Associations between back pain history and lumbar MRI findings

The association of lumbar intervertebral disc degeneration with low back pain is modified by underlying genetic propensity to pain

BACKGROUND CONTEXT

Associations between magnetic resonance imaging (MRI)-detected lumbar intervertebral disc degeneration (LDD) and LBP are often of modest magnitude. This association may be larger in specific patient subgroups.

PURPOSE

To examine whether the association between LDD and LBP is modified by underlying genetic predispositions to pain.

STUDY DESIGN

Cross-sectional study in UK Biobank (UKB) and TwinsUK.

PATIENT SAMPLES

A genome-wide association study (GWAS) of the number of anatomical chronic pain locations was conducted in 347,538 UKB participants. The GWAS was used to develop a genome-wide polygenic risk score (PRS) in a holdout sample of 30,000 UKB participants. The PRS model was then used in analyses of 645 TwinsUK participants with standardized LDD MRI assessments.

OUTCOME MEASURES

Ever having had LBP associated with disability lasting ≥1 month (LBP1).

METHODS

Using the PRS as a proxy for "genetically-predicted propensity to pain", we stratified TwinsUK participants into PRS quartiles. A "basic" model examined the association between an LDD summary score (LSUM) and LBP1, adjusting for covariates. A "fully-adjusted" model also adjusted for PRS quartile and LSUM x PRS quartile interaction terms.

RESULTS

In the basic model, the odds ratio (OR) of LBP1 was 1.8 per standard deviation of LSUM (95% confidence interval [CI] 1.4 -2.3). In the fully-adjusted model, there was a statistically significant LSUM-LBP1 association in quartile 4, the highest PRS quartile (OR = 2.5 [95% CI 1.7-3.7], p=2.6×10-6), and in quartile 3 (OR=2.0, [95% CI 1.3-3.0]; p=0.002), with small-magnitude and/or non-significant associations in the lowest two PRS quartiles. PRS quartile was a significant effect modifier of the LSUM-LBP1 association (interaction p≤0.05).

CONCLUSIONS

Genetically-predicted propensity to pain modifies the LDD-LBP association, with the strongest association present in people with the highest genetic propensity to pain. Lumbar MRI findings may have stronger connections to LBP in specific subgroups of people.

Prevalence of degenerative vertebral disc changes in elite female Crossfit athletes - a cross-sectional study

BACKGROUND

Crossfit athletes consistently recruit or transfer high levels of repetitive forces through the spine, and MRI has documented a higher rate of intervertebral disc degeneration in athletes compared with matched controls. The aim of this study was to evaluate early degenerative spinal disc changes in elite female CrossFit athletes quantified by 3.0 Tesla magnetic resonance imaging (MRI) matched with female none-athletes.

METHODS

In a cross-sectional single-center study 19 asymptomatic adult participants, nine German female elite Crossfit athletes and ten female participants underwent spinal MRI (3.0T). Demographic data, spinal clinical examination results and sport-specific performance parameters were collected prior to the MRI. The primary outcome was the prevalence of degenerative spinal disc changes. The secondary outcome was the grade of degeneration using Pfirrmann grading.

RESULTS

A total of 437 discs underwent spinal MRI (3.0T). The prevalence of early degenerative disc disease was not increased. Pfirrmann degenerative grade did not show significant differences among groups.

CONCLUSION

Asymptomatic female elite Crossfit athletes do not show an increased prevalence of degenerative disc disease. Compared to a sex-matched control group, high training volume in Crossfit does not correlate to a higher incidence of degenerative disc changes in young females.

Association between clinical findings and the presence of lumbar spine osteoarthritis imaging features: A systematic review

OBJECTIVE

Spinal osteoarthritis is difficult to study and diagnose, partly due to the lack of agreed diagnostic criteria. This systematic review aims to give an overview of the associations between clinical and imaging findings suggestive of spinal osteoarthritis in patients with low back pain to make a step towards agreed diagnostic criteria.

DESIGN

We searched MEDLINE, Embase, Web of Science, and CINAHL from inception to April 29, 2021 to identify observational studies in adults that assessed the association between selected clinical and imaging findings suggestive of spinal osteoarthritis. Risk of bias was assessed using the Newcastle Ottawa Scale and the quality of evidence was graded using an adaptation of the GRADE approach.

RESULTS

After screening 7902 studies, 30 met the inclusion criteria. High-quality evidence was found for the longitudinal association between low back pain (LBP) intensity, and both disc space narrowing and osteophytes, as well as for the association between LBP-related physical functioning and lumbar disc degeneration, the presence of spinal morning stiffness and disc space narrowing and for the lack of association between physical functioning and Schmorl's nodes.

CONCLUSIONS

There is high- and moderate-quality evidence of associations between clinical and imaging findings suggestive of spinal osteoarthritis. However, the majority of the studied outcomes had low or very low-quality of evidence. Furthermore, clinical and methodological heterogeneity was a serious limitation, adding to the need and importance of agreed criteria for spinal osteoarthritis, which should be the scope of future research.

MRI image features with an evident relation to low back pain: a narrative review

PURPOSE

Low back pain (LBP) is one of the most prevalent health condition worldwide and responsible for the most years lived with disability, yet the etiology is often unknown. Magnetic resonance imaging (MRI) is frequently used for treatment decision even though it is often inconclusive. There are many different image features that could relate to low back pain. Conversely, multiple etiologies do relate to spinal degeneration but do not actually cause the perceived pain. This narrative review provides an overview of all possible relevant features visible on MRI images and determines their relation to LBP.

METHODS

We conducted a separate literature search per image feature. All included studies were scored using the GRADE guidelines. Based on the reported results per feature an evidence agreement (EA) score was provided, enabling us to compare the collected evidence of separate image features. The various relations between MRI features and their associated pain mechanisms were evaluated to provide a list of features that are related to LBP.

RESULTS

All searches combined generated a total of 4472 hits of which 31 articles were included. Features were divided into five different categories:'discogenic', 'neuropathic','osseous', 'facetogenic', and'paraspinal', and discussed separately.

CONCLUSION

Our research suggests that type I Modic changes, disc degeneration, endplate defects, disc herniation, spinal canal stenosis, nerve compression, and muscle fat infiltration have the highest probability to be related to LBP. These can be used to improve clinical decision-making for patients with LBP based on MRI.

Do lumbar intervertebral disc parameters in patients with chronic low back pain differ quantitatively from healthy individuals? A comparative study

Objectives: Studies in the past were not able to find any definitive correlation between disc parameters and LBP. The objectives of the current study were to evaluate the association of the lumbar disc parameters with LBP and to find the quantitative differences between the discs in LBP patients and healthy individuals. Methodology: Fifty patients with chronic LBP (group A) and 25 healthy individuals (group B) were subjected to magnetic resonance imaging of lumbar spine. Disc parameters of orientation and size were estimated. Results: There was a statistically significant difference in disc angle at L1-L2 ( p = 0.01), L2-L3 ( p = 0.05), and L3-L4 ( p = 0.001), and skin angle at L2-L3 ( p = 0.03) and L4-L5 ( p = 0.05) level. Length and cross-sectional area (CSA) of anterior intervertebral height, posterior intervertebral height, intervertebral disc, anterior disc material, posterior disc material; and volume of anterior disc material and volume of posterior disc material were statistically significantly more at various disc levels in group A. Antero-posterior dural sac length and CSA of the sac were statistically significantly smaller at L4-L5 and L5-S1 levels. There was a significant association between average disc height and dural sac area at L1-L2 ( p-value = 0.0393) and L5-S1 ( p-value = 0.0022) and CSA of the disc and dural sac area at L5-S1 ( p-value = 0.049) in group A. Conclusions: There was a significant difference in the lumbar disc orientation and dimensions between LBP patients and healthy individuals. Larger disc parameters (height, volume, CSA, and length) and altered orientation may affect the biomechanics of the spine, thus predisposing to LBP.

