title: Longitudinal assessment of bone loss using quantitative ultrasound in a blood-induced arthritis rabbit model.
abstract: BACKGROUND
  Osteoporosis is common in haemophilic arthropathy. Quantitative ultrasound (QUS) can be a suitable alternative for dual-energy x-ray absorptiometry for diagnosing osteoporosis in haemophiliacs due to its lack of ionizing radiation, and ease to use.
  
  
  OBJECTIVE
  We investigated the intra- and inter-operator reliability of QUS, its responsiveness to bone growth, its ability to differentiate bone adjacent to blood-injected vs. control joints, and the effect of soft tissues on the speed of sound (SOS) QUS values in a juvenile white New Zealand rabbit model of blood-induced arthritis.
  
  
  METHODS
  Eight of 16 rabbits were injected with autologous blood (0.1 mL kg(-1) ) 8 times over a 17-week period, the remaining eight rabbits served as controls. SOS was measured at baseline, weeks 8 and 17 in vivo and after the bones were excised on week 17.
  
  
  RESULTS
  Intra- and inter-operator coefficients of variation for QUS data were <5% and intraclass correlation coefficients were >60% for 22/27 (81.5%) of bones assessed. The level of interval increase in SOS values from baseline to week 17 was significantly different in tibiae of injected, contralateral to injected and non-injected knee groups by anova (P = 0.01). In vivo (mean ± SD, 4147.17 ± 96.27 m s(-1) ) and postmortem (4457.85 ± 104.00 m s(-1) ) measurements on week 17 differed (P < 0.01) indicating an effect of soft tissues on SOS.
  
  
  CONCLUSIONS
  In conclusion, QUS' acceptable reliability, its responsiveness to growth-related changes and its ability to discriminate injected and non-injected joints make this technique a plausible candidate as a diagnostic tool for osteoporosis in the paediatric haemophilic population if these results are confirmed upon animal-human translation.
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: K C
authors.initials: KC
authors.lastname: Wang
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Amirabadi
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: K C
authors.initials: KC
authors.lastname: Wang
authors.affiliation: Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Moineddin
authors.affiliation: Department of Pathology, Mount Sinai Hospital, Toronto, ON, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Jong
authors.affiliation: Department of Neonatology, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Tomlinson
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: A S
authors.initials: AS
authors.lastname: Doria
mesh_terms: D000818:Animals; D001168:Arthritis / Q000097:blood* / Q000150:complications*; D001344:Autopsy; D001862:Bone Resorption / Q000150:complications / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D007270:Injections, Intra-Articular; D008137:Longitudinal Studies; D011817:Rabbits; D015203:Reproducibility of Results; D014463:Ultrasonography
keywords: blood-induced arthritis model; haemophilia; knees; osteoporosis; quantitative ultrasound; rabbit