UNDERSTANDING LOW BACK PAIN

The Low Back Pain Algorithm; Kieran Macphail

6 months ago

MRI Changes and CLBP- for those interested in more nuance and with 4 mins.

There have been many studies highlighting the lack of correlation between radiologic findings and LBP in asymptomatic (Baker 2014, Jensen et al. 1994) and symptomatic individuals (Chou et al. 2011, Endean et al. 2011). Early MRI after onset of LBP has been associated with worse outcomes in a two year follow-up of 3264 cases (Webster and Cifuentes 2010). For example Øiestad et al (2020) their systematic review found no associations structural imaging findings and back pain.
Even in patients with incidental findings tracked for 3 years there is not a strong association (Suri et al. 2014), although annular fissures, disc extrusions, and nerve root impingement were associated with incident symptom outcomes.
Carragee et al (2006) followed 200 subjects with no lifetime history of LBP but at high risk of developing LBP. Subjects had a physical assessment and MRI at baseline. 51 subjects developed LBP with only 2 showing clinically significant changes on MRI. 6 had progressive non-significant degeneration, the rest showed no change or regression. Radicular symptoms were more likely to be associated with new findings on MRI.

Figure 1 Table showing Age-Specific Prevalence estiates of degenerative Spine Imaging Findings in Asymptomatic Patients (Brinjikji et al 2015a)

Brinjikji et al (2015a) published imaging findings of spine degeneration in asymptomatic individuals as shown in figure 1. Many imaging-based degenerative features are likely part of normal aging and unassociated with pain. These imaging findings must be interpreted in the context of the patient’s clinical condition.
In contrast in the same year the same group published a meta-analysis of 280 studies comprising 3097 individuals demonstrated that MR imaging evidence of disc bulge, degeneration, extrusion, protrusion, Modic 1 changes, and spondylolysis are more prevalent in adults 50 years of age or younger with back pain compared with asymptomatic individuals (Brinjikji et al 2015b).
Maher et al's (2017) excellent review cites Steffens et al review of MRI findings as follows (incorrectly as 2014, actually 2013).
"Findings from a systematic review (12 studies) did not show consistent associations between MRI findings and future episodes of low back pain."
However, Steffens et al’s (2013) systematic review actually found it was not possible to pool findings due to lack of quality but single studies reported significant associations for type 1 Modic changes with pain, disc degeneration with disability in samples with current LBP and disc herniation with pain in a mixed sample. A quick scan of a Maher et al's review and you may think MRI's are fairly useless. Read the original and you may realise it's early stages in our research of the area, some associations have been found and more work is needed.
A prospective MRI study of 148 aymptomatic patients found no relationship between MRI changes and first onset of LBP but did find depression was an independent predictor (Jarvik et al 2005). All five subjects with new disc extrusions and all four subjects with new nerve root impingement had new pain. Central spinal stenosis and nerve root contact had the highest, though nonsignificant correlation with new onset.
Those with disc degeneration or herniation have double the incidence of low back pain (Cheung et al 2009), however only type one Modic changes and significant oedematous changes at the facet joints are associated with LBP (Ract et al 2015). Up to 47% of elderly people without back pain have facet joint arthritis, although “severe” facet joint arthritis is associated with back pain (Suri et al 2013).
Jensen et al (2018) conducted a latent class analysis of six subgroups of longitudinal data of 412 low back imaging findings in pain free subjects describing 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.

Zehra et al (2019) investigate the multi‐dimensional characteristics of lumbar endplate defects in humans in relation to disc degeneration and other MRI phenotypes as well as their role with pain and disability. A total of 108 subjects were recruited and underwent 3T MRI of the lumbar spine. Structural endplate defects were identified and their dimensions were measured in terms of maximum width and depth, and were then standardized to the actual width of the endplate and depth of the vertebral body, respectively. Both width and depth of all endplate defects in each subject were added separately and scores were assigned on the basis of size from 1 to 3. Combining both scores provided “cumulative endplate defect scores.” Disc degeneration scores, Modic changes, disc displacement, HIZ, and facet joint changes were assessed. Subject demographics, pain profile, and Oswestry Disability Index (ODI) were also obtained. Endplate defects were observed in 67.5% of the subjects and in 13.5% of the endplates. All dimensions of endplate defects showed significance with disc degenerative scores, Modic changes, and posterior disc displacement (p < 0.05). Maximum width (p = 0.009) and its standardized value (p = 0.02), and cumulative endplate defect scores (p = 0.004) increased with narrow facet joints. Cumulative endplate defect scores showed a strong positive association with ODI (p < 0.05) compared to disc degenerative scores. Large size endplate defects were strongly associated with degenerative spine changes and more back‐related disability.