Recent Advances in Coupled MBS and FEM Models of the Spine—A Review

How back pain is related to intervertebral disc degeneration, spinal loading or sports-related overuse remains an unanswered question of biomechanics. Coupled MBS and FEM simulations can provide a holistic view of the spine by considering both the overall kinematics and kinetics of the spine and the inner stress distribution of flexible components. We reviewed studies that included MBS and FEM co-simulations of the spine. Thereby, we classified the studies into unidirectional and bidirectional co-simulation, according to their data exchange methods. Several studies have demonstrated that using unidirectional co-simulation models provides useful insights into spinal biomechanics, although synchronizing the two distinct models remains a key challenge, often requiring extensive manual intervention. The use of a bidirectional co-simulation features an iterative, automated process with a constant data exchange between integrated subsystems. It reduces manual corrections of vertebra positions or reaction forces and enables detailed modeling of dynamic load cases. Bidirectional co-simulations are thus a promising new research approach for improved spine modeling, as a main challenge in spinal biomechanics is the nonlinear deformation of the intervertebral discs. Future studies will likely include the automated implementation of patient-specific bidirectional co-simulation models using hyper- or poroelastic intervertebral disc FEM models and muscle forces examined by an optimization algorithm in MBS. Applications range from clinical diagnosis to biomechanical analysis of overload situations in sports and injury prediction.

Effect of endplate reduction on endplate healing morphology and intervertebral disc degeneration in patients with thoracolumbar vertebral fracture

OBJECTIVE

To determine the effect of endplate reduction on the final healing morphology and degenerative changes in intervertebral discs.

METHODS

Forty-eight patients with single-level thoracolumbar fractures with endplate injury were included. All patients underwent posterior reduction and pedicle screw fixation, and postoperative imaging was used to determine whether endplate reduction was successful. The healing morphology of the endplate was divided into three types: increased endplate curvature, irregular healing and traumatic Schmorl node. MRI was performed at baseline and at the last follow-up evaluation to observe changes in disc degeneration (disc height and nucleus pulposus signal) and Modic changes.

RESULTS

The reduction rate in the central area was significantly lower than that in the peripheral area (P = 0.017). In patients with successful reduction, 90.9% (20/22) of the endplates healed with increased curvature. In patients with an unsuccessful endplate reduction, 63.4% (26/41) of the endplates healed irregularly, and 34.1% (14/41) of the endplates formed traumatic Schmorl nodes. Endplate reduction was closely related to the final healing morphology of the endplate (P < 0.001), which had a significant protective effect on the degeneration of the intervertebral disc. At the last follow-up evaluation, there was no statistically significant correlation between different endplate healing morphologies and new Modic changes.

CONCLUSIONS

The reduction rate in the central area is significantly lower than that in the peripheral area. Although all of the intervertebral discs corresponding to fractured endplates had degenerated to different degrees, successful endplate fracture reduction can obviously delay the degeneration of intervertebral discs.

Novel Methods to Measure Height and Volume in Healthy and Degenerated Lumbar Discs in MRIs: A Reliability Assessment Study

Background: In the regeneration and therapy of degenerated intervertebral discs, the height, volume or categorizing assessments, such as Pfirrmann classification, are used to quantify the discs themselves and the effects of therapy. Here, the question of transferability, in the sense of reliability, of the results arises in the common exchange. Methods: We have investigated two established and a newly developed (9-point measurement), easy to use methods for height measurement and volume measurement on degenerated and healthy lumbar intervertebral discs of 66 patients regarding inter- and intra-observer reliability. Results: In overview, we found very different reliabilities. While the intra-observer reliability showed good to excellent agreement for both healthy and degenerated lumbar discs for the height and volume measurements, the inter-observer reliability was low or moderate in some cases. The 9-point method for height determination consistently showed better reliability for both healthy and degenerated discs, for both intra- and inter-observer reliability, compared to the two established methods. Conclusions: We recommend using the 9-point measurement as the method to communicate lumbar disc height, both for healthy and degenerated discs. Due to the partly low or moderate reliability, significant differences in the measured heights can already occur, which can lead to a worsened comparability.

Distribution Patterns of Degeneration of the Lumbar Spine in a Cohort of 200 Patients with an Indication for Lumbar MRI

Lower back pain is one of the most common causes of a reduced quality of life. Magnetic resonance imaging (MRI) is the best suited imaging technique to detect causes of that pain. We retrospectively evaluated the MRIs of the lumbar spine for 200 patients in order to describe the distribution of signs of degeneration with regard to age, sex, and position of the disc affected. The number of spinal segments affected by degeneration increased with age, as did the number of signs of degeneration per segment. In patients aged between 21 and 30, 38.8% of discs were affected, while for patients aged between 51 and 60, 91.6% of discs were affected. There was no statistically significant gender difference. The lower two segments were most commonly affected by degeneration. The most common were structural changes to the discs, which affected 88.4% of patients over 50. Spondylosis was the most common bone-related change, found in 60.4% of patients over the age of 50. A reduction in disc height increases the likelihood of structural changes to the disc and bone-related changes. When investigating risk factors for developing disc-related diseases, the complex disc degeneration patterns described here should be taken into account.

Cross-cultural adaptation of the Revised Neurophysiology of Pain Questionnaire into the Turkish language based on Rasch analysis

BACKGROUND

The Revised Neurophysiology of Pain Questionnaire (Revised-NPQ-Tr) is used to evaluate the chain in pain knowledge. No study has explored its validity and reliability for the Turkish language.

OBJECTIVES

: This study aims to determine the psychometric properties of the Turkish version of the Revised-NPQ-Tr in chronic spinal pain patients.

METHODS

A total of 182 chronic spinal pain patients were included in the study. The Revised-NPQ-Tr results were analyzed using Rasch analysis to measure the psychometric properties.

RESULTS

The Revised-NPQ-Tr indicates misfit to the Rasch model, as evidenced by the borderline significant p value (LR test = 27.626; df = 11; p = .004; Bonferroni-adjusted α = 0.004). Two items were differentially affected by educational status. Removal of poor-functioning items did not improve the psychometric properties of the questionnaire. The Revised-NPQ-Tr is unidimensional and there was no local dependence between items. The questionnaire exhibits known group validity. Test-retest reliability of the questionnaire was moderate [intraclass correlation coefficient (ICC) = 0.629]; however, the internal consistency of the questionnaire was found to be low (Cronbach's α = 0.330; person separation index = 0.373).

CONCLUSION

Although the internal validity of the Revised-NPQ-Tr version was acceptable, its reliability was found to be low. Consequently, the results of Revised-NPQ-Tr should be interpreted carefully in the clinic.

Endplate defects, not the severity of spinal stenosis, contribute to low back pain in patients with lumbar spinal stenosis

BACKGROUND CONTEXT

It is controversial whether lumbar spinal stenosis (LSS) itself contributes to low back pain (LBP). Lower truncal skeletal muscle mass, spinopelvic malalignment, intervertebral disc degeneration, and endplate abnormalities are thought to be related to LBP. However, whether these factors cause LBP in patients with LSS is unclear.

PURPOSE

To identify factors associated with LBP in patients with LSS.

STUDY DESIGN/SETTING

Cross-sectional design.

PATIENT SAMPLE

A total of 260 patients (119 men and 141 women, average age 72.8 years) with neurogenic claudication caused by LSS, as confirmed by magnetic resonance imaging (MRI).

OUTCOME MEASURES

Ratings of LBP, buttock and leg pain, and numbness on a numerical rating scale (NRS), 36-Item Short Form Survey (SF-36) scores, muscle mass measured by bioelectrical impedance analysis, and radiographic measurements including slippage and lumbopelvic alignment. The severity of LSS, endplate defects, Modic endplate changes, intervertebral disc degeneration, and facet joint osteoarthritis were assessed on MRI.

METHODS

The presence of LBP was defined as an NRS score ≥3. The demographic data, patient-reported outcomes, and radiological and MRI findings were compared between patients with and without LBP. Multivariate logistic regression analysis was used to identify the factors that were independently associated with the presence of LBP.

RESULTS

There were significant differences between patients with and without LBP for buttock and leg pain and numbness on the NRS, general health on the SF-36, presence of endplate defects, presence of Modic changes, disc degeneration grading, and disc height grading (all p < .05). Multivariate logistic regression analysis showed significant associations between LBP and diabetes (OR 2.43; 95% CI 1.07-5.53), buttock and leg numbness on the NRS (OR 1.34; 95% CI 1.17-1.52), general health on the SF-36 (OR 0.97; 95% CI 0.95-0.99), and the presence of erosive endplate defects (OR 3.04; 95% CI 1.51-6.11) (all p < .05).

