Cranial Cruciate Ligament Disease

Signalment
Dogs of most any breed, sex or age can develop cranial cruciate ligament disease (CrCLD) or injury. Labrador Retrievers, Chesapeake Bay Retrievers, Rottweilers, Mas- tiffs, American Staffordshire Ter- riers, Akitas, Saint Bernards, and Newfoundlands are predisposed.
Neutered males and spayed females are at increased risk as are larger breeds and obese dogs.

History
The onset varies from peracute after a traumatic or athletic injury to an insidious onset, slowly progressive lameness typical of CrCLD.

Gait Evaluation
Dogs with even subtle lameness often lean away from the affected limb while standing. Sitting in a normal posture requires maximal stifle and hock flexion that is often uncomfortable in dogs with CrCLD causing them to abduct the limb or shift it cranially. Dogs with bilateral CrCLD often shift their weight to the thoracic limbs while sitting and rising.

Physical Exam
The standing exam is helpful in detecting subtle changes in muscle mass, periarticular fibrosis and joint effusion. Medial buttress, associated with CrCLD chronicity, is palpable as an exaggerated bump extending across the medial aspect of the stifle joint. The normal stifle has a discretely palpable patellar ligament that feels similar to a pencil with small indentations on each side that feel similar to a bruise on an apple. The loss of these normal findings indicates periarticular fibrosis, joint effusion or both. Pain upon forced full extension of the stifle is a simple test that is suggestive of early CrCLD. The cranial drawer test and tibial compression tests are important for assessing palpable instability and have been exhaustively described elsewhere. [...]