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.

Relationships between paraspinal muscle morphology and neurocompressive conditions of the lumbar spine: a systematic review with meta-analysis.

BACKGROUND: Individual study results have demonstrated unclear relationships between neurocompressive disorders and paraspinal muscle morphology. This systematic review aimed to synthesize current evidence regarding the relationship lumbar neurocompressive disorders may have with lumbar paraspinal muscle morphology. METHODS: Searches were conducted in seven databases from inception through October 2017. Observational studies with control or comparison groups comparing herniations, facet degeneration, or canal stenosis to changes in imaging or biopsy-identified lumbar paraspinal muscle morphology were included. Data extraction and risk of bias assessment were performed by review author pairs independent of one another. Morphological differences between individuals with and without neurocompressive disorders were compared qualitatively, and where possible, standardised mean differences were obtained. RESULTS: Twenty-eight studies were included. Lumbar multifidus fiber diameter was smaller on the side of and below herniation for type I [SMD: -0.40 (95% CI = -0.70, -0.09) and type II fibers [SMD: -0.38 (95% CI = -0.69, -0.06)] compared to the unaffected side. The distribution of type I fibers was greater on the herniation side [SMD: 0.43 (95% CI = 0.03, 0.82)]. Qualitatively, two studies assessing small angular fiber frequency and fiber type groupings demonstrated increases in these parameters below the herniation level. For diagnostic imaging meta-analyses, there were no consistent differences across the various assessment types for any paraspinal muscle groups when patients with herniation served as their own control. However, qualitative synthesis of between-group comparisons reported greater multifidus and erector spinae muscle atrophy or fat infiltration among patients with disc herniation and radiculopathy in four of six studies, and increased fatty infiltration in paraspinal muscles with higher grades of facet joint degeneration in four of five studies. Conflicting outcomes and variations in study methodology precluded a clear conclusion for canal stenosis. CONCLUSIONS: Based on mixed levels of risk of bias data, in patients with chronic radiculopathy, disc herniation and severe facet degeneration were associated with altered paraspinal muscle morphology at or below the pathology level. As the variability of study quality and heterogeneous approaches utilized to assess muscle morphology challenged comparison across studies, we provide recommendations to promote uniform measurement techniques for future studies. TRIAL REGISTRATION: PROSPERO 2015: CRD42015012985.

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain.

OBJECTIVE: To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. METHODS: Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. RESULTS: Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. CONCLUSION: The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. KEY POINTS: • The location of vertebral endplate signal changes supports a mechanical aetiology. • Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain. • Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology. • More knowledge of the clinical importance of sacroiliac joint MRI findings is needed.

Spinal degeneration and lumbar multifidus muscle quality may independently affect clinical outcomes in patients conservatively managed for low back or leg pain.

Few non-surgical, longitudinal studies have evaluated the relations between spinal degeneration, lumbar multifidus muscle (LMM) quality, and clinical outcomes. None have assessed the potential mediating role of the LMM between degenerative pathology and 12-month clinical outcomes. This prospective cohort study used baseline and 12-month follow-up data from 569 patients conservatively managed for low back or back-related leg pain to estimate the effects of aggregate degenerative lumbar MRI findings and LMM quality on 12-month low back and leg pain intensity (0-10) and disability (0-23) outcomes, and explored the mediating role of LMM quality between degenerative findings and 12-month clinical outcomes. Adjusted mixed effects generalized linear models separately estimated the effect of aggregate spinal pathology and LMM quality. Mediation models estimated the direct and indirect effects of pathology on leg pain, and pathology and LMM quality on leg pain, respectively. Multivariable analysis identified a leg pain rating change of 0.99 [0.14; 1.84] (unstandardized beta coefficients [95% CI]) in the presence of ≥ 4 pathologies, and a disability rating change of - 0.65 [- 0.14; - 1.16] for each 10% increase in muscle quality, but no effect on back pain intensity. Muscle quality had a non-significant mediating role (13.4%) between pathology and leg pain intensity. The number of different pathologies present demonstrated a small effect on 12-month leg pain intensity outcomes, while higher LMM quality had a direct effect on 12-month disability ratings but no mediating effect between pathology and leg pain. The relations between degenerative pathology, LMM quality, and pain-related outcomes appear complex and may include independent pathways.

