If your dog starts limping on a back leg, it may be experiencing one of the more common conditions seen and treated by veterinary orthopedic surgeons – a full or partially ruptured cranial cruciate ligament, (the equivalent of the “ACL” in humans.) Dr. Antonio Pozzi, an orthopedic surgery specialist, discusses causes of this injury, which occurs in the knee joint, or stifle, as well as how the disease is typically diagnosed, treatment options and what you should know if your dog needs to undergo surgery.