Intradiscal electrothermal treatment for chronic discogenic low back pain: prospective outcome study with a minimum 2-year follow-up

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.

What can we learn from long-term studies on chronic low back pain? A scoping review

PURPOSE

A scoping review was conducted with the objective to identify and map the available evidence from long-term studies on chronic non-specific low back pain (LBP), to examine how these studies are conducted, and to address potential knowledge gaps.

METHOD

We searched MEDLINE and EMBASE up to march 2021, not restricted by date or language. Experimental and observational study types were included. Inclusion criteria were: participants between 18 and 65 years old with non-specific sub-acute or chronic LBP, minimum average follow-up of > 2 years, and studies had to report at least one of the following outcome measures: disability, quality of life, work participation, or health care utilization. Methodological quality was assessed using the Effective Public Health Practice Project quality assessment. Data were extracted, tabulated, and reported thematically.

RESULTS

Ninety studies met the inclusion criteria. Studies examined invasive treatments (72%), conservative (21%), or a comparison of both (7%). No natural cohorts were included. Methodological quality was weak (16% of studies), moderate (63%), or strong (21%) and generally improved after 2010. Disability (92%) and pain (86%) outcomes were most commonly reported, followed by work (25%), quality of life (15%), and health care utilization (4%). Most studies reported significant improvement at long-term follow-up (median 51 months, range 26 months-18 years). Only 10 (11%) studies took more than one measurement > 2 year after baseline.

CONCLUSION

Patients with persistent non-specific LBP seem to experience improvement in pain, disability and quality of life years after seeking treatment. However, it remains unclear what factors might have influenced these improvements, and whether they are treatment-related. Studies varied greatly in design, patient population, and methods of data collection. There is still little insight into the long-term natural course of LBP. Additionally, few studies perform repeated measurements during long-term follow-up or report on patient-centered outcomes other than pain or disability.

Development, Pathogenesis, and Regeneration of the Intervertebral Disc: Current and Future Insights Spanning Traditional to Omics Methods

The intervertebral disc (IVD) is the fibrocartilaginous joint located between each vertebral body that confers flexibility and weight bearing capabilities to the spine. The IVD plays an important role in absorbing shock and stress applied to the spine, which helps to protect not only the vertebral bones, but also the brain and the rest of the central nervous system. Degeneration of the IVD is correlated with back pain, which can be debilitating and severely affects quality of life. Indeed, back pain results in substantial socioeconomic losses and healthcare costs globally each year, with about 85% of the world population experiencing back pain at some point in their lifetimes. Currently, therapeutic strategies for treating IVD degeneration are limited, and as such, there is great interest in advancing treatments for back pain. Ideally, treatments for back pain would restore native structure and thereby function to the degenerated IVD. However, the complex developmental origin and tissue composition of the IVD along with the avascular nature of the mature disc makes regeneration of the IVD a uniquely challenging task. Investigators across the field of IVD research have been working to elucidate the mechanisms behind the formation of this multifaceted structure, which may identify new therapeutic targets and inform development of novel regenerative strategies. This review summarizes current knowledge base on IVD development, degeneration, and regenerative strategies taken from traditional genetic approaches and omics studies and discusses the future landscape of investigations in IVD research and advancement of clinical therapies.

Autophagy as a potential therapeutic target in intervertebral disc degeneration

Autophagy is an evolutionarily conserved intracellular recirculation system that delivers cytoplasmic content to lysosomes for degradation, thereby maintaining metabolism and homeostasis. Recent studies have found that autophagy plays a dual role in intervertebral disc degeneration (IDD). Most studies have shown that inducing autophagy can slow down the process of IDD. A few studies have shown that extensive autophagy activation-mediated apoptosis accelerates IDD. In this review, we describe the pathophysiological characteristics of intervertebral disc (IVD), the mechanism of autophagy and the application of regulating autophagy in the treatment of IDD, hoping to provide a certain theoretical basis for the biotherapy of IDD.

Pioglitazone Protects Compression-Mediated Apoptosis in Nucleus Pulposus Mesenchymal Stem Cells by Suppressing Oxidative Stress

Excessive compression, the main cause of intervertebral disc (IVD) degeneration, affected endogenous repair of the intervertebral disc. Pioglitazone (PGZ) is the agonist of peroxisome proliferator-activated receptor γ, which has been widely used in the treatment of diabetes mellitus. The present study aim at investigating whether pioglitazone has protective effects on compression-mediated cell apoptosis in nucleus pulposus mesenchymal stem cells (NP-MSCs) and further exploring the possible underlying mechanism. Our results indicated that the isolated cells satisfied the criteria of MSC stated by the International Society for Cellular Therapy. Besides, our research revealed that pioglitazone could protect cell viability, cell proliferation of NP-MSCs and alleviated the toxic effects caused by compression. The actin stress fibers was suppressed obviously under compression, and pioglitazone alleviated the adverse outcomes. Pioglitazone exerted protective effects on compression-induced NP-MSCs apoptosis according to annexin V/PI double-staining and TUNEL assays. Pioglitazone suppressed compression-induced NP-MSCs oxidative stress, including decreasing compression-induced overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA), and alleviated compression-induced mitochondrial membrane potential (MMP) decrease. Ultrastructure collapse of the mitochondria exhibited a notable improvement by pioglitazone in compression-induced NP-MSCs according to transmission electron microscopy (TEM). Furthermore, the molecular results showed that pioglitazone significantly decreased the expression of apoptosis-associated proteins, including cyto.cytochrome c, Bax, cleaved caspase-9, and cleaved caspase-3, and promoted Bcl-2 expression. These results indicated that pioglitazone alleviated compression-induced NP-MSCs apoptosis by suppressing oxidative stress and the mitochondrial apoptosis pathway, which may be a valuable candidate for the treatment of IVD degeneration.