Can pathoanatomical pathways of degeneration in lumbar motion segments be identified by clustering MRI findings.

BACKGROUND: Magnetic Resonance Imaging (MRI) is the gold standard for detailed visualisation of spinal pathological and degenerative processes, but the prevailing view is that such imaging findings have little or no clinical relevance for low back pain. This is because these findings appear to have little association with treatment effects in clinical populations, and mostly a weak association with the presence of pain in the general population. METHODS: This study is a secondary analysis of data from 631 patients, from an outpatient spine clinic, who had been screened for inclusion in a randomised controlled trial. The available data created a total sample pool of 3,155 vertebral motion segments. The mean age of the cohort was 42 years (SD 10.8, range 18-73) and 54% were women. RESULTS: Twelve clusters of MRI findings were identified, described and grouped into five different hypothetical pathways of degeneration that appear to have face validity. CONCLUSIONS: This study has shown that Latent Class Analysis can be used to identify clusters of MRI findings from people with LBP and that those clusters can be grouped into degenerative pathways that are biologically plausible. If these clusters of MRI findings are reproducible in other datasets of similar patients, they may form a stable platform to investigate the relationship between degenerative pathways and clinically important characteristics such as pain and activity limitation.

Lumbar multifidus muscle morphology is associated with low back-related pain duration, disability, and leg pain: A cross-sectional study in secondary care.

BACKGROUND: Systematic reviews and studies exploring associations between morphologic change of paraspinal muscles and low back pain or related outcomes such as disability, radiculopathy, and physical workload, have reported conflicting results. This study explores the associations between lumbar multifidus muscle quality and clinical outcomes relating to low back pain. METHODS: Cross-sectional study of spinal clinic outpatients presenting with a primary complaint of low back and/or leg symptoms. Univariable and multivariable regression models were used to investigate associations between MRI-based multifidus muscle cross-sectional area at L4 and L5 and clinical outcomes for low back pain, leg pain, disability, restricted motion, and strenuous nature of work. Results were reported with ß-coefficients, odds ratios (OR), or incidence rate ratios (IRR) and their corresponding 95% confidence intervals, based on a 10% difference in muscle quality for each clinical variable. Multivariable analyses were adjusted for age, sex, and BMI. RESULTS: 875 patients [487 females; mean (SD) age: 43.6 (10.2) years] were included. In the multivariable analyses, muscle quality was significantly associated with disability (0-23 scale) [ß: -0.74, 95% CI: -1.14, -0.34], leg pain intensity (0-10 scale) [ß: -0.25, 95% CI: -0.46, -0.03], and current pain duration of more than 12 months [OR: 1.27, 95% CI: 1.03, 1.55]. No associations were found for low back pain intensity, morning stiffness, painful active range of motion, or work nature. CONCLUSIONS: Patients with higher lumbar multifidus muscle quality reported lower levels of low back pain-related disability and leg pain intensity, indicating that muscle quality may play a role in the etiology of lumbar spine disorders. However, the clinical importance of these associations is uncertain due to the low magnitude of identified associations. Future longitudinal studies are needed to understand the effect of lumbar multifidus muscle quality on lumbar-related pain and disability.

The association between cervical degenerative MRI findings and self-reported neck pain, disability and headache: a cross-sectional exploratory study.

