Step 3: Proper Diagnosis
Clinical signs of a torn cruciate can vary depending on severity of the injury as well as the activity of the dog. Tearing may be progressive, starting as a partial injury which may temporarily respond to time and rest. In many cases this progresses to a full tear, lameness is usually more consistent, and injury to the meniscus may also occur.
There are multiple tests your surgeon or veterinarian will perform to help diagnose a cranial cruciate ligament tear including physical examination. During the physical exam documenting pain on over-extension and instability in the knee-the “cranial drawer test” in which the tibia can be moved forward in relation to the femur. The knee will often feel thickened due to scar tissue and inflammation, and muscle is often temporarily lost due to reduced use. A ‘click’ may be felt in certain cases where a tear of the meniscus has developed.
An x-ray is performed even though the ligament itself is invisible; extra fluid in the knee, arthritis and abnormal positioning of the two bones can aid the diagnosis as well as helping to rule out other injuries. The x-rays will also be used for surgical planning purposes.