title: Evaluation of tibial torsion in Yorkshire Terriers with and without medial patellar luxation.
abstract: OBJECTIVE
  To determine if medial patellar luxation (MPL) in Yorkshire Terriers is associated with tibial torsion.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  Yorkshire Terriers (n = 30; 60 tibiae).
  
  
  METHODS
  Each MPL was graded using a categorical grading scheme. Computed tomography of the tibiae was performed and tibial torsion angle (TTA) was assessed. MPL grade was analyzed with a general linear model where the independent variables include sex, neutering status, age, weight, and TTA.
  
  
  RESULTS
  Factors that had collective impact on MPL grade were TTA, age, and weight squared. As MPL grade increased, TTA decreased by 0.05° and age increased by 0.13 years. As weight increased, MPL decreased. There was no effect (P > .05) from scorers, side, and neutering status.
  
  
  CONCLUSIONS
  Body weight squared, TTA, and age affect MPL grade, suggesting that a torsional deformity may contribute to the development of MPL in Yorkshire terriers along with weight and age.
authors.affiliation: Veterinary Specialties Referral Center, Pattersonville, NY, USA.
authors.forename: Courtney L
authors.initials: CL
authors.lastname: Fitzpatrick
authors.forename: Ursula
authors.initials: U
authors.lastname: Krotscheck
authors.forename: Margret S
authors.initials: MS
authors.lastname: Thompson
authors.forename: Rory J
authors.initials: RJ
authors.lastname: Todhunter
authors.forename: Zhiwu
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000151:congenital / Q000453:epidemiology; D004285:Dogs; D005260:Female; D008297:Male; D031222:Patellar Dislocation / Q000150:complications / Q000662:veterinary*; D013977:Tibia / Q000473:pathology; D014057:Tomography, X-Ray Computed; D014102:Torsion Abnormality / Q000662:veterinary