Treatment of contained lumbar disc herniations using radiofrequency assisted micro-tubular decompression and nucleotomy: four year prospective study results

Background

Patients with radiculopathy caused by contained disc herniations are less likely to have good outcomes following discectomy surgery than patients with disc herniations that are not contained. The author presents his 4-year results from a prospective trial regarding the efficacy and safety of a tubular transforaminal radiofrequency-assisted manual decompression and annulus modulation of contained disc herniations in 58 patients.

Methods

Fifty-eight patients with lumbar radiculopathy due to a contained disc herniation were enrolled in a prospective clinical study. Visual analog scores (VAS) for back pain and leg pain, quality of life assessment, Macnab criteria, and SF-12 were collected from patients before treatment, at 2-years and 4-years post-treatment.

Results

At 4 years, results were obtained from 47 (81%) of patients. Compared to mean pre- treatment assessments, mean 4-year VAS for back pain improved from 8.6 to 2.3 points, and mean VAS for leg pain improved from 7.8 to 2.3. Eighty-three percent of respondents reported that they were “satisfied” or “very satisifed” with their quality of life at 4-years as per SF-12. At 4 years, recurrence was noted in 3 (6.4%) of respondents and no complications were reported.

Conclusions

The 2-year and 4-year study results are nearly identical, suggesting durable benefit out to 4 years. These results also suggest that in carefully selected patients with sustained contained disc herniations who have failed conservative treatments, manual decompression combined with radiofrequency-assisted decompression and annulus modulation are very likely to have good outcomes 4 years post-treatment.

Minimally invasive discectomy versus microdiscectomy/open discectomy for symptomatic lumbar disc herniation

BACKGROUND

Microdiscectomy or open discectomy (MD/OD) are the standard procedures for symptomatic lumbar disc herniation and they involve removal of the portion of the intervertebral disc compressing the nerve root or spinal cord (or both) with or without the aid of a headlight loupe or microscope magnification. Potential advantages of newer minimally invasive discectomy (MID) procedures over standard MD/OD include less blood loss, less postoperative pain, shorter hospitalisation and earlier return to work.

OBJECTIVES

To compare the benefits and harms of MID versus MD/OD for management of lumbar intervertebral discopathy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (November 2013), MEDLINE (1946 to November 2013) and EMBASE (1974 to November 2013) and applied no language restrictions. We also contacted experts in the field for additional studies and reviewed reference lists of relevant studies.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) and quasi-randomised controlled trials (QRCTs) that compared MD/OD with a MID (percutaneous endoscopic interlaminar or transforaminal lumbar discectomy, transmuscular tubular microdiscectomy and automated percutaneous lumbar discectomy) for treatment of adults with lumbar radiculopathy secondary to discopathy. We evaluated the following primary outcomes: pain related to sciatica or low back pain (LBP) as measured by a visual analogue scale, sciatic specific outcomes such as neurological deficit of lower extremity or bowel/urinary incontinence and functional outcomes (including daily activity or return to work). We also evaluated the following secondary outcomes: complications of surgery, duration of hospital stay, postoperative opioid use, quality of life and overall participant satisfaction. Two authors checked data abstractions and articles for inclusion. We resolved discrepancies by consensus.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We used pre-developed forms to extract data and two authors independently assessed risk of bias. For statistical analysis, we used risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes with 95% confidence intervals (CI) for each outcome.

MAIN RESULTS

We identified 11 studies (1172 participants). We assessed seven out of 11 studies as having high overall risk of bias. There was low-quality evidence that MID was associated with worse leg pain than MD/OD at follow-up ranging from six months to two years (e.g. at one year: MD 0.13, 95% CI 0.09 to 0.16), but differences were small (less than 0.5 points on a 0 to 10 scale) and did not meet standard thresholds for clinically meaningful differences. There was low-quality evidence that MID was associated with worse LBP than MD/OD at six-month follow-up (MD 0.35, 95% CI 0.19 to 0.51) and at two years (MD 0.54, 95% CI 0.29 to 0.79). There was no significant difference at one year (0 to 10 scale: MD 0.19, 95% CI -0.22 to 0.59). Statistical heterogeneity was small to high (I(2) statistic = 35% at six months, 90% at one year and 65% at two years). There were no clear differences between MID techniques and MD/OD on other primary outcomes related to functional disability (Oswestry Disability Index greater than six months postoperatively) and persistence of motor and sensory neurological deficits, though evidence on neurological deficits was limited by the small numbers of participants in the trials with neurological deficits at baseline. There was just one study for each of the sciatica-specific outcomes including the Sciatica Bothersomeness Index and the Sciatica Frequency Index, which did not need further analysis. For secondary outcomes, MID was associated with lower risk of surgical site and other infections, but higher risk of re-hospitalisation due to recurrent disc herniation. In addition, MID was associated with slightly lower quality of life (less than 5 points on a 100-point scale) on some measures of quality of life, such as some physical subclasses of the 36-item Short Form. Some trials found MID to be associated with shorter duration of hospitalisation than MD/OD, but results were inconsistent.

