Cruciate Ligament Rupture in Dogs is diagnosed by evaluating the cranial drawer

Being that cruciate ligmament rupture in dogs is the most common orthopedic injury in all veterinary medicine, all veterinarians are trained on how to properly diagnose this type of injury. Yet, it is not always as black and white as it may seem. Many times dogs will only partially tear the ligament, making it sometimes very difficult to appreciate any instability in the knee.

The most common test used by veterinarians to diagnose a cruciate ligament rupture in dogs is a technique of manipulating force on the knee to evaluate what is commonly referred to as the cranial drawer sign. In order for the veterinarian to have best chance of appreciating this movement, many times the dogs need to be sedated to some degree. This allows the dog's muscles to relax and also the dog does not resist this uncomfortable movement placed on its knee.

The Cranial Drawer Technique

Because the ACL in dogs function is to prevent excess forward movement of the tibia, the veterinarian needs to strategically place their hands at certain locations both above and below the knee joint, in order to stabilize the knee, prior to attempting the cranial drawer sign. There are four points of reference; (above the joint) the index finger is placed on the patella and the thumb is placed on the femoral fabella. (below the joint) the opposite hands index finger is placed on the tibial tuberocity and thumb on the back of the tibia.

Once the points have been identified and the knee is held securely in place, the veterinarian then attempts to shift the tibia in a forward motion. If there is a complete cruciate ligament rupture in the dog then the tibia will freely shift forward in a "drawer link motion" ie. Like a dresser drawer. If there is only a partial tear then there may only be a slight laxity in the joint shifting forward.

To learn more about the surgery to correct cruciate ligament rupture in dogs simply click here