Comparison of clinical and computed tomographic features between medial and lateral trochlear ridge talar osteochondrosis in dogs.

Objective: To evaluate clinical and subchondral bone lesion differences between medial (MTRT-OC) and lateral trochlear ridge tarsocrural osteochondrosis (LTRT-OC).

Study Design: Retrospective case series.

Animals: Dogs (n = 66) with MTRT-OC or LTRT-OC.

Methods: Medical records (1997-2010) of dogs with MTRT-OC or LTRT-OC were reviewed. Clinical data (breed, age, gender, weight, and duration of clinical signs) were retrieved. Computed tomographic examinations of the tarsocrural joints were performed. Length, width, and depth of the subchondral bone lesions on the computed tomographic images, and surface and volume of the lesions were estimated. The location of the OC lesion on the trochlear ridge (proximal, dorsal, or distal) was determined. Data collected from dogs with MTRT-OC (n = 56) were compared with data from dogs with LTRT-OC (n = 10).

Results: Length, width, depth, surface, and volume of LTRT-OC lesions were significantly (P < .01) larger than those of MTRT-OC lesions. Dogs with LTRT-OC were significantly younger at the time of diagnosis (P < .01).

Conclusions: OC lesions on the lateral trochlear ridge are significantly larger than those on the medial trochlear ridge. Dogs with lesions on the lateral trochlear ridge are significantly younger at the time of diagnosis, and tend to have a shorter duration of lameness before presentation.