BACKGROUND: Neck pain and headache are highly prevalent conditions and leading causes of disability worldwide. Although MRI is widely used in the management of these conditions, there is uncertainty about the clinical significance of cervical MRI findings in patients with neck pain or headache. Therefore, this study aims to investigate the association between cervical degenerative MRI findings and self-reported neck pain, neck disability, and headache. METHODS: This study was a secondary analysis of a cohort of patients with low back pain aged 18-40 years recruited from a non-surgical outpatient spine clinic. The cervical MRI and outcome measures used in this analysis were collected at a four-year follow-up (2014-2017). Self-reported outcome measures included neck pain intensity, neck disability as measured by the Neck Disability Index, and headache as measured by a single NDI item. Cervical MRI findings included disc degeneration, disc contour changes, and vertebral endplate signal changes (VESC). Multivariable logistic regression analyses, adjusted for age and sex, were used to analyse the associations between MRI findings and neck pain, neck disability, and headache. RESULTS: A total of 600 participants who underwent MRI and completed the relevant questionnaires at follow-up were included. The median age was 37 years (interquartile range 31-41) and 325 (54%) were female. Of the included participants, 181 (31%) had moderate or severe neck pain, 274 (59%) had moderate or severe neck disability, 193 (42%) reported headaches, and 211 (35%) had one or more cervical degenerative MRI findings. Cervical disc degeneration and disc contour changes were positively associated with moderate or severe neck pain with odds ratio 1.6 (95% CI 1.1-2.4) and 1.6 (1.1-2.3), respectively. VESC was associated with moderate or severe neck disability with odds ratio 3.3 (1.3-8.4). No statistically significant associations were found between the MRI findings assessed and headache. CONCLUSIONS: In this cross-sectional exploratory study, we found that cervical disc degeneration and disc contour changes were associated with neck pain, and VESC was associated with neck disability. None of the MRI findings were associated with headache. The results suggest that cervical degenerative changes may contribute to the aetiology of neck symptoms, but the associations are modest and cannot guide clinical decisions.

Is the development of Modic changes associated with clinical symptoms? A 14-month cohort study with MRI.

PURPOSE: Modic changes (MCs) have been suggested to be a diagnostic subgroup of low back pain (LBP). However, the clinical implications of MCs remain unclear. For this reason, the aims of this study were to investigate how MCs developed over a 14-month period and if changes in the size and/or the pathological type of MCs were associated with changes in clinical symptoms in a cohort of patients with persistent LBP and MCs. METHODS: Information on LBP intensity and detailed information from MRI on the presence, type and size of MCs was collected at baseline and follow-up. Changes in type (type I, II, III and mixed types) and size of MCs were quantified at both time points according to a standardised evaluation protocol. The associations between change in type, change in size and change in LBP intensity were calculated using odds ratios (ORs). RESULTS: Approximately 40% of the MCs followed the expected developmental path from type I (here type I or I/II) to type II (here type II or II/III) or type I to type I/II. In general, the bigger the size of the MC at baseline, the more likely it was that it remained unchanged in size after 14 months. Patients who had MC type I at both baseline and 14-month follow-up were less likely to experience an improvement in their LBP intensity as compared to patients who did not have type I changes at both time points (OR 7.2, CI 1.3-37). There was no association between change in size of MCs type I and change in LBP intensity. CONCLUSIONS: The presence of MCs type I at both baseline and follow-up is associated with a poor outcome in patients with persistent LBP and MCs.

Spinal degeneration is associated with lumbar multifidus morphology in secondary care patients with low back or leg pain.

Associations between multifidus muscle morphology and degenerative pathologies have been implied in patients with non-specific low back pain, but it is unknown how these are influenced by pathology severity, number, or distribution. MRI measures of pure multifidus muscle cross-sectional area (CSA) were acquired from 522 patients presenting with low back and/or leg symptoms in an outpatient clinic. We explored cross-sectional associations between the presence, distribution, and/or severity of lumbar degenerative pathologies (individually and in aggregate) and muscle outcomes in multivariable analyses (beta coefficients [95% CI]). We identified associations between lower pure multifidus muscle CSA and disc degeneration (at two or more levels): - 4.51 [- 6.72; - 2.3], Modic 2 changes: - 4.06 [- 6.09; - 2.04], endplate defects: - 2.74 [- 4.58; - 0.91], facet arthrosis: - 4.02 [- 6.26; - 1.78], disc herniations: - 3.66 [- 5.8; - 1.52], and when > 5 pathologies were present: - 6.77 [- 9.76; - 3.77], with the last supporting a potential dose-response relationship between number of spinal pathologies and multifidus morphology. Our findings could hypothetically indicate that these spinal and muscle findings: (1) are part of the same degenerative process, (2) result from prior injury or other common antecedent events, or (3) have a directional relationship. Future longitudinal studies are needed to further examine the complex nature of these relationships.

