title: Degenerative Pathways of Lumbar Motion Segments--A Comparison in Two Samples of Patients with Persistent Low Back Pain.
abstract: 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.
authors.affiliation: Research Department, Spine Centre of Southern Denmark, Hospital Lillebaelt, Institute of Regional Health Research, University of Southern Denmark, Middelfart, Denmark.
authors.forename: Rikke K
authors.initials: RK
authors.lastname: Jensen
authors.affiliation: Research Department, Spine Centre of Southern Denmark, Hospital Lillebaelt, Institute of Regional Health Research, University of Southern Denmark, Middelfart, Denmark.|Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Kjaer
authors.affiliation: Research Department, Spine Centre of Southern Denmark, Hospital Lillebaelt, Institute of Regional Health Research, University of Southern Denmark, Middelfart, Denmark.
authors.forename: Tue S
authors.initials: TS
authors.lastname: Jensen
authors.affiliation: Department of Orthopaedics, Bartholomew's Hospital, London, England.
authors.forename: Hanne
authors.initials: H
authors.lastname: Albert
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Kent
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology*; D007405:Intervertebral Disc Displacement / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D017116:Low Back Pain / Q000453:epidemiology / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009038:Motion; D009408:Nerve Compression Syndromes / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D013126:Spinal Nerve Roots / Q000473:pathology; D013128:Spinal Osteophytosis / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D013130:Spinal Stenosis / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D013168:Spondylolisthesis / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult