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Provocative Discography
Abstract
Discography was introduced in the 1940s to diagnose herniation and internal annular disruption of the lumbar and subsequently cervical and thoracic intervertebral discs. While the development of CT and MRI scans unquestionably provides the physician with invaluable information, discography combined with a CT scan remains the most accurate method of detailing internal annular disruption and disc morphology. Unlike noninvasive imaging tests, pressurizing the disc adds critical information if significant; concordant pain is reproduced; and more importantly, a negative response to provocation discography assists in identifying negative discs for which surgery is not recommended. Theoretically, speed- and pressure-controlled injection of contrast media into the disc nucleus stimulates nerve endings via two mechanisms: a chemical stimulus from contact between contrast dye and sensitized nociceptors and a mechanical stimulus resulting from the fluid-distending stress simulating loading.
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Chronic neck pain represents a significant public health problem. Despite high prevalence rates, there is a lack of consensus regarding the causes or treatments for this condition. Based on controlled evaluations, the cervical intervertebral discs, facet joints, and atlantoaxial joints have all been implicated as pain generators. Cervical provocation discography, which includes disc stimulation and morphological evaluation, is often used to distinguish a painful disc from other potential sources of pain. Yet in the absence of validation and controlled outcome studies, the procedure remains mired in controversy.
A systematic review of the cervical discography literature.
To evaluate the validity and usefulness of cervical provocation discography in managing and diagnosing discogenic pain by means of a systematic review.
Following a comprehensive search of the literature, selected studies were subjected to a modified Agency for Healthcare Research and Quality (AHRQ) diagnostic accuracy evaluation. 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.
A systematic review of the literature demonstrated that cervical discography plays a significant role in selecting surgical candidates and improving outcomes, despite concerns regarding the false-positive rate, lack of standardization, and assorted potential confounding factors. Based on the studies utilizing the International Association for the Study of Pain (IASP) criteria, the data show a prevalence rate ranging between 16% and 20%. Based on the 3 studies that utilized IASP criteria during the performance of cervical discography, the evidence derived from studies evaluating the diagnostic validity of the procedure, the indicated level of evidence is Level II-2 based on modified U.S. Preventive Services Task Force (USPSTF) criteria.
Limitations include a paucity of literature, poor methodologic quality, and very few studies performed utilizing IASP criteria.
Cervical discography performed according to the IASP criteria may be a useful tool for evaluating chronic cervical pain, without disc herniation or radiculitis. Based on a modified AHRQ accuracy evaluation and USPSTF level of evidence criteria, this systematic review indicates the strength of evidence as Level II-2 for diagnostic accuracy of cervical discography.
Lumbar provocation discography is a controversial diagnostic test. Currently, there is a concern that the test has an unacceptably high false-positive rate.
Systematic review and meta-analysis.
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.
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.
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.
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.
The prevalence, validity and reliability of high-intensity zones in the annulus fibrosus seen on T2-weighted magnetic resonance images of patients with intractable low-back pain were determined. This sign was readily recognized by two independent observers. It occurred in 28% of 500 patients undergoing magnetic resonance imaging for back pain. The presence of a high-intensity zone correlated significantly with the presence of Grade 4 annular disruption and with reproduction of the patient's pain. Its sensitivity as a sign of either annular disruption or pain was modest but its specificity was high, and its positive predictive value for a severely disrupted, symptomatic disc was 86%. This sign is diagnostic of painful internal disc disruption.
Discitis after discography is due to bacterial penetration into the intervertebral disc by a contaminated needle and has an incidence of 1% to 4%. We have examined the prophylactic role of cephazolin administered at the time of discography. An experimental study in sheep using radiographic contrast containing Staphylococcus epidermidis showed that either adding the antibiotic to the intradiscal suspension or giving it intravenously 30 minutes before intradiscal inoculation of bacteria prevented any radiographic, macroscopic or histological signs of discitis; all the intervertebral disc cultures were negative. In a prospective clinical study of 127 consecutive patients having lumbar discography, the injected contrast contained cephazolin 1 mg per ml. None of the patients developed clinical or radiographic signs of discitis. We recommend the use of a suitable broad spectrum antibiotic in a single prophylactic dose whenever the intervertebral disc is entered.
Infection after intradiscal injections has been recognised as a distinct entity, but discitis after discography has often been attributed to an aseptic process or a chemical reaction to the contrast material. We examined the hypothesis that discitis after discography is always due to infection, and report a clinical review and an experimental study. Part I. We reviewed the case records and radiographs of 432 patients who had undergone lumbar discography. When an 18-gauge needle without a stilette had been used, discitis was diagnosed in 2.7% of 222 patients but stiletted needles and a two-needle technique at each level reduced the incidence to 0.7%. Seven patients with discitis after discography had undergone anterior discectomy and fusion; in them the histopathological findings were of a chronic inflammatory response. Bacteria were isolated from the discs of three of the four patients who had open biopsy less than six weeks from the time of discography. These findings suggest that bacteria were initiators rather than promoters of the response. Part II. Multiple level lumbar discography was carried out in mature sheep, injecting contrast material with or without various concentrations of bacteria. Radiographs were taken and the discs and end-plates were examined histologically and cultured for bacteria at intervals after injection. None of the controls showed any evidence of discitis but all sheep injected with bacteria had typical radiological and histopathological changes by six weeks, though cultures were almost all negative. However, at one and two weeks after injection, but usually not after three weeks, bacteria could be isolated. We suggest that all cases of discitis after discography are initiated by infection, and that a very strict aseptic technique should be used for all injections into intervertebral discs.