Reliability and validity of subjective radiologist reporting of temporal changes in lumbar spine MRI findings.

BACKGROUND: The importance of lumbar findings on magnetic resonance imaging (MRI) remains controversial. Changes in lumbar MRI findings over time may provide important insights into the causes of low back pain. However, the reliability and validity of temporal changes are unknown. OBJECTIVE: To (1) investigate the interrater reliability of subjective radiologist reporting of temporal changes in lumbar spine MRI findings and (2) determine how commonly temporal changes are reported when two scans are conducted 30 minutes apart (considered false positives). DESIGN: Cross-sectional study. SETTING: Radiology clinic. PARTICIPANTS: Forty volunteers (mean age 40; 53% female) with current (n = 31) or previous (n = 9) low back pain underwent initial lumbar MRI on a single 3T scanner. Participants then lay on a bed for 30 minutes before undergoing an identical MRI. In addition, we purposely selected five participants from a previous study with repeat lumbar MRI scans where temporal changes were reported in at least one MRI finding (1-12 weeks after initial scan) and another five participants where no temporal change was reported. The 10 participants were included in analyses for aim 1 only. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Two blinded radiologists reported on temporal changes between the baseline and repeat scan for 12 different MRI findings (eg, disk herniation, annular fissure) at five levels. RESULTS: The interrater reliability of subjective reporting of temporal changes was poor for all MRI findings based on Kappa values (≤ 0.24), but agreement was relatively high (≥ 90.8%). This is explained by the low prevalence of temporal changes as demonstrated by high values for Prevalence and Bias Adjusted Kappa (≥ 0.82). "False positive" temporal changes were reported by at least one radiologist for most MRI findings, but the rate was generally low. CONCLUSIONS: Caution is required when interpreting temporal changes in lumbar MRI findings owing to low reliability and some false positive reporting.

Reassuring Patients With Low Back Pain in Primary Care Consultations: Does it Happen, and Does it Matter? A ChiCo Cohort Study.

OBJECTIVES: Reassurance is an important part of treatment for low back pain (LBP). The Consultation-based Reassurance Questionnaire measures patients' perceived reassurance after health care consultations on 4 subdomains (ie, Data-gathering, Relationship-building, Generic reassurance, Cognitive reassurance). The objectives of this study were to investigate associations between the level of reassurance and outcomes and to investigate if the associations were moderated by patients' risk profile. MATERIALS AND METHODS: Adult patients consulting chiropractors for LBP were emailed the Consultation-based Reassurance Questionnaire directly after the consultation. Outcomes were Global Perceived Effect (GPE) after 2 weeks, and pain (Numeric Rating Scale) and disability (Roland-Morris Disability Questionnaire) 2 weeks and 3 months following treatment. Associations with GPE were tested in logistic mixed models. Associations between each reassurance domain and pain and disability were tested in longitudinal analyses using linear mixed models. Moderations by risk profile were tested by introducing an interaction between risk groups and reassurance level. All models were controlled for several potential confounders. RESULTS: A total of 2056 patients were included in the study, with 46% reporting LBP for less than a week. Associations between reassurance level and improvement in LBP intensity and disability were weak but positive, whereas associations with GPE were potentially clinically relevant. None of the associations were moderated by psychological risk profile. DISCUSSION: Identified associations between reassurance and outcomes were weak, however, for GPE the association might be of a clinically relevant magnitude. The causal relationship is unclear, but with communication always present in a consultation these results suggest that efforts to optimize clinician-patient communication might be worthwhile, also for people with very recent onset of LBP.

The Nordic maintenance care program: what are the indications for maintenance care in patients with low back pain? A survey of the members of the Danish Chiropractors' Association.

