA in patients with discogenic low back pain.

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.

Efficacy of coblation annuloplasty in discogenic low back pain: a prospective observational study

In degenerative disc, the innervated outer annulus is confirmed to the major origin resulted in discogenic pain. To alleviate the discogenic pain, annuloplasty with electrothermal technology was proved to be effective, which mainly involves the thermal heating of the annulus to denature collagen fibers and denervate posterior annular nerve fibers. However, little is known that efficacy of annuloplasty with coblation technology in treating discogenic pain through directly interrupting nerves in outer annulus.The purpose of this study was to evaluate the clinical outcomes of coblation annuloplasty for the treatment of discogenic low back pain.In a clinical prospective observational study, 17 consecutive patients with discogenic low back pain underwent coblation annuloplasty under local anesthesia. Pain visual analogue scale (VAS) scores, patient responses stating significant (≥50%) pain relief, and modified MacNab criteria were adopted to evaluate the pain intensity, degree of pain relief, and functional status after 6 months of follow-up.The preoperative pain VAS score was 6.5 ± 0.8(95% confidence interval [CI] 6.1-6.9) and the pain VAS score decreased to 2.9 ± 1.6 (95% CI 2.1-3.8), 2.9 ± 1.7 (95% CI 2.1-3.8), 3.2 ± 1.6 (95% CI 2.4-4.1), 3.2 ± 1.7 (95% CI 2.4-4.2) at 1 week and 1, 3 and 6 month postoperatively, respectively. 12 (70.6%), 11 (64.7%), 10 (58.8%) and 10 (58.8%) of patients reported significant pain relief at 1 week and 1, 3 and 6 months postoperatively. At 1, 3, and 6 months postoperatively, the numbers of patients with "excellent" or "good" ratings were 13 (76.5%), 11 (64.7%), and 10 (58.8%) according to the modified MacNab criteria. No serious complications were observed.The finds show that coblation annuloplasty is an effective, safe, and less uncomfortable procedure in managing discogenic low back pain.

The technological development of minimally invasive spine surgery

Minimally invasive spine surgery has its roots in the mid-twentieth century with a few surgeons and a few techniques, but it has now developed into a large field of progressive spinal surgery. A wide range of techniques are now called "minimally invasive," and case reports are submitted constantly with new "minimally invasive" approaches to spinal pathology. As minimally invasive spine surgery has become more mainstream over the past ten years, in this paper we discuss its history and development.

Diagnostic criteria and treatment of discogenic pain: a systematic review of recent clinical literature

BACKGROUND CONTEXT

Pain innate to intervertebral disc, often referred to as discogenic pain, is suspected by some authors to be the major source of chronic low back and neck pain. Current management of suspected discogenic pain lacks standardized diagnosis, treatment, and terminology.

PURPOSE

In an attempt to determine whether patterns existed that may facilitate standardization of care, we sought to analyze the terminologies used and the various modes of diagnosis and treatment of suspected discogenic pain.

STUDY DESIGN

A systematic review of the recent literature.

METHODS

A Medline search was performed using the terms degenerative disc disease, discogenic pain, internal disc disruption while using the limits of human studies, English language, and clinical trials, for the last 10 years. The search led to a total of 149 distinct citations, of which 53 articles, where the intervertebral disc itself was considered the principal source of patient's pain and was the main target of the treatment, were retained for further analysis.

RESULTS

The results of this review confirm and help quantify the significant differences that existed in the terminology and all the areas of diagnosis and treatment of presumed discogenic pain.

CONCLUSIONS

Our findings show that suspected discogenic pain, despite its extensive affirmation in the literature and enormous resources regularly devoted to it, currently lacks clear diagnostic criteria and uniform treatment or terminology.

Nonsurgical interventions for low back pain

A variety of nonoperative interventions are available to treat back pain. Careful assessment, discussion, and planning need to be performed to individualize care to each patient. This article discusses good to fair evidence from randomized controlled trials that injection therapy, percutaneous intradiscal radiofrequency thermocoagulation, intradiscal electrothermal therapy, and prolotherapy are not effective. Evidence is poor from randomized controlled trials regarding local injections, Botox, and coblation nucleoplasty; however, with a focused approach, the right treatment can be provided for the right patient. To be more effective in management of back pain, further high-grade randomized controlled trials on efficacy and safety are needed.

Adding triamcinolone to endoscopic ultrasound-guided celiac plexus blockade does not reduce pain in patients with chronic pancreatitis

BACKGROUND & AIMS

The efficacy of endoscopic ultrasound-guided celiac plexus blockade (EUS-CPB) for painful chronic pancreatitis (CP) is uncertain. Triamcinolone is often mixed with bupivacaine to lengthen the analgesic effect. We investigated whether addition of triamcinolone increases and lengthens pain relief compared with EUS-CPB with only bupivacaine.

