Cruciate Rupture in Dogs
What is a cruciate ligament rupture?
Cranial cruciate ligament rupture (CCLR) is one of the most common orthopaedic injuries encountered in dogs. The cruciate ligament is found inside the stifle (knee) joint and plays an important role in stabilising the stifle during weight bearing. In humans it is called the anterior cruciate ligament. It prevents the tibia (shin bone) from sliding forward in relation to the femur (thigh bone) during weight bearing.
What happens when the cranial cruciate ligament ruptures in dogs?
When the cranial cruciate ligament fails, the stifle is unstable which leads to pain and inflammation within the joint, leading to the development of osteoarthritis. Osteoarthritis develops rapidly in every case and is almost always present at the time of diagnosis.
Another consequence of CCLR is damage to the meniscus, a shock absorbing structure in the stifle which can be very painful. If your dog is undergoing surgery for CCLR then the meniscus will be inspected and any damaged sections removed.
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What causes CCLR?
In people, rupture of the cranial cruciate ligament tends to be traumatic (e.g. while skiing or playing rugby or football). However, in dogs CCLR generally occurs due to degenerative changes of the ligament that weakens it, predisposing it to rupture with minimal associated trauma. The reason for this degeneration is not well understood and research into this area is ongoing. There certainly appears to be breed predisposition with Labrador Retrievers, Golden Retrievers, Rottweilers, Mastiffs and Boxers being over-represented. A large number of patients are also overweight which suggests that this is a significant contributing factor.
How is it diagnosed?
CCLR can be complete and sudden or gradual and partial (usually leading to complete rupture if untreated). Common clinical signs include lameness, stiffness, sitting with the affected leg extended to one side and a swollen and painful knee joint. It is diagnosed on history, clinical examination and radiography (under general anaesthesia).
How is it treated?
Some dogs (generally the smaller breeds) can be treated with non-surgical management. This consists of exercise restriction, weight control, physiotherapy and hydrotherapy with painkilling drugs as necessary. However, pre-rupture exercise levels are rarely achieved and most dogs with CCLR have ongoing stifle pain and instability and need surgery to correct this. There are several different surgical treatment options for stabilising the cranial cruciate ligament, each changing the forces that act on the joint. Decision-making is based on individual patient assessment, owner preference, compliance and financial considerations. We perform the following procedures routinely based on the above criteria:
- Lateral fabello-tibial suture
- Tibial Plateau Levelling Osteotomy (TPLO)
Lateral fabello-tibial suture
This procedure involves placing a suture between the femur and the tibia to mimic the action of the cranial cruciate ligament. At TVC we generally use nylon leader line with the aim of stabilising the stifle, minimise pain and prevent any damage to the meniscus.
Tibial Plateau Levelling Osteotomy (TPLO)
Rather than trying to replace the action of the cruciate ligament artificially as with the Lateral Suture, a TPLO changes the mechanics of the joint so that it no longer needs the stabilisation of the ligament at all. With the TPLO, the angle of the top of the tibia (the shin bone) is changed by cutting the bone and using a plate and screws to stabilise it in a new position. The change in angle minimises the movement between the femur (the thigh bone) and the tibia and creates a stable joint again. The operation has a high success rate and is the most commonly performed at Towcester Vets to treat CCLR.
What happens after the surgery?
Patients are sent home with a detailed rehabilitation program to cover the first eight weeks after surgery, which are the most restrictive. It can take dogs up to 3-6 months to regain pre-rupture exercise levels. We would encourage owners to undertake physiotherapy after the initial period of restrictions and have close links with local therapists who we can refer you to. The veterinary surgeon will re-assess the patient regularly. If the dog has had a TPLO the leg will be re-radiographed (x-rayed) eight weeks post-operatively to ensure healing is progressing as expected so that off-lead exercise can commence.
Can hydrotherapy be of benefit?
We strongly recommend hydrotherapy as part of the rehabilitation program as it allows the muscles around the knee to strengthen with minimal forces acting on the joint itself. It is also an excellent weight loss tool. Again we can refer you to local centres offering hydrotherapy.
What is the prognosis for CCLR?
The prognosis for dogs with CCLR is generally good to excellent after surgery, though it is important to remember that the stifle never returns to normal function. All dogs inevitably develop osteoarthritis but the majority of dogs go on to lead an active, comfortable life with minimal lameness. However a few cases do need ongoing anti-inflammatory medication. Keeping your pet’s weight down is a very important part of post-operative management.
To talk to one of our surgeons, contact us today on 01327 350239.
