A 'drawer sign' is a specific abnormal movement of the bones of the knee joint. It occurs when the cruciate ligaments of the knee are torn. To assess the stability of ligaments in a knee, a veterinarian will place one hand around the femur (thigh bone) and one around the tibia (the bone below the knee) in a precise manner. By applying pressure on the knee, the veterinarian will feel the bones move abnormally in what is called a 'drawer sign.' It is called that because the movement of the femur in relation to the tibia is similar to pulling and pushing in the drawer of a cabinet.