Vertebral end-plate (Modic) changes on lumbar spine MRI: correlation with pain reproduction at lumbar discography

Predictors of new vertebral endplate signal (Modic) changes in the general population

Vertebral endplate signal changes (VESC), also known as Modic changes, have been reported to be associated with low back pain (LBP). However, little is known about predisposing factors for the development of new VESC. The aim of this study was to investigate the predictive value of lifestyle factors and disc-related magnetic resonance imaging (MRI) findings in relation to the development of new VESC. This prospective observational study included 344 people from the Danish general population who had an MRI and completed LBP questionnaires at the age of 40 and again at 44 years. Potential predictors of new VESC were female gender, disc-related MRI findings (disc degeneration, disc bulges, disc herniation, and other endplate changes) and lifestyle factors [high physical work or leisure activity, high body mass index (BMI), and heavy smoking]. Bivariate and multivariate logistic regressions were used to identify predictors of new VESC. New VESC at the age of 44 appeared in 67 of the 344. The majority (84%) of these new signal changes were type 1 VESC and almost half (45%) were only in the endplate and did not extend into the vertebral body. In the multivariate analysis, lumbar disc levels with disc degeneration, bulges or herniations at 40 were the only predictors of new VESC at age 44. Therefore, the development of new VESC at the age of 44 appears to be based on the status and dynamics of the disc, rather than being the result of gender or lifestyle factors such as smoking and physical load.

Long Term Efficacy of Posterior Lumbar Interbody Fusion with Standard Cages alone in Lumbar Disc Diseases Combined with Modic Changes

OBJECTIVE

Posterior lumbar interbody fusion (PLIF) is considered to have the best theoretical potential in promoting bony fusion of unstable vertebral segments by way of a load sharing effect of the anterior column. This study was undertaken to investigate the efficacy of PLIF with cages in chronic degenerative disc disease with Modic degeneration (changes of vertebral end plate).

METHODS

A total of 597 patients underwent a PLIF with threaded fusion cages (TFC) from 1993 to 2000. Three-hundred-fifty-one patients, who could be followed for more than 3 years, were enrolled in this study. Patients were grouped into 4 categories according to Modic classification (no degeneration : 259, type 1 : 26, type 2 : 55, type 3 : 11). Clinical and radiographic data were evaluated retrospectively.

RESULTS

The clinical success rate according to the Prolo's functional and economic outcome scale was 86% in patients without degeneration and 83% in patients with Modic degeneration. The clinical outcomes in each group were 88% in type 1, 84% in type 2, and 73% in type 3. The bony fusion rate was 97% in patients without degeneration and 83% in patients with Modic degeneration. The bony fusion rate in each group was 81% in type 1, 84% in type 2, and 55% in type 3. The clinical success and fusion rates were significantly lower in patients with type 3 degeneration.

CONCLUSION

The PLIF with TFC has been found to be an effective procedure for lumbar spine fusion. But, the clinical outcome and bony fusion rates were significantly low in the patients with Modic type 3. The authors suggest that PLIF combined with pedicle screw fixation would be the better for them.

Clinical diagnosis for discogenic low back pain

Discogenic lower back pain (DLBP) is the most common type of chronic lower back pain (LBP), accounting for 39% of cases, compared to 30% of cases due to disc herniation, and even lower prevalence rates for other causes, such as zygapophysial joint pain. Only a small proportion (approximately 20%) of LBP cases can be attributed with reasonable certainty to a pathologic or anatomical entity. Thus, diagnosing the cause of LBP represents the biggest challenge for doctors in this field. In this review, we summarize the process of obtaining a clinical diagnosis of DLBP and discuss the potential for serum-based diagnosis in the near future. The use of serum biomarkers to diagnose DLBP is likely to increase the ease of diagnosis as well as produce more accurate and reproducible results.

Interventional assessment of the lumbar disk: provocation lumbar diskography and functional anesthetic diskography

The diagnosis of diskogenic low back pain (LBP) can be elusive. Physical examination of the lumbar disk is limited and imaging offers few objective clues. While invasive, lumbar diskography is a method available to examine or "provoke" the disk directly and determine if LBP is coming from a disk and which disk(s) is responsible for the pain. Once identified, features of the abnormal disk can be evaluated, including the disk's response to intradiskal local anesthetic and disk architecture as observed on diskography imaging and postdiskogram computed tomography. Response to anesthetic can be correlated with imaging features potentially impacting treatment but can also stand alone as an independent objective marker of diskogenic LBP. Here we review the indications for lumbar diskography and the basic lumbar diskogram procedure. We also review the alternative more advanced technique for studying the anesthetic and mechanical features of the disk, functional anesthetic diskography.

Modic changes and interleukin 1 gene locus polymorphisms in occupational cohort of middle-aged men

According to recent systematic reviews, Modic changes are associated with low-back pain. However, their pathophysiology remains largely unknown. A previous study of Northern Finnish males implicated that IL1A and MMP3 polymorphisms play a role in type II Modic changes. The purpose of the current study was to examine the association of IL1 cluster polymorphisms with Modic changes amongst middle-aged men in Southern Finland. The final study sample consisted of 108 men from three different occupations, who underwent magnetic resonance imaging (MRI) with a 0.1 T-scanner. Six single nucleotide polymorphisms (SNP) in the IL1 gene cluster (IL1A c.1-889C>T; IL1B c.3954C>T; IL1RN c.1812G>A; IL1RN c.1887G>C; IL1RN c.11100T>C; IL1RN c.1506G>A) were genotyped with the SNP-TRAP method or by allele-specific primer extension on modified microarray. In all, 45 subjects had Modic changes at one or more disc levels. The presence of the minor allele of IL1A (c.1-889C>T) was associated with these changes (any Modic change p = 0.031, type II changes p = 0.036). The carriers of the T-allele had a 2.5-fold risk of Modic change and the association was independent of the other IL1 gene cluster loci studied. In addition, a minor haplotype, with a frequency of 7.5% in the study population, including the minor alleles of IL1A c.1-889C>T, IL1RN c.1812G>A, and IL1RN c.1506G>A, was significantly associated with Modic changes. This observation is in accordance with the previous finding from a different geographical area, and thus confirms the importance of the IL1A gene in the pathophysiology of Modic changes.

Prevalence of degenerative imaging findings in lumbar magnetic resonance imaging among young adults

STUDY DESIGN

A cross-sectional imaging study of young adults.

OBJECTIVE

To investigate the prevalence of disc degeneration (DD) and displacement, anular tears, and Modic changes in lumbar magnetic resonance imaging (MRI) among young adults.

SUMMARY OF BACKGROUND DATA

Although low back pain in young adulthood is common, the prevalence of spinal MRI findings at this age remains virtually unknown.

METHODS

The study population was a subcohort of the Northern Finland Birth Cohort 1986. Subjects living within 100 km of Oulu (n = 874) were invited to participate in lumbar MRI at 20 to 22 years of age (mean: 21.2 years). Degree of DD, type of Modic changes, and presence of disc bulges, herniations, high intensity zone (HIZ) lesions, and radial tears at all lumbar levels were assessed.

RESULTS

Three hundred twenty-five women and 233 men (n = 558) attended the MR imaging. DD was significantly more frequent in men (54% vs. 42%, P = 0.005), as was multiple DD (21% vs. 14%, P = 0.036). The prevalences of disc bulges and radial tears were 25% and 9.1%, respectively, without gender differences. HIZ lesions were more common among women than men (8.6% vs. 4.3%, P = 0.046), whereas herniations were significantly more common among men (5.6% vs. 2.5%, P = 0.047). Only 2 disc extrusions were observed, one in each gender. All degenerative disc findings were more common at the L5-S1 level except HIZ lesions, which were most likely at L4-L5. The prevalence of the Modic changes was 1.4%, without gender difference, type I being more common than type II. Typically, Modic changes were located adjacent to a DD Grade 4 disc and at the 2 lowest levels.

