The neuroradiographic diagnosis of lumbar herniated nucleus pulposus: II. A comparison of computed tomography (CT), myelography, CT-myelography, and magnetic resonance imaging

Symptom-imaging correlation in lumbar spine pain

Lumbar spine MRI is associated with a high prevalence of morphological abnormalities in both symptomatic and asymptomatic individuals. A difficult challenge, therefore, is distinguishing the relevant findings causing symptoms from incidental findings. The accurate diagnosis of pain generator is important because misdiagnosis can negatively impact patient management and outcome. Spine physicians use clinical symptoms and signs to interpret lumbar spine MRI and make treatment decisions. Symptom-MRI correlation enables the targeted inspection of images for pain generator. Radiologists can also use clinical information to improve diagnostic confidence and the value of dictated reports. Because high-quality clinical information may be difficult to obtain, radiologists often generate lists of lumbar spine abnormalities that are otherwise difficult to rank as pain generators. Based on the literature review, this article attempts to distinguish the MRI abnormalities that may represent incidental findings from the abnormalities that are more commonly associated with lumbar spine-related symptoms.

Value of imaging examinations in diagnosing lumbar disc herniation: A systematic review and meta-analysis

Purpose

To systematically review the clinical value of three imaging examinations (Magnetic Resonance Imaging, Computed Tomography, and myelography) in the diagnosis of Lumbar Disc Herniation.

Methods

Databases including PubMed, Embase, The Cochrane Library, Web of Science, CBM, CNKI, WanFang Data, and VIP were electronically searched to collect relevant studies on three imaging examinations in the diagnosis of Lumbar Disc Herniation from inception to July 1, 2021. Two reviewers using the Quality Assessment of Diagnostic Accuracy Studies-2 tool independently screened the literature, extracted the data, and assessed the risk of bias of included studies. Then, meta-analysis was performed by using Meta-DiSc 1.4 software and Stata 15.0 software.

Results

A total of 38 studies from 19 articles were included, involving 1,875 patients. The results showed that the pooled Sensitivity, pooled Specificity, pooled Positive Likelihood Ratio, pooled Negative Likelihood Ratio, pooled Diagnostic Odds Ratio, Area Under the Curve of Summary Receiver Operating Characteristic, and Q* were 0.89 (95%CI: 0.87-0.91), 0.83 (95%CI: 0.78-0.87), 4.57 (95%CI: 2.95-7.08), 0.14 (95%CI: 0.09-0.22), 39.80 (95%CI: 18.35-86.32), 0.934, and 0.870, respectively, for Magnetic Resonance Imaging. The pooled Sensitivity, pooled Specificity, pooled Positive Likelihood Ratio, pooled Negative Likelihood Ratio, pooled Diagnostic Odds Ratio, Area Under the Curve of Summary Receiver Operating Characteristic, and Q* were 0.82 (95%CI: 0.79-0.85), 0.78 (95%CI: 0.73-0.82), 3.54 (95%CI: 2.86-4.39), 0.19 (95%CI: 0.12-0.30), 20.47 (95%CI: 10.31-40.65), 0.835, and 0.792, respectively, for Computed Tomography. The pooled Sensitivity, pooled Specificity, pooled Positive Likelihood Ratio, pooled Negative Likelihood Ratio, pooled Diagnostic Odds Ratio, Area Under the Curve of Summary Receiver Operating Characteristic, and Q* were 0.79 (95%CI: 0.75-0.82), 0.75 (95%CI: 0.70-0.80), 2.94 (95%CI: 2.43-3.56), 0.29 (95%CI: 0.21-0.42), 9.59 (95%CI: 7.05-13.04), 0.834, and 0.767 respectively, for myelography.

Conclusion

Three imaging examinations had high diagnostic value. In addition, compared with myelography, Magnetic Resonance Imaging had a higher diagnostic value.

Lumbar Disc Herniation: Comparing Pain Relief After Medical and Surgical Intervention

Introduction

The most common degenerative abnormality of the lumbar spine is lumbar disc herniation. There are two options of treatment, i.e. medical and surgical. Due to the scarcity of literature, it is a need of the hour to further study and evaluate the benefits and efficacy of early surgical intervention versus conservative management of lumbar disc herniation.

Methods

This study was conducted in the neurology unit of a tertiary care hospital in Pakistan from April 2019 to March 2021. After obtaining informed consent, 250 patients with a lumbar disc herniation, between the ages of 20 and 50 years, were enrolled in the study. Out of them, 81 participants chose surgical intervention while 169 participants chose medical intervention. Before the intervention, the patient’s pain score was noted on the visual analog scale (VAS). The pain was assessed again 14 days after surgical intervention and 90 days after the start of medical intervention.

Results

There was a significant difference in the pain score in the post-intervention period in both the medical (7.01 ± 1.05 vs. 3.54 ± 0.51; p-value: <0.0001) and surgical intervention groups (6.92 ± 0.95 vs. 2.41 ± 0.42; p-value: <0.0001). Post-intervention, the VAS pain score was significantly lower in the surgical group as compared to the medical group (2.41 ± 0.42 vs. 3.54 ± 0.51; p-value: <0.0001).

Conclusion

In this study, there was a significant decline in pain in both groups; however, the reduction was more significant in the surgical group. Patients should be given both options for management of lumbar disc herniation and should be explained the pros and cons of each treatment option.

Axial Low Back Pain in Elite Athletes

Back pain in sport is a common complaint and seen by athletes, trainers, and treating physicians. Although there are a multitude of pain generators, mechanical sources are most common. Certain sports can lead to increased mechanical and axial loading, such as competitive weightlifting and football. Common mechanical causes of pain include disk herniation and spondylolysis. Patients typically respond to early identification and conservative treatment. In others, surgical intervention is required to provide stability and prevent long-term sequelae.

Myelography and the 20th Century Localization of Spinal Cord Lesions

In this article, we commemorate the centenary of myelography, a neuroradiological procedure that, despite certain disadvantages, significantly contributed to the diagnosis and localization of spinal cord lesions during the 20th century. From the start, the use of myelography was characterized by different views regarding the potential dangers associated with the prolonged exposure of a "foreign body" to the central nervous system. Such differences in attitude resulted in divergent myelography practices; its precise indications, technical performance, and adopted contrast material remaining subject to variability until the procedure were eventually replaced by MRI at the close of the 20th century.

Evaluation and management of paediatric and adolescent back pain: Epidemiology, presentation, investigation, and clinical management: A narrative review

This narrative review will summarise a clinical approach to the investigation of back pain in children and adolescent patients, including a discussion of the epidemiology, presentation, investigation and clinical management of back pain in children and adolescents. This will assist the prompt and accurate diagnosis of spinal disorders that require significant medical intervention. Existing evidence suggests a relatively high incidence of non-specific back pain among young people; 27-48% of presentations of back pain in children and adolescents are attributed to non-specific back pain. Low back pain among schoolchildren is often linked to psychosocial factors and only occasionally requires medical attention, as pain is benign and self-limiting. Nonetheless, those young patients who seek medical assistance exhibit a higher incidence of organic conditions underlying the major symptom of spinal pain. A cautious and comprehensive strategy - including a detailed history, examination, radiographic imaging and diagnostic laboratory studies - should be employed, which must be accurate, reliable, consistent and reproducible in identifying spinal pathologies. A specific diagnosis can be reached in 52-73% of the cases. For cases in which a specific diagnosis cannot be made, re-evaluation after a period of observation is recommended. At this later stage, minor symptoms unrelated to underlying pathology will resolve spontaneously, whereas serious pathologies will advance and become easily identified.