Objectives: To evaluate the safety and reliability of discography used to investigate thoracic disc degeneration observed on magnetic resonance (MR) imaging studies in patients with clinical pain, we analyzed retrospectively the results of thoracic discograms performed on 100 outpatients. Methods: After MR imaging, clinically suspect, morphologically abnormal thoracic discs and at least one, nearby, control level were injected with either nonionic contrast or saline, filmed, and individually described by the patient as concordant versus nonconcordant relative to clinical pain and rated in intensity on a scale of 0-10. Results: There were no serious complications in the series, and the authors resolved whether the injected discs related to pain in each case. They found discs with anular tears, intrinsic degeneration, and/or associated vertebral body endplate infractions to be painful approximately 75% of the time. Clinical concordance was approximately 50%. Control levels were usually painless. Conclusions: They conclude that thoracic discography can be performed safely by experienced individuals as a reliable tertiary diagnostic procedure to determine if degenerated discs on MR studies are related to clinical complaints.
Lumbar discography has been performed in over 1500 patients at St. Luke's Episcopal Hospital, and a report concerning 683 cases has been previously published. The authors review an additional 199 cases, finding that decision making was influenced by discography in 155 cases (78%). A positive discogram was surgically confirmed in 111 patients (56%). In 14(7%) the disc was found to be normal at surgery. One hundred six patients (53%) had positive discograms with negative or equivocal myelogram. In 36 patients with a positive myelogram, the discogram was corroborative, although most patients with positive myelograms did not have discography. Sixty-nine patients (35%) did not have surgery.
Es wird über 1005 Diskographien bei 380 Patienten mit einem Zervikalsyndrom berichtet. Dabei wurden 3 Fälle von Discitis intervertebralis beobachtet, von denen zwei mit Sicherheit als Komplikationen der Untersuchung beurteilt werden müssen. Ätiologie, Klinik, Diagnostik, differentialdiagnostische, therapeutische und prophylaktische Probleme der möglichen Zwischenfälle werden diskutiert. Bei einer Komplikationsrate von 2‰ (Promille) befürworten die Autoren die Kontrastdarstellung zervikaler Bandscheiben als ergänzende röntgendiagnostische Methode bei der Abklärung von Zervikalsyndromen.
Summary
The report deals with 1,005 discographic examinations in 380 patients with a cervical syndrome. Three cases of a discitis were observed, of which two had to be regarded as complications of the examination. The aetiology, clinical features, diagnosis and differential diagnosis are described: therapeutic and prophylactic problems and possible complications are discussed. With a complication rate of 0.2%, the authors recommend contrast demonstration of the cervical disc as a supplementary radiological method for the investigation of the cervical syndrome.
The computed tomography (CT)/discograms and discographic pain provocation reports of 291 clinical patients, 790 discs (mean age, 38; range, 17-79) were collected. The CT/discograms were classified separating anular disruption and degeneration and recording the pain provoked during discography as no pain, dissimilar, similar, or exact reproduction of the patient's clinical pain. Nondegenerated discs usually were found to be painless, and deteriorated discs painful. The proportion of severely degenerated but painless discs increased with age, as did the discs producing dissimilar pain. This may help explain the poor correlation of low-back pain with radiographic degenerative changes reported in previous epidemiologic studies.
(C) Lippincott-Raven Publishers.
To determine the prevalence of disc pain and zygapophysial joint pain occurring simultaneously in the same segment of the neck, 56 patients with post-traumatic neck pain underwent both provocation discography and cervical zygapophysial joint blocks. Both a symptomatic disc and a symptomatic zygapophysial joint were identified in the same segment in 41% of the patients. Discs alone were symptomatic in only 20% of the sample. Zygapophysial joints were symptomatic but discs asymptomatic in 23%. Only 17% of the patients had neither a symptomatic disc nor a symptomatic zygapophysial joint at the segments studied. These observations indicate that the investigation of neck pain by discography alone or by zygapophysial blocks alone constitutes an inadequate approach to neck pain which fails to identify the majority of patients whose symptoms stem from multiple elements in the 3-joint complexes of the neck.
Prospective, match-cohort study of disc degeneration progression over 10 years with and without baseline discography. Objectives. To compare progression of common degenerative findings between lumbar discs injected 10 years earlier with those same disc levels in matched subjects not exposed to discography. Summary of Background Data. Experimental disc puncture in animal and in vivo studies have demonstrated accelerated disc degeneration. Whether intradiscal diagnostic or treatment procedures used in clinical practice causes any damage to the punctured discs over time is currently unknown.
Seventy-five subjects without serious low back pain illness underwent a protocol MRI and an L3/4, L4/5, and L5/S1 discography examination in 1997. A matched group was enrolled at the same time and underwent the same protocol MRI examination. Subjects were followed for 10 years. At 7 to 10 years after baseline assessment, eligible discography and controlled subjects underwent another protocol MRI examination. MRI graders, blind to group designation, scored both groups for qualitative findings (Pfirrmann grade, herniations, endplate changes, and high intensity zone). Loss of disc height and loss of disc signal were measured by quantitative methods.
Well matched cohorts, including 50 discography subjects and 52 control subjects, were contacted and met eligibility criteria for follow-up evaluation. In all graded or measured parameters, discs that had been exposed to puncture and injection had greater progression of degenerative findings compared to control (noninjected) discs: progression of disc degeneration, 54 discs (35%) in the discography group compared to 21 (14%) in the control group (P = 0.03); 55 new disc herniations in the discography group compared to 22 in the control group (P = 0.0003). New disc herniations were disproportionately found on the side of the anular puncture (P = 0.0006). The quantitative measures of disc height and disc signal also showed significantly greater loss of disc height (P = 0.05) and signal intensity (P = 0.001) in the discography disc compared to the control disc.
Modern discography techniques using small gauge needle and limited pressurization resulted in accelerated disc degeneration, disc herniation, loss of disc height and signal and the development of reactive endplate changes compared to match-controls. Careful consideration of risk and benefit should be used in recommending procedures involving disc injection.