CONCLUSION

Almost half of young Finnish adult aged 21 years had at least one degenerated disc, and a quarter had a bulging disc. Modic changes and disc herniations were, however, relatively rare.

Modic changes on MR images as studied with provocative diskography: clinical relevance--a retrospective study of 2457 disks

PURPOSE

To assess the value of vertebral body endplate signal intensity (Modic) changes on magnetic resonance (MR) images in predicting a painful disk, with provocative diskography as the reference standard.

MATERIALS AND METHODS

Lumbar spine diskograms and prediskogram MR images of 736 patients (2457 disks) were retrospectively reviewed as part of an institutional review board-approved HIPAA-compliant protocol. Each disk was assigned a Modic subtype: type 0, normal; type 1, nonfatty high signal intensity; type 2, fatty; and type 3, sclerosis. Statistical analysis involved use of a 2 x 2 contingency table of diskogram results for each of the subtypes. The subtype sensitivity, specificity, positive predictive value (PPV), negative predictive value, and confidence intervals (CIs) were calculated. Similar analyses of other MR variables (such as disk herniation, high signal intensity zone, and spondylolisthesis) and type 1 signal intensity changes also were performed.

RESULTS

Type 1 changes (n = 155) had a high PPV (0.81; 95% CI: 0.74, 0.87) for a provocative diskogram. Type 2 changes (n = 126) had a lower PPV (0.64; 95% CI: 0.55, 0.72) for a positive diskogram. Type 3 changes (n = 21) had a PPV (0.57; 95% CI: 0.34, 0.78) that was not significant for a positive diskogram. The PPV of an endplate with a type 1 change (hereafter, type 1 endplate) for a tear in the annulus fibrosis of the disk was also insignificant (0.14; 95% CI: 0.09, 0.20). A similar analysis between a type 1 endplate and the presence of a disk herniation (PPV, 0.26; 95% CI: 0.19, 0.34) and between a type 1 endplate and vertebral body spondylolisthesis (PPV, 0.28; 95% CI: 0.20, 0.35) were significant.

CONCLUSION

Type 1 signal intensity changes on MR images have a high positive predictive value in the identification of a pain generator.

Management of symptomatic lumbar degenerative disk disease

Symptomatic lumbar degenerative disk disease, or discogenic back pain, is difficult to treat. Patients often report transverse low back pain that radiates into the sacroiliac joints. Radicular or claudicatory symptoms are generally absent unless there is concomitant nerve compression. Physical examination findings are often unremarkable. Radiographic examination may reveal disk space narrowing, end-plate sclerosis, or vacuum phenomenon in the disk; magnetic resonance imaging is useful for revealing hydration of the disk, annular bulging, or lumbar spine end-plate (Modic) changes in the adjacent vertebral bodies. The use of diskography as a confirmatory study remains controversial. Recent prospective, randomized trials and meta-analyses of the literature have helped expand what is known about degenerative disk disease. In most patients with low back pain, symptoms resolve without surgical intervention; physical therapy and nonsteroidal anti-inflammatory drugs are the cornerstones of nonsurgical treatment. Intradiskal electrothermal treatment has not been shown to be effective, and arthrodesis remains controversial for the treatment of discogenic back pain. Nucleus replacement and motion-sparing technology are too new to have demonstrated long-term data regarding their efficacy.

Modic changes in vertebral endplates: a comparison of MR imaging and multislice CT

OBJECTIVE

This paper aims to evaluate the presence of endplate sclerosis in different types of Modic changes and to assess the capability of MRI in detecting endplate sclerosis within these changes.

MATERIALS AND METHODS

The lumbar spines (L3-S1) of 70 patients were retrospectively reviewed to determine Modic changes and disc degeneration from MRI and endplate sclerosis from CT. T1- and T2-weighted signal intensity and Hounsfield unit (HU) measurements of type I and II Modic changes were recorded and the association of both Modic types I and II with endplate sclerosis was analyzed with a Mann-Whitney test.

RESULTS

Altogether 82 Modic changes in 36 subjects were recorded: 13% were type I, 12% mixed type I/II, 65% type II, 9% mixed type II/III, and 1% type III. Thirty-eight percent of the endplates with Modic changes had sclerosis in CT. Of specific Modic types, mixed I/II and II/III associated significantly with endplate sclerosis. Endplate sclerosis was not detected in MRI in a quantitative analysis.

CONCLUSION

Endplate sclerosis exists in all types of Modic changes, especially in mixed Modic types, and not only in type III changes, as previously assumed. Endplate sclerosis was not detected in MRI, which may depend on the amount of mineralization of the bone marrow.

Reliability of a modified Modic classification of bone marrow changes in lumbar spine MRI

OBJECTIVE

The purpose of this study was to determine the intra- and interobserver reliability of a modified Modic classification for bone marrow changes seen on lumbar spine magnetic resonance imaging (MRI), taking into consideration mixed signals.

METHODS

Lumbar MRI scans from 94 patients with low back pain were assessed independently by 2 spine specialists (senior [senior1], junior) and a radiologist (senior2). One reviewer (senior1) assessed the MR images twice at a three-week interval for evaluation of intraobserver reliability. Senior2 and junior reviewers assessed the MR images once. Pure edema endplate signal changes were classified as Modic type I, and pure fatty endplate changes as Modic type II. A mixture of types I and II but predominantly edema signal changes was classified as Modic I-2 and a mixture of types I and II but predominantly fatty changes was classified as Modic II-1.

RESULTS

The intraobserver agreement was excellent (weighted kappa 0.85). The interobserver agreement was moderate to substantial (weighted kappa range 0.56-0.74). Interobserver reliability depended on the experience of the observer, thus highlighting the importance of a learning curve.

CONCLUSION

This study shows that the modified Modic classification is reliable and easy to apply for observers with different clinical experience. The inclusion of mixed marrow changes in the modified classification may have clinical and therapeutic implications.

Painful disc lesion: can modern biplanar magnetic resonance imaging replace discography?

STUDY DESIGN

A new magnetic resonance imaging (MRI) classification of disc degeneration was correlated with discography. It was also studied for intraobserver and interobserver variability in interpreting disc abnormality and for the capability in predicting symptomatic disc.

OBJECTIVE

To correlate the results of discography with a new MRI classification for disc degeneration and the presence of the vertebral endplate changes and the high intensity zone (HIZ).

SUMMARY OF BACKGROUND DATA

MRI and discography have been compared in numerous studies as methods for detecting disc degeneration. The results were conflicting and the role of MRI in assessing discogenic pain remains ambiguous.

METHODS

One hundred thirty-one discs in 55 patients were studied with pain provocation discography and MRI. A new MRI classification was correlated to discography and assessed together with the presence of end plate changes and HIZ, by the sensitivity and specificity in predicting a painful disc.

RESULTS

MRI classification had a good intra and interobserver agreement and a significant correlation with discographic findings. The sensitivity and specificity of MRI in predicting painful disc was 94% and 77%. The sensitivities and specificity of HIZs was 27% and 87% and for end plate changes was 32% and 98%, respectively.

CONCLUSIONS

Although MRI is an excellent investigation for assessing disc morphology it should be interpreted along with discography findings before planning fusion surgery. The proposed MRI classification is a useful aid in predicting painful degenerative disc. The utility of HIZs and end plate changes is limited due to low sensitivity.