METHODS

We performed a single-center, blinded, randomized, controlled trial of 40 adult patients referred for EUS-CPB for treatment of painful CP. Patients were assigned randomly to groups that received EUS-CPB with triamcinolone and bupivacaine or EUS-CPB with only bupivacaine (control). Questionnaires were collected when the study began (baseline) and 1 month later. The primary end point was a decrease in the pain disability index of 10 or more points at 1 month after the procedure. Secondary end points included change in visual analogue scale, narcotic requirements, and quality of life at 1 month.

RESULTS

There were no significant differences in primary outcomes between groups (14.3% for patients who received triamcinolone vs 15.8% for controls; P = .64). The trial was stopped for futility. There was no significant difference between groups in immediate response rates (85.7% for patients who received triamcinolone vs 68.4% for control; P = .10), or other secondary end points, including change in pain visual analogue scale (0.4 vs 1.0; P = .83), treatment with morphine equivalents at 1 month (-7.8 vs 0.0; P = .35), change in quality of life at 1 month (SF-12 mental component: 1.3 vs -2.1; P = .44; and physical component: -0.2 vs 1.7; P = .54), or adverse events. The duration of response was shorter in the triamcinolone group (mean, 5.3 vs 0.6 mo; P = .01).

CONCLUSIONS

Triamcinolone does not increase pain relief or lengthen the effects of EUS-CPB.

A randomized double-blind controlled trial of intra-annular radiofrequency thermal disc therapy--a 12-month follow-up

The discTRODE probe applies radiofrequency (RF) current, heating the annulus to treat chronic discogenic low back pain. Randomized controlled studies have not been published. We assessed the long-term effect and safety aspects of percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) with the discTRODE probe in a prospective parallel, randomized and gender stratified, double-blind placebo-controlled study. Twenty selected patients with chronic low back pain and a positive one-level pressure-controlled provocation discography were randomized to either intra-annular PIRFT or intra-annular sham treatment. A blinded interim analysis was performed when 20 patients had been followed for six months. The 6-month analysis did not reveal any trend towards overall effect or difference between active and sham treatment for the primary endpoint: change in pain intensity (0-10). The inclusion of patients was therefore discontinued. After 12 months the overall reduction from baseline pain had reached statistical significance, but there was no significant difference between the groups. The functional outcome measures (Oswestry Disability Index, and SF 36 subscales and the relative change in pain) appeared more promising, but did not reach statistical significance when compared with sham treatment. Two actively treated and two sham-treated patients reported increased pain levels, and in both groups a higher number was unemployed after 12 months. The study did not find evidence for a benefit of PIRFT, although it cannot rule out a moderate effect. Considering the high number, reporting increased pain in our study, we would not recommend intra-annular thermal therapy with the discTRODE probe.

Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically assess benefits and harms of nonsurgical interventional therapies for low back and radicular pain.

SUMMARY OF BACKGROUND DATA

Although use of certain interventional therapies is common or increasing, there is also uncertainty or controversy about their efficacy.

METHODS

Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of local injections, botulinum toxin injection, prolotherapy, epidural steroid injection, facet joint injection, therapeutic medial branch block, sacroiliac joint injection, intradiscal steroid injection, chemonucleolysis, radiofrequency denervation, intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation, Coblation nucleoplasty, and spinal cord stimulation. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and by Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force.

RESULTS

For sciatica or prolapsed lumbar disc with radiculopathy, we found good evidence that chemonucleolysis is moderately superior to placebo injection but inferior to surgery, and fair evidence that epidural steroid injection is moderately effective for short-term (but not long-term) symptom relief. We found fair evidence that spinal cord stimulation is moderately effective for failed back surgery syndrome with persistent radiculopathy, though device-related complications are common. We found good or fair evidence that prolotherapy, facet joint injection, intradiscal steroid injection, and percutaneous intradiscal radiofrequency thermocoagulation are not effective. Insufficient evidence exists to reliably evaluate other interventional therapies.

CONCLUSION

Few nonsurgical interventional therapies for low back pain have been shown to be effective in randomized, placebo-controlled trials.

Histological changes and temperature distribution studies of a novel bipolar radiofrequency heating system in degenerated and nondegenerated human cadaver lumbar discs

OBJECTIVE AND STUDY DESIGN

The purpose of this experimentation was to investigate the safety of a novel cooled bipolar radiofrequency system by examining histology and monitoring temperature distribution in the disc, epidural space, and adjacent to the nerve roots. In our study we used two human cadaver lumbar spines, one moderately to severely degenerated and the other mildly degenerated.

SETTING AND INTERVENTIONS

Radiofrequency ablation of the disc posterior annulus is a theoretically plausible technique to ablate the nociceptors and to modify collagen of the annulus fibrosus. A novel cooled bipolar radiofrequency system is used to perform a procedure called intervertebral disc biacuplasty to heat the posterior annulus for the treatment of discogenic pain. Four lumbar intervertebral discs were treated in each spine sample using the bipolar system while two lumbar discs of each spine were used as controls.