Lumbar discography has been performed in over 1500 patients at St. Luke's Episcopal Hospital, and a report concerning 683 cases has been previously published. The authors review an additional 199 cases, finding that decision making was influenced by discography in 155 cases (78%). A positive discogram was surgically confirmed in 111 patients (56%). In 14(7%) the disc was found to be normal at surgery. One hundred six patients (53%) had positive discograms with negative or equivocal myelogram. In 36 patients with a positive myelogram, the discogram was corroborative, although most patients with positive myelograms did not have discography. Sixty-nine patients (35%) did not have surgery.
Thirty-nine patients with spinal epidural abscess were evaluated at the Massachusetts General Hospital between 1947 and 1974. Twenty had acute symptoms, and purulent epidural collections were present; 19 had prolonged courses, and epidural granulation tissue was observed at operation. Staphylococcus aureus was the most common etiologic agent (57 per cent), followed by streptococci (18 per cent) and gram-negative bacilli (13 per cent). The source of infection was osteomyelitis in 38 per cent of cases and bacteremia in 26 per cent. In 16 per cent epidural abscess was due to postoperative infection. The progression from spinal ache to root pain to weakness followed by paralysis continues to be characteristic of spinal epidural abscess. Although the disease is uncommon, the complications are so serious that prompt diagnosis and treatment are of paramount importance. The combination of back pain with fewer and local tenderness is an indication for cerebrospinal-fluid examination and, depending on the results, immediate performance of myelography.
We herein report the results of a prospective study to define the role of diskography in the diagnosis of low back pain in an emerging era of magnetic resonance imaging (MRI). The study involved 32 patients (78 disks) with a clinical diagnosis of lumbar disk herniation; all were studied by computed tomography-diskography (CT-D), and 25 (51 disks) were also examined using MRI. The disks were graded on these studies according to a staging scheme modified from Modic. Ten of the patients (13 disks) having both CT-D and MRI underwent exploratory surgery, and the staging at surgery served as the standard against which the evaluative studies were judged. Surgical staging was compatible with the CT-D and MRI results in five disks, while in another five disks it was compatible only with the CT-D results. In the remaining three disks, both CT-D and MRI misidentified the stages. In six disks, CT-D more accurately defined the stage of disease than did MRI, whereas MRI was more precise than CT-D in only one disk. While having documented the value of CT-D as a source of information, particularly when surgery is contemplated, and as an effective means of staging disk herniation, we recommend MRI as the ideal screening test for lumbar radiculopathy and low back pain, reserving diskography for problematic cases.
Twenty-three perioperative tissue samples from lumbar disc operations on 11 patients were studied immunohistochemically using the sensitive avidin-biotin-peroxidase complex (ABC) method and specific heterologous antisera for the presence of neurofilament-positive neural elements containing nociceptive neuropeptides substance P (SP) and/or calcitonin gene-related peptide (CGRP). Histologically, neural elements were especially abundant in the posterior longitudinal ligament, there being also a few demonstrable nerves in the peripheral anulus fibrosus. These nerves often showed a co-localization of cytoskeletal neurofilaments together with SP and/or CGRP immunoreactivity. It is suggested that pressure and chemical irritation of nociceptive nerves dependent on degenerated discs excite sensory neural elements, especially in the posterior longitudinal ligament and possibly also in the peripheral parts of the anulus fibrosus, while the disc itself, at least if not penetrated by vascular granular tissue, is painless and neuroanatomically lacks a structural basis for pain perception.
The origin, distribution, and termination pattern of nerves supplying the vertebral column and its associated structures have been studied in the human fetus by means of an acetylcholinesterase whole-mount method. The vertebral column is surrounded by ventral and dorsal nerve plexuses which are interconnected. The ventral nerve plexus consists of the nerve plexus associated with the anterior longitudinal ligament. This longitudinally oriented nerve plexus has a bilateral supply from many small branches of the sympathetic trunk, rami communicantes, and perivascular nerve plexuses of segmental arteries. In the thoracic region, the ventral nerve plexus also is connected to the nerve plexuses of costovertebral joints. The dorsal nerve plexus is made up of the nerve plexus associated with the posterior longitudinal ligament. This nerve plexus is more irregular and receives contributions only from the sinu-vertebral nerves. The sinu-vertebral nerves originate from the rami communicantes and, in the cervical region, also from the nerve plexus of the vertebral artery. Thick and thin sinu-vertebral nerves are found. Most frequently three types of thick sinu-vertebral nerves are observed, i.e., ascending, descending, or dichotomizing ones. Finally, the distribution of the branches of the ventral and dorsal nerve plexuses and of the sinu-vertebral nerves is described.
Substance P, a physiologically potent neuropeptide is known to participate in the sensory, and especially nociceptive, transmission of neural impulses. On histologic grounds, the nerve terminals of the sinuvertebral nerve formerly have been suggested to be sensory in character and to mediate the low-back pain syndrome. Samples of paramedullary ligamentous structures were collected on disc operations. A positive immunoreaction as an indicator of substance P was confirmed in some nerve terminals of the posterior longitudinal ligament. Neither the yellow ligament nor the intervertebral disc showed such nociceptive-type nerves.
Lumbar discography is a commonly employed diagnostic tool, but important questions about it remain unresolved. Why is an abnormal discogram painful in one patient and not in another? This study was performed to investigate the changes in Substance P (SP) and Vasoactive-Intestinal Peptide (VIP), found in the dorsal root ganglion, following discography in normal and abnormal canine lumber intervertebral discs. The data from this study suggest that dorsal root ganglion SP and VIP are indirectly affected by manipulations of the intervertebral disc. It may be that various neurochemical changes within the intervertebral disc are expressed by sensitized (injured) annular nociceptors, and in part modulated by the dorsal root ganglion. Therefore, the concomitant pain sometimes associated with an abnormal discogram image may in part be related to the chemical environment within the intervertebral disc and the sensitized state of its annular nociceptors.
