A giant herniated disc following intradiscal electrothermal therapy

The introduction of intradiscal electrothermal therapy for the management of discogenic back pain has been met with intense interest over the past few years. During this time there have been several noncontrolled studies published on the procedure, most of which have shown excellent outcomes but few, if any, complications. The authors describe a 29-year-old, 152-kg active duty male soldier who underwent two-level intradiscal electrothermal therapy for L4-L5 and L5-S1 discogenic pain. Before the procedure, the patient had a small L5-S1 contained herniation, with no signs of radiculitis. Postprocedure, the patient developed radicular symptoms and was noted on MRI to have a large L5-S1 disc herniation effacing the left S1 nerve root. Follow-up discography revealed a negative discogram at L4-L5. The patient proceeded to undergo a single-level lumbar fusion, which resulted in nearly complete relief of his radicular and axial low back pain. Two years post-surgery, he is off all narcotic medications and continues to work full-time as a soldier. This case illustrates both the potential benefits and complications that may be associated with intradiscal electrothermal therapy.     

Lumbar discography: a comprehensive review of outcome studies, diagnostic accuracy, and principles

BACKGROUND AND OBJECTIVES: Since its advent more than 50 years ago, the use of discography has been mired in controversy. The purpose of this review is to provide a clinical overview of lumbar discography and discogenic back pain, with special emphasis on determining the accuracy of discography and whether or not the procedure improves outcomes for surgery. METHODS: Material for this review was obtained from a MEDLINE search conducted from 1951 thru September 2004, bibliographic references, book chapters, and conference proceedings. RESULTS: Based on a large number of comparative studies, plain discography is less accurate than magnetic resonance imaging in diagnosing lumbar herniated nucleus pulposus and comparable or slightly more sensitive in detecting degenerative disc disease. For disc degeneration, CT discography remains the gold standard for diagnosis. There are very few studies comparing surgical outcomes between patients who have undergone preoperative provocative discography and those who have not. What little evidence exists is conflicting. Before disc replacement surgery, approximately half the studies have used preoperative discography. A comparison of outcomes did not reveal any significant difference between the 2 groups but none of the studies was controlled, and they used different outcome measures, follow-up periods, and surgical techniques. Because all intradiscal electrothermal therapy (IDET) studies have used discography before surgery, no conclusions can be drawn regarding its effects on outcome. CONCLUSIONS: Although discography, especially combined with CT scanning, may be more accurate than other radiologic studies in detecting degenerative disc disease, its ability to improve surgical outcomes has yet to be proven. In the United States and Europe, there are inconsistencies in the use of lumbar discography such that it is routinely used before IDET, yet only occasionally used before spinal fusion.     

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.     

椎间盘源性下腰痛的发病机制

目的探讨椎间盘源性下腰痛的发病机制。方法收集腰椎后路切除的17例椎间盘源性下腰痛患者的19个经腰椎间盘造影术证实的疼痛腰椎间盘;同时收集12个在MRI T2加权像上信号强度明显减弱、无腰痛症状的生理老化椎间盘和10个正常对照椎间盘,行组织学检查和P物质、神经丝蛋白和血管活性肠肽的免疫组织化学染色检查。结果椎间盘源性下腰痛患者的疼痛椎间盘在组织学上的显著特征表现为,一条从髓核至纤维环外层的血管化肉芽组织条带区,其间伴有1个或多个裂隙;肉芽组织条带区与椎间盘造影术后CT上显示的纤维环裂隙一致,肉芽组织之外的纤维环结构基本正常。生理老化椎间盘和正常对照椎间盘表现为与年龄相关的改变。免疫组织化学染色显示,疼痛椎间盘中P物质、神经丝蛋白和血管活性肠肽3种神经肽阳性神经纤维分布数量和比例,较正常对照椎间盘和生理老化椎间盘明显增多;神经纤维主要沿伴有裂隙的肉芽组织条带区分布;疼痛椎间盘髓核中可见P物质和神经丝蛋白的阳性神经纤维分布。结论椎间盘后方神经分布广泛的肉芽组织条带区是椎间盘造影术疼痛和椎间盘源性下腰痛的起源部位。肉芽组织条带可能起源于椎间盘的创伤修复过程。生理老化椎间盘和疼痛椎间盘的差异是后者形成组织学上的肉芽组织条带区。     

