title: Topographic bone density of the radius and ulna in greyhounds and labrador retrievers with and without medial coronoid process disease.
abstract: OBJECTIVE
  To quantify, using computed tomography (CT), cross-sectional ulnar bone density (UBD), and regional radial bone density (RRBD) at the level of the medial coronoid process (MCP) in elbows with and without medial coronoid process disease (MCPD) and with and without fragmentation of MCP (FCP).
  
  
  METHODS
  Retrospective clinical case-control and ex vivo study.
  
  
  METHODS
  Labrador Retriever elbows (n = 54) and normal cadaveric Greyhound elbows (11) undergoing elbow CT.
  
  
  METHODS
  Labrador Retriever elbows were divided into 2 groups: (1) clinically unaffected and (2) MCPD-affected elbows. This 2nd group was subdivided based on the presence of a displaced FCP. UBD was measured linearly, in Hounsfield units (HU) across the widest part of the ulna incorporating the MCP. The radial head was divided into 6 zones, with mean RRBD (HU) calculated for each group.
  
  
  RESULTS
  MCPD-affected Labrador Retriever elbows had significantly lower UBD within the MCP with a higher UBD in the cranial ulnar medulla. Lower RRBD was also seen in the radial head adjacent to the MCP in MCPD-affected Labrador Retriever elbows with FCP compared with Labrador Retriever elbows without FCP. Greyhounds had consistently lower RRBD and UBD at the apex of the MCP compared with clinically unaffected Labrador Retriever elbows.
  
  
  CONCLUSIONS
  Our results suggest a caudolateral load-transfer shift through the ulna in MCPD-affected elbow joints, unloading the MCP. Changes in regional radial head bone density suggest that the radial head is involved in the pathogenesis of MCPD.
authors.affiliation: University of Bristol, Centre for Comparative and Clinical Anatomy, Bristol, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Phillips
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Burton
authors.forename: Chris Mark Robert
authors.initials: CM
authors.lastname: Warren-Smith
authors.forename: Elvin R
authors.initials: ER
authors.lastname: Kulendra
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Parsons
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D002102:Cadaver; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000000981:diagnostic imaging*; D004285:Dogs; D005260:Female; D005552:Forelimb / Q000000981:diagnostic imaging; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000662:veterinary*; D008297:Male; D010375:Pedigree; D011884:Radius / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary; D014457:Ulna / Q000000981:diagnostic imaging