The normal appearance of CT myelograms

PURPOSE

CT myelography has been used since 1976 to diagnose neural compression in the axial skeleton. With the advent of routine MRI, its role in accurately diagnosing neural compression has been questioned as its normal appearances are not defined in the study. In this study, we examine a series of CT myelograms to define the normal appearances of the neural elements of the spine.

METHODS

The CT myelograms of patients with unilateral symptoms were examined by four independent physicians. The lateral extent of contrast was examined and recorded. Concordance between the recorded extents was assessed using kappa scores.

RESULTS

Thirty-six scans were reviewed. Kappa analysis shows that there is a fair agreement in the lateral extent of contrast at L1, L3 and L4. At L2 and L5, agreement is slight.

CONCLUSION

The interpretation of CT myelography shows significant interobserver variability. As a result, the usefulness of this diagnostic tool can be questioned, and if misinterpreted, it could lead to questionable diagnoses and inadvertently erroneous management if used in isolation. These slides can be retrieved under Electronic Supplementary Material.

Diagnostic accuracy of diagnostic imaging for lumbar disc herniation in adults with low back pain or sciatica is unknown; a systematic review

Main text

We aim to summarize the available evidence on the diagnostic accuracy of imaging (index test) compared to surgery (reference test) for identifying lumbar disc herniation (LDH) in adult patients.For this systematic review we searched MEDLINE, EMBASE and CINAHL (June 2017) for studies that assessed the diagnostic accuracy of imaging for LDH in adult patients with low back pain and surgery as the reference standard. Two review authors independently selected studies, extracted data and assessed risk of bias. We calculated summary estimates of sensitivity and specificity using bivariate analysis, generated linked ROC plots in case of direct comparison of diagnostic imaging tests and assessed the quality of evidence using the GRADE-approach.We found 14 studies, all but one done before 1995, including 940 patients. Nine studies investigated Computed Tomography (CT), eight myelography and six Magnetic Resonance Imaging (MRI). The prior probability of LDH varied from 48.6 to 98.7%. The summary estimates for MRI and myelography were comparable with CT (sensitivity: 81.3% (95%CI 72.3-87.7%) and specificity: 77.1% (95%CI 61.9-87.5%)). The quality of evidence was moderate to very low.

Conclusions

The diagnostic accuracy of CT, myelography and MRI of today is unknown, as we found no studies evaluating today's more advanced imaging techniques. Concerning the older techniques we found moderate diagnostic accuracy for all CT, myelography and MRI, indicating a large proportion of false positives and negatives.

Diagnosis of Compressed Nerve Root in Lumbar Disc Herniation Patients by Surface Electromyography

OBJECTIVE

To establish a logistic regression model using surface electromyography (SEMG) parameters for diagnosing the compressed nerve root at L₅ or S₁ level in patients with lumbar disc herniation (LDH).

METHODS

This study recruited 24 patients with L₅ nerve root compression and 23 patients with S₁ nerve root compression caused by LDH from May 2014 to May 2016. SEMG signals from the bilateral tibialis anterior and lateral gastrocnemius were measured. The root mean square (RMS), the RMS peak time, the mean power frequency (MPF), and the median frequency (MF) were analyzed. The accuracy, sensitivity, and specificity values were calculated separately. The areas under the curve (AUC) of the receiver-operating characteristic (ROC) curve and the kappa value were used to evaluate the accuracy of the SEMG diagnostic model.

RESULTS

The accuracy of the SEMG model ranged from 85.71% to 100%, with an average of 93.57%. The sensitivity, specificity, AUC, and kappa value of the logistic regression model were 0.98 ± 0.05, 0.92 ± 0.09, 0.95 ± 0.04 (P = 0.006), and 0.87 ± 0.11, respectively (P = 0.001). The final diagnostic model was: P=1-11+ey; y = 10.76 - (5.95 × TA_RMS Ratio) - (0.38 × TA_RMS Peak Time Ratio) - (5.44 × 44 × LG_RMS Peak Time Ratio). L₅ nerve root compression is diagnosed when P < 0.5 and S₁ nerve root compression when P ≥ 0.5.

CONCLUSIONS

The logistic regression model developed in this study showed high diagnostic accuracy in detecting the compressed nerve root (L₅ and S₁ ) in these patients with LDH.

The Diagnostic Accuracy of Gluteal Trigger Points to Differentiate Radicular From Nonradicular Low Back Pain

OBJECTIVES

Low back pain (LBP) is highly prevalent and costly to the society. Previous studies have shown an association between radicular LBP and trigger points (TrPs) in the superior-lateral quadrant of the gluteal area (GTrP). The objective of current study was to evaluate the diagnostic value of GTrP to predict nerve root involvement among patients with LBP.

MATERIALS AND METHODS

In a prospective, diagnostic accuracy study 325 consecutive patients with LBP were recruited. At first step, patients were evaluated for the presence or absence of the GTrP. A different investigator, blinded to the GTrP findings, then performed history taking and physical examination. Subsequently, all patients underwent a lumbar spine magnetic resonance imaging and, when indicated, electrodiagnostic tests. On the basis of the clinical and ancillary tests findings, a multidisciplinary panel of experts (the "reference standard"), blinded to the GTrP evaluation, allocated patients to radicular versus nonradicular LBP groups. The agreement between the GTrP findings, as a diagnostic test and the reference standard allocation was evaluated in a 2 by 2 contingency table.

RESULTS

The specificity of the GTrP test was 91.4% and its sensitivity was 74.1%. The area under the receiver operating characteristic curve was 0.827 (0.781 to 0.874). Positive likelihood ratio was 8.62 and negative likelihood ratio was 0.28. Positive and negative predictive values were 91.9% and 72.7%, respectively.

DISCUSSION

As a clinical finding, TrPs in superior-lateral quadrant of gluteal area are highly specific indicators for radicular LBP. Incorporating these TrPs evaluation in routine physical examination of patients with LBP could decrease the need for more costly, time-consuming, and invasive diagnostic tests.

Comparison of Root Images between Post-Myelographic Computed Tomography and Magnetic Resonance Imaging in Patients with Lumbar Radiculopathy

Objective

To evaluate the diagnostic value of computed tomography-myelography (CTM) compared to that of magnetic resonance imaging (MRI) in patients with lumbar radiculopathy.

Methods

The study included 91 patients presenting with radicular leg pain caused by herniated nucleus pulposus or lateral recess stenosis in the lumbar spine. The degree of nerve root compression on MRI and CTM was classified into four grades. The results of each imaging modality as assessed by two different observers were compared. Visual analog scale score for pain and electromyography result were the clinical parameters used to evaluate the relationships between clinical features and nerve root compression grades on both MRI and CTM. These relationships were quantified by calculating the receiver-operating characteristic curves, and the degree of relationship was compared between MRI and CTM.

Results

McNemar’s test revealed that the two diagnostic modalities did not show diagnostic concurrence (p<0.0001). Electromyography results did not correlate with grades on either MRI or CTM. The visual analog pain scale score results were correlated better with changes of the grades on CTM than those on MRI (p=0.0007).

Conclusion

The present study demonstrates that CTM could better define the pathology of degenerative lumbar spine diseases with radiculopathy than MRI. CTM can be considered as a useful confirmative diagnostic tool when the exact cause of radicular pain in a patient with lumbar radiculopathy cannot be identified by using MRI. However, the invasiveness and potential complications of CTM are still considered to be pending questions to settle.

