Osteochondrosis dissecans

Case example

A flattened talus is like a flat tire

A 2 year-old, male intact Labrador Retriever was presented with shifting pelvic limb lameness of 3 to 4 months duration.

CT findings

The proximal aspect of the medial trochlear ridge of the talus is flattened bilaterally with heterogeneity of the affected subchondral bone and surrounding sclerosis (image1). Bilateral tarsocrural degenerative changes are characterized by osteophytes, enthesophytes and subchondral bone sclerosis (image 2). The surrounding intracapsular soft tissues are bilaterally mildly enlarged.



  • Bilateral Osteochondrosis (OC) of the medial talar trochlear ridge with secondary degenerative joint disease and joint effusion/synovial proliferation.

Learning points

  • Survey radiographs (including flexed mediolateral and flexed dorsoplantar skyline images) can be sufficient, but CT allows for a more detailed evaluation (presence or absence, site, number and size) of osseous fragments (Osteochondritis dissecans (OCD)).
  • OC/OCD lesions tend to be larger if the lateral trochlear ridge is affected, the age at diagnosis is younger and the duration of lameness shorter.

More information

  • »Comparison of Clinical and Computed Tomographic Features Between Medial and Lateral Trochlear Ridge Talar Osteochondrosis in Dogs«
    — Vet Surg 201342:340-345.
  • »Radiographic, computed tomographic and arthroscopic findings in 23 dogs with osteochondrosis of the tarsocrural joint«
    — Vet Rec 2002; 150:442-447.

Images courtesy of the Anicura Haar, Germany.