AUTHORS' CONCLUSIONS

MID may be inferior in terms of relief of leg pain, LBP and re-hospitalisation; however, differences in pain relief appeared to be small and may not be clinically important. Potential advantages of MID are lower risk of surgical site and other infections. MID may be associated with shorter hospital stay but the evidence was inconsistent. Given these potential advantages, more research is needed to define appropriate indications for MID as an alternative to standard MD/OD.

Treatment of the degenerated intervertebral disc; closure, repair and regeneration of the annulus fibrosus

Degeneration of the intervertebral disc (IVD) and disc herniation are two causes of low back pain. The aetiology of these disorders is unknown, but tissue weakening, which primarily occurs due to inherited genetic factors, ageing, nutritional compromise and loading history, is the basic factor causing disc degeneration. Symptomatic disc herniation mainly causes radicular pain. Current treatments of intervertebral disc degeneration and low back pain are based on alleviating the symptoms and comprise administration of painkillers or surgical methods such as spinal fusion. None of these methods is completely successful. Current research focuses on regeneration of the IVD and particularly on regeneration of the nucleus pulposus. Less attention has been directed to the repair or regeneration of the annulus fibrosus, although this is the key to successful nucleus pulposus, and therewith IVD, repair. This review focuses on the importance of restoring the function of the annulus fibrosus, as well as on the repair, replacement or regeneration of the annulus fibrosus in combination with restoration of the function of the nucleus pulposus, to treat low back pain.

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.

Surgical outcome and postoperative work status of lumbar discogenic pain following transforaminal interbody fusion

The clinical outcome and resumption of work were investigated in 21 patients with lumbar discogenic pain (15 males and 6 females, mean age 37.2 years), who failed to respond to intensive conservative therapy, treated by transforaminal lumbar interbody fusion (TLIF) augmented with the pedicle screw system from January 2005 to December 2007. Perioperative assessment was performed using the modified Japanese Orthopaedic Association (mJOA) score, the Oswestry Disability Index, and the visual analogue scale (VAS). Type of occupation and work status of the patients were also assessed before and after surgery. Preoperative occupation was divided into two groups according to the work content (heavy labor vs. light labor). Follow-up period was mean 26.1 months, and greater than 1 year in all patients. Perioperative assessment showed postoperative improvement with statistical significance. Recovery rates at final follow-up examination were 53% of the mJOA score and 65% of the VAS. This study showed that postoperative overall resumption rate was 90%. However, only 23% of the heavy labor group returned to the previous work compared with 71% of the light labor group. TLIF is thought to be a safe and effective technique in patients with intractable chronic lumbar discogenic pain with an acceptable overall work resumption rate, whereas complete return to previous jobs was limited in the heavy labor group.

Pathophysiology, diagnosis, and treatment of discogenic low back pain

Discogenic low back pain is a serious medical and social problem, and accounts for 26%-42% of the patients with chronic low back pain. Recent studies found that the pathologic features of discs obtained from the patients with discogenic low back pain were the formation of the zones of vascularized granulation tissue, with extensive innervation in fissures extending from the outer part of the annulus into the nucleus pulposus. Studies suggested that the degeneration of the painful disc might originate from the injury and subsequent repair of annulus fibrosus. Growth factors such as basic fibroblast growth factor, transforming growth factor β1, and connective tissue growth factor, macrophages and mast cells might play a key role in the repair of the injured annulus fibrosus and subsequent disc degeneration. Although there exist controversies about the role of discography as a diagnostic test, provocation discography still is the only available means by which to identify a painful disc. A recent study has classified discogenic low back pain into two types that were annular disruption-induced low back pain and internal endplate disruption-induced low back pain, which have been fully supported by clinical and theoretical bases. Current treatment options for discogenic back pain range from medicinal anti-inflammation strategy to invasive procedures including spine fusion and recently spinal arthroplasty. However, these treatments are limited to relieving symptoms, with no attempt to restore the disc's structure. Recently, there has been a growing interest in developing strategies that aim to repair or regenerate the degenerated disc biologically.

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.

Results of intradiscal pulsed radiofrequency for lumbar discogenic pain: comparison with intradiscal electrothermal therapy

Background

We have developed an intradiscal pulsed radiofrequency (Disc PRF) technique, using Diskit II® needles (NeuroTherm, Wilmington, MA, USA), as a minimally invasive treatment option for chronic discogenic low back pain (LBP). The purpose of this study was to compare the representative outcomes of Disc PRF and Intradiscal Electrothermal Therapy (IDET) in terms of pain relief and reduction of disability.

Methods

Thirty-one patients with chronic discogenic LBP who underwent either Disc PRF (n = 15) or IDET (n = 16) were enrolled in the study. A Diskit II® needle (15-cm length, 20-gauge needle with a 20-mm active tip) was placed centrally in the disc. PRF was applied for 15 min at a setting of 5 × 50 ms/s and 60 V. The pain intensity score on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) were assessed pretreatment and at 1, 3, and 6 months post-treatment.