Vertebral endplate signal changes (Modic change): a systematic literature review of prevalence and association with non-specific low back pain

The prevalence of "vertebral endplate signal changes" (VESC) and its association with low back pain (LBP) varies greatly between studies. This wide range in reported prevalence rates and associations with LBP could be explained by differences in the definitions of VESC, LBP, or study sample. The objectives of this systematic critical review were to investigate the current literature in relation to the prevalence of VESC (including Modic changes) and the association with non-specific low back pain (LBP). The MEDLINE, EMBASE, and SveMED databases were searched for the period 1984 to November 2007. Included were the articles that reported the prevalence of VESC in non-LBP, general, working, and clinical populations. Included were also articles that investigated the association between VESC and LBP. Articles on specific LBP conditions were excluded. A checklist including items related to the research questions and overall quality of the articles was used for data collection and quality assessment. The reported prevalence rates were studied in relation to mean age, gender, study sample, year of publication, country of study, and quality score. To estimate the association between VESC and LBP, 2 x 2 tables were created to calculate the exact odds ratio (OR) with 95% confidence intervals. Eighty-two study samples from 77 original articles were identified and included in the analysis. The median of the reported prevalence rates for any type of VESC was 43% in patients with non-specific LBP and/or sciatica and 6% in non-clinical populations. The prevalence was positively associated with age and was negatively associated with the overall quality of the studies. A positive association between VESC and non-specific LBP was found in seven of ten studies from the general, working, and clinical populations with ORs from 2.0 to 19.9. This systematic review shows that VESC is a common MRI-finding in patients with non-specific LBP and is associated with pain. However, it should be noted that VESC may be present in individuals without LBP.

Modic changes: a systematic review of the literature

Modic changes (MC) are a common phenomenon on magnetic resonance imaging (MRI) in spinal degenerative diseases and strongly linked with low back pain (LBP). Histology, radiology, potential mechanisms, natural history and clinical studies of MC has formed the foundation on which our understanding of spinal degenerative diseases is built. The objective of this study was to provide a review of recent important advances in the study of MC and their clinical significance. This review article summarizes these studies, by delineating the possible mechanisms, and raising doubts and new questions. The related aspects such as discography and differential diagnosis with spinal infection and tumor on MRI are also discussed. Although most of researchers believe that MC are common findings in patients with spinal degenerative diseases and have an association with discogenic LBP, different results between studies may be produced from the differences in study design, inclusion criteria, and sample size. How the present knowledge of MC affects the management of spinal degenerative diseases remains unclear. Further studies of MC will explore therapeutic possibilities for future treatments of spinal degenerative diseases.

MRI follow-up of subchondral signal abnormalities in a selected group of chronic low back pain patients

Subchondral signal abnormalities have been suggested to play an important role in chronic low back pain (LBP) syndromes. Their natural course is not well known. In this study the morphology and natural course of isolated subchondral signal abnormalities in the lumbosacral spine were analyzed with MRI. Twenty-four chronic LBP patients with a subchondral hypointensity on T1-weighted image (hyperintense on T2), indicating edema, were selected from a base population of 1,015 consecutive LBP patients to a follow-up MRI study within 18-72 months. Exclusion criteria were age >60 years, nerve root compression, a more specific back disease or a recent or major spine operation. The size and location of each subchondral signal abnormality and endplate lesion and the degree of degenerative disc changes were evaluated and compared between the baseline and follow-up studies. Most subchondral hypointensities were found at the L4/L5 or L5/S1 disc space, anteriorly and in both adjacent endplates. Almost all (53/54) hypointensities were associated with an endplate lesion. Twelve of the 54 subchondral hypointensities enlarged, six remained constant and 36 decreased or disappeared while five new ones appeared. Twenty-two (41%) hypointensities changed totally to hyperintensities or to mixed lesions. If the hypointensity increased, decreased or changed into hyperintensity, a change tended to develop in the adjacent endplate. If the hypointensity was absent or unchanged, endplate lesions did not tend to progress. In the absence of disc herniation or other specific spinal disease, subchondral hypointensities indicating edema are uncommon. They seem to have a highly variable course. There appears to be a link between endplate lesions and subchondral signal abnormalities. Further study is needed to explain the contribution of these findings to low back symptoms.

Genetic factors are associated with modic changes in endplates of lumbar vertebral bodies

STUDY DESIGN

A cross-sectional genotype-phenotype evaluation.

OBJECTIVE

To evaluate the genetic background to Modic changes in an occupational cohort.

SUMMARY OF BACKGROUND DATA

Modic changes are vertebral endplate changes visible in magnetic resonance imaging. Twin studies suggest that intervertebral disc degeneration may be primarily explained by genetic factors, but no data exist on genetic factors of Modic changes.

METHODS

Thirteen variations in 8 genes (COL9A2, COL9A3, COL11A2, IL1A, IL1B, IL6, MMP3, and VDR) were genotyped in an occupational cohort of 159 male train engineers and 69 male paper mill workers. All the subjects were scanned by magnetic resonance imaging and evaluated for Modic changes.

RESULTS

Out of the 228 subjects, 128 (56%) were found to have Modic changes at one or more disc levels, exclusively of type I in 15%, of type II in 32%, and of both type I and type II in 10%. None of the single nucleotide polymorphisms was significantly associated with Modic changes when analyzed independently, but when gene-gene interactions were evaluated, interleukin-1A (IL1A) and matrix metalloproteinase-3 (MMP3) polymorphisms together were associated with type II Modic changes (OR = 3.2, 95% CI = 1.2-8.5; P = 0.038), as was the IL1 gene cluster together with the MMP3 polymorphism (OR = 8.14, 95% CI = 1.72-38.44; P = 0.008).

DISCUSSION

This is the first study evaluating the role of genetic factors in relation to Modic changes. Genetic variations in the IL1 cluster and the MMP3 gene together were found to be significantly associated with type II Modic changes.

Health technology assessment of magnetic resonance imaging of the spine and bone marrow

The high spatial resolution and the lack of ionizing radiation, makes magnetic resonance imaging the method of choice for imaging most spinal pathology, especially if associated with neurological symptoms. However, due to the high sensitivity of MR imaging, careful correlation between imaging findings and clinical findings is important to ensure appropriate treatment. Substituting radiographic evaluations for rapid MRI in the primary care setting may offer little additional benefit to patients. It may even increase the costs of care but the decisions about the use of imaging depend on judgments concerning whether the small observed improvement in outcome justifies additional cost. Because the presence of an abscess is a major factor in deciding between conservative and surgical treatment, MRI plays an essential role in the decision-making process concerning the treatment of spondylodiscitis. MR is also the method of choice for quantitative evaluation of bone marrow in lymphoma patients when a crucial therapeutic decision has to be made or for the qualitative evaluation of the spinal cord if compression is suspected in primary spinal malignancy or metastatic disease.

Are the determinants of vertebral endplate changes and severe disc degeneration in the lumbar spine the same? A magnetic resonance imaging study in middle-aged male workers

BACKGROUND

Modic changes are bone marrow lesions visible in magnetic resonance imaging (MRI), and they are assumed to be associated with symptomatic intervertebral disc disease, especially changes located at L5-S1. Only limited information exists about the determinants of Modic changes. The objective of this study was to evaluate the determinants of vertebral endplate (Modic) changes, and whether they are similar for Modic changes and severe disc degeneration focusing on L5-S1 level.

METHODS

228 middle-aged male workers (159 train engineers and 69 sedentary factory workers) from northern Finland underwent sagittal T1- and T2-weighted MRI. Modic changes and disc degeneration were analyzed from the scans. The participants responded to a questionnaire including items of occupational history and lifestyle factors. Logistic regression analysis was used to evaluate the associations between selected determinants (age, lifetime exercise, weight-related factors, fat percentage, smoking, alcohol use, lifetime whole-body vibration) and Modic type I and II changes, and severe disc degeneration (= grade V on Pfirrmann's classification).