CONCLUSIONS

These results suggest that LBP in patients with LSS should be carefully assessed not only for spinal stenosis but also clinical factors and endplate defects.

Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study

STUDY DESIGN

Population-based cohort study.

OBJECTIVE

We examined associations between common lumbar degenerative changes observed on magnetic resonance imaging (MRI) and present or future low back pain (LBP).

SUMMARY OF BACKGROUND DATA

The association between lumbar MRI degenerative findings and LBP is unclear. Longitudinal studies are sparse.

METHODS

Participants (n = 3369) from a population-based cohort study were imaged at study entry, with LBP status measured at baseline and 6-year follow-up. MRI scans were reported on for the presence of a range of MRI findings. LBP status was measured on a 0 to 10 scale. Regression models were used to estimate the cross-sectional and longitudinal associations between individual and multiple MRI findings and LBP severity. Separate longitudinal analyses were conducted for participants with and without baseline pain.

RESULTS

MRI findings were present in persons with and without back pain at baseline. Higher proportions were found in older age groups. 76.4% of participants had a least one MRI finding and 8.3% had five or more different MRI findings. Cross-sectionally, most MRI findings were slightly more common in those with LBP and pain severity was slightly higher in those with MRI findings (ranging from 0.06 for high intensity zone to 0.83 for spondylolisthesis). In the longitudinal analyses, we found most MRI findings were not associated with future LBP-severity regardless of the presence or absence of baseline pain. Compared to zero MRI findings, having multiple MRI findings (five or more) was associated with mildly greater pain-severity at baseline (0.84; 0.50-1.17) and greater increase in pain-severity over 6 years in those pain free at baseline (1.21; 0.04-2.37), but not in those with baseline pain (-0.30; -0.99 to 0.38).

CONCLUSION

Our study shows that the MRI degenerative findings we examined, individually or in combination, do not have clinically important associations with LBP, with almost all effects less than one unit on a 0 to 10 pain scale.Level of Evidence: 3.

Cross-cultural adaptation, validation and psychometric evaluation of the attitudes to back pain scale in musculoskeletal practitioners - Hebrew version

BACKGROUND

Research suggests that clinician's attitudes and beliefs towards low back pain (LBP) management may affect their patients' treatment course and outcomes. Attitudes to Back pain Scale in musculoskeletal practitioners (ABS-mp) is a questionnaire developed to assess musculoskeletal clinicians' attitudes and beliefs regarding LBP.

OBJECTIVE

This study aimed to translate, culturally adapt, and evaluate the psychometric properties of the Hebrew version of the ABS-mp questionnaire.

DESIGN

Cross-sectional study with nested prospective sub-sample.

METHODS

The translation was performed in several steps following the cross-cultural adaptation process. Test-retest and internal consistency reliability of the scales were evaluated along with convergent validity exploration between the ABS-mp and the Health Care Providers' Pain and Impairment Relationship Scale (HC-PAIRS). A convenience sample of 177 physical therapists were requested to participate in the study, out of which 132 have completed the survey, providing a 74% participation rate.

RESULTS

The forward-backward translation process revealed minor discrepancies that were addressed by the expert panel. The test-retest reliability of the Hebrew ABS-mp was excellent (ICC = 0.906). Five items were found to be irrelevant for the Israeli physiotherapy health settings and were omitted. For internal consistency, the average inter-item correlation reached appropriate values for the Psychological, Biomedical, Re-activation, and Limitation on Sessions subscales (0.437, 0.265, 0.341, 0.197, respectively). For convergent validity, the ABS-mp's Biomedical subscale and the HC-PAIRS's total score were moderately correlated (0.535).

CONCLUSIONS

The Hebrew version of the ABS-mp has been validated and has demonstrated excellent test-retest reliability, good convergent validity and acceptable internal consistency.

Understanding the Pathophysiology of L5-S1 Loss of Lordosis and Retrolisthesis: An EOS Study of Lumbopelvic Movement Between Standing and Slump Sitting Postures

OBJECTIVE

To understand the pathophysiology of L5-S1 loss of lordosis and retrolisthesis by comparing 2 commonly assumed physiological weight-bearing postures.

METHODS

This was a prospective comparative study of whole-body standing and slump sitting EOS radiographs in clinic patients presenting with back pain or lower limb radicular pain. Patients with prior spinal intervention, malignancy, trauma, inflammatory diseases, transitional lumbosacral vertebra, pregnancy, and L5-S1 retrolisthesis or spondylolisthesis from nondegenerative causes were excluded. C7 sagittal vertical axis, global cervical angle, global thoracic angle, global lumbar angle, thoracolumbar angle, T1-slope, pelvic incidence, pelvic tilt, sacral slope, L5-S1 angle, L5-S1 vertebral translation, L5-S1 disc height, and presence of L4-5 vertebral translation were measured. Univariate and multivariate analyses were performed to identify predictors of L5-S1 lordosis loss and retrolisthesis.

RESULTS

L5-S1 loss of lumbar lordosis (7.02 ± 9.90°, P < 0.001), retrolisthesis (0.07 ± 0.411 cm, P < 0.001), and loss of disc height (0.10 ± 0.23 cm, P < 0.001) occurred when changing from standing to slump sitting along with other sagittal profile changes (P < 0.001). Taller L5-S1 disc height (odds ratio [OR] 2.57, P = 0.04), larger lumbar range-of-motion change (OR 3.82, P = 0.012), lower sacral slope on sitting (OR 2.50, P = 0.043), and presence of L4-5 spondylolisthesis (OR 2.75, P = 0.032) were predictive of larger L5-S1 lordosis loss (>7°) on multivariate analysis, while larger lumbar range-of-motion change (OR 2.21, P = 0.050) and presence of L4-5 spondylolisthesis (OR 3.08, P = 0.023) were predictive of greater L5-S1 retrolisthesis (>0.07 cm).

CONCLUSIONS

Degenerative L5-S1 loss of lordosis and retrolisthesis likely result from long-standing lower lumbar spine bending forces against the posterior ligamentous complex with slump sitting, predisposed by a negatively sloped sacrum and increased lumbar flexibility.

T2 -weighted magnetic resonance imaging texture as predictor of low back pain: A texture analysis-based classification pipeline to symptomatic and asymptomatic cases

Low back pain is a very common symptom and the leading cause of disability throughout the world. Several degenerative imaging findings seen on magnetic resonance imaging are associated with low back pain but none of them is specific for the presence of low back pain as abnormal findings are prevalent among asymptomatic subjects as well. The purpose of this population-based study was to investigate if more specific magnetic resonance imaging predictors of low back pain could be found via texture analysis and machine learning. We used this methodology to classify T₂ -weighted magnetic resonance images from the Northern Finland Birth Cohort 1966 data to symptomatic and asymptomatic groups. Lumbar spine magnetic resonance imaging was performed using a fast spin-echo sequence at 1.5 T. Texture analysis pipeline consisting of textural feature extraction, principal component analysis, and logistic regression classifier was applied to the data to classify them into symptomatic (clinically relevant pain with frequency ≥30 days and intensity ≥6/10) and asymptomatic (frequency ≤7 days, intensity ≤3/10, and no previous pain episodes in the follow-up period) groups. Best classification results were observed applying texture analysis to the two lowest intervertebral discs (L4-L5 and L5-S1), with accuracy of 83%, specificity of 83%, sensitivity of 82%, negative predictive value of 94%, precision of 56%, and receiver operating characteristic area-under-curve of 0.91. To conclude, textural features from T₂ -weighted magnetic resonance images can be applied in low back pain classification.

Weight-Bearing Magnetic Resonance Imaging as a Diagnostic Tool That Generates Biomechanical Changes in Spine Anatomy

Weight-bearing magnetic resonance imaging (MRI) is a unique modality in diagnostic imaging that allows for the assessment of spinal pathology in ways considered previously inaccessible or insufficient with the conventional MRI technique. Due to limitations in positioning within the MRI machine itself, difficulties would be posed in determining the underlying cause of a patient’s pain or neurological symptoms, as the traditional supine position utilized can, in many cases, alleviate the severity of presented symptoms. Weight-bearing MRI addresses this concern by allowing a clinician to position a patient (to a certain degree) into flexion, extension, rotation, or side-bending with an axial load that can mimic physiologic conditions in order to replicate the conditions the patient experiences in order to give clinicians a clearer understanding of the anatomical relationship of the spine and surrounding tissues that may lead to a particular presentation of symptoms. These findings can then guide treatment approaches that are better tailored to a patient’s needs in order to initiate treatment earlier and shorten the duration of treatment necessary for patient benefit. The goal of this review is to describe and differentiate weight-bearing MRI from conventional MRI as well as examine the advantages and disadvantages of either imaging modality. This will include assessing cost-effectiveness and improvements in clinical outcomes. Further, the advancements of weight-bearing MRI will be discussed, including potentially unique clinical applications in development.

