Cranial Cruciate Ligament Disease or Injury is one of the most common causes of hind leg lameness that we see in dogs. The stifle (knee) is a hinge joint that allows the hind leg to bend and is also one of the joints in the body that is most prone to injury.
Inside each knee are two bands of tissue called the caudal and cranial cruciate ligaments which cross over each other inside and help to stabilise the joint. Problems can occur when the cranial cruciate ligament deteriorates and is torn or breaks completely. If it is left untreated it will not only cause pain and lameness in the affected leg, but will ultimately lead to irreversible degenerative joint changes.
Type Of Cruciate Damage
Traumatic Cruciate Damage is usually caused by a sudden and strenuous twisting of the knee joint when moving at speed and suddenly changing direction (similar to what happens in people during activities such as football, squash, rugby etc)
Cruciate Disease is a chronic (on going) problem that is often the result of general wear and tear such as everyday use during walking, running and jumping. This causes the ligament to deteriorate until it tears or ruptures completely (unfortunately it is not yet known what causes the canine cruciate ligament to deteriorate so fast in some dogs). This causes dogs to either become more lame over a period of time as the ligament deteriorates and tears or, to become very suddenly lame as the deteriorating ligament tears or ruptures completely (usually after engaging in strenuous activities or, in some dogs with severe ligament degeneration, the ligament may rupture after a small stumble or even when jumping off a sofa/chair). An important aspect of this gradual deterioration is that both knees are usually affected and 40%-60% of dogs with cruciate problems in one knee will develop problems in the other knee.
Which Dogs Are Affected?
Cruciate disease or injury can occur in a dog of any breed, sex or age, however it has been found to be more common in the following circumstances
- Overweight dogs (more stress is put on the joints in general)
- Unfit dogs who engage in sudden strenuous activity (weekend warriors!)
- Dogs with conformational abnormalities
- Dogs with poor body condition and muscle mass
- Certain breeds such as Labradors, Rottweilers, Staffies, Mastiffs, Saint Bernards and Akita’s seem to have a higher incidence of the problem, which suggests that it may be an inherited or conformational problem.
Symptoms of Cruciate Problem
Cruciate ligament disease may initially present as anything ranging from a mild, occasional limp to the sudden onset of complete lameness and is, in most cases, extremely painful. Symptoms of a problem can include one or more of the following
- Lameness/Limping/weakness in one or both hind legs
- Completely holding the hind leg up
- Lameness that gets worse with exercise but improves with rest
- Stiffness and/or difficulty getting up from sitting or lying down
- Swelling around the knee joint
- Reluctance to jump up or climb stairs/steps
- Sitting at an odd angle
- Abnormal posture when standing
A dog that is limping or holding it’s leg up will be in pain and should be seen by a vet as soon as possible.
Diagnosing Cruciate Problems
Initially the vet will physically examine the knee to check for any pain, swelling and looseness in the joint, an X-ray may then be taken to check for any other problems within the joint, such as arthritis. A CT Scan or Arthroscopy (keyhole procedure involving a tiny camera) may ALSO be performed if they are available, so that the vet can assess the extent of the damage to the ligament and whether there are other factors to consider such as arthritis, meniscus damage etc.
Surgical Treatment Of Cruciate Ligament Problems
The aim of any surgery is to stabilise the knee joint to prevent further damage (and pain) and improve mobility. The type of surgical procedure carried out will often depend on whether it is a straightforward (singular) problem i.e. just the cruciate ligament, or whether there are other complications to be taken into account e.g. a luxating patella or meniscal damage (these are the cartilaginous shock absorbers in the knees). It may also depend on the size and activity levels of the dog.
Because the surgery can be quite costly, especially for larger breeds of dog, it will be important to check that the surgery is covered by your pet insurance before your vet proceeds with the operation; this is usually done via a pre-authorisation claim between your vet and your pet insurance company.
The two most common procedures performed today are the Tibial Plateau Levelling Osteotomy (TPLO) and the Tibial Tuberosity Advancement (TTA); Both of these procedures alter the conformation of the joint and the way that forces are transmitted in the moving knee joint. The TPLO and TTA procedures greatly reduce the need for the cruciate ligament to stabilise the joint.
Cranial Cruciate Ligament Replacement Surgery may be performed to stabilise the joint and reduce rotational instability, by either replacing the torn or ruptured ligament using a graft (rarely performed nowadays) or by replacing the ligament with an extracapsular ‘non absorbable’ line and crimps. This is usually only suitable for small to medium sized dogs.
Some veterinary practices such as Castle Vets, may have an orthopaedic or specialist vet who is able to carry out these procedures, but other practices may need to refer their patients to another practice, especially if there are concurrent problems in the joint such as a luxating patella, meniscus tears, arthritis, bone spurs or bone fragments.
After any of these surgeries it is vitally important to follow the veterinary surgeon’s advice regarding,
- Exercise and activity: in most cases your pet’s activity will need to be severely restricted for the first six weeks after surgery.
- Physiotherapy: your dog will need physiotherapy and often hydrotherapy to help with building up their muscles and mobility. This is also vital for maintaining the stability and strength in the other knee.
- Weight Management: It is vitally important that your dog is at his or her correct body weight to ensure no extra stress is placed on the joints.
Non-Surgical Options For Cruciate Problems
Surgery is usually the recommendation and the best course of action for dogs with cruciate problems, especially those over 15kg in body weight, except when a general anaesthetic and surgery may put the patient’s life at risk (e.g. severe heart disease, immune related conditions).
A non-surgical approach to treatment may be tried in the case of a torn cruciate ligament. The dog will need a very strict and severely restricted exercise plan, proper weight management, medication/pain relief, physiotherapy and hydrotherapy; they may also require veterinary acupuncture, nutraceuticals and possibly, platelet-rich plasma therapy . We advise that if you want to try this option for your dog that a treatment plan is discussed thoroughly with your vet to ensure that you understand what is involved to best help your dog.
How You Can Help Lower The Chances Of Cruciate Injury
Unfortunately, there is no definite way to prevent a cruciate injury but you can help lower the risk if you
- Avoid sudden strenuous activities by ensuring that your dog has a good warm-up walk for at least 10-15 minutes before going off-lead to play with other dogs or chase balls etc. and by making sure that your dog starts chasing toys/balls from a standing position rather than from a sit or lying down position.
- Give regular, moderate exercise every day
- Ensure that the dog does not become overweight as this will add to the strain on his/her joints. If you need advice on your dog’s weight, please speak to one of our veterinary nurses.
- Feed a good quality diet that is appropriate for your dog’s age, size and activity levels.