RESULTS

The prevalences of the Modic changes and severe disc degeneration were similar in the occupational groups. Age was significantly associated with all degenerative changes. In the age-adjusted analyses, only weight-related determinants (BMI, waist circumference) were associated with type II changes. Exposure to whole-body vibration, besides age, was the only significant determinant for severe disc degeneration. In the multivariate model, BMI was associated with type II changes at L5-S1 (OR 2.75 per one SD = 3 unit increment in BMI), and vibration exposure with severe disc degeneration at L5-S1 (OR 1.08 per one SD = 11-year increment in vibration exposure).

CONCLUSION

Besides age, weight-related factors seem important in the pathogenesis of Modic changes, whereas whole-body vibration was the only significant determinant of severe disc degeneration.

The modic vertebral endplate and marrow changes: pathologic significance and relation to low back pain and segmental instability of the lumbar spine

Two decades following their description, the significance of Modic vertebral endplate and marrow changes remains a matter of debate. These changes are closely related to the normal degenerative process affecting the lumbar spine, and their prevalence increases with age. However, the exact pathogenesis underlying these changes and their relation to segmental instability of the lumbar spine and to low back pain remain unclear. In this paper, we review the literature relevant to this topic and discuss the currently available evidence regarding the pathologic and clinical significance of Modic changes.

Self-reported hard physical work combined with heavy smoking or overweight may result in so-called Modic changes

Background

Recently, the MRI finding of "Modic changes" has been identified as pathologic spinal condition that probably reflects a vertebral inflammatory process (VIP), which coincides with spinal pain in most. We hypothesized that heavy smoking in combination with macro- or repeated microtrauma could lead to VIP. The objectives were to investigate if combinations of self-reported heavy smoking, hard physical work, and overweight would be more strongly linked with VIP than with other spinal conditions, such as degenerated discs and non-specific low back pain (LBP).

Methods

Secondary analysis was made of a data base pertaining to a population-based cross-sectional study. A population-generated cohort of 412 40-yr old Danes provided questionnaire information on smoking, weight, height, type of work, and LBP. MRI was used to determine the presence/absence of disc degeneration and of VIP. Associations were tested between three explanatory variables (type of work, smoking, and body mass index) and four outcome variables (LBP in the past year, more persistent LBP in the past year, disc degeneration, and VIP). Associations with these four outcome variables were studied for each single explanatory variable and for combinations of two at a time, and, finally, in a multivariable analysis including all three explanatory variables.

Results

There were no significant associations between the single explanatory variables and the two pain variables or with disc degeneration. However, VIP was found in 15% of non-smokers vs. 26% of heavy smokers. Similarly, VIP was noted in 11% of those in sedentary jobs vs. 31% of those with hard physical work. Further, the prevalence of VIP in those, who neither smoked heavily nor had a hard physical job was 13%, 25% in those who either smoked heavily or had a hard physical job, and 41% in those who both smoked heavily and worked hard. The odds ratio was 4.9 (1.6–13.0) for those who were both heavy smokers and had a hard physical job as compared to those who were classified as "neither". Similar but weaker findings were noted for the combination of overweight and hard physical work but not for the combination of smoking and overweight.

Conclusion

Hard physical work in combination with either heavy smoking or overweight is strongly associated with VIP. If this finding can be reproduced in other studies, it may have consequences in relation to both primary and secondary prevention of LBP, because blue collar workers, who are most likely to experience the consequences of LBP, also are those who are most likely to smoke.

ISSLS prize winner: repeated disc injury causes persistent inflammation

STUDY DESIGN

An in vivo rat model of disc degeneration with emphasis on characterizing acute and chronic cytokine production.

OBJECTIVE

To compare the morphologic and proinflammatory response between a single and triple-stab injury in attempts to establish mechanisms of chronic disc inflammation.

SUMMARY OF BACKGROUND DATA

The features that distinguish physiologic (asymptomatic) from pathologic (symptomatic) degeneration are unclear. Epidemiologic evidence suggests that cumulative damage and elevated disc cytokine levels may be linked to increased low back pain rates. Although acute injury stimulates a healing response that includes transient cytokine production, repetitive damage may be necessary to trigger the persistent inflammation suspected to underlie chronic pain.

METHODS

Tail discs were exposed surgically and stabbed with a number 11 blade. During the subsequent acute healing phase, triple-stab discs were percutaneously injured with a 23-gauge needle at day 3 and then again at day 6 after the initial blade incision. Cytokine (IL-1 beta, IL-6, IL-8, and TNF-alpha) production was quantified using enzyme linked immunosorbent assay, and, in addition to MAPK signaling pathways (phosphorylated forms of ERK, JNK, and p38), was localized by immunohistochemistry. Disc architecture was evaluated using histology.

RESULTS

Both single-stab and triple-stab discs degenerated with time, yet degeneration was more severe with repeated injury where nuclear proteoglycan was replaced by disorganized collagen. Four days after single-stab, there was a transient peak in IL-1 beta and IL-8 production that was localized to the wound track and associated granulation tissue. By contrast, triple-stab induced an activated annular fibroblast phenotype (p38 positive) that caused a prolonged, diffuse inflammatory response with elevated levels of TNF-alpha, IL-1 beta, and IL-8 up to 28 days after injury. Disc inflammation was accompanied by reactive changes in the adjacent vertebral marrow spaces that was initially lytic at day 4, becoming sclerotic by day 56.

CONCLUSION

Our results demonstrate that repeated injury during active healing leads to persistent inflammation and enhanced disc degeneration. These data support the premise that damage accumulation and its associated inflammation may distinguish pathologic from physiologic disc degeneration. In the future, this triple-stab model may be useful to evaluate the efficacy of anti-inflammatory low back pain treatments.

Lumbar degenerative disk disease

The sequelae of disk degeneration are among the leading causes of functional incapacity in both sexes and are a common source of chronic disability in the working years. Disk degeneration involves structural disruption and cell-mediated changes in composition. Mechanical, traumatic, nutritional, and genetic factors all may play a role in the cascade of disk degeneration, albeit to variable degree in different individuals. The presence of degenerative change is by no means an indicator of symptoms, and there is a very high prevalence in asymptomatic individuals. The etiology of pain as the symptom of degenerative disease is complex and appears to be a combination of mechanical deformation and the presence of inflammatory mediators. The role of imaging is to provide accurate morphologic information and influence therapeutic decision making. A necessary component, which connects these two purposes, is accurate natural history data. Understanding the relationship of etiologic factors, the morphologic alterations, which can be characterized with imaging, and the mechanisms of pain production and their interactions in the production of symptoms will require more accurate and reproducible stratification of patient cohorts.

Neck and low back pain: neuroimaging

Spine imaging accounts for a major share of expenses related to neck and back pain. Improving image quality translates into better morphologic evaluation of the spine. Unfortunately, the morphologic abnormalities on spine imaging are common and nonspecific, obscuring the relevance to patient symptomatology. Furthermore, distinction between degenerative and age-related changes is not clear. The key is clinical correlation of imaging findings. This article presents a concise and illustrated discussion of spinal neuroimaging related to neck and back pain, with emphasis on degenerative disease.