Sequence variation at 8q24.21 and risk of back pain

Back pain (BP) is a common condition of major social importance and poorly understood pathogenesis. Intervertebral lumbar disc degeneration in all its guises is one of the major biological risk factors for BP. Previously, we identified the locus at 8q24.21 associated with chronic BP, which has been found elsewhere associated with sciatica after surgery for lumbar disc herniation. In the current study we used co-localisation methods to identify the gene most likely to harbor the causal variant. We show that the same functional variant at the 8q24.21 locus is responsible for both lumbar disc degeneration and BP, and we also studied the effects of this locus on related phenotypes. Our results link the locus to intervertebral disc and bone mineral density, but not to anthropometric measurements, thus corroborating the epidemiological evidence. Moreover, the same functional variant at the locus is more likely to affect the expression of the nearby FAM49B gene, rather than the GSDMC gene, which was previously proposed as a causative one for BP.

Insight into the genetic architecture of back pain and its risk factors from a study of 509,000 individuals

Back pain (BP) is a common condition of major social importance and poorly understood pathogenesis. Combining data from the UK Biobank and CHARGE consortium cohorts allowed us to perform a very large genome-wide association study (total N = 509,070) and examine the genetic correlation and pleiotropy between BP and its clinical and psychosocial risk factors. We identified and replicated 3 BP-associated loci, including one novel region implicating SPOCK2/CHST3 genes. We provide evidence for pleiotropic effects of genetic factors underlying BP, height, and intervertebral disk problems. We also identified independent genetic correlations between BP and depression symptoms, neuroticism, sleep disturbance, overweight, and smoking. A significant enrichment for genes involved in the central nervous system and skeletal tissue development was observed. The study of pleiotropy and genetic correlations, supported by the pathway analysis, suggests at least 2 strong molecular axes of BP genesis, one related to structural/anatomical factors such as intervertebral disk problems and anthropometrics, and another related to the psychological component of pain perception and pain processing. These findings corroborate with the current biopsychosocial model as a paradigm for BP. Overall, the results demonstrate BP to have an extremely complex genetic architecture that overlaps with the genetic predisposition to its biopsychosocial risk factors. The work sheds light on pathways of relevance in the prevention and management of low BP.

Lumbar vertebral endplate defects on magnetic resonance images: prevalence, distribution patterns, and associations with back pain

BACKGROUND CONTEXT

Although the roles of Modic Changes (MCs) and disc degeneration in back pain remain controversial, clues from cadaveric studies suggest that lumbar vertebral endplate lesions may be important in back pain. Endplate lesions can be detected on magnetic resonance (MR) images as various endplate defects, including focal, corner, and erosive defects. Yet, the clinical significance of such endplate defects remains unknown.

PURPOSE

To determine the prevalence and distribution patterns of lumbar vertebral endplate defects and their associations with back pain in a population-based sample.

STUDY DESIGN

Cross-sectional study.

PATIENT SAMPLE

Subjects were randomly selected from a typical community in Hangzhou Eastern China, regardless of back pain status.

OUTCOME MEASURES

Each subject underwent a structured interview and lumbar MR imaging. Back pain history, including today, over the past 4 weeks, 12 months, and lifetime, were acquired. Endplate defects, MCs, and disc degeneration were evaluated on MRIs. Age, gender and body mass index (kg/m²), as well as lifetime exposures, including smoking history, riding in motorized vehicles and associated vibration, and occupational physical demands were assessed.

METHODS

Descriptive statistics were used to depict prevalence and distribution patterns of endplate defects in the lumbar spine. Logistic regressions were used to examine associations of endplate defects with back pain. The research grant was obtained from the National Natural Science Foundation of China (115,000 USD), Key Platform Project of the Health Department of Zhejiang Province (14,000 USD), Technology Program of Traditional Chinese Medicine Department of Zhejiang Province (21,000 USD), and 2015 Qianjiang Talent Program of Zhejiang Province (7,000 USD) toward this work. There is no conflict to disclose.

RESULTS

There were 478 subjects (53.3±14.4 years, range 20-88 years) studied. Endplate defects presented in 301 (63.0%) subjects and 842 (16.0%) endplates. The presence of endplate defects, but not MCs and disc degeneration, was associated with lifetime back pain (odds ratio=1.64, p=.026) in multivariate analyses. Focal and erosive endplate defects were associated with lifetime back pain history (odds ratio=1.74-2.23, p<.05 for both), whereas all three types of defects were associated with intensity of worst back pain over the past 12 months (Coef=5.84-7.19, p<.05 for all).

CONCLUSIONS

Endplate defects are common findings on lumbar MRIs in adults. Specific types of endplate defects were associated with back pain history. Endplate defects may be an independent risk factor for back pain.

Association Between Self-Reported Spinal Morning Stiffness and Radiographic Evidence of Lumbar Disk Degeneration in Participants of the Cohort Hip and Cohort Knee (CHECK) Study

BACKGROUND

Low back pain (LBP) is very common and is a main cause of limited activity and work absence. Patients with LBP may also report spinal morning stiffness; this symptom could be useful for identifying subgroups with signs and symptoms related to spinal osteoarthritis.

OBJECTIVE

This study investigated whether an association exists between reported spinal morning stiffness and radiographic evidence of lumbar disk degeneration (LDD) in people with LBP and a history of pain of the hip and/or knee.

DESIGN

This cross-sectional study used 8-year follow-up data from the Cohort Hip and Cohort Knee study.

METHODS

The association between spinal morning stiffness and radiographic LDD features was assessed with multivariable logistic regression models.

RESULTS

The presence of osteophytes was significantly associated with spinal morning stiffness (odds ratio [OR] = 2.1 [95% confidence interval [CI] = 1.3-3.2]) as was the presence of grade 2 or 3 disk space narrowing (OR = 2.0 [95% CI = 1.1-3.5]). There was also a significant association between morning stiffness persisting for > 30 minutes and grade 2 osteophytes (OR = 2.6 [95% CI = 1.1-6.2]) and grade 1 disk space narrowing (OR = 2.0 [95% CI = 1.1-3.6]). Furthermore, there was a significant association between moderate spinal morning stiffness and the presence of osteophytes (OR = 2.0 [95% CI = 1.2-3.2]). Both the presence of osteophytes and disk space narrowing were significantly associated with severe spinal morning stiffness (for osteophytes: OR = 2.0 [95% CI = 1.2-3.7]; for narrowing at L1-S1: OR = 1.8 [95% CI = 1.1-3.1]).

LIMITATIONS

Only lumbar lateral radiographs were available for each participant, implying that the LDD features could have been underestimated. The quality of the radiographs was not consistent.

CONCLUSIONS

This study showed an association between self-reported spinal morning stiffness and symptomatic LDD. When morning stiffness lasted > 30 minutes, there was a significant association with the features of LDD. The association was stronger when the severity of spinal morning stiffness increased.

Descriptive Analysis of an Interdisciplinary Musculoskeletal Program

BACKGROUND

Interdisciplinary musculoskeletal programs address comorbidities confounding musculoskeletal conditions and serve as an alternative to the single provider model.

OBJECTIVE

Descriptive analysis of an interdisciplinary musculoskeletal program.

DESIGN

Retrospective descriptive analysis of patients enrolled in an interdisciplinary musculoskeletal program. Retrospective subanalysis: cohort of patients enrolled in interdisciplinary program with low back pain compared to historical cohort of patients in a single provider clinic.

SETTING

Academic interdisciplinary musculoskeletal health program.

PATIENTS

Patients referred to program with at least one follow-up visit over a 2-year period.

INTERVENTIONS

Interdisciplinary musculoskeletal program involving physiatry, pain anesthesia, nutrition, psychology, rheumatology, sleep medicine, nursing, and physical therapy.

