What are the Cruciate Ligaments?
The cruciate ligaments occur in the stifle (knee) of all mammals and help to stabilise the stifle. They stop the femur and tibia from moving forward and backward relative to each other and ensure that the stifle essentially acts like a hinge.
What is Cruciate disease?
Unfortunately it is very common for these ligaments to become damaged thus destabilising the stifle. Cruciate disease is easily the most common orthopaedic condition in dogs. In our practice it would account for over 70% of all lameness and arthritis problems in all breeds. Despite this fact and many years of research it is still unclear as to the exact causes of cruciate disease in dogs. In all likelihood cruciate ligament damage is a consequence of the combination of a variety of factors including:
Whilst we don’t necessarily know the exact cause of ACL damage in the dog what we do know is that once damaged the inflammation generated causes more damage causing more inflammation in a self perpetuating cascade. We also know that the ACL once damaged essentially never heals or repairs itself to any significant degree.
How do I know if my dog has Cruciate Disease?
Well, the simple answer is if your dog is lame in a hind legs for more than a couple of days then it probably has damaged it’s ACL! There are however some other problems that can cause hind leg lameness so it is important that your dog is assessed by a veterinarian.
There are a number of characteristics of dogs with cruciate disease. The stifle can be swollen, there may be swelling on the inside of the tibia (called “medial buttress”), many dogs stand or walk with the good leg swinging inwards to be directly under the body as opposed to under the hip, and many dogs will sit with their good leg tucked underneath them and the bad leg stretched out to the side (the “sit” test). Essentially though the diagnosis is made by feeling the stifle for instability and cranial drawer (or forward movement of the tibia compared to the femur). Sometimes however this movement is very subtle and if the dog is very tense it can be hard to feel this. Consequently your veterinarian may suggest sedating your dog to check the stifle and also to get radiographs of the leg.
Does my dog need X-rays?
Whilst radiographs are not essential for the diagnosis of cruciate disease in the dog they are helpful to rule out other diseases that may be occurring at the same time. Occasionally we also get very swollen stifles where it is difficult to feel a cranial drawer and the swelling could be due to growths or other problems and radiographs in these cases help to rule those other causes out and confirm a diagnosis of ACL damage. Radiographs are also important for planning the surgical repair.
Unlike humans cruciate disease in the dog cannot be treated with medical management. It just doesn’t work. While in some cases some short term pain relief can be achieved the stifle will continue to be unstable and inflamed developing significant amounts of scar tissue and fibrosis that restricts the movement of the stifle and the leg. In certain cases, very old animals where life expectancy is likely to be less than 12 months then the use of anti inflammatory medications, joint supplements and pain killers can provide reasonable quality of life for a short period of time. Long term use of medical management is ineffective, risks causing side effects and over a period of any longer than 2-3 years is likely to cost just as much as surgery.
There is little doubt that modern surgical techniques are the best option for treating cruciate disease in dogs. Older techniques including graft repairs and De Angelis or Lateral suture techniques provided some short to medium improvement however studies have clearly demonstrated that after 12 months both those techniques have failed and the stifle continues to be unstable and the joint chronically inflamed. What are known as tibial plateau slope modifying techniques e.g. TTA, TPLO, CBLO have revolutionised treatment of cruciate disease in dogs and have meant that we can now restore up to 90% of pre injury function long term in a majority of dogs. Kate Toyer our surgeon is trained and has performed all of the modern tibial osteotomy surgeries (and most of the older surgeries as well!). There is no one particular surgery which is the best and each have their advantages and disadvantages. The principle determining factor for which surgery is best is the size of the dog and what is known as the tibial slope determined from radiographs. After assessing radiographs and your dog clinically Kate will recommend what she believes to be the best surgery for your dog.
For more details on these surgeries please see our page here.