Intervertebral disc a source of pain? Low back pain: problems and future directions--case reports

OBJECTIVE: The objective of this article is to provide evidence supporting the idea that intervertebral disc is a source of low back pain. SUMMARY OF BACKGROUND DATA: Diagnostic tests currently available for diagnosis of a painful disc are inadequate. Treatment protocols for low back pain generally ignore the presence of a painful disc. Pathological processes that may be responsible for discogenic pain are incompletely understood. Without diagnosis and treatment, disc disruption evolves to advanced stages of spinal dysfunction. New treatment modalities are becoming available which if applied early may stop disc disruption. CASE REPORTS: We describe here two case reports where discogenic nature of patients' symptoms was suspected based on patients' history, MRI findings and discography. We highlight the inadequacies of spinal imaging and discography in detecting at painful disc. A treatment (Intradiscal electrothermal therapy) was then directed exclusively to the intervertebral discs. We provide arguments that link discal therapy to resolution of patients' symptoms. Resolution of patients' symptoms after the discal treatment raised our suspicion that pain emanated from the intervertebral discs. CONCLUSIONS: Intervertebral disc is a source of low back pain that is often ignored. No diagnostic test currently exists that can reliably confirm presence of a painful disc. Early diagnosis and treatment of a painful disc may reduce enormous pain and suffering from low back pain.     

腰椎间盘MRI高信号区的组织病理学特点和临床意义

目的研究椎间盘源性下腰痛患者腰椎间盘纤维环后方MRI高信号区的组织病理学特征及其临床意义。方法对52例经保守治疗无效、CT片显示无腰椎间盘突出的下腰痛患者行腰椎MR检查及腰椎间盘造影术。男39例,女13例;平均年龄38.8岁。选择纤维环后方出现高信号区的部分病例行腰椎后路椎间盘切除、椎体间融合、椎弓根螺钉内固定术,术中收集包括高信号区部位的椎间盘。对标本行矢状面连续组织学切片,光镜下观察高信号区椎间盘组织的组织病理学结构,并分析其临床意义。结果在行腰椎间盘造影的52例142个椎间盘中,17例17个椎间盘显示高信号区,且在椎间盘造影过程中全部呈现2或3级的纤维环破裂和疼痛复制反应。敏感性和特异性均为100%。高信号区与纤维环破裂程度分级呈正相关,说明纤维环破裂程度分级越高,越易出现高信号区(R=0.462,P<0.01)。共收集11例患者11个椎间盘,组织学研究发现对应高信号区的椎间盘组织表现为沿纤维环裂隙形成的不同程度的血管化肉芽组织,有成熟的瘢痕化胶原组织。结论症状性下腰痛患者的腰椎MRI上有椎间盘高信号区,可以作为椎间盘源性下腰痛诊断的重要征象。     

The pathogenesis of discogenic low back pain

Discogenic low back pain is a common cause of disability, but its pathogenesis is poorly understood. We collected 19 specimens of lumbar intervertebral discs from 17 patients with discogenic low back pain during posterior lumbar interbody fusion, 12 from physiologically ageing discs and ten from normal control discs. We investigated the histological features and assessed the immunoreactive activity of neurofilament (NF200) and neuropeptides such as substance P (SP) and vasoactive-intestinal peptide (VIP) in the nerve fibres. The distinct histological characteristic of the painful disc was the formation of a zone of vascularised granulation tissue from the nucleus pulposus to the outer part of the annulus fibrosus along the edges of the fissures. SP-, NF- and VIP-immunoreactive nerve fibres in the painful discs were more extensive than in the control discs. Growth of nerves deep into the annulus fibrosus and nucleus pulposus was observed mainly along the zone of granulation tissue in the painful discs. This suggests that the zone of granulation tissue with extensive innervation along the tears in the posterior part of the painful disc may be responsible for causing the pain of discography and of discogenic low back pain.     