MAIN OUTCOME MEASUREMENTS

Patient Specific Functional Scale (PSFS), Oswestry Low Back Disability Index (ODI), number of magnetic resonance imaging (MRI) scans, computed tomography (CT) scans, opioid prescriptions; Press Ganey scores.

RESULTS

One hundred and seventy-three patients were enrolled and had at least one follow-up visit. Twenty-four percent of patients with any musculoskeletal complaint demonstrated clinically significant improvements in total PSFS. Mean improvement in PSFS was + 0.864 (SD 1.94), which was a statistically significant improvement (P = .0005), but not clinically significant. Magnetic resonance imaging was ordered for 5% of patients, and no computed tomography scans were ordered. Six percent of patients received opioid prescriptions. Press Ganey scores: 96% responded favorably in regard to physician communication quality, 86% of patients responded favorably for access to care, and 78% responded favorably for care coordination. 27.8% of patients with low back pain in the interdisciplinary program achieved a significant decrease in their ODI, compared to 26.6% in the single provider clinic (P = .87).

CONCLUSIONS

Interdisciplinary musculoskeletal programs are a promising model to improve the functioning of patients with musculoskeletal pain and decrease downstream utilization. These programs may be more appropriate for patients at higher risk of developing chronic pain.

Human Disc Nucleotomy Alters Annulus Fibrosus Mechanics at Both Reference and Compressed Loads

Nucleotomy is a common surgical procedure and is also performed in ex vivo mechanical testing to model decreased nucleus pulposus (NP) pressurization that occurs with degeneration. Here, we implement novel and noninvasive methods using magnetic resonance imaging (MRI) to study internal 3D annulus fibrosus (AF) deformations after partial nucleotomy and during axial compression by evaluating changes in internal AF deformation at reference loads (50 N) and physiological compressive loads (∼10% strain). One particular advantage of this methodology is that the full 3D disc deformation state, inclusive of both in-plane and out-of-plane deformations, can be quantified through the use of a high-resolution volumetric MR scan sequence and advanced image registration. Intact grade II L3-L4 cadaveric human discs before and after nucleotomy were subjected to identical mechanical testing and imaging protocols. Internal disc deformation fields were calculated by registering MR images captured in each loading state (reference and compressed) and each condition (intact and nucleotomy). Comparisons were drawn between the resulting three deformation states (intact at compressed load, nucleotomy at reference load, nucleotomy at compressed load) with regard to the magnitude of internal strain and direction of internal displacements. Under compressed load, internal AF axial strains averaged -18.5% when intact and -22.5% after nucleotomy. Deformation orientations were significantly altered by nucleotomy and load magnitude. For example, deformations of intact discs oriented in-plane, whereas deformations after nucleotomy oriented axially. For intact discs, in-plane components of displacements under compressive loads oriented radially outward and circumferentially. After nucleotomy, in-plane displacements were oriented radially inward under reference load and were not significantly different from the intact state at compressed loads. Re-establishment of outward displacements after nucleotomy indicates increased axial loading restores the characteristics of internal pressurization. Results may have implications for the recurrence of pain, design of novel therapeutics, or progression of disc degeneration.

The association between occupational loading and spine degeneration on imaging - a systematic review and meta-analysis

Background

There are inconsistencies in findings regarding the relationship of occupational loading with spinal degeneration or structural damage. Thus, a systematic review was conducted to determine the current state of knowledge on the association of occupational loading and spine degeneration on imaging.

Methods

We performed electronic searches on MEDLINE, CINAHL and EMBASE. We included cross-sectional, case control and cohort studies evaluating occupational loading as the exposure and lumbar spine structural findings on imaging as the outcomes. When possible, results were pooled.

Results

Seventeen studies were included in the review. Ten studies evaluated the association of occupational loading with disc degeneration (signal intensity), four of which were pooled into a meta-analysis. Of the 10 studies, only two did not identify a relationship between occupation loading and disc degeneration. A meta-analysis including four of the studies demonstrated an association between higher loading and degeneration for all spinal levels, with odds ratios between 1.6 and 3.3. Seven studies evaluated disc height narrowing and seven evaluate disc bulge, with six and five identifying an association of loading and with imaging findings respectively. Three studies evaluated modic changes and one identified and association with occupational load.

Conclusions

There was moderate evidence suggesting a modest association between occupational loading and disc degeneration (signal intensity), and low-quality evidence of an association between occupational loading and disc narrowing and bulging.

Greater Lumbar Extension During Dolphin Kick and Psoas Major Tightness in Swimmers With Low Back Pain

CONTEXT

In competitive swimming, many swimmers experience low back pain (LBP). Lumbar hyperextension may cause LBP, and tight hip-flexor muscle may cause lumbar extension during swimming.

OBJECTIVE

The purpose of this study was to clarify the features of the elastic moduli of the muscles and the lumbar extension when swimmers with LBP perform a dolphin kick (DK).

DESIGN

Cross-sectional study.

SETTING

Single center.

OTHER PARTICIPANTS

Eleven male college swimmers were enrolled as the LBP group (who have LBP when swimming and during a lumbar extension), and 21 male college swimmers were recruited as the control group (no LBP).

INTERVENTIONS

The elastic moduli of the psoas major, iliacus, teres major, latissimus dorsi, pectoralis major, and pectoralis minor were measured through ultrasonic shear wave elastography. The lumbar and hip extension angles during a DK were measured using a video camera. The passive hip extension and shoulder-flexion range of motion (ROM) were measured using a goniometer.

MAIN OUTCOME MEASURES

Muscle elastic moduli and lumbar extension angles during DK.

RESULTS

The characteristics, muscle elastic moduli, DK motion, and ROM were compared between the 2 groups. LBP group demonstrated significantly higher elastic modulus of the psoas major and lower modulus of pectoralis minor compared with the control group. Also, LBP group showed greater lumbar extension during a DK and less hip extension ROM than the control group.

CONCLUSIONS

The higher elastic modulus of the psoas major and greater lumbar extension during a DK may be related to the LBP in swimmers.

Associations Between Intervertebral Disc Degeneration Grading Schemes and Measures of Disc Function

Disc degeneration is a major cause of spinal dysfunction and pain, but grading schemes concentrate on tissue changes rather than altered function. The aim of this study was to compare disc degeneration grading systems with each other, and with biomechanical measures of disc function. Sixty-six motion segments (T8-9 to L5-S1) were dissected from cadavers aged 48-98 years. Disc function was assessed by measuring nucleus pressure (IDP) and maximum stresses in the annulus under 1 kN of compression. Detailed "scores" of disc degeneration were based on independent radiographic, macroscopic, and microscopic evaluations. For each evaluation, scores were used to assign a degeneration "grade" (I-IV), and functional measures were then correlated with degeneration scores and grades. Results showed that all measures were reliable (intraclass correlation coefficients: 0.82-0.99). Macroscopic and microscopic assessments were highly correlated with each other (r: 0.57-0.89, p < 0.001) but only weakly correlated with radiographic features. The overall macroscopic and microscopic scores of degeneration increased significantly with age and at lower spinal levels, although the influence of age was less marked in the case of the microscopic scores. IDP decreased with age and at lower spinal levels, but annulus stresses were more variable. Importantly, IDP and annulus stresses decreased consistently with all measures of disc degeneration, and these associations remained strong after controlling for age, gender, and spinal level. We conclude that radiographic and tissue-based assessments of disc degeneration are consistent with each other, and are more closely related to mechanical (dys)function than to age or spinal level. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1946-1955, 2019.

MRI identifies biochemical alterations of intervertebral discs in patients with low back pain and radiculopathy

KEY POINTS

• Molecular intervertebral disc damage was associated with LBP and radiculopathy.• Patients with radiculopathy and LBP demonstrated a depletion of gagCEST values compared with healthy controls.• GagCEST imaging may be a non-invasive tool for investigation of degeneration processes of lumbar intervertebral discs (IVDs). GagCEST imaging may be an imaging biomarker for biochemical IVD alterations.

Novel Application of the Pfirrmann Disc Degeneration Grading System to 9.4T MRI: Higher Reliability Compared to 3T MRI

STUDY DESIGN

Reliability study.

OBJECTIVE

To evaluate the applicability and reliability of 9.4T magnetic resonance imaging (MRI) in the assessment of degenerative disc disease compared with 3T MRI.

