title: Quantitative comparison of bone mineral density characteristics of the distal epiphysis of third metacarpal bones from Thoroughbred racehorses with or without condylar fracture.
abstract: OBJECTIVE
  To compare regional proportions and spatial distributions of volumetric bone mineral density (BMDv) of the palmar aspect of the distal epiphysis of the third metacarpal bone (McIII) in limbs with or without a condylar fracture from Thoroughbred racehorses.
  
  
  METHODS
  McIIIs from cadavers of Thoroughbred racehorses with (n = 6 bones) and without (8) a condylar fracture.
  
  
  METHODS
  BMDv and spatial distributions of BMDv in peripheral quantitative CT images of the distal epiphysis of McIIIs were quantitatively assessed with spatial analysis software. Relative proportions of voxels within 9 threshold categories of BMDv and spatial statistics for BMDv distribution were compared between fractured and nonfractured limbs.
  
  
  RESULTS
  No significant differences in BMDv characteristics were identified between fractured and nonfractured limbs, although fractured limbs had a lower proportion of voxels in the BMDv thresholds 700 to < 800 mg/cm(3) and 800 to < 900 mg/cm(3) but a higher proportion of voxels in the BMDv threshold 1,000 to < 1,100 mg/cm(3) for the central condylar region of the medial condyle. Results of spatial analysis reflected the response of bone to race training rather than differences between fractured and nonfractured limbs. In both limb groups, uniform clusters of low BMDv with areas of high BMDv were identified.
  
  
  CONCLUSIONS
  BMDv characteristics of the distal epiphysis of McIII reflected training load, and fracture characteristics were subtle. Serial imaging techniques in conjunction with detailed training data are required to elucidate the onset of the pathological response to load in horses.
authors.forename: Sophie H
authors.initials: SH
authors.lastname: Bogers
authors.forename: Chris W
authors.initials: CW
authors.lastname: Rogers
authors.forename: Charlotte
authors.initials: C
authors.lastname: Bolwell
authors.forename: Wendi
authors.initials: W
authors.lastname: Roe
authors.forename: Erica
authors.initials: E
authors.lastname: Gee
authors.forename: C Wayne
authors.initials: CW
authors.lastname: McIlwraith
mesh_terms: D000818:Animals; D015519:Bone Density / Q000502:physiology*; D002102:Cadaver; D004838:Epiphyses / Q000502:physiology*; D050723:Fractures, Bone / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D006736:Horses / Q000293:injuries*; D050279:Metacarpal Bones / Q000473:pathology*