The role of antibiotics in the treatment of iatrogenic discitis remains controversial. This study was carried out to assess the ability of cephazolin (a first-generation cephalosporin) to penetrate the intervertebral disc and to establish the role of intravenous antibiotics in the prevention and treatment of iatrogenic discitis. Six sheep had 1 g of intravenous antibiotic administered between 30 minutes and 120 minutes before being killed. Two adjacent lumbar intervertebral discs were harvested and assayed for antibiotic concentration. Cephazolin could only be detected in the animals killed at 30 minutes. Intravenous cephazolin was administered 30 minutes before bacterial inoculation in 46 discs of nine sheep. In five animals, the bacterial suspension contained radiographic contrast and, in four sheep, reconstituted chymopapain. No evidence of discitis was found at any level at death. Eight sheep were treated with intravenous cephazolin commencing 1, 2, or 3 weeks after bacterial intradiscal inoculation and for periods of up to 21 days. All discs developed discitis, and the lesions appeared to be similar, irrespective of time between inoculation and the commencement, duration, and dosage of antibiotic therapy. Our study supports the use of a suitable broad-spectrum antibiotic during any surgical procedure that invades the intervertebral disc. Antibiotics, however, are unable to arrest the progression of discitis once it is established
A new classification method for CT/discography was developed. The Dallas discogram description (DDD) related five separate categories of information. Degeneration and annular disruption were regarded as separate phenomena. Additionally, provoked pain response, contrast volume, and miscellaneous information were recorded. Discogram findings of 59 patients with low-back and/or leg pain were graded according to the new method and compared with standard methods using routine anteroposterior and lateral discographic images. Findings from routine discography and CT/discography were graded and correlated with myelographic and plain computerized axial tomography (CAT) scans. This study demonstrated that the contrast-enhanced axial view provided by CT/discography served as a useful projection for demonstrating disc pathology. CT/discography analyzed according to DDD offered a more sensitive discriminator of disc degeneration from annular disruption (disc protrusion/leaking). This evaluation can be recommended as the procedure of choice when revision of spine surgery is considered or when there is an equivocal or negative correlation between clinical information and myelography or CAT scan.
A series of nine patients with post-discography discitis were evaluated to help delineate the clinical course. The most consistent sign was the marked exacerbation of neck or back pain. This then was followed by an elevated sedimentation rate at an average of 20 days, followed by a positive bone scan at an average of 33 days. Of note is that seven patients initially had negative bone scans at an average of 18 days. Five out of nine patients had changes on plain roentgenograms between 14 and 51 days after discography. Magnetic resonance imaging was performed in six patients; two of these patients were scanned twice. Three scans were negative and five were positive (2 patients initially had negative scans that later became positive). The course of lumbar discitis ranged from 8 to 11 weeks, and cervical discitis from 6 to 7 weeks, with the latter usually resulting in spontaneous fusion.
We reported 5 patients with spinal epidural abscess. They were two men and three women. Their ages ranged from 48 to 56 years (mean, 53 years). In three out of 5 cases, the etiology was thought to be infection after lumbar discography, tracheostomy and lumber surgery. In the other two cases the etiology could not be determined. The abscess was located at cervical, thoracic and lumbar levels in 2, 1 and 2 cases, respectively. The interval between initial symptoms and operation was from 1 to 3 months. Purulent epidural collection was found in four cases at operation. Irrigation and drainage were sufficiently performed postoperatively in 4 cases. Antibiotic therapy had been continued for at least 8 weeks in every case. As demonstrated in the case 2, CT scan was very useful in determining the extension of the abscess and degree of the cord compression by the abscess. Also in the case 2, the epidural abscess extending from cervical canal to extracanalicular space was completely drained by applying draining tubes without laminectomy. The present results indicate that emergency laminectomy is not always necessary for the treatment of epidural abscess, especially in subacute or chronic cases.
The CT/discographic findings from 225 discs in 91 low-back pain patients were compared to the pain provocation during the injection of contrast into the disc. The radiographic appearance of disc deterioration demonstrating disc degeneration and annular disruption of each disc was classified separately using a fourpoint scale: normal, slight, moderate, or severe. Pain reaction to the discogram at each level was recorded as follows: no pain, dissimilar pain, similar pain, or exact reproduction of the patient's clinical pain. This more precise analysis demonstrated a significant relationship between pain and deterioration of discs. The CT/discogram presents an axial view of the disc that allows a subgrouping of disc deterioration that can discriminate between peripheral deterioration (degeneration) and internal deterioration (disruption). The disruption supposedly occurs earlier and is more likely to be the source of exact pain reproduction.
One hundred and thirty-nine discs from cadaveric lumbar spines were injected with a mixture of radio-opaque fluid and dye. Discograms were taken and the discs were then sectioned in the sagittal plane. Examination of the sections revealed that injected fluid did not at first mix with the disc matrix but pushed it aside to form pools of injected fluid. The location of these pools, and hence the appearance of a discogram, depended on the stage of degeneration of the disc. It is concluded that useful clinical information can be obtained from discograms.
Fallbeschreibung einer Discitis intervertebralis cervicalis als Komplikation im Anschluß an eine zervikale Diskographie. Dabei handelt es sich um dieselben Vorgänge wie bei der bekannten postoperativen Discitis intervertebralis lumbalis. Ätiologisch ist eine bakterielle oder aseptische Entzündung zu diskutieren, dem Kontrastmittel kommt als auslösender Faktor keine Bedeutung zu. Röntgenologisch ist der Befund charakteristisch, kann jedoch ohne Kenntnis der Vorgeschichte und fehlendem Wissen über Komplikationen nach Diskographien als spezifische Discitis verkannt werden. Die Prognose ist unter einer entsprechenden Therapie mit Ausheilung als günstig anzusehen.