Exposure of the examiner to radiation during myelography versus radiculography and root block: A comparative study

BACKGROUND

Exposure to radiation over many years prompts concerns regarding potential health-related effects, particularly the incidence of cataracts and the development of cancer. The purpose of this study was to examine and compare the exposure of the examiner to radiation during myelography versus radiculography and root block.

METHODS

A total of 114 examinations were performed in our institute in the 6 months. Sixty-two examinations were performed during myelography in the first 3 months (MG group), while 52 were performed during radiculography and root block in the last 3 months (RB group). The examiner wore a torso protector, a neck protector, radiation protection gloves, and radiation protection glasses. Optically stimulated luminescence (OSL) dosimeter badges were placed on both the inside and the outside of each protector. The dosimeters were exchanged every month. Radiation doses (mSv) were measured as the integrated radiation quantity every month from the OSL dosimeters. The effective dose and the equivalent doses of hand, skin, and eyes were investigated.

RESULTS

The mean equivalent doses were significantly lower outside the neck, torso, eye protectors, and inside the torso protector in the RB group than in the MG group. Conversely, the mean equivalent dose was significantly lower outside the hand protector in the MG group than in the RB group. The use of a neck protector significantly decreased the effective dose compared to the non-use of a neck protector in the RB group.

CONCLUSIONS

The present study showed the standard radiation exposure to the examiner during myelography, radiculography, and root block. Receiving full protection including a neck protector and protection gloves is an easy and reliable means to reduce radiation exposure.

Low back pain, radiculopathy

Low back pain is a pervasive problem in the adult population. Most patients with low back pain will not require imaging as spontaneous recovery within 12 weeks is the rule. However, a small percentage of patients with low back pain will have serious underlying pathology requiring more intensive investigation. This chapter delineates the signs and symptoms related to potential serious underlying causes and discusses appropriate imaging modalities that should be utilized in patients with low back pain.

Combination of Magnetic Resonance Imaging and Electrophysiological Studies in Lumbar Disc Herniation

Objective We aimed to study the clinical value of magnetic resonance imaging (MRI) and electrophysiological studies in the diagnosis of lumbar disc herniation and in the evaluation of the therapeutic effect of discectomy. Methods In this study, 265 patients with LDH were treated with discectomy after assessment by the Japanese Orthopedic Association (JOA) score, MRI, and electrophysiological studies. All the patients were followed-up for 6 years. The effects of the operation were assessed by determining the angle between the nerve root canal and disc protrusion (AN value), the stenotic ratio of the spinal canal, the width of the lateral recess, motor conduction velocity (MCV), sensory conduction velocity (SCV), and nerve action potential (NAP) before and after operation. Results The AN value, stenotic ratio of the spinal canal, and the width of the lateral recess of protruding intervertebral discs showed significant differences from these values for the patients' unaffected intervertebral discs (P < 0.05). The MCV, SCV, and NAP of the affected limb showed significant differences from these values for the patients' unaffected limbs (P < 0.05). In all the patients the values for these indicators showed significant differences before and after operation (P < 0.05). Conclusion MRI and electrophysiological studies can be used in the diagnosis of lumbar disc herniation, and in the evaluation of the effect of surgery.

Lumbar herniated disc: spontaneous regression

BACKGROUND

Low back pain is a frequent condition that results in substantial disability and causes admission of patients to neurosurgery clinics. To evaluate and present the therapeutic outcomes in lumbar disc hernia (LDH) patients treated by means of a conservative approach, consisting of bed rest and medical therapy.

METHODS

This retrospective cohort was carried out in the neurosurgery departments of hospitals in Kahramanmaraş city and 23 patients diagnosed with LDH at the levels of L3-L4, L4-L5 or L5-S1 were enrolled.

RESULTS

The average age was 38.4 ± 8.0 and the chief complaint was low back pain and sciatica radiating to one or both lower extremities. Conservative treatment was administered. Neurological examination findings, durations of treatment and intervals until symptomatic recovery were recorded. Laségue tests and neurosensory examination revealed that mild neurological deficits existed in 16 of our patients. Previously, 5 patients had received physiotherapy and 7 patients had been on medical treatment. The number of patients with LDH at the level of L3-L4, L4-L5, and L5-S1 were 1, 13, and 9, respectively. All patients reported that they had benefit from medical treatment and bed rest, and radiologic improvement was observed simultaneously on MRI scans. The average duration until symptomatic recovery and/or regression of LDH symptoms was 13.6 ± 5.4 months (range: 5-22).

CONCLUSIONS

It should be kept in mind that lumbar disc hernias could regress with medical treatment and rest without surgery, and there should be an awareness that these patients could recover radiologically. This condition must be taken into account during decision making for surgical intervention in LDH patients devoid of indications for emergent surgery.

Diagnostic accuracy of contemporary multidetector computed tomography (MDCT) for the detection of lumbar disc herniation

OBJECTIVES

To evaluate the diagnostic accuracy of multidetector CT (MDCT) for detection of lumbar disc herniation with MRI as standard of reference.

METHODS

Patients with low back pain underwent indicated MDCT (128-row MDCT, helical pitch), 60 patients with iterative reconstruction (IR) and 67 patients with filtered back projection (FBP). Lumbar spine MRI (1.5 T) was performed within 1 month. Signal-to-noise ratios (SNR) of cerebrospinal fluid (CSF), annulus fibrosus (AF) and the spinal cord (SC) were determined for all modalities. Two readers independently rated image quality (IQ), diagnostic confidence and accuracy in the diagnosis of lumbar disc herniation using MRI as standard of reference. Inter-reader correlation was assessed with weighted κ.

RESULTS

Sensitivity, specificity, precision and accuracy of MDCT for disc protrusion were 98.8%, 96.5%, 97.1%, 97.8% (disc level), 97.7%, 92.9%, 98.6%, 96.9% (patient level). SNR of IR was significantly higher than FBP. IQ was significantly better in IR owing to visually reduced noise and improved delineation of the discs. κ (>0.90) was excellent for both algorithms.

CONCLUSION

MDCT of the lumbar spine yields high diagnostic accuracy for detection of lumbar disc herniation. IR improves image quality so that the provided diagnostic accuracy is principally equivalent to MRI.

KEY POINTS

• MDCT is an accurate alternative to MRI in disc herniation diagnosis. • By IR enhanced image quality improves MDCT diagnostic confidence similar to MRI. • Advances in CT technology contribute to improved diagnostic performance in lumbar spine imaging.

An evidence-based clinical guideline for the diagnosis and treatment of lumbar disc herniation with radiculopathy

BACKGROUND CONTEXT

The objective of the North American Spine Society's (NASS) Evidence-Based Clinical Guideline for the Diagnosis and Treatment of Lumbar Disc Herniation with Radiculopathy is to provide evidence-based recommendations to address key clinical questions surrounding the diagnosis and treatment of lumbar disc herniation with radiculopathy. The guideline is intended to reflect contemporary treatment concepts for symptomatic lumbar disc herniation with radiculopathy as reflected in the highest quality clinical literature available on this subject as of July 2011. The goals of the guideline recommendations are to assist in delivering optimum efficacious treatment and functional recovery from this spinal disorder.