BACKGROUND: Maintenance care (MC) is relatively commonly used among chiropractors. However, factual information is needed on its indications for use. OBJECTIVES: This study had two objectives: 1) to describe which role patients' past history and treatment outcome play in chiropractors' decision to use MC in patients with low back pain, 2) to investigate if the chiropractors' clinical/educational background has an effect on the frequency of using MC and their indications for use of MC. METHOD: An anonymous questionnaire was sent to all 413 chiropractors practising in Denmark. Its main part consisted of 3 sets of 4 questions relating to one basic case of low back pain. For each case, the chiropractors were asked if they would use MC as they self-defined the term (no/perhaps/yes). There were questions also on gender, age, educational and clinical background, and on the number of MC patients seen by these chiropractors. Their decision to recommend MC was reported. Associations between the demographic variables and 1) the frequency of MC-use and 2) their indications for use of MC were tested through multivariate analysis. RESULTS: The response rate was 72%. Non-indications for MC were: 1) a good outcome combined with no previous events, or 2) a past history of LBP and gradual worsening with treatment. Indications for MC were a good outcome combined with a previous history of low back pain between once a month and once a year. The mean proportion of MC patients per week were 22% (SD 19), ranging from 0% to 100%. The use of MC was highest among experienced chiropractors, those who were educated in North America, and clinic owners. However, in Denmark most chiropractors graduated before 1999, are educated abroad, whereas most chiropractors thereafter are educated in Denmark. Therefore, we cannot conclude whether this difference relates to education or years of experience. There were no associations detected between demographic variables and the indications for MC. CONCLUSIONS: There is relatively high consensus on when MC should and should not be used. A history of prior low back pain combined with a positive response to treatment encourages the use of MC, whereas no previous history of back pain or a worsening of symptoms discourages the use of MC. There seems to be a difference in the proportional use of MC between chiropractors with more experience educated in North America and those with less experience educated in Denmark.

Adherence to key domains in low back pain guidelines: A cross-sectional study of Danish physiotherapists.

OBJECTIVE: The aim of the study was threefold: Firstly, to investigate the adherence to clinical practice guidelines for low back pain (LBP) among Danish physiotherapists with regard to three key domains: (a) activity, (b) work and (c) psychosocial risk factors. Secondly, to investigate whether adherence differed between physiotherapists working in private clinics (private physiotherapists) and physiotherapists working at public healthcare centres (public physiotherapists). Thirdly, to describe the physiotherapists' treatment modalities for patients with LBP. METHODS: A cross-sectional online survey was conducted with 817 physiotherapists working in the Central Denmark Region. Adherence to the guideline domains was assessed using two vignettes. The difference in adherence between the groups was assessed using the Chi-squared test. Treatment modalities were reported using descriptive statistics. RESULTS: A total of 234 physiotherapists responded, hereof 163 private physiotherapists and 71 public physiotherapists (response rate 29%). The proportions of physiotherapists managing the patients strictly in line with the guideline domains were 32% (activity), 16% (work) and 82% (psychosocial risk factors) for Vignette 1 and 6% (activity), 53% (work) and 60% (psychosocial risk factors) for Vignette 2. Public physiotherapists were more likely to manage patients strictly in line with guidelines for assessing the psychosocial risk factors compared to private physiotherapist (Vignette 1: 92% vs. 77% p = .030; Vignette 2:70% vs. 55% p = .035). Regarding the other two domains, there was no significant difference between the two groups in terms of adherence (p > .05). Concerning treatment modalities, the majority of physiotherapists instructed the patients in adopting an exercise program or informed the patients about the benign nature and prognosis of LBP. CONCLUSION: Overall, the participating Danish physiotherapists strictly adhered to only one out of three key domains. This underlines the importance of bringing focus on implementing the current guidelines' recommendations in clinical practice.

Characteristics and natural course of vertebral endplate signal (Modic) changes in the Danish general population.