Summary
A case as described of an infected cervical intervertebral disk, which occurred as a complication of a cervical discography. It involves similar processes to those in the wellknown post-operative lumbar intervertebral discitis. Aetiologically it is regarded as a bacterial or aseptic infection, in which the contrast medium plays no part as a precipitating factor. The x-ray findings are characteristic, but, without any information about the previous history and lacking knowledge of complications after discography, it can be mistaken for a specific discitis. With appropriate treatment the prognosis with complete healing is regarded as favourable.
Résumé
»Disquite« intervertébrale cervicale après discographie
Description d'un cas de »disquite« intervertébrale, complication d'une discographie cervicale. Il s'agit là du même processus déjà connu après discographie lombaire. Etiologiquement la discussion porte sur une origine soit bactérienne soit aseptique, la substance de contraste n'entrant pas en considération. Les constatations radiologiques sont caractéristiques; elles peuvent cependant ne pas être attribuées à leur cause réelle en cas de méconnaissance de l'anamnèse ou de la notion des complications possibles après discographie. Le pronostic est favorable sous réserve d'une thérapeutique adéquate.
Thirty lower lumbar intervertebral discs (IVDs) removed for low-back pain were examined. There is a profuse non-myelinated axonal network and abundant free nerve terminals in the outer (lateral) half of the annulus fibrosus. The inner annulus and the nucleus pulposus did not contain nerve terminals. No significant changes in the nerve networks could be demonstrated in degenerate IVDs: in particular, ingrowth of nerve terminals into foci of granulomatous tissue was not seen. Early foci of degeneration are clearly shown by Marshall's silver method for metalophil cells. Mucinous filaments are argyrophilic and can be mistaken for axonal structures in the nucleus pulposus.
42 cases of spinal epidural abscesses were operated on in the years 1957-1980, among approximately 8,000 spinal operations. Staphylococcus aureus was the microorganism most commonly isolated from infected material and the primary source of infection was in most cases cutaneous and/or subcutaneous lesions. Typical clinical history included back pain and fever, with progressive nerve root and spinal cord involvement. The cases were divided into three groups according to the operative findings: (a) acute abscesses; (b) chronic abscesses, and (c) mixed or subacute abscesses. These three groups differed as to duration of illness, incidence of meningeal signs, white blood cell concentration and lumbar puncture results. Plain X-rays were positive in 20% of cases. Myelography, whose indications were maximally restricted, gave in some instances inaccurate results. Treatment consisted of extensive laminectomy of all the affected spinal segments, and drainage of infected material. Local and systemic appropriate antibiotic therapy was also given. An average of 16 daily sessions of barotherapy, consisting of 1.7-2.0 atm given in 40-60 min, were administered in the last 9 cases. When compared with the patients to which barotherapy was not given, these cases showed a lower rate of permanent disability (11 vs. 21%), even if they were managed under less favorable clinical and neurological conditions. These results seem to support a favorable role of hyperbaric treatment in the management of spinal epidural abscesses. Early diagnosis and appropriate management remain essential in order to have satisfactory treatment results.
Five hundred patients with negative or inconclusive pantopaque myelograms were investigated by lumbar discography. Discography remains the ideal complementary examination to demonstrate normal or diseased disc morphology and its findings were confirmed during surgery in 97.8% of explored discs. Discography is also a valuable clinical test since the injection may reproduce the patient's symptoms. Its observations were determinant in the surgeon's decision to explore a disc or not: 97.3% of patients submitted to laminectomy had an abnormal discogram and 73% of these patients experienced reproduction of clinical symptoms during the procedure. Myelography is superior to discography to demonstrate sequestered fragments, pachymeningitis and spinal stenosis, but was nevertheless not helpful in 56% of the patients in whom these diagnoses were made in the operating room.
The lumbar intervertebral discs are supplied by a variety of nerves. The posterior aspects of the discs and the posterior longitudinal ligament are innervated by the sinuvertebral nerves. The posterolateral aspects of the discs receive branches from adjacent ventral primary rami and from the grey rami communicantes near their junction with the ventral primary rami. The lateral aspects of the discs receive other branches from the rami communicantes. Some rami communicantes cross intervertebral discs and are embedded in the connective tissue of the disc deep to the origin of psoas. Such paradiscal rami are likely to be another source of innervation to the discs. The anterior longitudinal ligament is innervated by recurrent branches of rami communicantes.
To evaluate the safety and reliability of discography used to investigate thoracic disc degeneration observed on magnetic resonance (MR) imaging studies in patients with clinical pain, we analyzed retrospectively the results of thoracic discograms performed on 100 outpatients.
After MR imaging, clinically suspect, morphologically abnormal thoracic discs and at least one, nearby, control level were injected with either nonionic contrast or saline, filmed, and individually described by the patient as concordant versus nonconcordant relative to clinical pain and rated in intensity on a scale of 0-10.
There were no serious complications in the series, and the authors resolved whether the injected discs related to pain in each case. They found discs with anular tears, intrinsic degeneration, and/or associated vertebral body endplate infractions to be painful approximately 75% of the time. Clinical concordance was approximately 50%. Control levels were usually painless.
They conclude that thoracic discography can be performed safely by experienced individuals as a reliable tertiary diagnostic procedure to determine if degenerated discs on MR studies are related to clinical complaints.
This re-analysis was based on 833 computed tomography/discograms collected from 306 candidates for back surgery.