PURPOSE

To provide an evidence-based educational tool to assist spine specialists in the diagnosis and treatment of lumbar disc herniation with radiculopathy.

STUDY DESIGN

Systematic review and evidence-based clinical guideline.

METHODS

This guideline is a product of the Lumbar Disc Herniation with Radiculopathy Work Group of NASS' Evidence-Based Guideline Development Committee. The work group consisted of multidisciplinary spine care specialists trained in the principles of evidence-based analysis. A literature search addressing each question and using a specific search protocol was performed on English-language references found in Medline, Embase (Drugs and Pharmacology), and four additional evidence-based databases to identify articles. The relevant literature was then independently rated using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final recommendations to answer each clinical question were developed via work group discussion, and grades were assigned to the recommendations using standardized grades of recommendation. In the absence of Level I to IV evidence, work group consensus statements have been developed using a modified nominal group technique, and these statements are clearly identified as such in the guideline.

RESULTS

Twenty-nine clinical questions were formulated and addressed, and the answers are summarized in this article. The respective recommendations were graded by strength of the supporting literature, which was stratified by levels of evidence.

CONCLUSIONS

The clinical guideline has been created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients with symptomatic lumbar disc herniation with radiculopathy. The entire guideline document, including the evidentiary tables, suggestions for future research, and all the references, is available electronically on the NASS Web site at http://www.spine.org/Pages/PracticePolicy/ClinicalCare/ClinicalGuidlines/Default.aspx and will remain updated on a timely schedule.

Decision making in surgical treatment of chronic low back pain: the performance of prognostic tests to select patients for lumbar spinal fusion

Chronic low back pain (CLBP) is one of the main causes of disability in the western world with a huge economic burden to society. As yet, no specific underlying anatomic cause has been identified for CLBP. Imaging often reveals degenerative findings of the disc or facet joints of one or more lumbar motion segments. These findings, however, can also be observed in asymptomatic people. It has been suggested that pain in degenerated discs may be caused by the ingrowth of nerve fibers into tears or clefts of the annulus fibrosus or nucleus pulposus, and by reported high levels of pro-inflammatory mediators. As this so-called discogenic pain is often exacerbated by mechanical loading, the concept of relieving pain by spinal fusion to stabilise a painful spinal segment, has been developed. For some patients lumbar spinal fusion indeed is beneficial, but its results are highly variable and hard to predict for the individual patient. To identify those CLBP patients who will benefit from fusion, many surgeons rely on tests that are assumed to predict the outcome of spinal fusion. The three most commonly used prognostic tests in daily practice are immobilization in a lumbosacral orthosis, provocative discography and trial immobilization by temporary external transpedicular fixation. Aiming for consensus on the indications for lumbar fusion and in order to improve its results by better patient selection, it is essential to know the role and value of these prognostic tests for CLBP patients in clinical practice. The overall aims of the present thesis were: 1) to evaluate whether there is consensus among spine surgeons regarding the use and appreciation of prognostic tests for lumbar spinal fusion; 2) to verify whether a thoracolumbosacral orthosisis (TLSO) truly minimises lumbosacral motion; 3) to verify whether a TLSO can predict the clinical outcome of fusion for CLBP; 4) to assess whether provocative discography of adjacent segments actually predicts the long-term clinical outcome fusion; 5) to determine the incidence of postdiscography discitis, and whether there is a need for routine antibiotic prophylaxis; 6) to assess whether temporary external transpedicular fixation (TETF) can help to predict the outcome of spinal fusion; 7) to determine the prognostic accuracy of the most commonly used tests in clinical practice to predict the outcome of fusion for CLBP. The results of a national survey among spine surgeons in the Netherlands were presented in Study I. The surgeons were questioned about their opinion on prognostic factors and about the use of predictive tests for lumbar fusion in CLBP patients. The comments were compared with findings from the prevailing literature. The survey revealed a considerable lack of uniformity in the use and appreciation of predictive tests. Prognostic factors known from the literature were not consistently incorporated in the surgeons' decision making process either. This heterogeneity in strategy is most probably caused by the lack of sound scientific evidence for current predictive tests and it was concluded that currently there is not enough consensus among spine surgeons in the Netherlands to create national guidelines for surgical decision making in CLBP. In Study II, the hypothesized working mechanism of a pantaloon cast (i.e., minimisation of lumbosacral joint mobility) was studied. In patients who were admitted for a temporary external transpedicular fixation test (TETF), infrared light markers were rigidly attached to the protruding ends of Steinman pins that were fixed in two spinal levels. In this way three-dimensional motion between these levels could be analysed opto-electronically. During dynamic test conditions such as walking, a plaster cast, either with or without unilateral hip fixation, did not significantly decrease lumbosacral joint motion. Although not substantiated by sound scientific support, lumbosacral orthoses or pantaloon casts are often used in everyday practice as a predictor for the outcome of fusion. A systematic review of the literature supplemented with a prospective cohort study was performed (Study III) in order to assess the value of a pantaloon cast in surgical decision-making. It appeared that only in CLBP patients with no prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative treatment. In patients with prior spine surgery the test is of no value. It is believed by many spine surgeons that provocative discography, unlike plain radiographs or magnetic resonance imaging, is a physiologic test that can truly determine whether a disc is painful and relevant in a patient's pain syndrome, irrespective of the morphology of the disc. It has been suggested that in order to achieve a successful clinical outcome of lumbar fusion, suspect discs should be painful and adjacent control discs should elicit no pain on provocative discography. For this reason, a cohort of patients in whom the decision to perform lumbar fusion was based on an external fixation (TETF) trial, was analysed retrospectively in Study IV. The results of preoperative discography of solely the levels adjacent to the fusion were compared with the clinical results after spinal fusion. It appeared that in this select group of patients the discographic status of discs adjacent to a lumbar fusion did not have any effect on the clinical outcome. The most feared complication of lumbar discography is discitis. Although low in incidence, this is a serious complication for a diagnostic procedure and prevention by the use of prophylactic antibiotics has been advocated. In search for clinical guidelines, the risk of postdiscography discitis was assessed in Study V by means of a systematic literature review and a cohort of 200 consecutive patients. Without the use of prophylactic antibiotics, an overall incidence of postdiscography discitis of 0.25% was found. To prove that antibiotics would actually prevent discitis, a randomised trial of 9,000 patients would be needed to reach significance. Given the possible adverse effects of antibiotics, it was concluded that the routine use of prophylactic antibiotics in lumbar discography is not indicated. In Study VI, the middle- and long-term results of external fixation (TETF) as a test to predict the clinical outcome of lumbar fusion were studied in a group of back pain patients for whom there was doubt about the indication for surgery. The test included a placebo trial, in which the patients were unaware whether the lumbar segmental levels were fixed or dynamised. Using strict and objective criteria of pain reduction on a visual analogue scale, the TETF test failed to predict clinical outcome of fusion in this select group of patients. Pin track infection and nerve root irritation were registered as complications of this invasive test. It was concluded that in chronic low back pain patients with a doubtful indication for fusion, TETF is not recommended as a supplemental tool for surgical decision-making. In Study VII, a systematic literature review was performed regarding the prognostic accuracy of tests that are currently used in clinical practice and that are presumed to predict the outcome of lumbar spinal fusion for CLBP. The tests of interest were magnetic resonance imaging (MRI), TLSO immobilisation, TETF, provocative discography and facet joint infiltration. Only 10 studies reporting on three different index tests (discography, TLSO immobilisation and TETF) that truly reported on test qualifiers, such as sensitivity, specificity and likelihood ratios, could be selected. It appeared that the accuracy of all prognostic tests was low, which confirmed that in many clinical practices patients are scheduled for fusion on the basis of tests, of which the accuracy is insufficient or at best unknown. As the overall methodological quality of included studies was poor, higher quality trials that include negatively tested as well as positively tested patients for fusion, will be needed. It was concluded that at present, best evidence does not support the use of any prognostic test in clinical practice. No subset of patients with low back pain could be identified, for whom spinal fusion is a reliable and effective treatment. In literature, several studies have reported that cognitive behavioural therapy or intensive exercise programs have treatment results similar to those of spinal fusion, but with considerably less complications, morbidity and costs. As the findings of the present thesis show that the currently used tests do not improve the results of fusion by better patient selection, these tests should not be recommended for surgical decision making in standard care. Moreover, spinal fusion should not be proposed as a standard treatment for chronic low back pain. Causality of nonspecific spinal pain is complex and CLBP should not be regarded as a diagnosis, but rather as a symptom in patients with different stages of impairment and disability. Patients should be evaluated in a multidisciplinary setting or Spine Centre according to the so-called biopsychosocial model, which aims to identify underlying psychosocial factors as well as biological factors. Treatment should occur in a stepwise fashion starting with the least invasive treatment. The current approach of CLBP, in which emphasis is laid on self-management and empowerment of patients to take an active course of treatment in order to prevent long-term disability and chronicity, is recommended.

