title: Digital X-ray radiogrammetry better identifies osteoarthritis patients with a low bone mineral density than quantitative ultrasound.
abstract: This study assessed the ability of quantitative ultrasound (QUS) and digital X-ray radiogrammetry (DXR) to identify osteopenia and osteoporosis in patients with knee osteoarthritis (OA). One hundred and sixty-one patients with painful knee OA (81 men, 80 women; age 62.6+/-9.2 years, range 40-82 years) were included in this cross-sectional study and underwent dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine, QUS of the phalanges and calcanei of both hands and heels, and DXR using radiographs of both hands. Unpaired t-test, Mann-Whitney U test, ROC analysis and Spearman's rank correlation were used for comparisons and correlation of methods. Using DXA as the reference standard, we defined a low bone mineral density (BMD) as a T-score < or =-1.0 at the lumbar spine or proximal femur. In contrast to phalangeal or calcaneal QUS, DXR was able to discriminate patients with a low BMD at the lumbar spine (p<0.0001) or hips (p<0.0001). ROC analysis showed that DXR had an acceptable predictive power in identifying OA patients a low hip BMD (sensitivity 70%, specificity 71%). Therefore, DXR used as a screening tool could help in identifying patients with knee OA for DXA.
authors.affiliation: Institute of Diagnostic Radiology, Department of Medical Radiology, University Hospital Zurich, Raemistr. 100, CH-8091, Zurich, Switzerland. gerhard.goerres@usz.ch
authors.forename: Gerhard W
authors.initials: GW
authors.lastname: Goerres
authors.forename: Diana
authors.initials: D
authors.lastname: Frey
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Hany
authors.forename: Burkhardt
authors.initials: B
authors.lastname: Seifert
authors.forename: Hans Jörg
authors.initials: HJ
authors.lastname: Häuselmann
authors.forename: Annina
authors.initials: A
authors.lastname: Studer
authors.forename: Dagmar
authors.initials: D
authors.lastname: Hauser
authors.forename: Nathalie
authors.initials: N
authors.lastname: Zilic
authors.forename: Beat A
authors.initials: BA
authors.lastname: Michel
authors.forename: Didier
authors.initials: D
authors.lastname: Hans
authors.forename: Daniel
authors.initials: D
authors.lastname: Uebelhart
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002111:Calcaneus / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D005260:Female; D006615:Hip / Q000000981:diagnostic imaging; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D050279:Metacarpal Bones / Q000000981:diagnostic imaging; D008875:Middle Aged; D010003:Osteoarthritis / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*