Results

The mean NRS was significantly improved from 7.2 ± 0.6 pretreatment to 2.5 ± 0.9 in the Disc PRF group, and from 7.5 ± 1.0 to 1.7 ± 1.5 in the IDET group, at the 6-month follow-up. The mean RMDQ also showed significant improvement in both the Disc PRF group and the IDET group at the 6-month follow-up. There were no significant differences in the pretreatment NRS and RMDQ scores between the groups.

Conclusions

Disc PRF appears to be an alternative to IDET as a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

Avaliação prospectiva dos resultados a longo prazo da terapia intradiscal percutânea lombar por radiofrequência

OBJETIVO: Avaliar os resultados do tratamento da lombalgia crônica discogênica com a técnica IDET (Intradiscal Electrothermal Therapy) em um acompanhamento maior que dois anos de pós-operatório (PO). MÉTODOS: Estudo prospectivo, avaliando 23 pacientes consecutivos com diagnóstico de lombalgia crônica discogênica tratados com IDET entre fevereiro de 2003 e fevereiro de 2006. A dor foi considerada discogênica em caso de discografia positiva ou imagem compatível com a ressonância magnética, segundo os critérios de Horton e Daftari. Os parâmetros clínicos (EVA e Oswestry) foram avaliados no pré-operatório, no retorno com 6, 12, 18, 24 e mais de 48 meses de pós-operatório. RESULTADOS: A média de idade dos pacientes foi de 42,09 (variação de 26 a 51 anos). A média do período do acompanhamento foi de 32,55 meses (variação de 6 a 68 meses). A média do índice de dor (EVA) foi de 7,07 ± 1,90, reduzindo-se para 2,47 ±1,876 em 6 meses, 2,69 ±1,82 em 12 meses, 3,63 ±1,75 em 18 meses e 5,73 ±2,12 em 24 meses. A média do índice Oswestry foi de 39,26 ± 11,96 no pré-operatório, reduzindo-se para 19,44±15,72 em 6 meses, 19,8 8 ±15,45 em 12 meses, 26,62 ±13,84 em 18 meses e 31,87 ±14,94 em 24 meses. Os resultados não se mantiveram no acompanhamento de 48 meses. CONCLUSÃO: O IDET mostrou resultados satisfatórios como alternativa paliativa no controle da dor e da incapacidade funcional num período de 24 meses. Os bons resultados deterioraram-se com 48 meses e houve uma tendência de retorno à sintomatologia inicial.

A randomized placebo-controlled trial of intradiscal methylene blue injection for the treatment of chronic discogenic low back pain

A preliminary report of clinical study revealed that chronic discogenic low back pain could be treated by intradiscal methylene blue (MB) injection. We investigated the effect of intradiscal MB injection for the treatment of chronic discogenic low back pain in a randomized placebo-controlled trial. We recruited 136 patients who were found potentially eligible after clinical examination and 72 became eligible after discography. All the patients had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-six were allocated to intradiscal MB injection and 36 to placebo treatment. The principal criteria to judge the effectiveness included alleviation of pain, assessed by a 101-point numerical rating scale (NRS-101), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. At the 24-month follow-up, both the groups differed substantially with respect to the primary outcomes. The patients in MB injection group showed a mean reduction in pain measured by NRS of 52.50, a mean reduction in Oswestry disability scores of 35.58, and satisfaction rates of 91.6%, compared with 0.70%, 1.68%, and 14.3%, respectively, in placebo treatment group (p<0.001, p<0.001, and p<0.001, respectively). No adverse effects or complications were found in the group of patients treated with intradiscal MB injection. The current clinical trial indicates that the injection of methylene blue into the painful disc is a safe, effective and minimally invasive method for the treatment of intractable and incapacitating discogenic low back pain.

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.

Percutaneous endoscopic laser annuloplasty for discogenic low back pain

BACKGROUND

Laser-assisted spinal endoscopy (LASE) kit has been used for percutaneous intradiscal decompression to evaporate and shrink the posterior and central nucleus for improvement of leg and radicular pain due to contained disc herniation. Percutaneous endoscopic laser annuloplasty (PELA), a new minimally invasive technique, uses LASE to directly coagulate the inflamed disc granulation tissue associated with annular tears. The small diameter of the endoscope including Ho:YAG laser, irrigation, and light, plus the extreme posterolateral approach into the posterior annulus, enables one to minimize damage to normal nuclear tissue. The authors sought to demonstrate the safety and efficacy of PELA for controlling discogenic low back pain (DLBP) due to abnormal disc tissues, new vessels, and nerves in the central torn posterior annulus.

METHODS

Clinical outcomes of PELA were investigated in patients having DLBP with an annulus-torn degenerative disc or contained disc herniation. Thirty patients treated at a single level and achieving a mean follow-up of 9.7 months were analyzed. Outcomes were assessed using the visual analog scale (VAS) for back pain, the Korean Oswestry Disability Index (KODI), and the modified Macnab's criteria.

RESULTS

The mean back pain VAS score improved from 8.0 to 2.4, and the mean KODI score improved from 79.0 to 22.4 (P < .001). Results by the modified Macnab's criteria also showed a good outcome, with a success rate of 90.0%. There were no serious complications observed during follow-up.

CONCLUSIONS

Percutaneous endoscopic laser annuloplasty using the Ho:YAG laser provides favorable outcomes for carefully selected groups of patients with DLBP.

