Evaluation of Tibial Torsion in Yorkshire Terriers with and without Medial Patellar Luxation

• Published in: Veterinary surgery 2012-11, Vol.41 (8), p.966-972
• Main Authors: Fitzpatrick, Courtney L., Krotscheck, Ursula, Thompson, Margret S., Todhunter, Rory J., Zhang, Zhiwu
• Format: Article
• Language: English
• Subjects: Animals; Cross-Sectional Studies; Dog Diseases - congenital; Dog Diseases - epidemiology; Dogs; Female; Knee; Male; Medical imaging; Patellar Dislocation - complications; Patellar Dislocation - veterinary; Tibia - pathology; Tomography, X-Ray Computed; Torsion Abnormality - veterinary; Veterinary medicine
• ISSN: 0161-3499; 1532-950X
• DOI: 10.1111/j.1532-950X.2012.01041.x

Objective To determine if medial patellar luxation (MPL) in Yorkshire Terriers is associated with tibial torsion. Study Design Prospective cross‐sectional study. Animals 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. Conclusion 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.