title: Morphometric vertebral assessments via the use of dual X-ray absorptiometry for the evaluation of radiographic damage in ankylosing spondylitis: a pilot study.
abstract: We performed a pilot study to compare vertebral fracture assessments (VFA) and lateral X-rays in terms of inter- and intraobserver reliability and degree of correlation for the detection of syndesmophytes in ankylosing spondylitis (AS). We recruited 19 patients with AS and recent lumbar or cervical lateral X-rays with at least one syndesmophyte. Each patient underwent dual-energy X-ray absorptiometry with measurement of bone mineral density and dorso-lumbar VFA. Intra- and interreader reliability for VFA and X-rays were measured using 2 independent, blinded observers and Cohen's kappa values. An adapted modified Stoke Ankylosing Spondylitis Spinal Score (amSASSS) was generated with each method, and these 2 values correlated. For X-rays, intraobserver and interobserver agreement were 94.3% (κ = 0.83) and 98.6% (κ = 0.96), respectively; for VFA, corresponding values were 92.8% (κ = 0.79) and 93.8% (κ = 0.82). Overall agreement between the 2 techniques was 88.6% (κ = 0.72). The Pearson correlation coefficient for the 2 methods was 0.95 for the modified Stoke Ankylosing Spondylitis Spinal Score . Per dual-energy X-ray absorptiometry-generated bone mineral density, >50% of patients were osteopenic and 10% osteoporotic. In terms of reproducibility and correlation with X-rays, performing a VFA appears to be a candidate for assessing radiographic damage in AS, thought further research is necessary to justify this indication.
authors.affiliation: Division of Rheumatology, Department of Bone and Joint Diseases, Lausanne University Hospital, Lausanne, Switzerland; Center for Bone Diseases, Department of Bone and Joint Diseases, Lausanne University Hospital, Lausanne, Switzerland. Electronic address: Berengere.aubry@chuv.ch.
authors.forename: Bérengère
authors.initials: B
authors.lastname: Aubry-Rozier
authors.affiliation: Center for Bone Diseases, Department of Bone and Joint Diseases, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Didier
authors.initials: D
authors.lastname: Hans
authors.affiliation: Center for Bone Diseases, Department of Bone and Joint Diseases, Lausanne University Hospital, Lausanne, Switzerland; Department of Rheumatology, Physical Medicine and Rehabilitation, Fribourg Hospital, Fribourg, Switzerland.
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Krieg
authors.affiliation: Center for Bone Diseases, Department of Bone and Joint Diseases, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Lamy
authors.affiliation: Department of Rheumatology, Physical Medicine and Rehabilitation, Fribourg Hospital, Fribourg, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: Dudler
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D015519:Bone Density; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010024:Osteoporosis / Q000175:diagnosis* / Q000209:etiology; D010865:Pilot Projects; D015203:Reproducibility of Results; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000209:etiology; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000000981:diagnostic imaging*
keywords: Ankylosing spondylitis; VFA; inter-rater reliability; mSASSS score; syndesmophyte