Cruciate Liagment Disease

There are multiple factors that can contribute to the disease of the cranial cruciate ligament, and typically we see a couple of different clinical pictures. One is a younger or middle-aged, healthy and active dog who presents with lameness after a bout of exercise. At-risk breeds for this type of rupture include Golden Retriever, Rottweiler, Mastiff, Newfoundland, Akita, St Bernard, and Staffordshire Bull Terrier. The other scenario we see are older, often overweight dogs where the lameness has been mild but chronic, with a sudden worsening.

There are several key signs that your veterinarian will look for to ascertain whether your dog has ruptured their cruciate ligament. These include swelling of the joint, pain on extension of the knee, and the “drawer sign”. The drawer sign is where there is forward and back instability of the bottom bone (the tibia) compared to the top bone (the femur) in the knee joint. Sometimes a dog needs to be sedated in order to determine whether there is instability here. A positive drawer sign indicates that the cruciate ligament no longer has integrity. The difficulty with cruciate disease diagnosis is when there is a partial tear. Swelling in the knee, pain on extension and even the smallest amount of movement between the two bones may indicate a partial rupture, and the earlier we detect this and the sooner we repair the knee joint, the better prognosis for future mobility for your dog.

There are several different techniques to repair a ruptured cruciate ligament. The technique your veterinarian recommends will depend on your dog’s size, their activity levels, and the surgeon’s experience. The two main techniques we offer at Busselton Veterinary Hospital are called a Lateral Tie Repair for small and inactive dogs or a Triple Tibial Osteotomy for large or highly active dogs. For more information on these please contact us.

Without an intact cruciate ligament, there is instability in the knee joint causing abnormal wear and tear between the cartilages and bones, and the joint begins to develop degenerative changes. These changes result in bone spurs developing which cause chronic pain and impairment of joint function. This process can be halted or slowed by surgery, but cannot be reversed. If surgery is not performed, your pet will require lifelong pain management, which may include pain relief, Zydax injections, weight control, physiotherapy and supplements.

There are shock-absorbing cartilages in the knee called menisci. These crescent-shaped pieces of tissue sit between the two bones of the knee joint and cushion impact as the animal weight bears. If the knee joint is unstable, weight bearing produces a shearing force, which can crush and tear the menisci resulting in more pain and chronic inflammation. This sequelae is almost definitely going to occur if the surgery is not performed, but cannot be 100% prevented even with surgery. The menisci are visualised during the time of cruciate repair and if they are damaged they can be removed. Rarely several weeks or months after the initial surgery, a patient will become acutely sore again indicating a meniscal tear, and another surgery is required to treat this process.