A comparison of minimally invasive techniques in percutaneous treatment of lumbar herniated discs. A review

Low back pain is the commonest spine disease causing absence from work in developed countries. Low back pain with classical irradiation along the course of the nerve root affected is more frequently due to disc disease. In 60-80% of patients with herniated disc, radicular symptoms disappear with conservative treatment after about six weeks, the remainder are treated surgically with a 2-6% of incidence of true recurrence of herniation post-intervention and with failed back surgery syndrome in 15% of cases. Recently minimally invasive techniques have developed as "alternative" treatments to surgical intervention. This review aimed to assess the pathogenesis of low back pain caused by lumbar disc hernia as a basis for action of minimally invasive techniques; to illustrate the techniques already used or currently in use, to compare them in technical guidance, indications and complications, exposing for each of them the inclusion/exclusion criteria in enrolling patients and the imaging guide technique of choice. Minimally invasive techniques can be a valuable alternative to traditional surgery with low cost, low risk of complications, easy feasibility, and in the event of failure they do not exclude subsequent surgery.

Intervertebral disc biacuplasty for the treatment of lumbar discogenic pain: results of a six-month follow-up

OBJECTIVE

Intradiscal biacuplasty (IDB) is a novel bipolar cooled radiofrequency system for the treatment of degenerative disk disease. We present the results of a pilot trial with 6-month follow-up. DESIGN, SETTING, PATIENTS, AND INTERVENTIONS: Fifteen patients, 22-55 years old, underwent one- or two-level IDB treatment of their painful lumbar discs. All had chronic low back pain >6 months, back pain exceeding leg pain, concordant pain on provocative discography, disc height >50% of control, and evidence of single- or two-level degenerative disc disease without evidence of additional changes on magnetic resonance imaging. IDB was performed under fluoroscopy using two radiofrequency probes positioned bilaterally in the intervertebral disc. Thirteen patients completed follow-up questionnaires at 1, 3, and 6 months. Pain disability was evaluated with Oswestry and Short Form (SF)-36 questionnaires.

RESULTS

Median visual analog scale pain scores were reduced from 7 (95% confidence interval [CI] 6, 8) to 4 (2, 5) cm at 1 month, and remained at 3 (2, 5) cm at 6 months. The Oswestry improved from 23.3 (SD 7.0) to 16.5 (6.8) points at 1 month and remained similar after 6 months. The SF-36 Physical Functioning scores improved from 51 (18) to 70 (16) points after 6 months, while the SF-36 Bodily Pain score improved from 38 (15) to 54 (23) points. Daily opioid use did not change significantly from baseline: from 40 (95% CI 40, 120) before IDB to 5 (0, 40) mg of morphine sulfate equivalent 6 months after IDB. No procedure-related complications were detected.

CONCLUSIONS

Patients showed improvements in several pain assessment measures after undergoing IDB for discogenic pain. A randomized controlled study is warranted and needed to address the efficacy of the procedure.

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 efficacy of repeat intradiscal electrothermal therapy

Nine consecutive patients with discogenic low back pain who obtained excellent pain relief from intradiscal electrothermal therapy were treated with a repeat procedure after the beneficial effects had diminished. Although 4 of 9 patients obtained > or =50% pain relief and were satisfied with the results, both the degree and duration of benefit were less pronounced than after the first procedure. Prospective studies are needed to identify the best candidates for repeat intradiscal electrothermal therapy.

Evidence-based clinical practice guidelines for interdisciplinary rehabilitation of chronic nonmalignant pain syndrome patients

This is an update to evidence-based practice guidelines for chronic nonmalignant pain syndrome patients first published in 1995 and revised in 1999. The current guidelines recommend interdisciplinary-focused rehabilitation, which is goal-directed and time-limited. Emphasis is placed on educating patients in active self-management techniques that stress maximizing function. Integrated treatment involving medical, psychological/behavioral, physical/occupational therapy, and disability/vocational interventions are recommended on an outpatient basis whenever clinically possible. Patient selection criteria are delineated. Updated references providing evidence-based support for the recommendations are provided, including the use of opioids and sedative-hypnotic medications, injection and block procedures, acupuncture, implantable spinal infusion and stimulation devices, and other invasive spinal surgery procedures such as intradiscal electrothermal therapy. Guideline integration and early detection and intervention with chronic pain syndrome patients are encouraged.

Efficacy of IDET for relief of leg pain associated with discogenic low back pain

Intradiscal electrothermal annuloplasty (IDET) is an effective treatment for chronic discogenic low back pain (LBP). However, efficacy of IDET for the treatment of referred leg pain has not been examined. This study was performed to assess the long-term efficacy of IDET for the treatment of referred leg pain in chronic discogenic LBP patients. Data were retrospectively analyzed as an IDET case series from January 1999 to December 2000. The IDET procedure was performed at 1-3 symptomatic levels confirmed by pressure-controlled discography. General pain outcome was evaluated by Visual Analog Scale (VAS). LBP and leg pain were assessed separately using five-point pain scales (subsets of the North American Spine Society [NASS] LBP outcome assessment instrument: 0 = no pain, 4 = worst pain) at the 18-month follow-up. Among 129 patients who underwent IDET, 30 patients underwent subsequent back surgery and were excluded from the study, giving a total of 99 patients. Eighty-three patients (83.8%) had leg pain without sciatica. Fifty-two (52.5%), 21 (21.2%), and 8 (8.0%) patients showed LBP > leg pain, LBP = leg pain and LBP < leg pain, respectively. Fifty-three out of 83 patients (63.9%) showed post-IDET improvement in pain, with a mean VAS score of 3.28 +/- 2.31. Thirty patients (36.1%) showed no improvement. A statistically significant (P < 0.05) improvement in subjective back and referred leg pain was observed. Improvements in back and referred leg pain were well-correlated (r = 0.721, P < 0.01). A relatively large number of LBP patients who underwent IDET (84%) presented with referred leg pain without sciatica. The IDET procedure afforded improvements in leg pain that correlated well with improvements in back pain (0.75/4 and 0.88/4, respectively). These data suggest that IDET may relieve associated limb pain in chronic discogenic LBP patients.

