Systematic review of patellar luxation in dogs

Objective: To systematically review the literature reporting on the development of patella luxation (PL) and to identify areas in need of research. Study Design: Systematic Literature Review Animals: Dogs with PL. Methods: A computer-based search was conducted through July 2016 using the following databases: PubMed, Agricola, and Web of Science. Studies were graded using the Oxford Centre of Evidence chart and categorized into one or more of the following categories: etiology and/or pathophysiology. Studies were excluded if they were not peer- reviewed, were not in the English or French language, dealt with a species other than dogs, were focused on surgical management, and/or were irrelevant to patella luxation. Results: Twenty-five out of 301 studies were included and reviewed. Breeds at greatest risk for PL are: Great Pyrenees, Pomeranian, Silky Terrier, Miniature Pincher, Chinese Shar-Pei Yorkshire Terriers, Chihuahuas, Miniature and Toy Poodles, and Boston Terriers. PL prevalence has recently increased in Labrador Retrievers. All studies reporting on more than one breed found that MPL is more common than LPL. Smaller dogs have an increased incidence than larger breeds. Even though medial PL is the most common directional luxation across all dog sizes, lateral PL prevalence increases as dog weight increases. Genetic research looks promising in a link between Chromosome 7 and PL in dogs. The relationship between PL and CCLR is still controversial along with results for unilateral and bilateral luxation. Discussion: When considering the owners, genetic studies that benefit breeding programs and research into the specific causes of PL will aid in preventing dogs bred with musculoskeletal abnormalities