SUMMARY OF BACKGROUND DATA

MRI is a reliable indicator of biochemical changes in the intervertebral disc (IVD) including hydration status, proteoglycan content, and disc degeneration compared with anatomical and histological studies. High-field 9.4T MRI has been shown to provide superior resolution and anatomical detail. However, it has not been tested against current standard MRI techniques.

METHODS

Disc degeneration was initiated in 36 skeletally mature ewes 6 months prior to necropsy via validated surgical IVD injury models using either scalpel injury or drill-bit injury techniques at lumbar spine levels L2/3 and L3/4 with L1/2, L4/5, and L5/6 serving as control discs. All ex vivo IVDs were examined with 9.4T MRI and 3T MRI. All scans were analyzed using the Pfirrmann grading system by four independent observers. Intra- and interobserver reliability was assessed using kappa statistics and Spearman correlation.

RESULTS

Inter- and intraobserver agreement for 9.4T MRI was excellent, both at κ 0.91 (P < 0.001). Comparatively, 3T interobserver reliability demonstrated substantial agreement at κ 0.61 (P < 0.001). Complete agreement was obtained in 92.7% to 100% of discs at 9.4T compared with 69.7% to 83.1% at 3T. A difference of one grade or more occurred in 6.7% at 9.4T and 39.3% at 3T. 9.4T MRI scored 97.3% of discs as grade 1 to 2 compared with 71.3% at 3T. 3T MRI tended to over-score the extent of disc degeneration with 28.6% of discs scored as grade 3 or higher compared with 2.7% at 9.4T MRI.

CONCLUSION

9.4T MRI study of IVD degeneration using the Pfirrmann grading system demonstrated excellent inter- and intraobserver reliability. Comparatively, 3T MRI demonstrated a tendency to over score the extent of disc degeneration. This improved reliability of 9.4T MRI holds great potential for its clinical applications.

LEVEL OF EVIDENCE

3.

Biomechanics of Back Pain

This paper offers a mechanistic account of back pain which attempts to incorporate all of the most important recent advances in spinal research. Anatomical and pain-provocation studies show that severe and chronic back pain most often originates in the lumbar intervertebral discs, the apophyseal joints, and the sacroiliac joints. Psychosocial factors influence many aspects of back pain behaviour but they are not important determinants of who will experience back pain in the first place. Back pain is closely (but not invariably) associated with structural pathology such as intervertebral disc prolapse and endplate fractures, although age-related biochemical changes such as those revealed by a ‘dark disc’ on MRI have little clinical relevance. All features of structural pathology (including disc prolapse) can be re-created in cadaveric specimens by severe or repetitive mechanical loading, with a combination of bending and compression being particularly harmful to the spine. Structural disruption alters the mechanical environment of disc cells in a manner that leads to cell-mediated degenerative changes, and animal experiments confirm that surgical disruption of a disc is followed by widespread disc degeneration. Some people are more vulnerable to spinal degeneration than others, largely because of their genetic inheritance. Age-related biochemical changes and loading history can also affect tissue vulnerability. Finally the concept of ‘functional pathology’ is introduced, according to which, back pain can arise because postural habits generate painful stress concentrations within innervated tissues, even though the stresses are not high enough to cause physical disruption.

Notochordal cell matrix: An inhibitor of neurite and blood vessel growth?

Blood vessel and neurite ingrowth into the degenerating intervertebral disc (IVD) are related to pain. In reported studies, notochordal cell (NC)-conditioned medium (NCCM) induced a regenerative response of nucleus pulposus (NP) cells, but also inhibition of neurite and vessel formation. NC matrix (NCM) derived from NC-rich NP tissue, induced even stronger anabolic effects than NCCM. Thus, the aim was to investigate whether NCM has similar anti-neurogenic and -angiogenic properties as NCCM. NCM and NCCM where produced from porcine NC-rich NP tissue. Human umbilical vein endothelial cells (HUVECs) were cultured in base medium (BM, 300 mOsm), NCCM (produced at 300 and 400 mOsm), NCM, or with chondroitin sulfate (CS, positive control) in angiogenesis-inducing medium, after which vessel length was measured. Although CS alone inhibited vessel growth, NCCM (both osmolarities) stimulated vessel formation by HUVECs. NCM did not affect vessel growth relative to BM. SH-SY5Y cells were cultured in BM, NCCM, and NCM on poly-D-lysine coated and polystyrene surfaces, and analyzed for neurite length and percentage of neurite expressing cells. On coated surfaces, neither NCCM nor NCM affected neurite growth. On a polystyrene surface, NCCM and NCM induced a higher number of neurite-expressing cells. NCCM's previously reported anti-angiogenic and -neurogenic effects were not observed in this study. Although addition of CS inhibited HUVEC vessel formation, other factors may be present in NCCM and NCM that affect neurite and vessel growth. Therefore, future studies testing an NC-based regenerative strategy should carefully assess the risk of such adverse effects in an in vivo setting. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. J Orthop Res 36:3188-3195, 2018.

Lumbar Vertebral Endplate Defects on Magnetic Resonance Images: Classification, Distribution Patterns, and Associations with Modic Changes and Disc Degeneration

STUDY DESIGN

A cross-sectional magnetic resonance (MR) imaging study.

OBJECTIVE

To classify and characterize endplate defects using routine lumbar MR images and to determine associations of endplate defects with Modic changes (MCs) and disc degeneration.

SUMMARY OF BACKGROUND DATA

Previously, a cadaveric study revealed that endplate lesions were common and associated with back pain history. New in vivo approaches appropriate for clinical studies are needed to further this potentially important line of research on the clinical significance of endplate lesions, including their relation with MCs, disc degeneration, and back pain.

METHODS

Using a MRI archive, 1564 endplates of 133 subjects (59 men and 74 women, mean age 58.9 ± 11.9 years) with the presence of MCs were retrospectively collected from April of 2014 to June of 2015. On the basis of morphological characteristics, a protocol was proposed to identify three distinct types of endplate defects, including focal, corner, and erosive defects. The location, size, and distribution patterns of various endplate lesions were characterized. MCs and disc degeneration were measured to examine their associations with endplate defects.

RESULTS

Endplate defects were observed in 27.8% of endplates studied. Greater age was associated with the presence of endplate defects. Focal defects were the most common (13.5%), followed by erosive defects (11.1%) and corner defects (3.2%). Defect types also differed in size and distribution patterns. Endplate defects and MCs had similar distribution patterns in the lumbar spine. The presence of endplate defects were associated with the presence of MCs (odds ratio = 4.29, P < 0.001), and associated with less disc signal intensity and disc height, and greater disc bulging (P < 0.05).

CONCLUSION

The three endplate defects identified on routine MR images appear to represent different pathologies and may play a key role in the pathogenesis of MCs. This classification system may facilitate clinical studies on endplate defects.

LEVEL OF EVIDENCE

4.

The association between subgroups of MRI findings identified with latent class analysis and low back pain in 40-year-old Danes

Background

Research into the clinical importance of spinal MRI findings in patients with low back pain (LBP) has primarily focused on single imaging findings, such as Modic changes or disc degeneration, and found only weak associations with the presence of pain. However, numerous MRI findings almost always co-exist in the lumbar spine and are often present at more than one lumbar level. It is possible that multiple MRI findings are more strongly associated with LBP than single MRI findings. Latent Class Analysis is a statistical method that has recently been tested and found useful for identifying latent classes (subgroups) of MRI findings within multivariable datasets. The purpose of this study was to investigate the association between subgroups of MRI findings and the presence of LBP in people from the general population.

Methods

To identify subgroups of lumbar MRI findings with potential clinical relevance, Latent Class Analysis was initially performed on a clinical dataset of 631 patients seeking care for LBP. Subsequently, 412 participants in a general population cohort (the ‘Backs on Funen’ project) were statistically allocated to those existing subgroups by Latent Class Analysis, matching their MRI findings at a segmental level. The subgroups containing MRI findings from the general population were then organised into hypothetical pathways of degeneration and the association between subgroups in the pathways and the presence of LBP was tested using exact logistic regression.

Results

Six subgroups were identified in the clinical dataset and the data from the general population cohort fitted the subgroups well, with a median posterior probability of 93%–100%. These six subgroups described two pathways of increasing degeneration on upper (L1-L3) and lower (L4-L5) lumbar levels. An association with LBP was found for the subgroups describing severe and multiple degenerative MRI findings at the lower lumbar levels but none of the other subgroups were associated with LBP.