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.

Treatment of multilevel degenerative disc disease with intradiscal electrothermal therapy

Intradiscal electrothermal therapy is a frequently performed procedure for the pain of internal disc disruption. It is typically performed on one to two discs; the discal treatment is followed by a long period of rest and rehabilitation. In patients with multilevel disc disease, intradiscal electrothermal therapy is either not contemplated or only one to two discs are treated at a time. This approach therefore either denies these patients the potential benefits of intradiscal electrothermal therapy or significantly prolongs the period of pain and disability. A 25-year-old female patient presented with internal disc disruption at four lumbar disc levels, diagnosed by provocative discography and post discography CT scan. All these discs were treated simultaneously by intradiscal electrothermal therapy. The patient tolerated the procedure well and responded favourably with significant and prolonged decrease in her symptoms. She reported sustained reduction in her pain and showed no clinical evidence of early neurological or infectious complications during 18 months of follow-up. This report indicates that intradiscal electrothermal therapy can be performed at multiple levels at a single sitting, compared to intradiscal electrothermal therapy performed at one to two discs at a time, this approach may obviate the need for surgery and may reduce the duration of pain and disability incurred. However, the influence of multilevel intradiscal electrothermal therapy on long-term complications or outcome is not known.

Industrial medicine and acute musculoskeletal rehabilitation. 5. Interventional procedures for work-related lumbar spine conditions

This chapter emphasizes the importance of establishing a differential diagnosis for low back pain (LBP) with and without referred lower-limb pain and outlines potential interventional treatments appropriate for each diagnosis. It is part of the study guide on industrial rehabilitation and acute musculoskeletal rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. The article specifically focuses on the various interventions used to diagnose or treat those conditions commonly seen in patients with work-related LBP or referred pain in the lower limb. Current criterion treatments for lumbar disk pain, including surgical options, are reviewed.

OVERALL ARTICLE OBJECTIVE

To give an overview of the current state of diagnosis and treatment options for low back pain with or without referred leg pain focusing on interventional procedures.

Spinal injury in sport

Spinal injuries are very common among professional or amateur athletes. Spinal sport lesions can be classified in overuse and acute injuries. Overuse injuries can be found after years of repetitive spinal load during sport activity; however specific overuse injuries can also be found in adolescents. Acute traumas are common in contact sports. Most of the acute injuries are minor and self-healing, but severe and catastrophic events are possible. The aim of this article is to review the wide spectrum of spinal injuries related to sport activity, with special regard to imaging finding.

Interventions for low back pain: what does the evidence tell us

Although interventional therapy for chronic spinal pain continues to be popular among patients and providers, the scientific evidence supporting these techniques has lagged behind their presence in the market. This article collates both classic and more recent experimental results involved in the interventional assessment and treatment of chronic spinal pain, and presents key findings for physicians. Although much of the body of evidence is either unsupportive or inconclusive, there are some definitive findings involving each technique that can help shape rational practice. As interventional pain medicine seeks to become a more validated specialty, introspection and advancing science will be key to this development.

Intradiscal methylene blue injection for the treatment of chronic discogenic low back pain

This article was a preliminary report of prospective clinical trial of a group of patients with chronic discogenic low back pain who met the criteria for lumbar interbody fusion surgery but were treated instead with an intradiscal injection of methylene blue (MB) for the pain relief. Twenty-four patients with chronic discogenic low back pain underwent diagnostic discography with intradiscal injection of MB. The principal criteria to judge the effectiveness included alleviation of pain, assessed by visual analog scale (VAS), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. The mean follow-up period was 18.2 months (range 12-23 months). Of the 24 patients, 21 (87%) reported a disappearance or marked alleviation of low back pain, and experienced a definite improvement in physical function. A statistically significant and clinically meaningful improvement in the changes in the ODI and the VAS scores were obtained in the patients with chronic discogenic low back pain (P=0.0001) after the treatment. The study suggests that the injection of MB into the painful disc may be a very effective alternative for the surgical treatment of chronic discogenic low back pain.

Intradiscal electrothermal coagulation and percutaneous neuromodulation therapy in the treatment of discogenic low back pain

Low back pain (LBP) is a major physical and socioeconomic entity. A significant percentage of LBP is attributable to internal disc disruption. The management of internal disc disruption has traditionally been limited to either conservative treatment or spinal fusion. Intradiscal electrothermal coagulation (IDET) and percutaneous neuromodulation therapy (PNT) are now being performed as an alternative to these therapies. Scientific data regarding the pathophysiology, biologic effects, and clinical results are relatively scarce. Early biomechanical and histologic investigations into the effects of IDET are conflicting. However, in early prospective human trials, IDET seems to provide some benefit with little risk. PNT represents a new less invasive technique for the treatment of discogenic pain, but limited research is available to determine long-term clinical efficacy. IDET and PNT are potentially beneficial treatments for internal disc disruption in carefully selected patients as an alternative to spinal fusion. More basic science and clinical research with long-term follow-up evaluation is necessary.

