title: MRI vertebral corner inflammation followed by fat deposition is the strongest contributor to the development of new bone at the same vertebral corner: a multilevel longitudinal analysis in patients with ankylosing spondylitis.
abstract: OBJECTIVE
  To study the sequential relationship between MRI vertebral corner inflammation (VCI), vertebral corner fat deposition (VCFD) and the development/growth of radiographic syndesmophytes at the same vertebral corner (VC).
  
  
  METHODS
  Baseline, 24 and 102 weeks spinal MRIs were assessed for the presence/absence of VCI and VCFD. Anterior VCs of lateral radiographs of the cervical and lumbar spine (baseline and 102 weeks) were assessed for the development of new bone (syndesmophyte formation or syndesmophyte formation/growth combined). Data from 161 to 177 patients were analysed at the VC level using two-way and multilevel analyses adjusting for within-patient correlation and MRI reader (generalised estimating equations for binomial outcomes).
  
  
  RESULTS
  The presence of VCI (adjusted (adj) OR 1.75 to 1.98) as well as the presence of VCFD (adjOR 1.60 to 2.32) at any time point (TP) were significantly associated with the development of new bone. The combination of VCI and VCFD at the same VC increased the strength of the association, both for the sequential or simultaneous presence of VCI and VCFD across the three TPs (adjOR 2.12 to 2.73), as well as for the development of new VCFD preceded by VCI at a previous TP (adjOR 2.12 to 3.01). The complete absence of both VCI and VCFD across the three TPs 'protected' against new bone formation (adjOR 0.45 to 0.62). However, 40-66% of new bone still developed in VCs without MRI inflammation or fat degeneration at any of the three TPs.
  
  
  CONCLUSIONS
  Both VCI and VCFD contribute to new bone formation in ankylosing spondylitis (AS), especially if VCI precedes VCFD. However, VCI, VCFD and this particular sequence of events only partially explain the development of new bone in AS.
authors.affiliation: Rheumatology Department, Leiden University Medical Center, Leiden, The Netherlands Clínica Universitária de Reumatologia, Faculty of Medicine, University of Coimbra, Portugal.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Machado
authors.affiliation: Rheumatology Department, Rheumazentrum Ruhrgebiet Herne, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Xenofon
authors.initials: X
authors.lastname: Baraliakos
authors.affiliation: Rheumatology Department, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Désirée
authors.identifier: http://orcid.org/0000-0002-5781-158X
authors.initials: D
authors.lastname: van der Heijde
authors.affiliation: Rheumatology Department, Rheumazentrum Ruhrgebiet Herne, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Braun
authors.affiliation: Department of Rheumatology & Clinical Immunology, Amsterdam Rheumatology & Clinical Immunology Center, Amsterdam, The Netherlands Rheumatology Department, Atrium Medical Center, Heerlen, The Netherlands.
authors.forename: Robert
authors.initials: R
authors.lastname: Landewé
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000473:pathology*; D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010000:Osteitis / Q000000981:diagnostic imaging / Q000209:etiology*; D010012:Osteogenesis / Q000502:physiology*; D011859:Radiography; D013131:Spine / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology
chemical_list: D018501:Antirheumatic Agents; D000069285:Infliximab
keywords: Ankylosing Spondylitis; Inflammation; Magnetic Resonance Imaging; Outcomes research; Spondyloarthritis