BACKGROUND: Vertebral endplate signal changes (VESC) are more common among patients with low back pain (LBP) and/or sciatica than in people who are not seeking care for back pain. The distribution and characteristics of VESC have been described in people from clinical and non-clinical populations. However, while the clinical course of VESC has been studied in patients, the natural course in the general population has not been reported. The objectives of this prospective observational study were to describe: 1) the distribution and characteristics of VESC in the lumbar spine, 2) its association with disc degeneration, and 3) its natural course from 40 to 44 years of age. METHODS: Three-hundred-and-forty-four individuals (161 men and 183 women) sampled from the Danish general population had MRI at the age of 40 and again at the age of 44. The following MRI findings were evaluated using standardised evaluation protocols: type, location, and size of VESC, disc signal, and disc height. Characteristics and distribution of VESC were analysed by frequency tables. The association between VESC and disc degeneration was analysed by logistic regression analysis. The change in type and size of VESC was analysed by cross-tabulations of variables obtained at age 40 and 44 and tested using McNemar's test of symmetry. RESULTS: Two-thirds (67%) of VESC found in this study were located in the lower part of the spine (L4-S1). VESC located at disc levels L1-L3 were generally small and located only in the anterior part of the vertebra, whereas those located at disc levels L4-S1 were more likely to extend further into the vertebra and along the endplate. Moreover, the more the VESC extended into the vertebra, the more likely it was that the adjacent disc was degenerated. The prevalence of endplate levels with VESC increased significantly from 6% to 9% from age 40 to 44. Again, VESC that was only observed in the endplate was more likely to come and go over the four-year period compared with those which extended further into the vertebra, where it generally persisted. CONCLUSION: The prevalence of VESC increased significantly over the four-year period. Furthermore, the results from this study indicate that the distribution of VESC, its association with disc degeneration and its natural course, is dependent on the size of the signal changes.

Exploratory study for clinical signs of MODIC changes in patients with low-back pain in the Netherlands armed forces.

Background: Magnetic resonance imaging (MRI) is being used extensively in the search for pathoanatomical factors contributing to low back pain (LBP) such as Modic changes (MC). However, it remains unclear whether clinical findings can identify patients with MC. The purpose of this explorative study was to assess the predictive value of six clinical tests and three questionnaires commonly used with patients with low-back pain (LBP) on the presence of Modic changes (MC). Methods: A retrospective cohort study was performed using data from Dutch military personnel in the period between April 2013 and July 2016. Questionnaires included the Roland Morris Disability Questionnaire, Numeric Pain Rating Scale, and Pain Self-Efficacy Questionnaire. The clinical examination included (i) range of motion, (ii) presence of pain during flexion and extension, (iii) Prone Instability Test, and (iv) straight leg raise. Backward stepwise regression was used to estimate predictive value for the presence of MC and the type of MC. The exploration of clinical tests was performed by univariable logistic regression models. Results: Two hundred eighty-six patients were allocated for the study, and 112 cases with medical records and MRI scans were available; 60 cases with MC and 52 without MC. Age was significantly higher in the MC group. The univariate regression analysis showed a significantly increased odds ratio for pain during flexion movement (2.57 [95% confidence interval (CI): 1.08-6.08]) in the group with MC. Multivariable logistic regression of all clinical symptoms and signs showed no significant association for any of the variables. The diagnostic value of the clinical tests expressed by sensitivity, specificity, positive predictive, and negative predictive values showed, for all the combinations, a low area under the curve (AUC) score, ranging from 0.41 to 0.53. Single-test sensitivity was the highest for pain in flexion: 60% (95% CI: 48.3-70.4). Conclusion: No model to predict the presence of MC, based on clinical tests, could be demonstrated. It is therefore not likely that LBP patients with MC are very different from other LBP patients and that they form a specific subgroup. However, the study only explored a limited number of clinical findings and it is possible that larger samples allowing for more variables would conclude differently.

What Level of Inflammation Leads to Structural Damage in the Sacroiliac Joints? A Four-Year Magnetic Resonance Imaging Follow-Up Study of Low Back Pain Patients.