Quality of life of lumbar stenosis–treated patients in whom the X STOP interspinous device was implanted

Object

This study was conducted to compare the quality of life (QOL) in patients with neurogenic intermittent claudication (NIC) secondary to lumbar spinal stenosis (LSS). Using the 36-Item Short Form (SF-36) questionnaire, the authors compared the results obtained in patients treated with the X STOP Interspinous Process Decompression (IPD) System with those obtained in patients who underwent nonoperative therapies.

Methods

Patients with LSS were enrolled in a prospective 2-year multicenter study and randomized either to the X STOP or nonoperative group. The SF-36 survey was used to assess the QOL before treatment and at 6 weeks, 6 months, 1 year, and 2 years posttreatment. An analysis of variance was used to compare individual pre- and posttreatment mean SF-36 domain scores between the two groups and within each treatment group.

At all posttreatment time points, the authors observed the following: 1) mean domain scores in X STOP–treated patients were significantly greater than those in patients treated nonoperatively, with the exception of the mean General Health (GH), Role Emotional, and Mental Component Summary scores at 2 years; and 2) mean posttreatment domain scores documented in X STOP–treated patients were significantly greater than mean pretreatment scores, with the exception of mean GH scores at 6, 12, and 24 months.

Conclusions

The results of this study demonstrate that the X STOP device is significantly more effective than non-operative therapy in improving the QOL in patients with LSS. The results are comparable with those reported in other studies involving traditional decompressive techniques for LSS and suggest that the X STOP implant can provide an effective treatment compared with nonoperative and conventional surgical therapies.

Sensory neurons and fibers from multiple spinal cord levels innervate the rabbit lumbar disc

OBJECTIVE

To establish the neurotransmission pathway from the lumbar L5/6 intervertebral disc (IVD) to the spinal cord in the rabbit.

DESIGN

Fluorogold particles injected into the posterior portion of the rabbit L5/6 IVD were traced by examining gold-positive neurons and fibers in the dorsal root ganglion (DRG) and spinal cord at various root levels.

RESULTS

Fluorogold-labeled neurons were observed bilaterally in primary afferent DRG neurons from the L3 through L5 segments; a small number of gold-labeled neurons were found at the L1 level. Fluorogold-labeled neurons were predominantly present in the ipsilateral DRG (the side of the injection) at the L5 level, but they were more equally distributed (on both sides) at the L4 and L3 levels. In the posterior horn of the spinal cord, Fluorogold particles were found in nerve fibers as rostral as the T12 level.

CONCLUSIONS

Our study has shown that Fluorogold particles injected into the rabbit L5/6 IVD are taken up by primary sensory neurons in the DRGs and primary sensory fibers in the posterior horn of the spinal cord at multiple levels. This diffuse innervation pattern of the lumbar disc may help explain why discogenic back pain in humans is often poorly localized.

Diagnosis and minimally invasive treatment of lumbar discogenic pain--a review of the literature

Diagnosis and treatment of lumbar discogenic pain due to internal disc disruption (IDD) remains a challenge. It accounts for 39% of patients with low back pain. The mechanism of discogenic pain remains unclear and its clinical presentation is atypical. Magnetic resonance imaging (MRI) can find high-intensity zone as an indirect indication of IDD. However, relative low sensitivity (26.7% to 59%) and high false-positive (24%) and false-negative (38%) rates reduce the value of MRI in screening for the existence of painful IDD. Provocative discography can provide unique information about the pain source and the morphology of the disc. It may also provide information for selecting appropriate treatment for the painful annular tear. Adjunctive therapies, including nonsteroidal anti-inflammatory drugs, physical therapy, rehabilitation, antidepressants, antiepileptics, and acupuncture, have been used for low back pain. The value of these treatments for discogenic pain is yet to be established. Intradiscal steroid injection has not been proved to provide long-term benefits. Intradiscal electrothermal therapy may offer some pain relief for a group of well-selected patients. No benefits have been found for the intradiscal radiofrequency thermocoagulation. A block in the ramus communicans may interfere with the transition of painful information from the discs to the central nervous system. Disc cell transplantation is in the experimental stage. It has the potential to become a useful tool for the prevention and treatment of discogenic pain. Minimally invasive treatments provide alternatives for discogenic pain with the appeal of cost-effectiveness and, possibly, less long-term side effects. However, the value of most of these therapies is yet to be established. More basic science and clinical studies are needed to improve the clinical efficacy of minimally invasive treatments.

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.

Meta-Analysis of the Efficacy and Safety of Intradiscal Electrothermal Therapy (IDET)

OBJECTIVE

The objective of this study was to determine the representative outcomes of the intradiscal electrothermal therapy (IDET) procedure in terms of pain relief, reduction of disability, and risk of complications.

DESIGN

Meta-analysis, using a random-effects model. A Medline literature search was conducted using search terms associated with the IDET procedure including IDET, intradiscal electrothermal therapy, intervertebral disk, and annuloplasty.

OUTCOME MEASURES

The outcomes analyzed were the visual analog scale (VAS) assessment of pain, the bodily pain, and physical functioning subscales of the SF-36 health survey, and the Oswestry disability index.