RESULTS

Temperatures developed in the posterior annulus of the disc were on average 52.35 +/- 5.07 degrees C, while in the intervertebral foramen and in the spinal canal were 38.84 +/- 1.7 degrees C and 38.29 +/- 2.04 degrees C, respectively. There was no histological evidence of damage to any other structures including vertebral end plates, epidural space, or nerve roots. Additionally, there were no histological changes in the posterior annulus that were consistent with heat-induced changes to collagen structure.

CONCLUSIONS

Temperatures reached in the posterior annulus during transdiscal biacuplasty were greater than required (45 degrees C) for neuroablation. Temperatures reached at the neural foramina and epidural were low enough to avoid neural damage.

Intervertebral disc: anatomy-physiology-pathophysiology-treatment

This review article describes anatomy, physiology, pathophysiology and treatment of intervertebral disc. The intervertebral discs lie between the vertebral bodies, linking them together. The components of the disc are nucleus pulposus, annulus fibrosus and cartilagenous end-plates. The blood supply to the disc is only to the cartilagenous end-plates. The nerve supply is basically through the sinovertebral nerve. Biochemically, the important constituents of the disc are collagen fibers, elastin fibers and aggrecan. As the disc ages, degeneration occurs, osmotic pressure is lost in the nucleus, dehydration occurs, and the disc loses its height. During these changes, nociceptive nuclear material tracks and leaks through the outer rim of the annulus. This is the main source of discogenic pain. While this is occurring, the degenerative disc, having lost its height, effects the structures close by, such as ligamentum flavum, facet joints, and the shape of the neural foramina. This is the main cause of spinal stenosis and radicular pain due to the disc degeneration in the aged populations. Diagnosis is done by a strict protocol and treatment options are described in this review. The rationale for new therapies are to substitute the biochemical constituents, or augment nucleus pulposus or regenerate cartilaginous end-plate or finally artificial disc implantation..

Evidence-informed management of chronic low back pain with intradiscal electrothermal therapy

The management of chronic low back pain (CLBP) has proven very challenging in North America, as evidenced by its mounting socioeconomic burden. Choosing among available nonsurgical therapies can be overwhelming for many stakeholders, including patients, health providers, policy makers, and third-party payers. Although all parties share a common goal and wish to use limited health-care resources to support interventions most likely to result in clinically meaningful improvements, there is often uncertainty about the most appropriate intervention for a particular patient. To help understand and evaluate the various commonly used nonsurgical approaches to CLBP, the North American Spine Society has sponsored this special focus issue of The Spine Journal, titled Evidence-Informed Management of Chronic Low Back Pain Without Surgery. Articles in this special focus issue were contributed by leading spine practitioners and researchers, who were invited to summarize the best available evidence for a particular intervention and encouraged to make this information accessible to nonexperts. Each of the articles contains five sections (description, theory, evidence of efficacy, harms, and summary) with common subheadings to facilitate comparison across the 24 different interventions profiled in this special focus issue, blending narrative and systematic review methodology as deemed appropriate by the authors. It is hoped that articles in this special focus issue will be informative and aid in decision making for the many stakeholders evaluating nonsurgical interventions for CLBP.

The impact of pain on daily activities following open mesh inguinal hernia repair

BACKGROUND

In groin hernia repair studies, chronic pain is a frequently used primary endpoint. However, its impact on daily life activities has been less investigated. Such an outcome is relevant for the patient and surgeon and cannot be extrapolated out of pain scores. The Pain Disability Index (PDI), a questionnaire wherein patients rate their impairment, could reveal the consequences of pain. The PDI was therefore introduced in a trial upon open mesh-based inguinal hernia repair.

METHODS

A total of 172 patients received an open preperitoneal repair or Lichtenstein procedure. Primary endpoints for this report were the PDI scores measured preoperatively, after 2 weeks and 3 months. The Visual Analogue Scale pain (VAS) scores were assessed simultaneously. Chronic pain was defined as any VAS score at 3 months postoperatively.

RESULTS

The PDI scores of all measure moments were available for 146 patients (85%). A correlation between the PDI and VAS score was found at all moments (P<0.001). A total of 47 patients reported chronic pain. The intensity of their pain correlated more significantly with the PDI than VAS scores at 2 weeks postoperatively (R=0.286, P<0.001 vs. R=0.175, P=0.036). Thirty chronic pain patients reported restrictions. The main disabilities were for the recreation, occupation and sexual subscale. Their PDI scores were not influenced whether work was rated as light or heavy (P=0.570). Twelve patients without chronic pain reported impairment in daily life (mean PDI score 8.8+/-10.8).

