Lateral patellar luxation in dogs: a retrospective study of 65 dogs

Objective: To report the signalment and clinical features of dogs with non-traumatic lateral patellar luxation and to report the complications and outcomes following surgery. Methods: A multicentre retrospective study was performed. Medical records were reviewed and the signalment, clinical features, and treatment of dogs presenting with lateral patellar luxation were recorded. In dogs treated surgically, the outcome and complications were investigated. Results: Sixty-five dogs (95 stifles) were included; 39 were male and median age at presentation was 10 months. Breeds were classified as small (n = 6), medium (n = 23), large (n = 27), and giant (n = 9). Lateral patellar luxation was classified as grade I (n = 14), II (n = 41), III (n = 29), and IV (n = 11). Conformational abnormalities were noted in; 34 stifles; genu valgum was the most common (n = 28). Higher-grade luxation was associated with a younger age at presentation (p = 0.032) and genu valgum (p = 0.01). Surgery was performed on 58 stifles, 22 of which sustained one or more Complications; 16 complications were managed conservatively, four with implant removal and six with revision surgery. Surgeon-assessed outcome was good or excellent in 47 of the 51 dogs available for review. Conclusions: Non-traumatic lateral patellar luxation is a disease of predominantly medium and large breed dogs. It has several similar clinical features and can be surgically treated in a similar manner to medial patellar luxation with similar types of complications and outcomes expected.