Accuracy, intermethod agreement, and inter-reviewer agreement for use of magnetic resonance imaging and myelography in small-breed dogs with naturally occurring first-time intervertebral disk extrusion

OBJECTIVE

To determine accuracy, intermethod agreement, and inter-reviewer agreement for multisequence magnetic resonance imaging (MRI) and 2-view orthogonal myelography in small-breed dogs with first-time intervertebral disk (IVD) extrusion.

DESIGN

Prospective evaluation study.

ANIMALS

24 dogs with thoracolumbar IVD extrusion.

PROCEDURES

Each dog underwent MRI and myelography. Images obtained with each modality were independently evaluated and assigned standardized scores in a blinded manner by 3 reviewers. Results were compared with surgical findings. Inter-reviewer and intermethod agreements were assessed via κ statistics. Accuracy was assessed as the percentage of dogs for which ≥ 2 of 3 reviewers recorded findings identical to those determined surgically.

RESULTS

Inter-reviewer agreement was substantial for site (κ = 0.70) and side of IVD extrusion (κ = 0.62) in T2-weighted magnetic resonance images and was substantial for site (κ = 0.72) and fair for side of extrusion (κ = 0.37) in myelographic images. Agreement for site between each modality and surgical findings was near perfect (κ = 0.94 and 0.88 for MRI and myelography, respectively). Intermethod agreement was substantial for site (κ = 0.71) and moderate for side of extrusion (κ = 0.40). Accuracy of MRI for site and side was 100% when results for T1-weighted, T2-weighted, and contrast-enhanced T1-weighted sequences were combined. Accuracy of myelography was 90.9% and 54.5% for site and side, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Agreement between imaging results and surgical findings for identification of IVD extrusion sites in small-breed dogs was similar for MRI and myelography. However, MRI appeared to be more accurate than myelography and allowed evaluation of extradural compressive mass composition.

Square-cut: a segmentation algorithm on the basis of a rectangle shape

We present a rectangle-based segmentation algorithm that sets up a graph and performs a graph cut to separate an object from the background. However, graph-based algorithms distribute the graph's nodes uniformly and equidistantly on the image. Then, a smoothness term is added to force the cut to prefer a particular shape. This strategy does not allow the cut to prefer a certain structure, especially when areas of the object are indistinguishable from the background. We solve this problem by referring to a rectangle shape of the object when sampling the graph nodes, i.e., the nodes are distributed non-uniformly and non-equidistantly on the image. This strategy can be useful, when areas of the object are indistinguishable from the background. For evaluation, we focus on vertebrae images from Magnetic Resonance Imaging (MRI) datasets to support the time consuming manual slice-by-slice segmentation performed by physicians. The ground truth of the vertebrae boundaries were manually extracted by two clinical experts (neurological surgeons) with several years of experience in spine surgery and afterwards compared with the automatic segmentation results of the proposed scheme yielding an average Dice Similarity Coefficient (DSC) of 90.97±2.2%.

Magnetic resonance imaging for diagnosing lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review

PURPOSE

In about 5% of all cases LBP is associated with serious underlying pathology requiring diagnostic confirmation and directed treatment. Magnetic resonance imaging (MRI) is often used for this diagnostic purpose yet its role remains controversial. Consequently, this review aimed to summarize the available evidence on the diagnostic accuracy of MRI for identifying lumbar spinal pathology in adult low back pain (LPB) or sciatica patients.

METHODS

MEDLINE, EMBASE and CINAHL were searched (until December 2009) for observational studies assessing the diagnostic accuracy of MRI compared to a reference test for the identification of lumbar spinal pathology. Two reviewers independently selected studies for inclusion, extracted data and assessed methodological quality. Pooled summary estimates of sensitivity and specificity with 95% confidence intervals were calculated for homogenous subsets of studies.

RESULTS

Eight studies were included in this review. Strata were defined for separate pathologies i.e. lumbar disc herniation (HNP) and spinal stenosis. Five studies comparing MRI to findings at the surgery for identifying HNP were included in a meta-analysis. Pooled analysis resulted in a summary estimate of sensitivity of 75% (95% CI 65-83%) and specificity of 77% (95% CI 61-88%). For spinal stenosis pooling was not possible.

CONCLUSIONS

The results suggest that a considerable proportion of patients may be classified incorrectly by MRI for HNP and spinal stenosis. However, the evidence for the diagnostic accuracy of MRI found by this review is not conclusive, since the results could be distorted due to the limited number of studies and large heterogeneity.

Computed tomography for the diagnosis of lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review

Aim

In low back pain if serious pathology is suspected diagnostic imaging could be performed. One of the imaging techniques available for this purpose is computed tomography (CT), however, insight in the diagnostic performance of CT is unclear.

Method

Diagnostic systematic review. Studies assessing the diagnostic accuracy of CT in adult patients suggested having low back pain caused by specific pathology were selected. Two review authors independently selected studies for inclusion, extracted data and assessed risk of bias. Pooled summary estimates of sensitivity and specificity with 95% CI were calculated.

Results

Seven studies were included, all describing the diagnostic accuracy of CT in identifying lumbar disc herniation. Six studies used surgical findings as the reference standard and were considered sufficiently homogenous to carry out a meta-analysis. The pooled summary estimate of sensitivity was 77.4% and specificity was 73.7%.

Conclusions

We found no studies evaluating the accuracy of CT for pathologies such as vertebral cancer, infection and fractures and this remains unclear. Our results should be interpreted with some caution. Sensitivity and specificity, regarding the detection of lumbar disc herniation, showed that a substantial part of the patients is still classified as false-negative and false-positive. In future, the diagnostic performance of CT must be assessed in high quality prospective cohort studies with an unselected population of patients with low back pain.

