WHAT CAUSES CRUCIATE LIGAMENT PROBLEMS?
In humans the anterior cruciate ligament (ACL) is usually torn as a result of a sports-related injury. Such injuries typically involve either hyperextension of the knee, forcible internal rotation of the lower leg, or combination of these. It is generally an acute injury that the person is immediately aware of. For many years it was assumed that the mechanism of dog knee injuries mimicked what was seen in humans. Probably, some dogs truly injure their knees this way, for example a running dog that steps into a hole and hyperextends the knee as it continues forward. However, many of the knee injuries in dogs seem to occur without any such violent trauma, and this suggests that there may be some other factor(s) at play. The main functions of the cranial/anterior cruciate ligament are to prevent forward sliding of the tibia relative to the femur, excessive internal rotation of the lower leg, and over-extension (straightening) of the joint. It is not surprising then that forcefully exceedi
