An update of the systematic appraisal of the accuracy and utility of lumbar discography in chronic low back pain.

BACKGROUND: The intervertebral disc has been implicated as a major cause of chronic lumbar spinal pain based on clinical, basic science, and epidemiological research. There is, however, a lack of consensus regarding the diagnosis and treatment of intervertebral disc disorders. Based on controlled evaluations, lumbar intervertebral discs have been shown to be the source of chronic back pain without disc herniation in 26% to 39% of patients. Lumbar provocation discography, which includes disc stimulation and morphological evaluation, is often used to distinguish a painful disc from other potential sources of pain. Despite the extensive literature, intense debate continues about lumbar discography as a diagnostic tool. STUDY DESIGN: A systematic review of the diagnostic accuracy of lumbar provocation and analgesic discography literature. OBJECTIVE: To systematically assess and re-evaluate the diagnostic accuracy of lumbar discography. METHODS: The available literature on lumbar discography was reviewed. A methodological quality assessment of included studies was performed using the Quality Appraisal of Reliability Studies (QAREL) checklist. Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were included in the analysis. However, studies scoring less than 50% are presented descriptively and critically analyzed. The level of evidence was classified as good, fair, and limited or poor based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to September 2012, and manual searches of the bibliographies of known primary and review articles. RESULTS: Over 160 studies were considered for inclusion. Of these, 33 studies compared discography with other diagnostic tests, 30 studies assessed the diagnostic accuracy of discography, 22 studies assessed surgical outcomes for discogenic pain, and 3 studies assessed the prevalence of lumbar discogenic pain. The quality of the overall evidence supporting provocation discography based on the above studies appears to be fair. The prevalence of internal disc disruption is estimated to be 39% to 42%, whereas the prevalence of discogenic pain without assessing internal disc disruption is 26%. CONCLUSION: This systematic review illustrates that lumbar provocation discography performed according to the International Association for the Study of Pain (IASP) criteria may be a useful tool for evaluating chronic lumbar discogenic pain.

An assessment of a new navigatable percutaneous disc decompression device (l'DISQ) through histologic evaluation and thermo-mapping in human cadaveric discs.

STUDY DESIGN: This is an in vitro experimental study of the technical capability and safety study of a navigable percutaneous disc decompression device named L'DISQ. OBJECTIVES: The objectives of this study were to determine if L'DISQ could adequately reach certain target zones in the disc and to measure the distribution of rises in temperature in the surrounding tissue when the device was used to ablate the disc. METHODS: Placement of the wand of L'DISQ was attempted into the posterior annulus of the discs of four fresh human cadavers. During disc ablation, thermocouple probes were used to measure the temperature within the nucleus pulposus and annulus fibrosus, on the surface of the annulus, and on the posterior longitudinal ligament. Tissues harvested from around the disc were examined histologically. RESULTS: The tip of the wand could be successfully navigated to the posterolateral or posterocentral annulus at all levels above L5-S1 using a lateral approach. Rises in temperature did not exceed 13.25 ± 0.84°C within the disc, and did not exceed 1°C on the surface of the disc. Histology demonstrated no thermal damage to the surrounding neural tissues. CONCLUSION: L'DISQ can be successfully navigated to the target zones, and disc tissue ablated without thermal or structural damage to the adjacent neural tissues.

Functional anatomy and pathophysiology of axial low back pain: disc, posterior elements, sacroiliac joint, and associated pain generators.

Careful consideration of functional lumbosacral anatomy reveals the capacity for pain generation in the disc, zygapophysial joint, sacroiliac joint, and surrounding ligaments. However, the methods used to definitively implicate a particular anatomic structure in axial low back pain have limitations. Anatomically and biomechanically, the discs and posterior elements are inextricably connected to a dynamic biotensegrity network of ligaments, muscles, and fascia. This article examines key lumbosacral anatomic structures and their functional interdependence at the macroscopic, microscopic, and biomechanical level. Particular attention is given to the capacity of each structure to generate low back pain.

A critical review of the American Pain Society clinical practice guidelines for interventional techniques: part 1. Diagnostic interventions.