Conclusion

Although MRI findings are common in asymptomatic people and the association between single MRI findings and LBP is often weak, our results suggest that subgroups of multiple and severe lumbar MRI findings have a stronger association with LBP than those with milder degrees of degeneration.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-1978-x) contains supplementary material, which is available to authorized users.

The associations between magnetic resonance imaging findings and low back pain: A 10-year longitudinal analysis

PURPOSE

To conduct a 10-year longitudinal analysis of the relationship between magnetic resonance imaging (MRI) findings and low back pain (LBP).

MATERIALS AND METHODS

Ninety-one volunteers with a history of LBP, but without current LBP were recruited between 2005 and 2006. Participants' baseline demographics and MRI findings were recorded. All volunteers were invited for a follow-up MRI in 2016; of these, 49 volunteers (53.8%) participated in the follow-up. We enquired whether they had LBP history during the 10 years between the baseline and follow-up examinations. Sagittal T1 and T2-weighted MRI were used to assess the intervertebral space from T12/L1 to L5/S1. We evaluated the presence of disc degeneration by Pfirrmann's grading system, disc bulging, high intensity zone (HIZ), spondylolisthesis, and any type of Modic changes in the follow-up MRIs. We compared the follow-up MRI findings with the baseline findings; the progress of each finding over the 10 years were also compared between the groups with (n = 36) and without (n = 13) LBP.

RESULTS

Average age of the study participants at follow-up was 44.8 years; 25 were female and 24 were male. Average age, sex, body mass index, and smoking habits of those who did and did not participate in the follow-up study, as well as the demographic characteristics of those who did and did not have LBP history during the 10 years, were not significantly different. Compared with the group without LBP history, the group that had LBP history during the 10 years did not have a significantly increased prevalence of disc degeneration, disc bulging, and HIZ in the follow-up and baseline MRIs. Spondylolisthesis and any type of Modic changes were also not associated with LBP history during the 10 years.

CONCLUSIONS

Follow-up MRI findings consistent with Pfirrmann grading ≥4, disc bulging, HIZ, spondylolisthesis, and any type of Modic changes were not associated with LBP history during the 10 years between the baseline and follow-up study. The progresses of these findings were also not associated with the LBP history. In addition, baseline MRI findings were not associated with LBP history during the 10 years; therefore, our data suggest that baseline MRI findings cannot predict future LBP.

Using Electronic Health Records and Clinical Decision Support to Provide Return-to-Work Guidance for Primary Care Practitioners for Patients With Low Back Pain

OBJECTIVE

The aim of this study was to describe the process by which a group of subject matter experts in the area of return to work developed a resource tool to provide clinical decision support (CDS) for primary care clinicians.

METHODS

A common musculoskeletal disorder, low back pain (LBP), was selected, pertinent literature reviewed, and specific recommendations for action in the clinical setting developed.

RESULTS

Primary care practitioners (PCPs) are routinely expected to create work activity prescriptions. The knowledge base for a CDS tool that could be embedded in electronic health records has been developed.

CONCLUSION

Improved clinical support should help prevent and manage work limitations associated with LBP not caused by work. The proposed decision support should reduce administrative burden and stimulate PCPs to explore the role of occupation and its demands on patients.

Do Occupational Risks for Low Back Pain Differ From Risks for Specific Lumbar Disc Diseases?: Results of the German Lumbar Spine Study (EPILIFT)

STUDY DESIGN

A multicenter, population based, case-control study.

OBJECTIVE

The aim of the present analysis is to clarify potential differences in the "occupational risk profiles" of structural lumbar disc diseases on the one hand, and low back pain (LBP) on the other hand.

SUMMARY OF BACKGROUND DATA

Physical workplace factors seem to play an important etiological role.

METHODS

We recruited 901 patients with structural lumbar disc diseases (disc herniation or severe disc space narrowing) and 233 control subjects with "low-back-pain." Both groups were compared with 422 "low-back pain free" control subjects. Case history, pain data, neurological deficits, and movement restrictions were documented. LBP was recorded by the Nordic questionnaire on musculoskeletal symptoms. All magnetic resonance imaging, computed tomography, and X-rays were inspected by an independent study radiologist. The calculation of cumulative physical workload was based on a computer-assisted interview and a biomechanical analysis by 3-D-dynamic simulation tool. Occupational exposures were documented for the whole working life.

RESULTS

We found a positive dose-response relationship between cumulative lumbar load and LBP among men, but not among women. Physical occupational risks for structural lumbar disc diseases [odds ratio (OR) 3.7; 95% confidence interval (95% CI) 2.3-6.0] are higher than for LBP (OR 1.9; 95% CI 1.0-3.5).

CONCLUSION

Our finding points to potentially different etiological pathways in the heterogeneous disease group of LBP. Results suggest that not all of the structural disc damage arising from physical workload leads to LBP.

LEVEL OF EVIDENCE

4.

The Association Between Self-reported Low Back Pain and Radiographic Lumbar Disc Degeneration of the Cohort Hip and Cohort Knee (CHECK) Study

STUDY DESIGN

Cross-sectional study, nested in a prospective cohort (Cohort Hip and Knee, CHECK).

OBJECTIVE

Low back pain (LBP) is very common and the main cause of activity limitations and work absence throughout the world. Although lumbar disc degeneration (LDD) is suggested as a cause of LBP, this association remains debatable. Therefore, this study assessed the association between the radiographic features of LDD and the presence of self-reported LBP, LBP persisting longer than 3 months, the perceived severity of LBP and presence of neuropathic pain.

SUMMARY OF BACKGROUND DATA

Previous literature suggests an association between LBP and both the LDD definitions osteophytes and disc space narrowing. There are no studies that have explored the association between LDD and neuropathic pain.

METHODS

Associations between the radiographic LDD using two definitions (i.e., osteophytes, disc space narrowing) versus the presence of LBP, LBP > 3 months, severe LBP and neuropathic pain, were analyzed with logistic regression models.

RESULTS

A total of 699 participants completed the questionnaire and had a lumbar radiograph. Radiographs were scored by two independent observers. Osteophytes were present in 98% of the population and disc space narrowing in 67%. Osteophytes were not significantly associated with LBP (OR = 1.2, 95% CI 0.9-1.7). Disc space narrowing was significantly associated with the presence of LBP and neuropathic pain (OR = 1.7, 95% CI = 1.2-2.4 and OR 1.7, 95% CI 1.1-2.7, respectively). The presence of a LBP severity score of ≥4, and LBP persisting > 3 months were not significantly associated with the two definitions of LDD.

CONCLUSION

This study shows the presence of an association between disc space narrowing, whereas no association was found between osteophytes and LBP. We are the first to report an association between disc space narrowing and neuropathic pain.

LEVEL OF EVIDENCE

3.

The Lumbodorsal Fascia as a Potential Source of Low Back Pain: A Narrative Review

The lumbodorsal fascia (LF) has been proposed to represent a possible source of idiopathic low back pain. In fact, histological studies have demonstrated the presence of nociceptive free nerve endings within the LF, which, furthermore, appear to exhibit morphological changes in patients with chronic low back pain. However, it is unclear how these characteristics relate to the aetiology of the pain. In vivo elicitation of back pain via experimental stimulation of the LF suggests that dorsal horn neurons react by increasing their excitability. Such sensitization of fascia-related dorsal horn neurons, in turn, could be related to microinjuries and/or inflammation in the LF. Despite available data point towards a significant role of the LF in low back pain, further studies are needed to better understand the involved neurophysiological dynamics.

Static axial overloading primes lumbar caprine intervertebral discs for posterior herniation

Introduction

Lumbar hernias occur mostly in the posterolateral region of IVDs and mechanical loading is an important risk factor. Studies show that dynamic and static overloading affect the nucleus and annulus of the IVD differently. We hypothesize there is also variance in the effect of overloading on the IVD’s anterior, lateral and posterior annulus, which could explain the predilection of herniations in the posterolateral region. We assessed the regional mechanical and cellular responses of lumbar caprine discs to dynamic and static overloading.

