Rikke Krüger Jensen

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

The diagnostic value of three sacroiliac joint pain provocation tests for sacroiliitis identified by magnetic resonance imaging

Objectives: The aim of the current study was to investigate the diagnostic value of three sacroiliac (SI) joint pain provocation tests for sacroiliitis identified by magnetic resonance imaging (MRI) and stratified by gender. Method: Patients without clinical signs of nerve root compression were selected from a cohort of patients with persistent low back pain referred to an outpatient spine clinic. Data from Gaenslen’s test, the thigh thrust test, and the long dorsal sacroilia ligament test and sacroiliitis identified by MRI were analysed. Results: The median age of the 454 included patients was 33 (range 18–40) years and 241 (53%) were women. The prevalence of SI joints with sacroiliitis was 5%. In the whole study group, only the thigh trust test was associated with sacroiliitis, the area under the receiver operating characteristic (ROC) curve (AUC) was 0.58 [95% confidence interval (CI) 0.51–0.65], sensitivity 31% (95% CI 18–47), and specificity 85% (95% CI 82–87). In men, sacroiliitis was associated with all the SI joint tests assessed and multi-test regimens, with the greatest AUC found for at least one positive out of three tests [AUC 0.68 (95% CI 0.56–0.80), sensitivity 56% (95% CI 31–79), and specificity 81% (95% CI 77–85)]. In women, no significant associations were observed between the SI joint tests and sacroiliitis. Conclusions: Only in men were the SI joint tests found to be associated with sacroiliitis identified by MRI. Although, the diagnostic value was relatively low, the results indicate that the use of SI joint tests for sacroiliitis may be optimized by gender-separate analyses.

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.