BACKGROUND: Clinical guidelines are defined as systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances. The clinical guideline industry has been erupting even faster than innovation in health care, constantly adding unhealthy perspectives with broad and complex mandates to health care interventions. Clinical guidelines are based on evidence-based medicine (EBM) and comparative effectiveness research (CER). Multiple issues related to the development of clinical guidelines are based on conflicts of interest, controversies, and limitations of the guideline process. Recently, the American Pain Society (APS) developed and published multiple guidelines in managing low back pain resulting in multiple publications. However, these guidelines have been questioned regarding their development process, their implementation, and their impact on various specialties. OBJECTIVES: To reassess the APS guidelines' evidence synthesis for low back pain diagnostic interventions using the same methodology utilized by the APS authors. The interventions examined were diagnostic techniques for managing low back pain of facet joint origin, discogenic origin, and sacroiliac joint origin. METHODS: A literature search by two authors was carried out utilizing appropriate databases from 1966 through July 2008. Methodologic quality assessment was also performed by at least 2 authors utilizing the same criteria applied in APS guidelines. The guideline reassessment process included the evaluation of individual studies and systematic reviews and the translation into practice recommendations. RESULTS: Our reassessment of Chou et al's evaluation, utilizing Chou et al's criteria, showed good evidence for lumbar facet joint nerve blocks, fair evidence for lumbar provocation discography, and fair to poor evidence for sacroiliac joint blocks to diagnose sacroiliac joint pain. The reassessment illustrates that Chou et al have utilized multiple studies inappropriately and have excluded appropriate studies. Also, Chou et al failed to eliminate their bias in their study evaluations. CONCLUSION: The reassessment, using appropriate methodology and including high quality studies, shows evidence that differs from published APS guidelines.

Evidence-based medicine, systematic reviews, and guidelines in interventional pain management: Part 7: systematic reviews and meta-analyses of diagnostic accuracy studies.

Appropriate diagnosis is essential in providing proper and effective therapy. The field of diagnostic accuracy tests is dynamic with new tests being developed at a fast pace along with improvement in technology of existing tests on a continuous basis. Well-designed diagnostic test accuracy studies can help in making appropriate health care decisions, provided that they transparently and fully report their participants, tests, methods, and results. Exaggerated and biased results from poorly designed and reported diagnostic test studies can trigger their premature dissemination and lead physicians into making incorrect treatment decisions. Consequently, a diagnostic test is useful only to the extent that it distinguishes between conditions or disorders that might otherwise be confused. Since it is unlikely that clinicians, patients, and policy makers have the time, skills, and resources to find, appraise, and interpret the evidence and incorporate it into their health care decisions, systematic reviews and meta-analysis provide an accurate and reliable synthesis of vast quantities of data. A systematic review can identify what is known and what is unknown, giving guidance for future research. Systematic reviews have been considered as a vital link in the great chain of evidence that stretches from the laboratory to the bedside by helping to separate the insignificant, unsound, or redundant deadwood from the salient and critical studies that are worthy of reflection. A dangerous discrepancy exists between experts and evidence with all types of evidence. Historically, it has been reported that in only 15% of all cases can a pathoanatomical explanation be found for patients with chronic low back pain of more than 3 months resulting in the assumption that very little can be done in our present state of ignorance to treat these patients and improve their natural histories. On the other end of the spectrum, due to lack of sound diagnostic information, excessive health care is utilized with exploding costs. The validity of all diagnostic techniques has been described with variable accuracy and reliability. Lack of understanding of reference standards and their unavailability with interventional diagnostic techniques and misinterpretation secondary to interpretation bias may adversely influence the applicability of diagnostic interventions. This manuscript provides a review of the literature, a checklist, and a flow diagram describing the preferred way to present the abstract, introduction, methods, results, and discussion sections of the report of an analysis in a systematic review of diagnostic accuracy studies.

Comprehensive evidence-based guidelines for interventional techniques in the management of chronic spinal pain.

BACKGROUND: Comprehensive, evidence-based guidelines for interventional techniques in the management of chronic spinal pain are described here to provide recommendations for clinicians. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain. DESIGN: Systematic assessment of the literature. METHODS: Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. OUTCOMES: Short-term pain relief was defined as relief lasting at least 6 months and long-term relief was defined as longer than 6 months, except for intradiscal therapies, mechanical disc decompression, spinal cord stimulation and intrathecal infusion systems, wherein up to one year relief was considered as short-term. RESULTS: The indicated evidence for accuracy of diagnostic facet joint nerve blocks is Level I or II-1 in the diagnosis of lumbar, thoracic, and cervical facet joint pain. The evidence for lumbar and cervical provocation discography and sacroiliac joint injections is Level II-2, whereas it is Level II-3 for thoracic provocation discography. The indicated evidence for therapeutic interventions is Level I for caudal epidural steroid injections in managing disc herniation or radiculitis, and discogenic pain without disc herniation or radiculitis. The evidence is Level I or II-1 for percutaneous adhesiolysis in management of pain secondary to post-lumbar surgery syndrome. The evidence is Level II-1 or II-2 for therapeutic cervical, thoracic, and lumbar facet joint nerve blocks; for caudal epidural injections in managing pain of post-lumbar surgery syndrome, and lumbar spinal stenosis, for cervical interlaminar epidural injections in managing cervical pain (Level II-1); for lumbar transforaminal epidural injections; and spinal cord stimulation for post-lumbar surgery syndrome. The indicated evidence for intradiscal electrothermal therapy (IDET), mechanical disc decompression with automated percutaneous lumbar discectomy (APLD), and percutaneous lumbar laser discectomy (PLDD) is Level II-2. LIMITATIONS: The limitations of these guidelines include a continued paucity of the literature, lack of updates, and conflicts in preparation of systematic reviews and guidelines by various organizations. CONCLUSION: The indicated evidence for diagnostic and therapeutic interventions is variable from Level I to III. These guidelines include the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. Further, these guidelines also do not represent "standard of care."