Modic changes, possible causes and relation to low back pain

In patients with low back pain (LBP) it is only possible to diagnose a small proportion, (approximately 20%), on a patho-anatomical basis. Therefore, the identification of relevant LBP subgroups, preferably on a patho-anatomical basis, is strongly needed. Signal changes on MRI in the vertebral body marrow adjacent to the end plates also known as Modic changes (MC) are common in patients with LBP (18-58%) and is strongly associated with LBP. In asymptomatic persons the prevalence is 12-13%. MC are divided into three different types. Type 1 consists of fibro vascular tissue, type 2 is yellow fat, and type 3 is sclerotic bone. The temporal evolution of MC is uncertain, but the time span is years. Subchondral bone marrow signal changes associated with pain can be observed in different specific infectious, degenerative and immunological diseases such as osseous infections, osteoarthritis, ankylosing spondylitis and spondylarthritis. In the vertebrae, MC is seen in relation to vertebral fractures, spondylodiscitis, disc herniation, severe disc degeneration, injections with chymopapain, and acute Schmorl's impressions. The aim of this paper is to propose two possible pathogenetic mechanisms causing Modic changes. These are: A mechanical cause: Degeneration of the disc causes loss of soft nuclear material, reduced disc height and hydrostatic pressure, which increases the shear forces on the endplates and micro fractures may occur. The observed MC could represent oedema secondary to the fracture and subsequent inflammation, or a result of an inflammatory process from a toxic stimulus from the nucleus pulposus that seeps through the fractures. A bacterial cause: Following a tear in the outer fibres of the annulus e.g. disc herniation, new capilarisation and inflammation develop around the extruded nuclear material. Through this tissue it is possible for anaerobic bacteria to enter the anaerobic disc and in this environment cause a slowly developing low virulent infection. The MC could be the visible signs of the inflammation and oedema surrounding this infection, because the anaerobic bacteria cannot thrive in the highly aerobic environment of the MC type 1.

PERSPECTIVES

One or both of the described mechanisms can - if proven - be of significant importance for this specific subgroup of patients with LBP. Hence, it would be possible to give a more precise and relevant diagnosis to 20-50% of patients with LBP and enable in the development of efficient treatments which might be antibiotics, special rehabilitation programmes, rest, stabilizing exercise, or surgical fixation, depending on the underlying cause for the MC.

Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain

Clinical practice guidelines state that the tissue source of low back pain cannot be specified in the majority of patients. However, there has been no systematic review of the accuracy of diagnostic tests used to identify the source of low back pain. The aim of this systematic review was therefore to determine the diagnostic accuracy of tests available to clinicians to identify the disc, facet joint or sacroiliac joint (SIJ) as the source of low back pain. MEDLINE, EMBASE and CINAHL were searched up to February 2006 with citation tracking of eligible studies. Eligible studies compared index tests with an appropriate reference test (discography, facet joint or SIJ blocks or medial branch blocks) in patients with low back pain. Positive likelihood ratios (+LR) > 2 or negative likelihood ratios (-LR) < 0.5 were considered informative. Forty-one studies of moderate quality were included; 28 investigated the disc, 8 the facet joint and 7 the SIJ. Various features observed on MRI (high intensity zone, endplate changes and disc degeneration) produced informative +LR (> 2) in the majority of studies increasing the probability of the disc being the low back pain source. However, heterogeneity of the data prevented pooling. +LR ranged from 1.5 to 5.9, 1.6 to 4.0, and 0.6 to 5.9 for high intensity zone, disc degeneration and endplate changes, respectively. Centralisation was the only clinical feature found to increase the likelihood of the disc as the source of pain: +LR = 2.8 (95%CI 1.4-5.3). Absence of degeneration on MRI was the only test found to reduce the likelihood of the disc as the source of pain: -LR = 0.21 (95%CI 0.12-0.35). While single manual tests of the SIJ were uninformative, their use in combination was informative with +LR of 3.2 (95%CI 2.3-4.4) and -LR of 0.29 (95%CI 0.12-0.35). None of the tests for facet joint pain were found to be informative. The results of this review demonstrate that tests do exist that change the probability of the disc or SIJ (but not the facet joint) as the source of low back pain. However, the changes in probability are usually small and at best moderate. The usefulness of these tests in clinical practice, particularly for guiding treatment selection, remains unclear.

Modic changes in endplates of lumbar vertebral bodies: prevalence and association with low back and sciatic pain among middle-aged male workers

STUDY DESIGN

Cross-sectional comparison of self-reported low back pain (LBP) symptoms and Modic findings on magnetic resonance imaging (MRI).

OBJECTIVES

To investigate associations of frequency and intensity of LBP and sciatic pain with Modic changes in a sample of middle-aged male workers with or without whole-body vibration exposure.

SUMMARY OF BACKGROUND DATA

Vertebral endplate changes are bone marrow lesions visible on MRI and are assumed to be associated with degenerative intervertebral disc disease. Associations of these so-called Modic changes with clinical symptoms are controversial. Furthermore, most of these studies have been performed in selected series of patients.

METHODS

A total of 228 middle-aged male workers (159 train engineers and 69 sedentary controls) from northern Finland underwent sagittal T1 and T2-weighted MRI. Both endplates of 1140 lumbar interspaces were graded for type and extent of Modic changes. Logistic regression was used to analyze associations of pain variables with Modic changes.

RESULTS

Train engineers had on the average higher sciatic pain scores than the sedentary controls, but the prevalence of Modic changes was similar in both occupational groups. Altogether, 178 Modic changes in 128 subjects were recorded: 30% were type I, 66% type II, and 4% both types I and II. Eighty percent of changes occurred at L4-L5 or L5-S1. Modic changes at L5-S1 showed significant association with pain symptoms with increased frequency of LBP (odds ratio [OR] 2.28; 95% confidence interval [CI] 1.44-3.15) and sciatica episodes (OR 1.44; 95% CI 1.01-1.89), and with higher LBP visual analog scores during the past week (OR 1.36; 95% CI 1.06-1.70). Type I lesions and extensive lesions in particular were closely associated with pain.

CONCLUSIONS

Modic changes at L5-S1 and Modic type I lesions are more likely to be associated with pain symptoms than other types of Modic changes or changes located at other lumbar levels.

Reverse transformation of Modic type 2 changes to Modic type 1 changes during sustained chronic low-back pain severity. Report of two cases and review of the literature

Modic Type 2 (MT2) neuroimaging changes are considered stable or invariant over time and relatively quiescent, whereas Modic Type 1 (MT1) changes are considered unstable and more symptomatic. The authors report two cases in which MT2 changes were symptomatic and evidently unstable, and in which chronic low-back pain severity remained unaltered despite a MT2-MT1 reverse transformation. Two women (41 and 48 years old) both presented with chronic low-back pain. Magnetic resonance (MR) images demonstrated degenerating discs at L5-S1 associated with well-established MT2 changes in adjacent vertebrae. Repeated MR imaging in these two patients after 11 months and 7 years, respectively, revealed reverse transformation of the MT2 changes into more florid MT1 changes, despite unaltered chronic low-back pain severity. Following anterior discectomy and disc arthroplasty, immediate abolition of chronic low-back pain was achieved in both patients and sustained at 3-year follow up. Modic Type 2 changes are therefore neither as stable nor as quiescent as originally believed. Each type can change, with equal symptom-generating capacity. More representative imaging-pathological correlates are required to determine the precise nature of MT changes.

Inter- and Intraexaminer Reliability in Identifying and Classifying Degenerative Marrow (Modic) Changes on Lumbar Spine Magnetic Resonance Scans

OBJECTIVE

Signal intensity changes noted on magnetic resonance imaging scans in degenerated disks and adjacent bone marrow have been described and labeled "Modic" changes. Three types are identified, with type 1 being linked to low back pain. This study reports on the reliability of identifying and categorizing Modic marrow changes as would be done in the normal course of clinical practice.

METHODS

Fifty-one lumbar spine sagittal magnetic resonance imaging scans of adult male patients older than 40 years were used. Two radiologists independently read each case at 2 different periods; scans were reordered for the second reading. The radiologists recorded the presence or absence of Modic changes anywhere in the lumbar spine for each case and classified each one as type 1, type 2, or type 3, and the level or levels where they were noted. The kappa statistic was used to evaluate inter- and intraexaminer agreement overall and by disk level. Percent agreement was also calculated.

