Though only a portion of the ligament may be torn, the whole ligament is damaged. When a cranial cruciate ligament is torn, it causes sudden pain and often results in the pet holding its leg up. It also causes an instability in the knee joint. The pet may put the leg down and start using it within a day or so, but will continue to limp for several weeks. This abnormal motion causes wear and tear on the joint cartilage, causing pain and leading to arthritis.
Surgery is the only corrective measure for cranial cruciate ligament injuries.
Knees that suffer this injury are never completely normal even after surgery is performed. Surgery does, though, stabilize the knee, allowing it to regain normal motion and thereby reducing the formation of arthritis. Surgery has been and remains the treatment of choice for this injury. If surgery is not performed, progressive arthritis will occur and the lameness will worsen with time. There are many different ways to stabilize a knee with a cruciate ligament injury.