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.
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 β-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.
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) β: -0.74, 95% CI: -1.14, -0.34, leg pain intensity (0-10 scale) β: -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.
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.
Although previous studies have investigated the association between paraspinal muscle morphology and low back pain (LBP), the results are conflicting.
This systematic review examined the relationship ...between size and composition of the paraspinal muscles and LBP.
A systematic review was carried out.
No patient sample was required.
This review had no outcome measures.
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.
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.
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.
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.
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.
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.
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.
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.
PROSPERO 2015: CRD42015012985.
Abstract
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.
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
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The location of vertebral endplate signal changes supports a mechanical aetiology
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Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain
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Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology
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More knowledge of the clinical importance of sacroiliac joint MRI findings is needed
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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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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