RESULTS

The overall kappa value for the interexaminer agreement of diagnosing the presence/absence of Modic changes for the entire lumbar spine as well as classifying them when present was kappa = 0.52 (moderate) with 71% agreement. At the L4 through 5 level, the kappa value was 0.81 (substantial) with 92% agreement, and at the L5 through S1 level, the kappa value was 0.58 (upper moderate) with 76% agreement. The L3 through L4 level had a kappa value of 0.66 (strong) but was considered "unstable" because of the lack of variability within the cells of the contingency table. The intraexaminer reliability gave a kappa value of 0.71 (strong) (82% agreement) for examiner 1 and a kappa value of 0.87 (almost perfect) (92%) for examiner 2.

CONCLUSIONS

The Modic classification system shows moderate to almost perfect inter- and intraexaminer reliability in this study, simulating the methods of diagnosis used in clinical/radiological practice. The results of studies using the Modic system before investigations of its reliability can be viewed with more confidence, and future studies can continue to evaluate the link with patient symptoms and treatment outcomes.

Relation of inflammatory modic changes to intradiscal steroid injection outcome in chronic low back pain

The purpose of this study was to analyze the association between the severity of inflammatory endplate changes (Modic) on MRI and the clinical response to intradiscal injection of corticosteroids (IDIC) in chronic low back pain (LBP). A total of 74 patients with LBP and inflammatory Modic changes who showed no response to 3-month conservative treatment received lumbar IDIC. Two spine specialists and a radiologist assessed independently the endplate marrow changes of the injected discs. We classified patients with a pure edema endplate changes on MRI as Modic type I (n = 37); those with a mixture of Modic type I and type II changes but predominantly edema changes as Modic I-2 (n = 25) and those with predominantly fatty changes as Modic II-1 (n = 12). The primary outcome was the change in LBP intensity between baseline and 1 month after IDIC, as measured on a visual analog scale (range 0-100 mm). At 1 month, reduction in pain score was significantly higher in the Modic I and Modic I-2 groups than in the Modic II-1 group (30.2 +/- 26.6 and 29.4 +/- 21.5 vs 5.3 +/- 25.5; P = 0.009 and P = 0.017, respectively). At 3 and 6 months, IDIC tended to be more effective in the Modic I and Modic I-2 groups but not significantly. No complications such as infection or hematoma were reported. IDIC could be a short-term efficient treatment for patients with chronic LBP and predominantly inflammatory endplate changes when conservative treatments have failed.

Prevalence of Modic Degenerative Marrow Changes in the Cervical Spine

OBJECTIVE

The prevalence and distribution of Modic degenerative marrow changes as seen on magnetic resonance imaging scans have been reported for the lumbar spine, and research suggests that type 1 Modic changes are linked to low back pain. The purpose of this study was to report on the prevalence, types, and distribution of the changes found for the cervical spine.

METHODS

One hundred thirty-three cervical spine T1-weighted and T2-weighted sagittal magnetic resonance imaging scans were viewed retrospectively by two radiologists. Data were recorded for patient age, patient sex, and the presence or absence of Modic changes. If Modic changes were present, then the precise vertebral levels of these changes and the specific Modic type were recorded. Descriptive statistics were calculated for the prevalence of Modic changes overall, the prevalence of types 1, 2, and 3 changes, and the prevalence in male vs female patients. The frequency of these changes by spinal level was also determined.

RESULTS

One hundred eighteen patients met the inclusion criteria. Modic changes were seen in 19 patients (16%), with 4 showing changes in more than one segmental level. The most common Modic change observed was type 1. Type 3 marrow changes were the second most common category to be noted. Only 3 patients had Modic type 2 marrow changes. The most common cervical spinal level to show Modic changes was C5-6.

CONCLUSIONS

Modic degenerative bone marrow changes are observed in the cervical spine, with the C5-6 level being the most commonly involved. Unlike in the lumbar spine in which Modic type 2 changes predominate, type 1 marrow changes were far more common in the cervical spine. Further studies should focus on the clinical relevance of these findings.

Technology Insight: imaging of low back pain

Chronic low back pain is a common condition that has significant economic consequences for affected patients and their communities. Despite the prevailing view that an anatomic diagnosis is often impossible, an origin for the pain can frequently be found if current diagnostic techniques are fully used. Such techniques include a mixture of noninvasive and invasive imaging. Prevalence data suggest that the intervertebral disc is one of the most common sources of back pain, accounting for around 40% of cases. The pathologic basis for discogenic low back pain might be full-thickness radial tears of the annulus fibrosus. Unfortunately, only MRI can image the internal morphology of the disc, and both CT and MRI lack the necessary specificity to validate this hypothesis. Many so-called radiographic abnormalities seen on CT and MRI are commonly encountered in asymptomatic individuals. Invasive techniques such as joint injections, nerve blocks and provocative discography can show the connection between an abnormal image and the source of low back pain, but do have notable related risks. The development of a noninvasive, low-risk technique that can show this connection is desirable.

Diagnostic relevance of pressure-controlled discography

Discogenic pain is a leading cause of chronic low back pain. The authors investigated the efficacy of pressure-controlled discography to determine its role in clinical decision-making for the management of patients with discogenic pain. Pressure-controlled discography was performed in 21 patients (51 discs) with pain-provocation, followed by post-discography computerized tomography scans. Pain response was classified as positive response and negative response, and measured with visual analog scale scores. Discographic findings were graded by the modified Dallas discogram scale. Elastance, pain provocation on intradiscal pressure, pressure and volume of initial pain response, and pain response intensity were statistically analyzed. Elastance showed significant differences between Grade 0 and Grade 4 and 5. Decreased elastance with positive pain response group was a good indicator to imply that disc degeneration presumably is a pain generator. Results of pain response were well correlated with intradiscal pressure but not with the amount of injected volume. Among 31 discs of Grade 4 and 5, 74% showed negative pain response and 26% showed positive response. It was concluded that pressure-controlled discography was useful to diagnose discogenic pain and excellent guide in decision-making for spinal operations.

Surgical technique of lumbar artificial disc replacement with the Charité artificial disc

Lumbar artificial disc technology has been commercially available outside the United States for nearly 2 decades. With the Food and Drug Administration approval of the Charité Artificial Disc in October 2004, an entirely new spinal surgeon population will be able to offer this technology to their patients as a treatment option. As with other techniques in spinal surgery, indications for lumbar total disc replacement are paramount to the success of the procedure. The correct surgical technique is also important to a successful outcome. This article describes the technique for placement of the Charité Artificial Disc in indicated patients. The technique is similar to that of an anterior lumbar interbody fusion procedure, but many differences between the techniques make lumbar total disc replacement a unique procedure in the spinal surgeon's armamentarium. Although this article is thorough in its description of the surgical technique for total disc replacement with the Charité Artificial Disc, it should not be used as a substitute for company-sponsored training.

Predictive value of MRI vertebral end-plate signal changes (MODIC) on outcome of surgically treated degenerative disc disease

OBJECTIVE

To assess the predictive value of MRI vertebral end-plate changes (Modic) on clinical outcome of surgically treated lumbar single-level degenerative disc disease (DDD).

METHODS

A cohort of 60 patients was included. Patient groups were similar in respect of age, gender and clinical presentation, allowing comparisons. Patient age ranged from 30 to 72 years (mean: 45.8 years). All patients suffered severe chronic low back pain for more than 6 months, with single-level symptomatic DDD. All patients experienced segmental instrumented interbody (n = 22) or posterolateral (n = 38) fusion. Clinical outcome was assessed by using a visual analog scale (VAS) and the functional disability scale of the Japanese Orthopaedic Association (JOA) for lumbar spine. The number of patients for each Modic group was as follows: Modic type 0, n = 15; Modic type I, n = 22; Modic type II, n = 14; and Modic type I/II, n = 9. Fusion rates were similar for each Modic group of patients. Mean follow-up was 14 months.