OBJECTIVE: Sacroiliac (SI) joint bone marrow edema (BME) is considered to be pivotal in the detection of early spondyloarthritis. However, the link between BME and development of spondyloarthritis-related bone remodeling remains unclear. This study was undertaken to investigate the evolution of BME and structural lesions in the SI joints over time. METHODS: Baseline and 4-year follow-up magnetic resonance imaging scans were conducted in 604 patients ages 18-40 years who were referred with low back pain to an outpatient spine clinic. Eight SI joint regions were scored for BME and categorized as absent, limited (<25% of subcortical bone region), intermediate (25-50%), or extensive (>50%). Structural lesions including erosions and fat lesions were scored as absent or present. RESULTS: SI joint BME was seen at either time point (baseline or at 4 years) in 41% of participants but was persistent at both time points in only 16% of participants. Structural SI joint lesions developed according to the extent of BME at baseline: limited, intermediate, and extensive BME (as compared to absent BME) were independently associated with erosion at follow-up with odds ratios (ORs) of 3, 5, and 46, respectively, and with fat lesions (ORs 3, 7, and 33, respectively). In regions with limited and intermediate BME at baseline, 60% and 50% had resolved by follow-up, respectively, while only 2% and 7% had evolved into extensive BME by follow-up. CONCLUSION: While extensive SI joint BME was a strong independent predictor of development of structural lesions, limited and intermediate BME were mostly transient and only rarely evolved into extensive BME or structural lesions. These findings enhance our understanding of the natural development of SI joint lesions and indicate different progression patterns for limited/intermediate versus extensive BME, possibly due to different etiologies.

Association Between Inflammatory Back Pain Characteristics and Magnetic Resonance Imaging Findings in the Spine and Sacroiliac Joints.

OBJECTIVE: To investigate the association between magnetic resonance imaging (MRI) findings at the sacroiliac (SI) joints and vertebral endplates and pain characteristics assumed to be indicative of axial inflammation. METHODS: Patients ages 18-40 years with persistent low back pain referred to an outpatient spine clinic participated, including an unknown proportion of axial spondyloarthritis patients. Data included MRI of the spine and SI joints and self-reported responses to questions covering the Calin, Berlin, Assessment of Spondyloarthritis International Society, and Bailly inflammatory back pain (IBP) definitions. RESULTS: In the 1,020 included patients, 53% were women, and the median age was 33 years. Positive associations were found between the SI joint MRI findings and pain characteristics, odds ratios ranging from 1.4 to 2.7. SI joint bone marrow edema (BME) was associated with morning stiffness >60 minutes, and SI joint erosions with the Calin, Berlin, and Bailly IBP definitions, alternating buttock pain, and good response to nonsteroidal antiinflammatory drugs. SI joint fatty marrow deposition (FMD) was associated with insidious onset, and SI joint sclerosis with pain at night. In addition, the spinal MRI changes were associated with IBP, odds ratios ranging from 1.4 to 2.0; vertebral endplate BME was associated with morning stiffness, and vertebral endplate FMD with the Calin and Bailly IBP definitions, improvement with exercise, morning stiffness >30 minutes, and pain worst in the morning. CONCLUSION: The identified associations between inflammatory MRI findings and pain characteristics indicate that axial inflammation to some degree induces a specific pain pattern. Thus, the results add to knowledge of axial inflammatory processes. However, all identified associations were weak, which compromises the use of IBP as a marker of axial inflammation.

Is the Number of Different MRI Findings More Strongly Associated With Low Back Pain Than Single MRI Findings?

STUDY DESIGN: A cross-sectional and longitudinal analysis using two different datasets. OBJECTIVE: To investigate if the number of different magnetic resonance imaging (MRI) findings present is more strongly associated with low back pain (LBP) than single MRI findings. SUMMARY OF BACKGROUND DATA: Most previous studies have investigated the associations between single MRI findings and back pain rather than investigating combinations of MRI findings. If different individuals have different pathoanatomic sources contributing to their pain, then combinations of MRI findings may be more strongly associated with LBP. METHODS: This study used data from two previous studies that investigated the association between single MRI findings and LBP. One study was a cross-sectional population cohort of 412 people of 40 years; the second was a longitudinal cohort of 76 people recently recovered from LBP who were followed for 12 months. The outcome for the cross-sectional study was presence of LBP during the last year. The outcome for the longitudinal study was days to recurrence of activity limiting LBP. In both datasets, we created an aggregate score of the number of different MRI findings present in each individual and assessed the relationship between this aggregate score and LBP. RESULTS: The risk of LBP outcome increased with increasing numbers of different MRI findings. Compared with those with no MRI findings, those with three MRI findings were at substantially greater risk of LBP in the last year (odd ratio = 14.1; 95% confidence interval, 4.32-49.47) in the cross-sectional study, or of future recurrence of LBP (hazard ratio = 12.2; 95% confidence interval 1.26-118.21) in the longitudinal study. CONCLUSION: The aggregate MRI score was more strongly associated with LBP outcomes than single MRI findings in both datasets. Further investigation of this approach is indicated. LEVEL OF EVIDENCE: 2.