椎间盘造影阴性在椎间盘源性腰痛诊断中的分析评价

[目的]通过对一组有典型椎间盘源性下腰痛症状和影像学表现但椎间盘造影阴性的患者进行前瞻性分析,观察椎间盘造影阴性是否能完全排除椎间盘源性下腰痛的诊断.[方法] 2008年6月～2011年2月连续诊治的具有典型椎间盘源性疼痛症状和影像学表现(Dallas V型)但椎间盘造影阴性的一组患者共59例,其中男16例,女43例;年龄36～ 51岁,平均43.8岁;病史6个月～4年,平均1.8年.将59例患者随机分为两组,实验组(29例)于造影剂注射完后于椎间隙再给予注射利多卡因10 mg和地塞米松2.5 mg的混悬液,对照组(30例)则不注射药物并结束造影.两组患者于椎间盘造影术术前、术中、术后行VAS及ODI评分并观察结果.[结果]实验组术后2周内可见VAS评分下降,与对照组相比有统计学意义(P＜0.01),术后第3周随访时两组间VAS评分无明显差别(P＞0.05).实验组中18例VAS评分下降的患者在术后第1、4、8周时进行VAS评分及ODI评分时均较术前明显改善(P＜0.01),在第12周随访时总体上VAS评分及ODI评分与术前比较无明显差别(P＞0.05),对照组患者VAS评分及ODI评分与术前比较均无明显差别(P＞0.05).[结论]本研究结果表明椎间盘造影阴性,但同时合并典型的症状和影像学表现时,并不能完全排除椎间盘源性疼痛的诊断.     

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.     

Intervertebral disc degeneration

Summary Disc degeneration in the human spine is a complex phenomenon characterised by biochemical change in the nucleus pulposus and inner annulus and the formation of clefts and fissures radiating from the central area of the disc towards the periphery. In addition, and probably independent of these phenomena, discrete defects in the outer annular attachement are seen which are likely to be due to mechanical stress and failure. The presence of stress tears in disc tissue and their failure to heal can initiate or accelerate the degeneration of the central component of the intervertebral disc. We postulate that discogenic pain may be linked to damage to the outer portion of the annulus fibrosus. Although it would seem logical to assume that discs with sustained high intradiscal pressure would be more prone to pain referred in the outer annular layers because of higher tensile strain, analysis of prospective studies has failed to confirm a relationship between typical pain reproduction at discography and high pressure values. It is concluded that, at present, the only consistent morphological changes present in patients with pain reproduction at discography are the presence of various annular defects involving the outer layers. Whether nerve ingrowth during attempts at repair of these defects is a consistent feature remains to be established.     

椎间盘封闭术对纤维环破裂型椎间盘源性腰痛的诊治价值

 目的 探讨椎间盘封闭术对纤维环破裂型椎间盘源性腰痛的诊治价值。方法 临床高度怀疑椎间盘源性腰痛行椎间盘造影及单个椎间盘封闭术且有完整随访资料的患者120例,男72例,女48例;年龄25～60岁,平均48岁。根据造影术中纤维环破裂Dallas分级将患者分为0级组7例、1级组36例、2级组48例、3级组29例。采用疼痛视觉模拟评分(visual analogue scale,VAS)及罗兰莫里斯功能评分表(Roland Morris Disability Questionnaire,RMDQ)对术前及术后2周、2个月、6个月、12个月及24个月的疗效进行评估。结果 对高度怀疑的“责任椎间盘”进行封闭阻滞后患者腰痛症状明显改善,术后疼痛VAS和RMDQ评分与术前比较差异有统计学意义;Dallas 3级组中期疗效优于Dallas 1级组及2级组,差异有统计学意义;重度纤维环破裂患者(Dallas分级3级)术后各时间点腰痛症状复发率均低于其他各组患者。结论 椎间盘封闭术能有效缓解椎间盘源性腰痛的症状,并有一定的诊断价值,可作为造影术不能复制疼痛病例的补充诊断依据;纤维环破裂型椎间盘源性腰痛患者,特别是重度纤维环破裂患者,接受椎间盘局部封闭术后缓解疼痛的效果确切。     

Lumbar discogenic pain. Disk degeneration and minimally invasive interventional therapies