RESULTS

From 1998 to March 2005, 62 peer-reviewed articles were identified regarding the IDET procedure. Forty-five articles were excluded, leaving a total of 17 unique published reports included in this review. The overall mean improvement in pain intensity was 2.9 points as measured by the VAS. The overall mean improvement in physical function was 21.1 points as measured by the SF-36. The overall mean improvement in bodily pain was 18.0 points as measured by the SF-36. The overall mean improvement in disability was 7.0 points as measured by the Oswestry disability index. The overall incidence of complications was 0.8%.

CONCLUSION

Although variation exists in the reported outcomes among the various studies of the IDET procedure, the pooled results of the published studies provide compelling evidence of the relative efficacy and safety of the IDET procedure.

Changes on MRI in lumbar disc protrusions in two patients after intradiscal electrothermal therapy

We examined changes to the protruded lumbar disc after intradiscal electrothermal therapy (IDET) using magnetic resonance imaging (MRI) in two patients with chronic discogenic low back pain who underwent IDET. MRI was performed before and 6 months after the treatments. In the follow-up MRI studies, the protrusions were almost abolished and normalized in both patients. We thus confirmed shrinkage of the protruded disc by IDET on MRI images in two patients.

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

OBJECTIVE

Two minimally invasive techniques have been used more recently as a possible treatment for painful internal disk disruption (IDD). Intradiscal thermal annuloplasty (IDTA), known as IDET, has already shown promising results in pain reduction and functional restoration. The second technique, radiofrequency posterior annuloplasty (RFA), is used in many interventional pain practices, although studies on the technique's efficacy are lacking. This study compares the effectiveness of those two methods.

DESIGN AND PATIENTS

We matched 42 patients (21 had IDTA and 21 radiofrequency annuloplasty) for age, sex, weight, smoking history, manual labor, and number of intervertebral disks treated. Enrolled patients completed pain disability index (PDI) questionnaires before receiving either IDTA or RFA; at 2 weeks; and 2, 3, 6, 9, and 12 months following either treatment.

RESULTS

From the third to the twelfth month after the procedure, the IDTA group had significantly lower mean pain scores than the RFA group. Visual analog scale (VAS) pain scores decreased from 6.6 +/- 2.0 before to 4.4 +/- 2.4 at 1 year after radiofrequency annuloplasty (P = 0.001), while in the IDTA group the average VAS pain score decreased from 7.4 +/- 1.9 before IDTA to 1.4 +/- 1.9 at 1 year follow-up. Similarly, PDI scores in the IDTA group had a significantly larger improvement than those for patients who received radiofrequency annuloplasty.

CONCLUSIONS

This study shows significant improvement in pain scores and patients' PDI following IDTA but not after RFA of the intervertebral disks. IDTA appears to be more efficacious than RFA based on PDI and VAS scores measured at 1 year following procedure.

Histological and molecular structure characterization of annular collagen after intradiskal electrothermal annuloplasty

The mechanism of pain relief of intradiskal electrothermal annuloplasty (IDET) in the treatment of lumbar diskogenic pain is uncertain. Theories include sealing of annular fissures via collagen denaturation and contraction. Prior studies offer conflicting qualitative data on the ability of IDET to denature collagen. The objective of the present study is to evaluate IDET treatment effect on annular collagen using quantitative data supplied by Fourier-transform infrared imaging spectroscopy. The posterior annulus of disks (n = 3) from an intact human cadaveric spine at room temperature were treated with two different radiothermal catheters using standard intradiskal electrothermal annuloplasty (IDET) heating protocols. Disks were dissected free with catheters in place and fixed in formalin. Channels created by the catheters were marked and catheters were removed. Tissue samples of treated areas adjacent to the channels and internal control areas from the same disk were stained for light microscopy and placed on barium sulfate windows for Fourier transform infrared imaging spectroscopy (FT-IRIS) analysis. Treated areas showed evidence of disruption in the fibrillar organization of annular collagen by light microscopy compared to intact stroma from control areas. Quantitative FT-IRIS analysis compared ratios of wavenumber regions known to be sensitive to collagen denaturation. Mean values for the ratios amide II/1,338 cm(-1) (137.21 +/- 25.84 treated, 76.94 +/- 16.77 control) and 1,640/1,660 cm(-1) (0.98 +/- 0.03 treated, 0.89 +/- 0.03 control) were significantly different between treated and control samples (p < 0.001), indicating a breakdown in collagen integrity. Separate analysis by catheter type suggests that catheter design may impact treatment effect.

Diskography in the evaluation of low back pain

Diskography is evolving to play a crucial role in the evaluation of axial low back pain, especially in regard to surgical decision making. Despite advances in other forms of imaging, diskography remains unique in that it is the only test that seeks to provoke a pain response during the study. It has been suggested that patients with axial low back pain who experience a concordant pain response during diskography are more likely to respond favorably to surgical intervention. However, the efficacy of using this potential correlation is dependent on the technical application and interpretation. The validity of diskography remains controversial, in part because postdiskography surgical outcomes have been inconsistent. Therefore, in select patients with recalcitrant back pain, diskography remains a second-line diagnostic modality that is used to clarify surgical indications. Despite well-defined guidelines, the technical aspects of diskography and its interpretation are still evolving.