CONCLUSION

The PDI is feasible in inguinal hernia repair and can be used as an adjuvant in pain measurement. It can identify patients still suffering postoperatively who might otherwise be missed. Furthermore, the PDI could serve as a predictor for chronic pain.

A Review of Spinal Injuries in the Invasive Cardiologist II: Prevention and Treatment

This review provides a perspective of spinal injuries related to invasive cardiology, an understanding of the anatomy and physiology of the spine, the etiology and pathophysiology of spinal injuries, and options for prevention and treatment. In this part of our review, conventional surgical and minimally invasive options are discussed as well as emerging techniques for the treatment of back pain. We also discuss methods of preventing back injuries by modifications to the work environment as well as preventive measures that may be practiced by the invasive cardiologist. Our final objective is to describe and illustrate proven techniques for strengthening the supportive musculature to avoid spinal injury as well as to reduce painful exacerbations.

Novel Intradiscal Biacuplasty (IDB) for the Treatment of Lumbar Discogenic Pain

Reported here is the treatment of severe axial discogenic pain in a young man utilizing the new minimally invasive transdiscal radiofrequency technique called intradiscal biacuplasty (Baylis Medical Inc., Montreal, Canada). The new procedure is detailed and step-by-step fluoroscopic imaging presented. There were no intra- and postoperative complications, and significant improvements in patient functional capacity, and pain scores were noted. Visual analog scale pain score decreased from 5 to 1 cm at 6-month follow-up, Oswestry disability scores improved from 14 (28% or moderate disability) to 6 points (12% or minimal disability) and SF-36-PF (physical function) score changed from 67 to 82. Potential advantages of cooled, bipolar radiofrequency to heat the posterior annulus are discussed.

Percutaneous thermocoagulation intradiscal techniques for discogenic low back pain

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically review the evidence on the efficacy, effectiveness, and safety of percutaneous thermocoagulation intradiscal techniques for discogenic low back pain.

SUMMARY OF BACKGROUND DATA

The intervertebral disc is thought to be the source of pain in a relevant proportion of cases of low back pain (LBP). Two percutaneous thermocoagulation intradiscal techniques have been described to treat discogenic LBP: percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) and intradiscal electrothermal therapy (IDET).

METHODS

An electronic search was performed in MEDLINE, EMBASE, and the Cochrane Library databases up to 2005, to identify nonrandomized controlled trials and randomized controlled trials (RCTs) on those techniques. All relevant studies were methodologically assessed independently by 3 reviewers. RCTs were assessed following the criteria recommended by the Cochrane Back Review Group. A qualitative synthesis of results was performed.

RESULTS

Six studies were included with a total of 283 patients. Two open, nonrandomized trials (95 patients) showed positive results for IDET compared with rehabilitation and PIRFT. Results from 2 RCTs showed no differences between PIRFT and placebo, and between different PIRFT techniques. Two RCTs compared IDET with placebo. One suggested differences only in pain and in disability, while the best quality RCT showed no differences.

CONCLUSIONS

The available evidence does not support the efficacy or effectiveness of percutaneous thermocoagulation intradiscal techniques for the treatment of discogenic low back pain.

IDET: a critical appraisal of the evidence

Smith and Nephew (Endoscopy division, Andover, MA, USA) have estimated that 60,000 Intra-Discal Electrothermal Therapy (IDET) procedures have been performed world wide up to June 2005. Despite the large number of procedures performed, a critical appraisal of the evidence of efficacy of IDET has not appeared in the literature. This paper reviews the current evidence of clinical efficacy for IDET obtained via a systematic review of the literature. Studies were included if they used at least one of four specified primary outcome measures; pain intensity as assessed by a visual analogue score (VAS), global measurement of overall improvement, back specific functional status such as Oswestry disability Index (ODI) and return to work. Levels of evidence were assigned according to the hierarchy described by the Oxford Centre for Evidence-Based Medicine (www.cebm.net). Papers addressing possible mechanisms of action of IDET were not considered as the focus of the literature review was clinical effectiveness. Eleven prospective cohort studies (level II evidence) were reported on a total of 256 patients with a mean follow-up of 17.1 months (range 12-28 months). The mean improvement in the VAS for back pain was 3.4 points (range 1.4-6.5) and the mean improvement in ODI was 5.2 points (range 4.0-6.4). A total of 379 patients were reported in five retrospective studies (level III evidence). Between 13 and 23% of patients subsequently underwent surgery for low back pain within the study period. Two randomised controlled trials of IDET have been reported in the literature. The first randomised 64 patients (37 to IDET, 27 to Sham). The advantage for IDET patients amounted to 1.3 points on the VAS and seven points on the ODI. The second study randomised 57 subjects (38 to IDET, 19 to Sham) and showed no benefit from IDET over placebo. The evidence for efficacy of IDET remains weak and has not passed the standard of scientific proof.