Cruciate Disease in Dogs
One of the most common orthopaedic disorders veterinary orthopaedic surgeons encounter is cruciate disease or cruciate rupture. This is a rather debilitating degenerative disease affecting one of two main ligaments of the knee or stifle joint in the hind limb of the dog (although we do see this in cats too!).
It can affect most breeds of dog, although we mostly see in larger middle-aged breeds (Labrador Retriever, Rottweiler, Newfoundland, Mastiffs etc.) but also Springer and Cocker Spaniels, Beagles and the terrier breeds. West Highland Whites Terriers are very commonly affected. It is unusual to see this disorder in Whippets and Greyhounds. The larger breeds can occasionally be affected even before 12 months of age.
It is more common in overweight dogs, bitches, and particularly in neutered animals. Around 50% of animals with have both knee joints affected.
As the ligament deteriorates chemicals are released into the joint beginning the process of synovitis (inflammation of the lining of the joint) which slowly leads to arthritis. This process cannot be reversed, but prompt intervention may slow the progression. However, the ligament itself has a very poor blood supply and relies on the joint fluid for nutrition and for the vital building blocks for repair. This is sufficient for tiny amounts of ongoing repair but not when the ligament begins to break down. This is why non-surgical (conservative) management rarely produces the results we desire and usually results in poor stifle function.
The factors which actually lead to the degenerative changes in the ligament are not fully understood, but it is known that if the weight bearing surface of the top of the shin bone (tibia) slopes excessively from front to back, the ligament is subjected to excessive forces as the thigh bone (femur) effectively slides down this slope with only the cranial cruciate to resist the motion. Certain chemical compounds are released by adipose tissue, such as Leptin. If the amount of fat tissue relative to lean tissue is great, then the levels of these compounds in the blood increases. Studies have shown these levels to be increased in the joint fluid of dogs with cruciate disease leading to the suggestion of a likely link.
Affected dogs often have a niggling lameness for a few days to a few months, sometimes with a sudden deterioration, or with a characteristic toe touching stance when the dog is standing. Occasionally when both knees are affected your dog may be unable to rise from sitting or lying, prompting people to think they may have a back problem.
As I mentioned above, surgery is nearly always the preferred option. At Glenthorne we offer several types of surgery, each tailored to suit the individual. As a general rule the following are our preferred option:
Dogs with very unstable joint. We use a nylon suture between the back of the femur and the front of tibia, effectively replacing the function of the damaged ligament.
Small breeds and terriers. These dogs often have a steep tibial plateau, and the optimal result is achieved by removing a wedge of bone to reduce the slope of the plateau. A plate is placed to secure the bone. This surgery is termed a Cranial (Closing) Wedge Osteotomy or CCWO / CWO
For medium sized dogs (10-25kg) with moderate tibial plateau slope, we usually offer a Tibial Tuberosity Advancement (TTA)
For larger dogs we sometimes offer a TTA, or a Tibial Plateau Levelling Osteotomy, using a special radial curved saw, coupled with a special locking bone plate for maximum stability of the bone during healing.
We are able to help with all orthopaedic cases at reasonable prices and have a large amount of experience with cruciate cases. Please feel free to get in touch if we can help you with a particular case.