RESULTS

The pre-operative mean VAS improved by 53.5% (from 8.2+/-2.0 to 3.8+/-1.9, p < 0.05) and the pre-operative mean JOA score by 58% (from 5.5+/-2.1 to 11.0+/-2.4, p < 0.05). Patients harboring Modic type I changes improved much better than others (p < 0.05). Conversely, clinical outcome of patients presenting with Modic type II lesions was poor.

CONCLUSION

This study confirms instrumented fusion as an effective treatment in symptomatic lumbar DDD. Preoperative combination of low back pain of discal origin and severe DDD with Modic type I lesion on MRI may lead to excellent results after fusion in a large proportion of patients. Conversely, arthrodesis for patients harboring Modic type II abnormalities implicates smaller benefit of doubtful clinical significance.

A three-year follow-up of lumbar spine endplate (Modic) changes

STUDY DESIGN

A longitudinal follow-up of Modic changes on magnetic resonance imaging (MRI).

OBJECTIVES

To assess the prevalence and natural course Modic changes over a 3-year follow-up period.

SUMMARY OF BACKGROUND DATA

Modic changes are bone marrow and endplate lesions visible on MRI. To the authors' knowledge, no follow-up studies on their natural course have been published.

METHODS

The study population consisted of 60 unoperated sciatica patients 23 to 76 years of age. Baseline and 3-year lumbar MR images from L1-L2 through L5-S1 were analyzed independently by 2 radiologists and a consensus reading was performed.

RESULTS

At baseline, the prevalence of Modic changes was 23%. Seven discs had mixed Type I/II, and 63 Type II change. Changes typically occurred at L4-L5 and L5-S1, and associated positively with age (P = 0.009). Ten of 70 discs (14%) with Modic changes at baseline displayed another type at 3 years. Furthermore, the nonconverted changes increased significantly in size. The incidence of new Modic changes during the follow-up was 6% (13 of 230).

CONCLUSIONS

Modic changes are common MRI findings in patients with degenerative lumbar disc disease. We found evidence that Modic Type II changes may be less stable than previously assumed.

Tumor necrosis factor-immunoreactive cells and PGP 9.5-immunoreactive nerve fibers in vertebral endplates of patients with discogenic low back Pain and Modic Type 1 or Type 2 changes on MRI

STUDY DESIGN

Immunohistochemistry for tumor necrosis factor (TNF) and protein gene product (PGP) 9.5 in vertebral endplates of patients with discogenic low back pain and Modic Type 1 or Type 2 endplate changes on MRI.

OBJECTIVES

To examine whether inflammatory cytokines and nerve in-growth into the vertebral endplate are associated with discogenic low back pain.

SUMMARY AND BACKGROUND DATA

Degenerated discs and endplate abnormalities can be a cause of discogenic low back pain. However, the presence of TNF-immunoreactive cells and PGP 9.5-immunoreactive nerve fibers has not been studied in patients with discogenic low back pain and endplate changes on MRI.

METHODS

Eighteen endplates showing either normal intensity signals on MRI (endplate change -), Modic Type 1 signals (low intensity on T1-weighted spin-echo images), or Modic Type 2 signals (high intensity) from patients with discogenic low back pain (n = 14) or controls requiring surgery for other back problems (n = 4; scoliosis and traumatic injury of vertebra) were harvested during surgery. Endplates were immunostained using antibodies to TNF and PGP 9.5 and immunostained cells and nerve fibers in the endplates were counted.

RESULTS

Vertebral endplates from patients with Modic Type 1 or Type 2 endplate changes on MRI had significantly more PGP 9.5-immunoreactive nerve fibers and TNF-immunoreactive cells in comparison with patients with normal endplates on MRI (P < 0.01). The number of TNF-immunoreactive cells in endplates exhibiting Modic Type 1 changes was significantly higher than in endplates exhibiting Modic Type 2 changes (P < 0.05).

CONCLUSIONS

The results suggest that endplate abnormalities are related to inflammation and axon growth induced by TNF. TNF expression and PGP 9.5-positive nerve in-growth in abnormal endplates may be a cause of low back pain.

Interobserver reliability in the interpretation of diagnostic lumbar MRI and nuclear imaging

BACKGROUND CONTEXT

Assessment of patients with complaints of low back or leg pain varies with the subspecialty of the treating physician. The evaluation of the spine patient may include magnetic resonance imaging (MRI), bone scan, or single-photon emission computed tomography (SPECT) imaging. The interpretation of these tests and the examiner's biases will impact the outcome of patient treatment and the cost to the health-care system.

PURPOSE

To evaluate interobserver reliability of MRI and nuclear imaging studies and determine the predictability of nuclear medicine results based upon MRI findings.

STUDY DESIGN/SETTING

Retrospective radiographic review for patients with low back pain. MRI, planar bone scan imaging, and SPECT imaging techniques were evaluated.

PATIENT SAMPLE

Seventeen patients (80 lumbar levels) who presented to an orthopedic spine specialist with a complaint of mechanical low back or leg pain were randomly selected. Inclusion criteria were age greater than 21 years and a workup that included MRI, bone scan, and SPECT scan images.

OUTCOME MEASURES

Interobserver reliability was determined using kappa values (0.6 to <0.8=substantial; 0.8-1=perfect). Interobserver reliability was evaluated for all studies and compared with a "group consensus."

METHODS

A team of orthopedists and radiologists of varying experience levels were assembled to interpret the imaging studies. All readings were performed independently followed by group interpretation and discussion. The reviewers were asked to assess each lumbar level (L1-L2 through L5-S1). Phase one: Is the level degenerative? Is there a spondylolisthesis present? Does the level have Modic changes on MRI? Phase two: Based on the MRI, will the planar bone scan be positive? After this prediction, was the planar scan positive? Identify the lesion location (anterior column vs. posterior column). Phase three: Based on their assessment and predicted results on planar bone scan, was the SPECT scan able to improve this assessment?

RESULTS

High kappa values were demonstrated in the identification of a degenerative disc, spondylolisthesis, and Modic change (0.773, 0.728, and 0.669, respectively). Bone scan and SPECT scan yielded poorer kappa results (0.539 and 0.460, respectively). Reviewer-predicted bone scan results demonstrated a positive predictive value of 68% and a negative predictive value of 84%. Predicated SPECT results were similar (positive predictive value 66% and negative predictive value 84%). SPECT identified 24% more lesions in the lumbar spine when compared with bone scan.

CONCLUSIONS

MRI interpretation of the lumbar spine is comparable between specialties. Nuclear imaging studies (bone scan/SPECT) demonstrated a poorer correlation between examiners. The presence of MRI changes enables an accurate prediction of bone scan or SPECT scan findings. SPECT scan demonstrates an increased sensitivity in the detection of spinal abnormalities and the ability to localize a lesion when compared with planar bone scan.

Minimally invasive procedures for the treatment of failed back surgery syndrome

Failed back surgery syndrome has become unfortunately a common clinical entity. FBSS does not have one specific treatment because it does not have one specific cause. Some features are shared with chronic low back pain (CLBP) and some pathological processes are specific. Both pathologies are leading causes of disability in the industrialized world and costly medical and surgical treatments are continuously used despite their limited efficacy. Nonetheless, evidence based practice guidelines are systematically developed. In this chapter we cautiously review the vast, complex and at times contradictory literature regarding the treatment of FBSS. Interventional Pain literature suggests that there is moderate evidence (small randomized or non randomized or single group or matched case controlled studies) for medial branch neurotomy and limited evidence (non experimental one or more center studies) for intra-discal treatments in mechanical low back pain. There is moderate evidence for the use of transforaminal epidural steroid injections, lumbar percutaneous adhesiolysis and spinal endoscopy for painful lumbar radiculopathy and spinal cord stimulation and intrathecal pumps mostly after spinal surgery. In reality there is no gold standard for the treatment of FBSS but, these results seem promising.