Discogenic pain has been responsible for a countless number of missed workdays and millions if not billions of dollars of lost revenue. Minimally invasive interventional therapies of the discogenic back pain gained significant acceptance among the proceduralists. The centuries old dilemma of discogenic low back pain has by no means been answered. We know today that discogenic low back pain has a multitude of causes. The leaking "chemical soup" within the nucleus pulposus is certainly responsible for causing inflammation and thus pain. However, neuropeptides released from peripheral endings of nociceptive afferents are also inflammatory mediators and pain generators. The nerves innervating the discs have been identified and in many cases denervated with good results. These nerves from posterior to anterior include the sinuvertebral nerve, the rami communicantes, and the sympathetic trunk. Diagnosing discogenic low back pain is the key to successful treatment. Classically this should be a low back pain in a "band-like" distribution without radiculopathy that is worse in the morning, worse with Valsalva, and aggravated by standing in flexion. Provocative discography with manometric monitoring is essential in aiding the diagnosis. Once the diagnosis is confirmed, a multitude of invasive therapy may be offered including: L2 root sleeve blocks, intradiscal RFTC, RFTC of the rami communicantes, or Comparative data on the effectiveness of the above-mentioned procedures is lacking and may in fact be an excellent topic for future discussion.     

Acute biomechanical and histological effects of intradiscal electrothermal therapy on human lumbar discs

STUDY DESIGN: Human cadaver lumbar spines were used to assess the acute effects of intradiscal electrothermal therapy in vitro. OBJECTIVE: To determine whether intradiscal electrothermal therapy produces acute changes in disc histology and motion segment stability. SUMMARY OF BACKGROUND DATA: Intradiscal electrothermal therapy has been introduced as an alternative for the treatment of discogenic low back pain. Several hypothesized mechanisms for the effect of intradiscal electrothermal therapy have been suggested including shrinkage of the nucleus or sealing of the anulus fibrosus by contraction of collagen fibers, and thermal ablation of sensitive nerve fibers in the outer anulus. METHODS: Intradiscal electrothermal therapy was performed with the Spinecath by Oratec on 19 fresh, frozen human lumbar cadaver specimens. In a separate study, eight specimens were tested biomechanically and instrumented to map the thermal distribution, whereas five specimens were tested only biomechanically, both before and after intradiscal electrothermal therapy. Six additional specimens were heated with intradiscal electrothermal therapy, and the resulting canal was backfilled with a silicone rubber compound to allow colocalization of the catheter and anular architecture. RESULTS: A consistent pattern of increased motion and decreased stiffness was observed. For the specimens in which only biomechanical measurements were taken, a 10% increase in the motion, on the average, at 5 Nm torque was observed after intradiscal electrothermal therapy. No apparent alteration of the anular architecture was observed around the catheter site in the intradiscal electrothermal therapy-treated discs. CONCLUSION: The data from this study suggest that the temperatures developed during intradiscal electrothermal therapy are insufficient to alter collagen architecture or stiffen the treated motion segment acutely.     

Intradiscal electrothermal therapy (IDET) provides effective symptom relief in patients with discogenic low back pain

STUDY DESIGN: Single-arm, prospective clinical trial. OBJECTIVE: To evaluate back pain severity, physical function, and quality of life outcomes in highly selected patients with lumbar discogenic pain treated with intradiscal electrothermal therapy (IDET). SUMMARY OF BACKGROUND DATA: Degeneration and disruption of the intervertebral disc can be the source of severe low back pain and the associated physical dysfunction. IDET is a minimally invasive treatment option in the continuum of care between conservative nonoperative management and spinal surgery. METHODS: Using magnetic resonance imaging, pressure-controlled discography, and postdiscogram computed tomography findings, 56 patients with lumbar discogenic pain were identified, underwent IDET treatment and followed for 20.5+/-4.4 months, on average. Outcomes included assessments of back pain severity by visual analog scale, sitting, standing, and walking tolerances, and health-related quality of life using the SF-36. RESULTS: Mean pain severity scores (visual analog scale) improved from 6.1+/-1.8 pretreatment to 2.4+/-2.6 at final follow-up (P=0.0001). Mean tolerance times (minutes) improved from 40.9+/-40.6 to 84.5+/-54.4, 46.8+/-42.9 to 84.4+/-54.2, and 39.2+/-39.6 to 77.9+/-50.8 between baseline and final follow-up for sitting, standing, and walking, respectively (P=0.0001 for all comparisons). Seven of 8 quality of life domains showed significant (P=0.0001 for all comparisons) improvement over baseline. Forty-two patients (75%) were classified as a treatment success by virtue of a >or=2-point improvement in pain severity or a >or=10-point improvement in either the physical functioning or bodily pain domain of the SF-36. CONCLUSIONS: The findings of this study suggest that durable clinical improvements can be realized after IDET in highly selected patients with mild disc degeneration, confirmatory imaging evidence of annular disruption, and concordant pain provocation by low pressure discography.     