Are the size and composition of the paraspinal muscles associated with low back pain? A systematic review.

BACKGROUND CONTEXT: Although previous studies have investigated the association between paraspinal muscle morphology and low back pain (LBP), the results are conflicting. PURPOSE: This systematic review examined the relationship between size and composition of the paraspinal muscles and LBP. STUDY DESIGN/SETTING: A systematic review was carried out. PATIENT SAMPLE: No patient sample was required. OUTCOME MEASURES: This review had no outcome measures. METHODS: A systematic search of electronic databases was conducted to identify studies investigating the association between the cross-sectional area or fatty infiltration of the paraspinal muscles (erector spinae, multifidus, psoas, and quadratus lumborum) and LBP. Descriptive data regarding study design and methodology were tabulated and a risk of bias assessment was performed. RESULTS: Of the 119 studies identified, 25 met the inclusion criteria. Eight studies were reported as having low to moderate risk of bias. There was evidence for a negative association between cross-sectional area (CSA) of multifidus and LBP, but conflicting evidence for a relationship between erector spinae, psoas, and quadratus lumborum CSA and LBP. Moreover, there was evidence to indicate multifidus CSA was predictive of LBP for up to 12 months in men, but insufficient evidence to indicate a relationship for longer time periods. Although there was conflicting evidence for a relationship between multifidus fat infiltration and LBP, there was no or limited evidence for an association for the other paraspinal musculature. CONCLUSIONS: This review found evidence that multifidus CSA was negatively associated with and predictive of LBP up to 12 months but conflicting evidence for an association between erector spinae, psoas, and quadratus lumborum CSA and LBP. To further understand the role of the paraspinal musculature in LBP, there is a need for high-quality cohort studies which extend over both the short and longer term.

Degenerative Pathways of Lumbar Motion Segments--A Comparison in Two Samples of Patients with Persistent Low Back Pain.

BACKGROUND: Magnetic resonance imaging (MRI) is used to identify spinal pathoanatomy in people with persistent low back pain. However, the clinical relevance of spinal degenerative MRI findings remains uncertain. Although multiple MRI findings are almost always present at the same time, research into the association with clinical outcomes (such as pain) has predominantly focused on individual MRI findings. This study aimed to: (i) investigate how multiple MRI lumbar spine findings cluster together within two different samples of patients with low back pain, (ii) classify these clusters into hypothetical pathways of degeneration based on scientific knowledge of disco-vertebral degeneration, and (iii) compare these clusters and degenerative pathways between samples. METHODS: We performed a secondary cross-sectional analysis on two dissimilar MRI samples collected in a hospital department: (1) data from the spinal MRI reports of 4,162 low back pain patients and (2) data from an MRI research protocol of 631 low back pain patients. Latent Class Analysis was used in both samples to cluster MRI findings from lumbar motion segments. Using content analysis, each cluster was then categorised into hypothetical pathways of degeneration. RESULTS: Six clusters of MRI findings were identified in each of the two samples. The content of the clusters in the two samples displayed some differences but had the same overall pattern of MRI findings. Although the hypothetical degenerative pathways identified in the two samples were not identical, the overall pattern of increasing degeneration within the pathways was the same. CONCLUSIONS: It was expected that different clusters could emerge from different samples, however, when organised into hypothetical pathways of degeneration, the overall pattern of increasing degeneration was similar and biologically plausible. This evidence of reproducibility suggests that Latent Class Analysis may provide a new approach to investigating the relationship between MRI findings and clinically important characteristics such as pain and activity limitation.