Material and methods

IVDs (n = 125) were cultured in a bioreactor and subjected to simulated-physiological loading (SPL), high dynamic (HD), or high static (HS) overloading. The effect of loading was determined in five disc regions: nucleus, inner-annulus and anterior, lateral and posterior outer-annulus. IVD height loss and external pressure transfer during loading were measured, cell viability was mapped and quantified, and matrix integrity was assessed.

Results

During culture, overloaded IVDs lost a significant amount of height, yet the distribution of axial pressure remained unchanged. HD loading caused cell death and disruption of matrix in all IVD regions, whereas HS loading particularly affected cell viability and matrix integrity in the posterior region of the outer annulus.

Conclusion

Axial overloading is detrimental to the lumbar IVD. Static overloading affects the posterior annulus more strongly, while the nucleus is relatively spared. Hence, static overloading predisposes the disc for posterior herniation. These findings could have implications for working conditions, in particular of sedentary occupations, and the design of interventions aimed at prevention and treatment of early intervertebral disc degeneration.

Can group-based reassuring information alter low back pain behavior? A cluster-randomized controlled trial

BACKGROUND

Low back pain (LBP) is common in the population and multifactorial in nature, often involving negative consequences. Reassuring information to improve coping is recommended for reducing the negative consequences of LBP. Adding a simple non-threatening explanation for the pain (temporary muscular dysfunction) has been successful at altering beliefs and behavior when delivered with other intervention elements. This study investigates the isolated effect of this specific information on future occupational behavior outcomes when delivered to the workforce.

DESIGN

A cluster-randomized controlled trial.

METHODS

Publically employed workers (n = 505) from 11 Danish municipality centers were randomized at center-level (cluster) to either intervention (two 1-hour group-based talks at the workplace) or control. The talks provided reassuring information together with a simple non-threatening explanation for LBP-the 'functional-disturbance'-model. Data collections took place monthly over a 1-year period using text message tracking (SMS). Primary outcomes were self-reported days of cutting down usual activities and work participation. Secondary outcomes were self-reported back beliefs, work ability, number of healthcare visits, bothersomeness, restricted activity, use of pain medication, and sadness/depression.

RESULTS

There was no between-group difference in the development of LBP during follow-up. Cumulative logistic regression analyses showed no between-group difference on days of cutting down activities, but increased odds for more days of work participation in the intervention group (OR = 1.83 95% CI: 1.08-3.12). Furthermore, the intervention group was more likely to report: higher work ability, reduced visits to healthcare professionals, lower bothersomeness, lower levels of sadness/depression, and positive back beliefs.

CONCLUSION

Reassuring information involving a simple non-threatening explanation for LBP significantly increased the odds for days of work participation and higher work ability among workers who went on to experience LBP during the 12-month follow-up. Our results confirm the potential for public-health education for LBP, and add to the discussion of simple versus multidisciplinary interventions.

The relationship between findings on magnetic resonance imaging and previous history of low back pain

The objective of this study was to evaluate the relationship between magnetic resonance imaging (MRI) findings and previous low back pain (LBP) in participants without current LBP. Current LBP was defined as LBP during the past month. Previous LBP was defined as a history of medical consultation for LBP. Ninety-one participants without current LBP were included. Sagittal T2-weighted MRI was used to assess the intervertebral space from T12/L1 to L5/S1. These images were classified into five grades based on the Pfirrmann grading system. Furthermore, we evaluated the presence of disk bulging, high-intensity zone, and spondylolisthesis. We compared the MRI findings between groups with (27 participants) and without (64 participants) previous LBP without current LBP. Intraobserver and interobserver kappa values were evaluated. Participants had an average age of 34.9 years; 47 were female and 44 were male; and their average body mass index was 21.8 kg/m². Compared to the group of participants without previous LBP, the group of participants with previous LBP had a significantly higher incidence of disk degeneration such as a Pfirrmann grade ≥3, disk bulging, and high-intensity zone in the analyses adjusted by age and sex. There were no significant differences in spondylolisthesis between the groups. An odds ratio of >10 was only found for Pfirrmann grade ≥3, ie, a Pfirrmann grade ≥3 was strongly associated with a history of previous LBP in participants without current LBP.

Chapter 6. Sickness absence due to back and neck disorders

The scientific evidence on the causes for sick leave attributed to back and neck disorders was reviewed. Categories were established for acute, recurring, and chronic problems based on the duration of the sick leave period. Forty-eight articles were found to be relevant, whereof two were of high quality and 26 were of medium or low quality. Quality was assessed exclusively in relation to the aim of this systematic review. The results reveal limited published research on causes for sick leave from back and neck disorders. The generalisability of the findings is also limited since most of the subjects were men and employees in manufacturing industries. Women, white-collar workers, employees in the public sector (care, social services, schools, etc) were underrepresented in the studies. Hence, these groups and areas should be studied further to verify conclusions and enhance knowledge about the causes for sick leave from back and neck disorders. The following factors were found to have consistent, but limited, support as regards their influence on the risk for sick leave due to back and neck disorders: (a) heavy physical workload, bent or twisted working position, and low work satisfaction increases the risk for short-term and long-term sick leave; (b) specific back diagnoses and previous sick leave due to back disorders increases the risk for short-term and long-term sick leave; (c) female gender, smoking, exposure to vibration, and deficient social support were not found to significantly increase the risk for short-term and long-term sick leave; (d) self-reported pain and functional impairments were associated with a high risk for long-term sick leave; (e) longer employment periods reduced the risk for short-term sick leave; (f) perceived demands at work did not influence short-term sick leave; (g) female gender and higher age increases the risk for disability pension.

Identification of subgroups of inflammatory and degenerative MRI findings in the spine and sacroiliac joints: a latent class analysis of 1037 patients with persistent low back pain

Background

The aim of this study was to investigate subgroups of magnetic resonance imaging (MRI) findings for the spine and sacroiliac joints (SIJs) using latent class analysis (LCA), and to investigate whether these subgroups differ in their demographic and clinical characteristics.

Methods

The sample included 1037 patients aged 18–40 years with persistent low back pain (LBP). LCA was applied to MRI findings of the spine and SIJs. The resulting subgroups were tested for differences in self-reported demographic and clinical characteristics.

Results

A five-class model was identified: Subgroup 1, ‘No or few findings’ (n = 116); Subgroup 2, ‘Mild spinal degeneration’ (n = 540); Subgroup 3, ‘Moderate to severe spinal degeneration’ (n = 229); Subgroup 4, ‘Moderate to severe spinal degeneration with mild SIJ findings’ (n = 68); and Subgroup 5, ‘Mild spinal degeneration with moderate to severe SIJ findings’ (n = 84). The two SIJ subgroups (Subgroups 4 and 5) had a higher median activity limitation score (Roland Morris Disability Questionnaire calculated as a proportional score: 65 (IQR 48–78)/65 (48–78)) compared with Subgroups 1–3 (48 (35–74)/57 (39–74)/57 (39–74)), a higher prevalence of women (68 % (95 % CI 56–79)/68 % (58–78)) compared with Subgroups 2 and 3 (51 % (47–55)/40 % (33–46)), a higher prevalence of being overweight (67 % (95 % CI 55–79)/53 % (41–65)) compared with Subgroup 1 (36 % (26–46)) and a higher prevalence of previous LBP episodes (yes/no: 81 % (95 % CI 71–91)/79 % (70–89)) compared with Subgroup 1 (58 % (48–67)). Subgroup 5 was younger than Subgroup 4 (median age 29 years (IQR 25–33) versus 34 years (30–37)) and had a higher prevalence of HLA-B27 (40 % (95 % CI 29–50)) compared with the other subgroups (Subgroups 1–4: 12 % (6–18)/7 % (5–10)/6 % (3–9)/12 % (4–20)). Across the subgroups with predominantly spinal findings (Subgroups 1–3), median age, prevalence of men, being overweight and previous LBP episodes were statistically significantly lower in Subgroup 1, higher in Subgroup 2 and highest in Subgroup 3.

Conclusions

Five distinct subgroups of MRI findings in the spine and SIJs were identified. The results indicate that SIJ MRI findings not only can be seen as a part of the spondyloarthritis disease entity, but also are associated with age, gender and being overweight. Furthermore, the results indicate that LBP patients with SIJ MRI findings are more disabled compared with patients without SIJ MRI findings, and that moderate to severe spinal degeneration and/or SIJ MRI findings may be associated with recurrent pain.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1131-x) contains supplementary material, which is available to authorized users.