The goal was to test the hypothesis that outer anular ruptures are the main determinant of the pain of discography.
Previous analyses indicated univariate associations of pain with disc degeneration and anular ruptures.
If present, pain was classified as "exact", "similar", or "dissimilar" reproduction of the previously experienced pain. For each disc, ruptures and degeneration were separately evaluated by a four-point scale. Multiple logistic regression with random effects was used in the analysis.
Outer anular ruptures were the only predictor of the responses "similar" and "exact". General disc degeneration was the only predictor of the response "dissimilar". There was no effect modification due to gender, age, and spinal level.
During discography, the outer anulus appears to be the origin of pain reproduction.
The relation between abnormalities in the lumbar spine and low back pain is controversial. We examined the prevalence of abnormal findings on magnetic resonance imaging (MRI) scans of the lumbar spine in people without back pain.
We performed MRI examinations on 98 asymptomatic people. The scans were read independently by two neuroradiologists who did not know the clinical status of the subjects. To reduce the possibility of bias in interpreting the studies, abnormal MRI scans from 27 people with back pain were mixed randomly with the scans from the asymptomatic people. We used the following standardized terms to classify the five intervertebral disks in the lumbosacral spine: normal, bulge (circumferential symmetric extension of the disk beyond the interspace), protrusion (focal or asymmetric extension of the disk beyond the interspace), and extrusion (more extreme extension of the disk beyond the interspace). Nonintervertebral disk abnormalities, such as facet arthropathy, were also documented.
Thirty-six percent of the 98 asymptomatic subjects had normal disks at all levels. With the results of the two readings averaged, 52 percent of the subjects had a bulge at at least one level, 27 percent had a protrusion, and 1 percent had an extrusion. Thirty-eight percent had an abnormality of more than one intervertebral disk. The prevalence of bulges, but not of protrusions, increased with age. The most common nonintervertebral disk abnormalities were Schmorl's nodes (herniation of the disk into the vertebral-body end plate), found in 19 percent of the subjects; annular defects (disruption of the outer fibrous ring of the disk), in 14 percent; and facet arthropathy (degenerative disease of the posterior articular processes of the vertebrae), in 8 percent. The findings were similar in men and women.
On MRI examination of the lumbar spine, many people without back pain have disk bulges or protrusions but not extrusions. Given the high prevalence of these findings and of back pain, the discovery by MRI of bulges or protrusions in people with low back pain may frequently be coincidental.
To determine the incidence and magnitude of complications of cervical discography as well as to assess the clinical results of operative treatment based on discographic findings, a series of 31 patients who underwent cervical discography was reviewed. Twenty-six patients (84%) experienced provocative concordant symptomatology and were considered positive. The overall complication rate was 13% (4/31), including the development of an acute epidural abscess that led to myelopathy and eventual quadriplegia. Of the twenty-two patients who underwent anterior cervical discectomy and fusion on the basis of cervical discography, one patient had an excellent result (5%), nine patients had good results (41%), and six patients each had fair and poor results (54%). Diagnostic cervical discography was found not to provide the degree of clinical predictive value necessary to substantiate its potential risks and complications.
A comprehensive review of the literature dealing with lumbar discography was conducted.
The purpose of the review was to generate a position statement addressing criticisms of lumbar discography, identify indications for its use, and describe a technique for its performance.
Lumbar discography remains a controversial diagnostic procedure. There are concerns about its safety and clinical value, although others support its use in specific applications.
Articles dealing with lumbar discography were reviewed and summarized in this report.
Most of the recent literature supports the use of discography in select patients. Although not to be taken lightly, many of the serious and high complication rates were reported before 1970 and have decreased since because of improvement in injection technique, imaging, and contrast materials.
Most of the current literature supports the use of discography in select situations. Particular applications include patients with persistent pain in whom disc abnormality is suspect, but noninvasive tests have not provided sufficient diagnostic information or the images need to be correlated with clinical symptoms. Another application is assessment of discs in patients in whom fusion is being considered. Discography's role in such cases is to determine if discs within the proposed fusion segment are symptomatic and if the adjacent discs are normal. Discography appears to be helpful in patients who have previously undergone surgery but continue to experience significant pain. In such cases, it can be used to differentiate between postoperative scar and recurrent disc herniation and to investigate the condition of a disc within, or adjacent to, a fused spinal segment to better delineate the source of symptoms. When minimally invasive discectomy is being considered, discography can be used to confirm a contained disc herniation, which is generally an indication for such surgical procedures. Lumbar discography should be performed by those well experienced with the procedure and in sterile conditions with a double needle technique and fluoroscopic imaging for proper needle placement. Information assessed and recorded should include the volume of contrast injected, pain response with particular emphasis on its location and similarity to clinical symptoms, and the pattern of dye distribution. Frequently, discography is followed by axial computed tomography scanning to obtain more information about the condition of the disc.
To examine the management of traumatic pneumothorax in a department where some of these injuries do not receive chest drains.
A retrospective study of the management of traumatic pneumothorax was performed on a unit where historically many of these injuries have been treated conservatively.
54 pneumothoraces in a three year period were identified. Of these, 29 injuries (54.7%) were initially managed without drainage. Two patients subsequently had chest drains inserted as a result of asymptomatic radiological enlargement of the pneumothorax while inpatients. No patients deteriorated clinically during conservative treatment.
Chest drain insertion for small or moderate sized traumatic pneumothoraces, in the absence of other significant injuries or the need for intermittent positive pressure ventilation (IPPV), may be unnecessary.
Asymptomatic subjects and chronic head/neck pain sufferers were studied with high-field magnetic resonance imaging and cervical discography to compare and correlate both tests.
To assess the accuracy of magnetic resonance imaging and discography in identifying the source(s) of cervical discogenic pain.
