title: A computer-based measure of irregularity in vertebral alignment is a BMD-independent predictor of fracture risk in postmenopausal women.
abstract: Prevalent fracture and BMD are core elements of fracture prediction. In this control study case, we demonstrate that a simple computer-based estimation of local irregularities in the alignment of the lumbar vertebrae independently contributes to the fracture risk, thus supplementing current diagnostic tools.
  
  
  BACKGROUND
  We tested the hypothesis that degree of lordosis and/or irregularity in the alignment of lumbar vertebrae could be contributors to the risk of fragility fractures.
  
  
  METHODS
  This was a case-control analysis including 144 elderly women; 108 maintaining skeletal integrity, whereas 36 sustaining a lumbar vertebral fracture during a 7.5-year observation period. The two groups of women were carefully matched for age, BMI, spine BMD and numerous classic risk factors. Lateral X-rays of the lumbar spine were digitized and the four corner points of endplates on each vertebra from Th12 to L5 were annotated. The degree of lordosis and irregularity of vertebral alignment was assessed by image analysis software.
  
  
  RESULTS
  Degree of lordosis was not predictive for fractures. In contrast, irregularity was significantly higher in those who later sustained a fracture (1.6 x 10(-2)vs. 2.0 x 10(-3) cm(-1), p < 0.001), and further increased upon a sustained fracture (2.8 x 10(-2) cm(-1), p < 0.001), but was unchanged in controls (1.6 x 10(-2) cm(-1)). The predictive value of irregularity was independent of classic risk factors of fractures, including BMD (p < 0.01).
  
  
  CONCLUSIONS
  Our results suggest that the herein introduced simple measure of irregularities in vertebral alignment could provide useful supplement to the currently used diagnostic tools of fracture prediction in elderly women.
authors.affiliation: Center for Clinical and Basic Research, Ballerup Byvej 222, 2750 Ballerup, Denmark. pp@ccbr.dk
authors.forename: P C
authors.initials: PC
authors.lastname: Pettersen
authors.forename: M
authors.initials: M
authors.lastname: de Bruijne
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: Q
authors.initials: Q
authors.lastname: He
authors.forename: C
authors.initials: C
authors.lastname: Christiansen
authors.forename: L B
authors.initials: LB
authors.lastname: Tankó
mesh_terms: D000368:Aged; D015992:Body Mass Index; D015519:Bone Density; D018450:Disease Progression; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008141:Lordosis / Q000150:complications* / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications; D011379:Prognosis; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D016103:Spinal Fractures / Q000209:etiology* / Q000503:physiopathology