Comparison of growth factor and cytokine expression in patients with degenerated disc disease and herniated nucleus pulposus.

OBJECTIVES: This study was conducted to investigate the expression of cytokines and growth factors in disc specimens obtained from patients with herniated nucleus pulposus (HNP) and degenerated disc disease (DDD). DESIGN AND METHODS: MRI and Western blot analyses were performed to evaluate the levels of disc degeneration and the expression levels of cytokines and growth factors. RESULTS: The levels of TNF-alpha and IL-8 were significantly greater in the DDD group than in the HNP group, but no statistical differences were observed in the expression of IL-1beta, IL-6 and IL-12 between the HNP and DDD groups. In addition, the expression of TGF beta, VEGF and NGF was significantly higher in the DDD group than in the HNP group. CONCLUSION: The greater levels of cytokine and growth factor expression in the DDD group than in the HNP explain why discogenic patients usually have more severe back pain than patients with herniated discs.

Are outer annular fissures stimulated during diskography the source of diskogenic low-back pain? An analysis of analgesic diskography data.

OBJECTIVE: This study aimed to clarify whether painful annular fissures stimulated during provocation diskography are the likely source of diskogenic pain. DESIGN: A retrospective analysis was conducted of prospectively collected data. SETTING: Multidisciplinary, academic spine center. PATIENTS: The study was completed in a cohort of 28 consecutive patients were enrolled presenting with 6 months duration of axial low-back pain recalcitrant to physical therapy, oral analgesics, and epidural steroid injections and who have diskogenic pain based on history, exam, magnetic resonance imaging, and diskography. INTERVENTIONS: Subjects underwent provocation diskography and analgesic diskography utilizing a balloon-tipped intradiskal catheter allowing intradiskal injection of anesthetic. OUTCOME MEASURES: Visual analog scale, finger-to-floor distance were utilized as outcome measures. RESULTS: 80% of painful intervertebral disks as detected by provocation diskography were sufficiently anesthetized resulting in >50% reduction in low-back pain during analgesic diskography. CONCLUSION: Diskogenic pain is in varying degrees caused by the sensitized nociocepters within annular tears.

Evidence-based medicine, systematic reviews, and guidelines in interventional pain management: part 5. Diagnostic accuracy studies.

Diagnosis is a critical component of health care. The world of diagnostic tests is highly dynamic. New tests are developed at a fast pace and technology of existing tests is continuously being improved. However, clinicians, policy makers, and patients routinely face a range of questions regarding diagnostic tests. Well designed diagnostic test accuracy studies can help in making these decisions, provided that they transparently and fully report their participants, tests, methods, and results (as facilitated). For example, by the standards for the reporting of diagnostic accuracy studies (STARD) statement. Exaggerated and biased results from poorly designed and reported diagnostic test studies can trigger their premature dissemination and lead physicians into making incorrect treatment decisions. Thus, a diagnostic test is useful only to the extent that it distinguishes between conditions or disorders that might otherwise be confused. While almost any test can differentiate healthy persons from severely affected ones, appropriate diagnostic tests should differentiate mild and moderate forms of disease. Shortcomings in a study design and interpretation can affect estimates of diagnostic accuracy. Thus, quality diagnostic studies are essential in medicine in general and interventional pain management in particular. The STARD initiative was developed to improve the accuracy and completeness in the reporting of studies of diagnostic accuracy and provide guidance to assist in reducing the potential for bias in the study and to evaluate a study's generalizability. In the practice of interventional pain management, in addition to diagnostic tests which include laboratory tests, imaging tests, and physical examination, diagnostic interventional techniques are crucial. Interventional techniques as a diagnostic tool in painful conditions is important due to multiple challenging clinical situations, which include the purely subjective nature of pain and underdetermined and uncertain pathophysiology in most painful spinal conditions. Precision diagnostic blocks are used to clarify these challenging clinical situations in order to determine the pathophysiology of clinical pain, the site of nociception, and the pathway of afferent neural signals. Part 5 of evidence-based medicine (EBM) in interventional pain management describes the various aspects of diagnostic accuracy studies.