Previous retrospective studies describe a generally poor correlation between magnetic resonance imaging and provocative discography in the cervical spine.
Ten lifelong asymptomatic subjects and 10 nonlitigious chronic neck/head pain patients underwent discography at C3-C4 through C6-C7 after magnetic resonance imaging. Disc morphology and provoked responses were recorded at each level studied.
Of 20 normal discs by magnetic resonance from the asymptomatic volunteers, 17 proved to have painless anular tears discographically. The average response per disc (N = 40) for this group was 2.42, compared to 5.2 (N = 40) for the neck pain group. In the pain patients, 11 discs appeared normal at magnetic resonance imaging, whereas 10 of these proved to have anular tears discographically. Two of these 10 proved concordantly painful with intensity ratings of at least 7/10. Discographically normal discs (N = 8) were never painful (both groups), whereas intensely painful discs all exhibited tears of both the inner and outer aspects of the anulus.
Significant cervical disc anular tears often escape magnetic resonance imaging detection, and magnetic resonance imaging cannot reliably identify the source(s) of cervical discogenic pain.
In the healthy back only the outer third of the annulus fibrosus of the intervertebral disc is innervated. Nerve ingrowth deeper into diseased intervertebral disc has been reported, but how common this feature is and whether it is associated with chronic pain are unknown. We examined nerve growth into the intervertebral disc in the pathogenesis of chronic low back pain.
We collected 46 samples of intervertebral discs from 38 patients during spinal fusion for chronic back pain. 30 samples were from pain levels clinically established by discography and 16 samples were from adjacent vertebral levels with no pain. We obtained 34 control samples of intervertebral disc from previously healthy individuals with normal histology within 8 h of recorded death. We used standard immunohistochemical techniques to test for a general nerve marker, a nociceptive neurotransmitter (substance P), and a protein expressed during axonogenesis (growth-associated protein 43 [GAP43]).
We identified nerve fibres in the outer third of the annulus fibrosus in 48 (60%) of the 80 samples of intervertebral discs. Nerves were restricted to the outer or middle third of the annulus fibrosus in the 34 control samples. Among the patients with chronic low back pain, nerves extended into the inner third of the annulus fibrosus and into the nucleus pulposus in 21 (46%) and ten (22%) samples, respectively. Nerves usually accompanied blood vessels, but in 14 of the samples from back-pain patients, isolated nerve fibres were seen in the discal matrix. Both types of nerve fibres expressed substance P, but only non-vessel-associated fibres expressed GAP43. Deep nerve ingrowth into the inner third of the annulus fibrosus, the nucleus pulposus, or both was seen in four (25%) of 16 biopsy samples from non-pain levels and in 17 (57%) samples from pain levels. Of the 16 paired samples from both pain and non-pain levels, five pain-level samples and one non-pain-level sample showed deep nerve ingrowth.
Our finding of isolated nerve fibres that express substance P deep within diseased intervertebral discs and their association with pain suggests an important role for nerve growth into the intervertebral disc in the pathogenesis of chronic low back pain.
The patient who suffered from pain in both lower legs and in whom discography was performed experienced a rare complication after discography. The findings and method of discography is described, as is usefulness of magnetic resonance imaging to image this rare complication.
To establish the possibility of getting a spinal epidural abscess after discography, how to make the diagnosis, and how to treat the complication.
Discitis after discography is a well-known complication, but epidural abscess is rare.
C-reactive protein concentration was measured and was more than 100 mg/L. Infection was suspected, and antibiotic therapy was started immediately. Magnetic resonance imaging was performed, and the diagnosis became clear. A laminotomy was performed.
Symptoms due to epidural abscess disappeared soon after laminotomy.
Some harmful and unpleasant complications are possible after discography. Antibiotic prophylaxis and stiletted needles should be used. Magnetic resonance imaging is the best radiologic procedure to image the complication, and surgery must be performed as soon as possible.
The authors investigated the innervation of discographically confirmed degenerated and "painful" human intervertebral discs.
To determine the type and distribution patterns of nerve fibers present in degenerated human intervertebral discs.
The innervation of intervertebral discs has previously been extensively described in fetal and adult animals as well as humans. However, little is yet known about the innervation of severely degenerated human lumbar discs. The question may be posed whether a disc that has been removed for low back pain possesses an increased innervation compared with normal discs.
The presence of nerve fibers was investigated using acetylcholinesterase enzyme histochemistry, as well as neurofilament and substance P immunocytochemistry. From 10 degenerated and 2 control discs, the anterior segments were excised and their nerve distribution studied by examining sequential sections.
In all specimens, nerve fibers of different diameters were found in the anterior longitudinal ligament and in the outer region of the disc. In 8 of 10 degenerated discs, fibers were also found in the inner parts of the disc. Substance P-immunoreactive nerve fibers were sporadically observed in the anterior longitudinal ligament and the outer zone of the anulus fibrosus.
Findings indicate a more extensive disc innervation in the severely degenerated human lumbar disc compared with normal discs. The nociceptive properties of at least some of these nerves are highly suggested by their substance P immunoreactivity, which provides further evidence for the existence of a morphologic substrate of discogenic pain.
A multicenter, retrospective study of long-term surgical and nonsurgical patient outcomes, after lumbar discography.
To investigate the efficacy and surgical outcome predictive value of categorizing positive discography findings, using a pressure x pain provocation categorization system.
With the use of pressure-controlled manometric discography, improved and more specific diagnostic categorization is possible. The literature suggests that more specific categorization of positive discographic findings may predict surgical and nonsurgical outcomes. Studies have shown that intertransverse fusions may not fully protect the disc from anterior loading. Consequently, in patients who have low-pressure-sensitive discs, surgery that includes interbody fusion should provide a more favorable long-term outcome than intertransverse fusion only.