Evaluation of diagnosis techniques used for spinal injury related back pain

Back pain is a prevalent condition affecting much of the population at one time or the other. Complications, including neurological ones, can result from missed or mismanaged spinal abnormalities. These complications often result in serious patient injury and require more medical treatment. Correct diagnosis enables more effective, often less costly treatment methods. Current diagnosis technologies focus on spinal alterations. Only approximately 10% of back pain is diagnosable, with current diagnostic technologies. The objective of this paper is to investigate and evaluate based on specific criteria current diagnosis technique. Nine diagnostic techniques were found in the literature, namely, discography, myelography, single photon emission computer tomography (SPECT), computer tomography (CT), combined CT & SPECT, magnetic resonance imaging (MRI), upright and kinematic MRI, plain radiography and cineradiography. Upon review of the techniques, it is suggested that improvements can be made to all the existing techniques for diagnosing back pain. This review will aid health service developers to focus on insufficient areas, which will help to improve existing technologies or even develop alternative ones.

Contrast-enhanced CT for localizing compressive thoracolumbar intervertebral disc extrusion

Thoracolumbar intervertebral disc extrusion is a common disease in dogs. Surgical decompression of the spinal cord is the preferred treatment. Localization of the compressive material is critical for surgical planning. Myelography has been used for localizing extruded disc material, but this procedure carries risk of complications. Computed tomography (CT) is becoming more available for use in veterinary medicine and CT myelography is used for localization of extruded disc material. This report compares CT with intravenous contrast medium and CT myelography for identifying extruded intervertebral discs. CT with intravenous contrast medium is as effective as CT myelography for determining level and laterality of compressive disc extrusions.

Comparison of spinal anatomy between 3-Tesla MRI and CT-myelography under healthy and pathological conditions

PURPOSE

In many centres both MRI and CT-myelography are performed for treatment planning of degenerative spine disease. More and more centres acquire 3-Tesla MRI scanners in which some artefacts, which lead to difficulties in image evaluation, are more pronounced than at 1.5 Tesla. Aim of this study was to compare spinal physiological and pathological anatomy between 3-Tesla MRI and CT-myelography and to review current imaging standards.

METHODS

In 47 spinal segments commonly used 3-Tesla T2-weighted sequences and CT-myelography studies were evaluated retrospectively. Spinal canal, neural foraminal, spinal cord and disc protrusion diameters were measured.

RESULTS

The spinal canal was found to be 10% tighter with the utilized MRI sequences, in comparison to CT-M and foraminal diameters were found to be 19.7% tighter in MRI. This was more pronounced in narrowed than in healthy segments. Spinal cord size and size of disc protrusions displayed no significant difference between MRI and CT-myelography.

CONCLUSIONS

The main advantage of CT-myelography, in comparison to 3-Tesla MRI, is the reliable information about the bony structures. Soft tissues like the spinal cord or disc protrusions were visualised equivalently with both modalities concerning diameters.

Lumbar discectomy: a national survey of neurosurgeons and literature review

BACKGROUND

To ascertain neurosurgical practices in the surgical management of one-level lumbar discectomies in the Canadian adult population.

METHODS

One page questionnaire faxed to each Neurosurgeon in Canada with questions relating to their practice in the management of this common neurosurgical procedure. All data analyzed using Chi-square statistics.

RESULTS

112 completed surveys were returned hence, giving a 64% response rate with the respondents being predominantly adult neurosurgeons. Of the respondents, 88% perform lumbar discectomy in adults. Only 15% of respondents had a Spine Fellowship. For preoperative imaging, 44% use BOTH CT and MRI whereas 28% use only MRI and 15% use only CT. Prior to initial skin incision, 57% use a localization X-ray image. Preoperative antibiotics are prescribed by 92% of respondents. Majority of respondents (60%) use a pre-incision local anesthetic, whereas only a minority (44%) of respondents employ pre-closure intramuscular injection. With respect to magnification, 70% use microscope, 19% loupes, and 8% neither. Only 12% use minimally invasive tubular retractors. 68% remove "as much disc as possible", while 31% remove "ONLY herniated part". In the case of dural tears, 77% of respondents use fibrin glue (Tisseel). Prior to skin closure, majority of neurosurgeons do NOT use a fat graft (72%), whereas 61% of respondents use epidural steroids. With respect to discharge from the hospital, 58% are discharged on the next day, 18% on the same day, and 23% in two days. Return to work is not recommended until at least six weeks post-op (96%). Most neurosurgeons (93%) would not operate on an individual with a chief complaint of low back pain.

CONCLUSIONS

Our survey has identified variations in practice patterns amongst Canadian Neurosurgeons with respect to performing one-level lumbar discectomies. This survey is expected to form a basis for the design of a randomized controlled trial in the evaluation of the best management approach for this common neurosurgical procedure.

Missed lumbar disc herniations diagnosed with kinetic magnetic resonance imaging

STUDY DESIGN

A novel dynamic magnetic resonance imaging (MRI) system, kinetic MRI (kMRI), was used to study lumbar disc herniations.

OBJECTIVE

The objective of this study was to determine if adding flexion and extension MRI studies to the traditional neutral views would be beneficial in the diagnosis of lumbar disc herniations.

SUMMARY OF BACKGROUND DATA

Prior studies demonstrate that only 70% of patients with lumbar disc herniations based on physical examinations are confirmed by MRI studies. Recently, kMRI delivers the ability to scan patients in neutral, flexion, and extension positions, which may allow for improved diagnosis of this problem.

METHODS

Five hundred fifty-three patients underwent kMRI with assessment of the degree of disc bulge in neutral and flexion and extension. The images were analyzed using computer measurement technology to objectively quantify the amount of disc herniation.

RESULTS

For patients with normal or <3 mm of disc bulge in neutral, 19.46% demonstrated an increase in herniation to >3 mm bulge in extension, and 15.29% demonstrated an increase to >3 mm bulge in flexion. For patients in the neutral view that had a baseline disc bulge of 3 to 5 mm, 13.28% had increased herniations to >5 mm in extension and 8.47% had increased herniations to >5 mm in flexion. For patients with a baseline disc bulge of 5 to 7 mm in neutral, 10.58% increased in extension and 5.78% increased in flexion. In addition, for patients with a baseline disc bulge of 7 to 9 mm in neutral, 9.09% increased in extension and 4.55% increased in flexion.

CONCLUSION

A significant increase in the degree of lumbar disc herniation was found by examining flexion and extension views when compared with neutral views alone. kMRI views provide valuable added information, especially in situations where symptomatic radiculopathy is present without any abnormalities demonstrated on conventional MRI.

Multidetector CT in patients suspected of having lumbar disk herniation: comparison of standard-dose and simulated low-dose techniques

PURPOSE

To compare standard-dose and simulated low-dose multidetector computed tomography (CT) in patients suspected of having lumbar disk herniation.

MATERIALS AND METHODS

The institutional review board approved the research protocol with a waiver of patient informed consent. Sixty consecutive patients underwent multidetector CT with four detector rows at 1 mm collimation at 140 kVp, with tube current-time product adapted to body mass index (BMI): 200 (BMI< 22 kg/m(2)), 300 (BMI > or =22 to <30 kg/m(2)), and 400 effective mAs (BMI > or =30 kg/m(2)). Simulated doses at 65%, 50%, 35%, and 20% of the dose were used for acquisition. During two separate sessions, three independent radiologists coded each of three caudal disks as normal, bulging, or herniated and graded canal and foramen compromise. Median numbers of discrepancies between the standard and reduced doses were compared with Friedman and Wilcoxon tests. Agreements within and between readers were evaluated through kappa statistics.