Systematic review of lumbar discography as a diagnostic test for chronic low back pain.

BACKGROUND: The intervertebral disc has been implicated as an etiology of chronic lumbar spine pain based on clinical, basic science, and epidemiological research. However, there is lack of consensus regarding the diagnosis and treatment of intervertebral disc disorders. Based on controlled evaluations, the lumbar intervertebral discs have been shown to be sources of chronic back pain without disc herniation in 26% to 39%. Lumbar provocation discography, which includes disc stimulation and morphological evaluation, is often used to distinguish a painful disc from other potential sources of pain. Despite the extensive literature, controversy continues about provocation lumbar discography. STUDY DESIGN: A systematic review of the lumbar provocation discography literature. OBJECTIVES: To systematically assess the diagnostic accuracy of lumbar discography. METHODS: A systematic review of the literature was performed to assess the diagnostic accuracy of lumbar discography with respect to chronic low back pain. Study inclusion/exclusion criteria were based on International Association for the Study of Pain (IASP) standards with pain provocation and determination of controlled discs. Selected studies were then subjected to a rating instrument for diagnostic accuracy studies. Specific data were then culled from these studies and tabulated. Quality of evidence was assessed using modified Agency for Healthcare Research and Quality (AHRQ) diagnostic accuracy evaluation. Studies meeting methodologic quality criteria scores of 50 or higher were included in the assessment of the level of evidence. Qualitative analysis was conducted using 5 levels of evidence, ranging from Level I to III, with 3 subcategories in Level II. The rating scheme was modified to evaluate the diagnostic accuracy. RESULTS: Based on a modified U.S. Preventive Services Task Force (USPSTF) level of evidence criteria, this systematic review indicates the strength of evidence as Level II-2 for the diagnostic accuracy of lumbar provocation discography utilizing IASP criteria. LIMITATIONS: Limitations include a paucity of literature, poor methodologic quality, and very few studies performed utilizing IASP criteria. CONCLUSION: Based on the current systematic review, lumbar provocation discography performed according to the IASP criteria with control disc (s) with minimum pain intensity of 7 of 10, or at least 70% reproduction of worst pain (i.e. worst spontaneous pain of 7 = 7 x 70% = 5) may be a useful tool for evaluating chronic lumbar discogenic pain. Discography is an important imaging and pain evaluation tool in identifying a subset of patients with chronic low back pain secondary to intervertebral disc disorders.

Systematic review of lumbar provocation discography in asymptomatic subjects with a meta-analysis of false-positive rates.

BACKGROUND: Lumbar provocation discography is a controversial diagnostic test. Currently, there is a concern that the test has an unacceptably high false-positive rate. STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To perform a systematic review of lumbar discography studies in asymptomatic subjects and discs with a meta-analysis of the specificity and false-positive rate of lumbar discography. METHODS: A systematic review of the literature was conducted via a PUBMED search. Studies were included/excluded according to modern discography practices. Study quality was scored using the Agency for Healthcare Research and Quality (AHRQ) instrument for diagnostic accuracy. Specific data was extracted from studies and tabulated per published criteria and standards to determine the false-positive rates. A meta-analysis of specificity was performed. Strength of evidence was rated according to the AHRQ U.S. Preventive Services Task Force (USPSTF) criteria. RESULTS: Eleven studies were identified. Combining all extractable data, a false-positive rate of 9.3% per patient and 6.0% per disc is obtained. Data pooled from asymptomatic subjects without low back pain or confounding factors, shows a false-positive rate of 3.0% per patient and 2.1% per disc. In data pooled from chronic pain patients, asymptomatic of low back pain, the false-positive rate is 5.6% per patient and 3.85% per disc. Chronic pain does not appear to be a confounding factor in a chronic low back pain patient's ability to distinguish between positive (pathologic) and negative (non-pathologic) discs. Among additional asymptomatic patient subgroups analyzed, the false-positive rate per patient and per disc is as follows: iliac crest pain 12.5% and 7.1%; chronic neck pain 0%; somatization disorder 50% and 22.2%, and, post-discectomy 15% and 9.1%, respectively. In patients with chronic backache, no false-positive rate can be calculated. Low-pressure positive criteria (< or = 15 psi a.o.) can obtain a low false-positive rate. Based on meta-analysis of the data, using the ISIS standard, discography has a specificity of 0.94 (95% CI 0.88 - 0.98) and a false-positive rate of 0.06. CONCLUSIONS: Strength of evidence is level II-2 based on the Agency for Healthcare Research Quality (USPSTF) for the diagnostic accuracy of discography. Contrary to recently published studies, discography has a low false-positive rate for the diagnosis of discogenic pain.