MRI & Modic Changes
Jensen et al (2012) investigated LBP intensity and Modic changes on MRI at baseline and 18-month follow-up. Approximately 40% of the Modic changes followed the expected developmental path from Type I towards Type III. In general, the bigger the size of the Modic change at baseline, the more likely it was that it remained unchanged in size after 14 months. Patients who had Modic changes 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. There was no association between change in size of Modic changes Type I and change in LBP intensity.
Herlin et al (2018) conducted a systematic review of asscoaitions between Modic changes and LBP. They concluded that the associations between MCs and LBP-related outcomes are inconsistent. The high risk of bias and the heterogeneity in terms of study samples, clinical outcomes and prevalence estimates of MCs and LBP may explain these findings. Lower lumbar disc levels l4/5 and l5/S1 were more closely associated with LBP. Disc degeneration was reported to reduce the estimates of association between MCs and LBP by 10–28%.
Based on one of the largest MRI studies to assess lumbar Modic changes, Mok et al (2016) noted that Modic changes were associated with both disc degeneration and the presence and severity of LBP.
Cheung et al (2012) compared patients with multilevel continuous degeneration with subjects with a normal level between degenerative discs in a population-based study of 3099 Southern Chinese patients. Skipped level disc degernation was further classified into 5 types by the relative location of nondegenerated normal disc(s) to degenerated disc levels. Continuous multilevel disc degeneration increased the likelihood of historical LBP and pain severity in comparison with skipped level disc degernation. A significant increasing trend of number of levels with disc degeneration, overall disc degeneration severity, and presence of disc bulges/extrusions was noted from skipped level disc degeneration type I (least severe) to skipped level disc degeneration type V (most severe). A higher prevalence of LBP and a higher pain intensity were observed in skipped level disc degernation classification type V. Functional disability scores did not differ between groups or sub classifications.

References
Brinjikji, W., Luetmer, P.H., Comstock, B., Bresnahan, B.W., Chen, L.E., Deyo, R.A., Halabi, S., Turner, J.A., Avins, A.L., James, K. and Wald, J.T., 2015a. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. American Journal of Neuroradiology, 36(4), pp.811-816.
Brinjikji, W., Diehn, F.E., Jarvik, J.G., Carr, C.M., Kallmes, D.F., Murad, M.H. and Luetmer, P.H., 2015b. MRI findings of disc degeneration are more prevalent in adults with low back pain than in asymptomatic controls: a systematic review and meta-analysis. American Journal of Neuroradiology, 36(12), pp.2394-2399.
Carragee, E., Alamin, T., Cheng, I., Franklin, T., van den Haak, E. and Hurwitz, E., 2006. Are first-time episodes of serious LBP associated with new MRI findings?. The Spine Journal, 6(6), pp.624-635.
Cheung, K.M., Karppinen, J., Chan, D., Ho, D.W., Song, Y.Q., Sham, P., Cheah, K.S., Leong, J.C. and Luk, K.D., 2009. Prevalence and pattern of lumbar magnetic resonance imaging changes in a population study of one thousand forty-three individuals. Spine, 34(9), pp.934-940.
Cheung, K.M., Samartzis, D., Karppinen, J. and Luk, K.D., 2012. Are “patterns” of lumbar disc degeneration associated with low back pain?: new insights based on skipped level disc pathology. Spine, 37(7), pp.E430-E438.
Herlin, C., Kjaer, P., Espeland, A., Skouen, J.S., Leboeuf-Yde, C., Karppinen, J., Niinimäki, J., Sørensen, J.S., Storheim, K. and Jensen, T.S., 2018. Modic changes—Their associations with low back pain and activity limitation: A systematic literature review and meta-analysis. PloS one, 13(8), p.e0200677.
Jarvik JG, Hollingworth W, Heagerty PJ, Haynor DR, Boyko EJ, Deyo RA. Three‐year incidence of low back pain in an initially asymptomatic cohort: clinical and imaging risk factors. Spine. 2005;30(13):1541–1548
Jensen, R.K., Leboeuf-Yde, C., Wedderkopp, N., Sorensen, J.S., Jensen, T.S. and Manniche, C., 2012. Is the development of Modic changes associated with clinical symptoms? A 14-month cohort study with MRI. European Spine Journal, 21(11), pp.2271-2279.AA
Jensen et al 2018 bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-018-1978-x#Sec2
Maher, C., Underwood, M. and Buchbinder, R., 2017. Non-specific low back pain. The Lancet, 389(10070), pp.736-747.
Mok, F.P., Samartzis, D., Karppinen, J., Fong, D.Y., Luk, K.D. and Cheung, K.M., 2016. Modic changes of the lumbar spine: prevalence, risk factors, and association with disc degeneration and low back pain in a large-scale population-based cohort. The Spine Journal, 16(1), pp.32-41.
Øiestad, B.E., Hilde, G., Tveter, A.T., Peat, G.G., Thomas, M.J., Dunn, K.M. and Grotle, M., 2020. Risk factors for episodes of back pain in emerging adults. A systematic review. European Journal of Pain, 24(1), pp.19-38.
Ract, I., Meadeb, J.M., Mercy, G., Cueff, F., Husson, J.L. and Guillin, R., 2015. A review of the value of MRI signs in low back pain. Diagnostic and interventional imaging, 96(3), pp.239-249.
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Webster, B.S. and Cifuentes, M., 2010. Relationship of early magnetic resonance imaging for work-related acute low back pain with disability and medical utilization outcomes. Journal of Occupational and Environmental Medicine, 52(9), pp.900-907.
Zehra, U., Cheung, J.P.Y., Bow, C., Lu, W. and Samartzis, D., 2019. Multidimensional vertebral endplate defects are associated with disc degeneration, modic changes, facet joint abnormalities, and pain. Journal of Orthopaedic Research®, 37(5), pp.1080-1089. ...