Long-term outcome was ascertained in 96 patients who had lumbar discography and subsequently underwent interbody fusion alone, combined fusion, intertransverse fusion or no surgery. Patients were retrospectively placed into specific diagnostic categories, according to a four-point scale. Progressively restrictive subgroups, beginning with the entire sample and ending with the most sensitive group (chemically sensitive), were examined for long-term surgical outcome differentiation.
There were no significant differences in long-term surgical outcome across the entire sample. However, significant outcome differences existed across the subgroup of patients with chemically sensitive discs. In this group, patients undergoing interbody/combined fusion had a significantly better outcome than patients who had intertransverse fusion. Nonsurgical patients had the worst outcome overall.
Patients with highly (chemically) sensitive discs appear to achieve significantly better long-term outcomes with interbody/combined fusion than with intertransverse fusion. Patients without disc surgery have the least favorable outcome. Precise prospective categorization of positive discographic diagnoses may predict outcomes from treatment, surgical or otherwise, thereby greatly facilitating therapeutic decision-making.
Experimental disc injections in subjects with no history of low back symptoms.
To determine in an experimental model the reliability of patients' subjective interpretation of pain concordancy during provocative disc injection.
Discography in the evaluation of low back pain relies on a patient's subjective assessment of pain magnitude and quality during disc injection. Reproduction of significant pain on disc injection, which is similar to patients' usual pain, is believed to prove that the disc injected is the source of the patient's low back pain. In the current study, this hypothesis was tested in a controlled setting on patients with known nonspinal pain in a common referral area of discogenic pain.
Patients with no history of low back pain were recruited to participate in a study of discography. Patients scheduled to undergo posterior iliac crest bone graft harvesting for nonthoracolumbar procedures were evaluated with lumbar radiography, magnetic resonance imaging, and psychometric testing. Two to 4 months after bone graft harvesting, patients underwent lumbar discography by strict blinded protocol. Patients were asked to compare the sensations elicited at discography to their usual back/buttock pain since bone graft harvesting. Pain was rated as 0-5 on a pain thermometer and concordancy was rated as none, dissimilar, similar, or exact.
Eight subjects completed the study, and 24 discs were injected. Of the 14 disc injections causing some pain response, 5 were believed to be "different" (nonconcordant) pains (35.7%); 7 were "similar" (50.0%), and 2 were "exact" pain reproductions (14.3%). The presence of anular disruption predicted concordant pain reproduction (P < 0.05). Of 10 discs with anular tears, injection of 5 elicited pain that was similar to or an exact reproduction of pain at the iliac crest bone graft harvest sites. By the usual criteria for positive discography, 4 of the 8 patients (50%) would have been classified as positive. In these patients, the pain on a single disc injection was very painful, and the pain quality was noted to be exact or similar to the usual discomfort. All subjects had a negative control disc.
The findings of this study demonstrate that patients with no history of low back pain who had undergone posterior iliac bone graft harvesting for nonlumbar procedures often experienced a concordant painful sensation on lumbar discography with their usual gluteal area pain. Thus, the ability of a patient to separate spinal from nonspinal sources of pain on discography is questioned, and a response of concordant pain on discography may be less meaningful than often assumed.
Wound infection remains a considerable cause of morbidity and mortality among surgical patients, despite the relative success of prophylactic antibiotics. In modern efforts to control healthcare costs while improving the quality of patient care, we must not overlook the basic principles of wound infections and their appropriate treatment. Predisposing factors for the development of surgical wound infection include the creation of a surgical wound, the presence of bacteria, and a susceptible host. The selection of an appropriate antimicrobial drug depends on the identification of the most likely pathogens associated with a given procedure, as well as the expected antibiotic susceptibility of those pathogens. Ideally, a prophylactic antibiotic should achieve high peak tissue concentration at the site of the wound before the first incision and should be maintained until the time of closure. Currently, the administration of prophylactic antibiotics is indicated for contaminated and clean-contaminated wounds. Despite the proven effectiveness of antibiotic prophylaxis, many researchers would argue that contemporary dosing regimens should be reevaluated. The debates concerning the dosage and timing of ideal prophylactic administration are likely to continue.
Experimental disc injections in subjects with no history of low back symptoms.
To determine in an experimental setting the relative pain response and pain-related behavior in selected subjects without a history of low back pain undergoing lumbar discography. This study aimed to select a study population that more closely represented patients undergoing discography in clinical practice.
Previous work has shown that in young, healthy men with little degenerative disc disease and no history of low back problems, discographic injections usually did not cause significant pain. This group differed from the patients who usually undergo discographic evaluation in clinical practice. Most clinical patients are older, have significant degenerative disc disease, have behavioral changes associated with chronic pain, and often have confounding psychosocial troubles. The authors undertook to study discography in subjects without low back pain but with clinical profiles similar to patients undergoing discography in clinical practice.
Twenty-six individuals, mean age 43 years, with no history of low back pain had lumber discography according to the strict protocol of Walsh et al. Of these, 10 were pain-free; 10 had chronic neck and arm pain, but no low back symptoms; and 6 had primary somatization disorders without low back symptoms.-
Significant positive pain response and pain-related behavior with discography were found in 10% of the pain-free group, in 40% of the chronic cervical pain group, and in 83% of the somatization disorder group completing the injections. Twenty-four subjects had negative control discs. Discs with annular disruption were more likely to be painful on injection, particularly in those individuals with ongoing compensation issues, chronic pain, or abnormal psychological testing.-
If strict criteria are applied, the rate of false-positive discography may be low in subjects with normal psychometric profiles and without chronic pain. Significantly painful injections were very common in subjects with annular disruption and chronic pain or abnormal psychometric testing.
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.