RESULTS

Dose reduction had no effect on a reader's ability to identify bulging disks (P = .128) and left and right foramen compromises (P = .413 and .665, respectively). However, for normal disks (P = .002), herniated disks (P = .004), and canal compromise (P = .002), dose reduction did have a significant effect. For normal disks and canal compromise, a reduction dose effect was not detected at 65% (P = .121 and .250, respectively) but appeared at 50% (P = .004 and .008, respectively). For herniation, a dose reduction effect was detected at 35% (P = .031). Agreements within and between readers ranged from poor to excellent and tended to decrease with dose reduction.

CONCLUSION

For patients suspected of having lumbar disk herniation, tube charge settings could be reduced to 65% of the standard dose adapted to the BMI.

Observer variation in the evaluation of lumbar herniated discs and root compression: spiral CT compared with MRI

Spiral CT is considered the best alternative for MRI in the evaluation of herniated discs. The purpose of this study was to compare radiological evaluation of spiral CT with MRI in patients suspected of herniated discs. 57 patients with lumbosacral radicular syndrome underwent spiral CT and 1.5 T MRI. Two neuroradiologists independently evaluated 171 intervertebral discs for herniation or "bulge" and 456 nerve roots for root compression, once after CT and once after MRI. We compared interobserver agreement using the kappa statistic and we performed a paired comparison between CT and MRI. For detection of herniated or bulging discs, we observed no significant difference in interobserver agreement (CT kappa 0.66 vs MRI kappa 0.71; p = 0.40). For root compression, we observed significantly better interobserver agreement at MRI evaluation (CT kappa 0.59 vs MRI kappa 0.78; p = 0.01). In 30 of 171 lumbar discs (18%) and in 54 of 456 nerve roots (12%), the observers disagreed on whether CT results were similar to MRI. In the cases without disagreement, CT differed from MRI in 6 discs (3.5%) and in 3 nerve roots (0.7%). For radiological evaluation of lumbar herniated discs, we found no evidence that spiral CT is inferior to MRI. For evaluating lumbar nerve root compression, spiral CT is less reliable than MRI.

Pelvic tumor presenting as chronic back pain in a young adult

A large proportion of Emergency Department visits are for chronic pain, specifically for chronic back pain. Often this entity requires minimal diagnostics. However, certain populations and presentations require a higher vigilance and a more detailed evaluation. This report describes the clinical presentation of a young adult with chronic back pain who exhibited new symptoms and subtle examination findings that expedited the ultimate diagnosis of pelvic chondrosarcoma.

Lumbar disc herniations: surgical versus nonsurgical treatment

Lumbar disc herniation is among the most common causes of lower-back pain and sciatica. The cause(s) of lumbar disc herniation and the relation of lumbar disc herniation to back pain and sciatica have not been fully elucidated, but most likely comprise a complex combination of mechanical and biologic processes. Furthermore, the natural history of lumbar disc herniation seems generally to be favorable, leaving the optimum treatment for lumbar disc herniation a debate in the literature. Various nonoperative and operative treatment strategies have been tried with varying degrees of success. Treatment often involves patient education, physical therapy, alternative medicine options, and pharmaco-therapy. If these fail, surgical intervention is usually recommended. A literature search was conducted to evaluate the currently known effectiveness of traditional and novel non-operative and surgical techniques for the treatment lumbar disc herniation and to determine if there are substantive new advantages in these newer contemporary treatments or combinations thereof. A structured approach to treatment of a patient who may have a symptomatic lumbar disc herniation is presented, based on analysis of the current literature. No one method of nonoperative or operative treatment would seem definitively to be superior to another. Appropriate multidisciplinary treatment including behavioral analysis and support may offer the hope of improved outcomes for patients with lumbar disc herniation.

LEVEL OF EVIDENCE

Level V (expert opinion). See the Guidelines for Authors for a complete description of the levels of evidence.

Radicular Pain Avoidance During Needle Placement in Lumbar Diskography

OBJECTIVE

The objective of our study was to determine whether a method could be found to reduce iatrogenic radicular pain during needle placement in lumbar diskography.

MATERIALS AND METHODS

After obtaining permission from the institutional review board at the University of Pittsburgh Medical Center, we conducted a study using medical records and existing data that were recorded for quality control during lumbar diskography. A coaxial technique was being used for lumbar diskography. We evaluated data for 71 intervertebral disks in 26 patients in which the needle placement was randomly high (superior) or low (inferior), and the associated pain response during needle placement was recorded. In an attempt to minimize iatrogenic pain during needle placement, we identified a potentially "safe window" for needle placement on MRI of the lumbar spine. On oblique fluoroscopy of the lumbar spine, the safe window is a triangle formed by the superior articular facet medially, the superior endplate of the lower vertebra inferiorly, and an imaginary line joining the tip of the superior articular facet and the superolateral tip of the vertebral body. This safe window was then used for needle placement in another 73 intervertebral disks in 27 patients. Pain response to needle placement was recorded for quality control, and the medical records were retrospectively compared with the initial 71 intervertebral disks in which needle placement was random.

RESULTS

In the initial group with random needle placement, lower extremity radicular pain occurred in 13 (18.3%) of 71 intervertebral disks with superior needle placement and in 23 (32.4%) of 71 intervertebral disks with inferior needle placement (total, 50.7%). The pain responses of the superior and inferior groups were not significantly different (p = 0.27). On MRI, the average distances between the nerve ganglion-fascicle-rami and the superior articular facets at the superior disk level were 1.1, 1.4, and 2.5 mm at L3-L4, L4-L5, and L5-S1, respectively. The average distances between the nerve ganglion-fascicle-rami and the superior articular facets at the inferior disk level were 3.0, 3.6, and 6.6 mm at L3-L4, L4-L5, and L5-S1, respectively. When the safe window was used, only five (6.8%) of 73 patients reported radicular pain. The decrease in radicular pain between the two groups was significant (p < 0.001).

CONCLUSION

Iatrogenic lower extremity radicular pain is common during random needle placement at lumbar diskography. High or low needle placement in the intervertebral disk could not predict whether radicular pain would be averted. We identified a safe window that can be used for needle placement during lumbar diskography to minimize iatrogenic lower extremity radicular pain and thereby improve the reliability of the test.

Imaging of adults with low back pain in the primary care setting

The evidence for the diagnostic accuracy of the four main imaging modalities used in low back pain (plain radiographs, CT, MR imaging, radionuclide bone scans) is variable in quality and limits the ultimate conclusions regarding the effectiveness and cost-effectiveness of diagnostic strategies. In addition, the frequent finding of abnormalities in normal adults limits the specificity of all of these tests. Nevertheless, MR imaging is likely in most cases to offer the greatest sensitivity and specificity for systemic diseases, and its performance is superior to that of radiographs and comparable with CT and radionuclide bone scans for most conditions causing neurologic compromise.

Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression

OBJECTIVE

To evaluate patient characteristics, symptoms, and examination findings in the clinical diagnosis of lumbosacral nerve root compression causing sciatica.

METHODS

The study involved 274 patients with pain radiating into the leg. All had a standardised clinical assessment and magnetic resonance (MR) imaging. The associations between patient characteristics, clinical findings, and lumbosacral nerve root compression on MR imaging were analysed.