No correlation between patient outcome and abnormal lumbar MRI findings 21 years after posterior or posterolateral fusion for isthmic spondylolisthesis in children and adolescents

Between 1977 and 1987, posterior (n=29) or posterolateral (n=73) fusion was performed for mild to moderate (slip <50%) isthmic spondylolisthesis on 102 patients (46 females, 56 males). The patients' average age at the time of operation was 15.9 (range, 8.1-19.8) years. Clinical (physical examination and Oswestry disability index (ODI)) and radiological (MRI and plain radiographs) examinations were performed on these patients after an average follow-up time of 21.0 (range, 26.2-15.1) years. In the radiographs, the mean slip preoperatively was 27% (range, 5-50%) and at the last follow-up visit 26% (range, 5-78%). Inside the fusion, there were a total of 148 intervertebral discs, 121 (82%) of them had decreased signal intensity in T2-weighted MR images and 113 (76%) were narrowed. Above the fusion level, 27 (27%) discs were speckled and 27 (27%) were black; 21 (21%) intervertebral disc spaces were narrowed. Two levels above the fusion level the numbers were 8 (8%), 16 (16%) and 16 (16%), respectively. Six (6%) patients had a prolapse. Degenerative facet joint hypertrophy above fusion was seen at 80 (79%) of the levels studied. When compared to healthy subjects higher frequency of disc and facet joint degeneration was found. In MR images, none of the patients had lumbar spinal stenosis inside or above the fusion. Narrowing of one or both of the neural foramina at the level of the L5-S1 interververtebral disc was noted in 32 (31%) patients. Seventeen (17%) of the patients had, usually mild, muscular atrophy of the psoas and 33 (32%) of the paraspinal muscles. There was no difference in frequency of abnormal MRI findings between patients (n=93) with ODI 20 or less compared with patients (n=9) with ODI more than 20. In situ fusion due to isthmic spondylolsthesis at adolescence is associated with moderate degenerative changes in the lumbar spine during a 20-year follow-up. Changes were most commonly found at the level of the spondylolisthesis and above fusion level. Neural foramina stenosis seems to be associated with spondylolisthesis and its severity to severity of the slip. Muscle atrophy tended to be mild. However, there was no correlation between patient outcome (ODI) and abnormal lumbar MRI findings.

Lumbale Bandscheibenprothesen

Lumbar interbody fusion used to be the most common surgical treatment for painful lumbar disc degeneration. With the technical development of total disc prostheses, replacement of the degenerated disc by a motion preserving implant has become a widely discussed alternative. The advantages of such replacement appear to include the prevention of adjacent segment disease as well as less perioperative morbidity. Three types of total disc prostheses are currently in common use. Although numerous studies have been made, a review of the literature reveals only two multicenter randomized studies comparing the outcome of disc prostheses with a control group of fusion patients. After 2 years, the available results show similar improvement after both types of surgery without significant differences. However, there is a trend towards faster recovery and improvement in disc arthroplasty patients. The long-term results of current and future randomized studies, including studies comparing results after disc arthroplasty, with results of standardized conservative therapies will determine the fate of lumbar disc prostheses.

Guidelines for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 6: magnetic resonance imaging and discography for patient selection for lumbar fusion

Discography is an exquisitely sensitive but not specific diagnostic test for the diagnosis of discogenic low-back pain. The restriction of the definition of a positive discographic study to one that elicits concordant pain from a morphologically abnormal disc improves the definition's accuracy. Fusion surgery based on discography alone, however, is not reliably associated with clinical success. Therefore, discography is not recommended as a standalone test for treatment decisions in patients with low-back pain. Magnetic resonance imaging is a sensitive and noninvasive test for the presence of degenerative disc disease. Discography should not be attempted in patients with normal lumbar MR images. Discography appears to have a role in the evaluation of patients with low-back pain, but it is best limited to the evaluation of abnormal interspaces identified on MR imaging, the investigation of adjacent-level disc disease, and as a means to rule out cases of nonorganic pain from surgical consideration.

Magnetic resonance imaging and low back pain in adults: a diagnostic imaging study of 40-year-old men and women

STUDY DESIGN

Cross-sectional cohort study of a general population.

OBJECTIVE

To investigate "abnormal" lumbar spine magnetic resonance imaging (MRI) findings, and their prevalence and associations with low back pain (LBP).

SUMMARY OF BACKGROUND DATA

The clinical relevance of various "abnormal" findings in the lumbar spine is unclear. Distinguishing between inevitable age-related findings and degenerative findings with deleterious consequences is a challenge.

METHODS

Lumbar spine MRI was obtained in 412, 40-year-old individuals. Predefined "abnormal" MRI findings were interpreted without any knowledge of patient symptoms. Associations between MRI abnormalities and LBP were calculated using odds ratios. The "overall picture" of each MRI finding was established on the basis of the frequencies, diagnostic values, and the strength and consistency of associations.

RESULTS

Most "abnormal" MRI findings were found at the lowest lumbar levels. Irregular nucleus shape and reduced disc height were common (>50% of individuals). Relatively common (25% to 50%) were hypointense disc signal, anular tears, high intensity zones, disc protrusions, endplate changes, zygapophyseal joint degeneration, asymmetry, and foraminal stenosis. Nerve root compromise, Modic changes, central spinal stenosis, and anterolisthesis/retrolisthesis were rare (<25%). Most strongly associated with LBP were Modic changes and anterolisthesis (odds ratios >4). Significantly positive associations with all LBP variables were seen for hypointense disc signals, reduced disc height, and Modic changes. All disc "abnormalities" except protrusion were moderately associated with LBP during the past year.

CONCLUSION

Most degenerative disc "abnormalities" were moderately associated with LBP. The strongest associations were noted for Modic changes and anterolisthesis. Further studies are needed to define clinical relevance.

Reactive endplate marrow changes: a systematic morphologic and epidemiologic evaluation

PURPOSE

To evaluate the morphology and location of vertebral endplate changes, and to analyze their association with age, gender, and body mass index (BMI).

DESIGN AND PATIENTS

At 1.5 T (T1-weighted, T2-weighted/STIR) 100 lumbar spines were evaluated separately by three observers. The readers classified the endplate bone marrow abnormalities on sagittal MR images according to the definitions of Modic et al. Findings were localized by disc segment; whether in the upper and/or lower endplate; and within each endplate divided into 15 segments. Disc space narrowing, as well as disc desiccation, was also noted at each vertebral level. In addition, endplate changes were correlated with age, gender, and BMI (weight(kg)/height(m)2).

RESULTS

A total of 15,000 data points were studied and 422 total changes recorded. A total of 99 vertebral levels were affected in 58 patients. Of these, 171 were of type I, 242 were of type II, and 9 were of type III. L4-L5 and L5-S1 vertebral levels were most commonly involved, having (142, 4.73%) and (116, 3.87%) changes respectively (P<0.0001). The upper and lower aspects of the endplate were affected similarly. Changes most frequently occurred at the anterior aspect of the endplate (P<0.0001). Endplate marrow changes were associated with increasing age (P<0.0001) and, surprisingly, male gender (P<0.0001). Endplate changes were not associated with BMI.

CONCLUSION

The fatty pattern was most common, with the sclerotic pattern being rare. Endplate marrow changes most often occurred at the anterior aspect of the endplate, particularly at L4--L5 and L5--S1 levels. Modic changes occur more frequently with aging, evidence of their degenerative etiology. They were, however, not related to body habitus, but to weight and male gender.