title: Influence of chondrodystrophy and brachycephaly on geometry of the humerus in dogs.
abstract: OBJECTIVE
  To assess the geometry of canine humeri as seen on radiographs in chondrodystrophic dogs (CD) and brachycephalic dogs (BD) compared to non-chondrodystrophic dogs (NCD).
  
  
  METHODS
  Mediolateral (ML) and craniocaudal (CC) radiographs of skeletally mature humeri were used (CD [n = 5], BD [n = 9], NCD [n = 48]) to evaluate general dimensions (length, width, canal flare, cortical thickness), curvature (shaft, humeral head, and glenoid), and angulation (humeral head and condyle). Measurements from CD, BD, and NCD were compared.
  
  
  RESULTS
  Mean humeral length was shorter in CD (108 mm) compared to BD (184 mm, p = 0.001) and NCD (183 mm, p <0.001). Craniocaudal cortical thickness at 70% of humeral length and ML cortical thickness at 30%, 50%, and 70% of humeral length were less in CD compared to BD and NCD. Humeral shaft curvature was greater in CD (9.9°) compared to BD (6.7°, p = 0.023). The ratio of glenoid radius of curvature / humeral length was greater for CD (11.1%) compared to NCD (9.7%, p = 0.013). The ratio of humeral width / humeral length was greater for BD (29.4%) compared to NCD (26.2%, p = 0.043). The ratio of glenoid length / humeral length was greater in CD (18.0%) than BD (16.4%, p = 0.048) and NCD (15.6%, p <0.001).
  
  
  CONCLUSIONS
  Bone proportions and curvature in CD differ from BD and NCD. Differences are minor and unlikely to have clinical significance.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Smith
authors.affiliation: Dr. Marcellin-Little, North Carolina State University, Department of Clinical Sciences (DoCS), NCSU CVM VH #2563, 1052 William Moore Drive, Raleigh, NC 27607, United States, E-mail: denis_marcellin@ncsu.edu.
authors.forename: Denis J
authors.initials: DJ
authors.lastname: Marcellin-Little
authors.forename: Ola L A
authors.initials: OL
authors.lastname: Harrysson
authors.forename: Emily H
authors.initials: EH
authors.lastname: Griffith
mesh_terms: D000818:Animals; D003398:Craniosynostoses / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D004285:Dogs; D005552:Forelimb / Q000000981:diagnostic imaging / Q000473:pathology*; D058430:Humeral Head / Q000000981:diagnostic imaging; D010009:Osteochondrodysplasias / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D011859:Radiography / Q000662:veterinary
keywords: Dog; anatomy; humerus