RESULTS

Nerve root compression was associated with three patient characteristics, three symptoms, and four physical examination findings (paresis, absence of tendon reflexes, a positive straight leg raising test, and increased finger-floor distance). Multivariate analysis, analysing the independent diagnostic value of the tests, showed that nerve root compression was predicted by two patient characteristics, four symptoms, and two signs (increased finger-floor distance and paresis). The straight leg raise test was not predictive. The area under the curve of the receiver-operating characteristic was 0.80 for the history items. It increased to 0.83 when the physical examination items were added.

CONCLUSIONS

Various clinical findings were found to be associated with nerve root compression on MR imaging. While this set of findings agrees well with those commonly used in daily practice, the tests tended to have lower sensitivity and specificity than previously reported. Stepwise multivariate analysis showed that most of the diagnostic information revealed by physical examination findings had already been revealed by the history items.

The Longitudinal Assessment of Imaging and Disability of the Back (LAIDBack) Study: baseline data

STUDY DESIGN

Prospective cohort study of randomly selected Veterans Affairs (VA) outpatients.

OBJECTIVE

To determine the prevalence of magnetic resonance imaging (MRI) findings in the lumbar spine among persons without current low back pain or sciatica and to examine which findings are related to age or previous back symptoms.

SUMMARY OF BACKGROUND INFORMATION

Previous studies of patients without low back pain have not explored the possible association of various MRI findings to past symptoms.

METHODS

We randomly selected an age-stratified sample of subjects without low back pain in the past 4 months from clinics at a VA hospital. We collected information on demographics, comorbidity, functional status, and quality of life. MR images were obtained using a standardized protocol through each of the five lumbar disc levels.

RESULTS

Of 148 subjects, 69 (46%) had never experienced low back pain. There were 123 subjects (83%) with moderate to severe desiccation of one or more discs, 95 (64%) with one or more bulging discs, and 83 (56%) with loss of disc height. Forty-eight subjects (32%) had at least one disc protrusion and 9 (6%) had one or more disc extrusions.

CONCLUSION

Many MR imaging findings have a high prevalence in subjects without low back pain. These findings are therefore of limited diagnostic use. The less common findings of moderate or severe central stenosis, root compression, and extrusions are likely to be diagnostically and clinically relevant.

Role of weight-bearing flexion and extension myelography in evaluating the intervertebral disc

Magnetic resonance imaging has many advantages compared with myelography and/or computed tomography in evaluating the lumbar spine for herniated nucleus pulposus. The authors have included a series of three patients whose histories and physical examinations were clinically suggestive of herniated nucleus pulposus but whose magnetic resonance imaging scans were interpreted by a radiologist as a disc bulge without nerve root compression. Because all patients had not responded to a conservative care treatment program and surgical intervention was to be considered, subsequent testing with lumbar myelography with weight-bearing flexion and extension views demonstrated more clearly the presence of herniated nucleus pulposus along with compression of the nerve root; it also revealed that a positional change in the disc occurred with flexion and extension.

Lumbar spinal stenosis assessment with computed tomography, magnetic resonance imaging, and myelography

Degenerative spinal stenosis of the lumbar spine is caused by many factors, some of which include: disc herniation, ligamentum flavum and facet hypertrophy, spondylolisthesis, and compression fracture. Most often the stenosis is caused by a combination of these factors. The imaging modalities in routine use to evaluate these conditions are computed tomography, magnetic resonance imaging and computed tomography-myelogram. They each have their advantages and disadvantages although any one of these modalities can adequately diagnose lumbar stenosis. The overall accuracy rate of computed tomography, magnetic resonance imaging, and computed tomography-myelogram has been reported to be similar and even complimentary. It is recommended that the least invasive modality be performed first. Magnetic resonance imaging should be the first choice because it does not require ionizing radiation or contrast injection. The aim of the current study is to present the common causes of lumbar stenosis. Where appropriate, each case is shown with images from each modality so that their similarities and differences can be highlighted.

Classification, diagnostic imaging, and imaging characterization of a lumbar herniated disk

The absence of universal nomenclature standardization with respect to the definition of a disk herniation and its different categories, especially regarding type and location, is still a major problem that will only be overcome when major national or international scientific societies join efforts to support a particular scheme. Meanwhile, it is important to realize that the two models that are currently most used are based on a different [figure: see text] perspective. Trying to straddle the two by opposing, for instance, bulging disk and herniation is doomed to failure because this exercise defies formal logic. MR imaging is currently the most accurate noninvasive imaging modality to diagnose a disk herniation and to determine its exact location. The determination of some pathoanatomic characteristics of herniated disks (type and composition) may require the use of CT, diskography, or CT diskography.

Lumbar spine traction: evaluation of effects and recommended application for treatment

Despite the widespread use of traction, little is known of the mode of effect, and application remains largely anecdotal. The efficacy of traction is also unclear because of generally poor design of the clinical trials to date, and because subgroups of patients most likely to benefit have not been specifically studied. These observations prompted this review, the purposes of which are to evaluate the mechanisms by which traction may provide benefit and to provide rational guidelines for the clinical application of traction. Traction has been shown to separate the vertebrae and it appears that large forces are not required. Vertebral separation could provide relief from radicular symptoms by removing direct pressure or contact forces from sensitised neural tissue. Other mechanisms proposed to explain the effects of traction (e.g. reduction of disc protrusion or altered intradiscal pressure) have been shown not to occur. We conclude that traction is most likely to benefit patients with acute (less than 6 weeks' duration) radicular pain with concomitant neurological deficit. The apparent lack of a dose-response relationship suggests that low doses are probably sufficient to achieve benefit.

When does the patient with a disc herniation undergo lumbosacral discectomy?

OBJECTIVES

To design a model that could accurately predict eventual lumbar disc surgery in the patient initially presenting with clinical findings of nerve root compression.

METHODS

Prospective study in 183 patients with nerve root compression sampled from a primary care population. All patients underwent a standardised history, physical examination, and MRI. Surgery carried out in the next 6 months was recorded. Models were constructed to predict whether patients eventually received surgery.

RESULTS

Two models were constructed. Reduced model A was based on baseline findings, only, and contained six variables. Model B incorporated change over time as well and contained 10 variables. The area under the curve (in a receiver operating characteristic) for these models was 0.86 and 0.92, respectively. It was shown that at a probability cut off of 0.60, model B predicted eventual surgery with a sensitivity of 57% and a specificity of 100%.

CONCLUSIONS

Given the requirement of a high specificity, eventual operation could be adequately predicted in a sample of 183 patients with clinical nerve root compression. The application of the model in patients with nerve root compression might lead to earlier operation in a subset of patients resulting in a reduction of duration of illness and associated indirect costs. An important prerequisite for future application would be the validation of the prediction rule in another population.

Electromyography and magnetic resonance imaging in the evaluation of radiculopathy

Electromyography (EMG) and magnetic resonance imaging (MRI) are commonly used in the diagnosis of cervical and lumbosacral radiculopathy, but the agreement between the two studies is unknown. We retrospectively studied 47 patients with a clinical history compatible with either cervical or lumbosacral radiculopathy who were evaluated with both an EMG and a spine MRI within 2 months of each other. Among these patients, 55% had an EMG abnormality and 57% had an MRI abnormality that correlated with the clinically estimated level of radiculopathy. The two studies agreed in a majority (60%) of patients, with both normal in 11 and both abnormal in 17; however, only one study was abnormal in a significant minority (40%), suggesting that the two studies remain complementary diagnostic modalities. The agreement was higher in patients with abnormal findings on neurologic examination, underscoring the difficulty of confirming the diagnosis in mild radiculopathy.