Quantitative annular thermometry in humans and sheep during radiofrequency and electrothermal annuloplasty

Discogenic low back pain is a pervasive, disabling, and costly problem. Internal disc disruption accounts for approximately 40% of all patients who have the chief symptom of axial low back pain. The majority of episodic back pain will resolve without specific treatment. Unfortunately, pain may persist in spite of comprehensive conservative care. Historically, a gulf has existed between the standard conservative treatments of physiotherapy, medication, cognitive therapy, and therapeutic injection and the more aggressive surgical interventions such as fusion. To bridge this gap, percutaneous techniques have been developed to deliver thermal energy to the disc. Heating of the intervertebral disc is hypothesized to decrease nocioception by coagulation of annular nocioceptors, modification of annular collagen, and physiochemical effect on nuclear inflamagens. Success has been reported in clinical trials of intradiscal electrothermal annuloplasty. Single needle intradiscal radiofrequency is clinically ineffective, but a new means of delivering radiofrequency-induced thermal energy to the posterior annulus is now available. Despite clear and increasing interest in percutaneous disc heating, little data is available on in vivo annular thermometry. The thermal dose (temperature × time) required to provide a consistent clinical response is unknown. Thorough knowledge of in vivo annular temperatures achieved with the different heating strategies is necessary to optimize existing technology, safely develop new techniques, and understand mechanisms underlying thermal modulation of discogenic pain. This study reports annular thermometry data obtained in sheep and humans during application of electrothermal conductive and ionic heating to the intervertebral disc. Included are data from the first 4 human intervertebral discs treated with the radiofrequency catheter ionic heating. Copyright © 2001 by W.B. Saunders Company     

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.     

Annuloplasty procedures for chronic discogenic back pain

Recently, several new minimally invasive intradiscal annuloplasty techniques for treatment of discogenic lower back pain have been introduced, but clinical evidence of their efficacy and extent of application is lagging behind. However, now we know that discTRODE annuloplasty and conventional intradiscal nuclear radiofrequency are ineffective in reducing pain and improving functional capacity. Intradiscal electrothermal therapy and intradiscal biacuplasty do produce positive therapeutic effect in an appropriately selected patient group. Based on procedural ease of radiofrequency needle placement, recent positive results from sham-randomized, prospective study, and lack of complications, biacuplasty is the only annuloplasty procedure that can be currently recommended as an appropriate minimally invasive lumbar disc annuloplasty.     

椎间盘源性腰痛的病理形态学观察

目的观察椎间盘源性腰痛的病理形态学特征,探讨其病理机制。方法选取20例椎间盘源性腰痛的椎间盘手术标本,常规HE染色,光学显微镜观察分析。结果镜下见椎间盘髓核面积减少,髓核中活性软骨细胞少,退变细胞多;纤维环增厚,从内层至外层纤维环可见不同程度的破裂,纤维环软骨细胞减少,软骨基质增多。结论椎间盘源性腰痛的主要致病机制可能是椎间盘形态结构的改变作用。     

High-intensity zone,intradiscal electrothermal therapy,and magnetic resonance imaging

Magnetic resonance imaging changes to the symptomatic intervertebral disc following intradiscal electrothermal therapy were determined in this prospective study. Magnetic resonance images before the intradiscal electrothermal therapy procedure were compared with those taken at 6 months postprocedure in 10 patients. The presence and absence of high-intensity zone, the disc height and hydration, and Modic changes were determined from the images. In six of the 10 patients, a high-intensity zone was present on the magnetic resonance images of the disc before the intradiscal electrothermal therapy procedure. In all six patients, a high-intensity zone was still present after the procedure. In all 10 patients, there were no changes to other disc parameters assessed. Our findings question the clinical relevance of the high-intensity zone. They also suggest that the main mechanism of action of intradiscal electrothermal therapy may be other than that of sealing the anular tear.