Canine cruciate ligament disease

Cranial cruciate ligament (CCL) ruptures are the most common orthopaedic condition. It normally follows a degenerative process rather than being a traumatic injury. The causes of ligament failure are still poorly understood but likely have multiple causes. These include breed, genetics, bodyweight and many others. For the majority of patients surgical
management will provide the best outcomes for resolution of lameness and long term stability. A range of surgical options are available, however the tibial plateau levelling osteotomy (TPLO) is currently considered to give the best outcomes.

The anatomy of our pets is similar to ours. The knee (stifle) join is a hinge which allows the leg to bend. There are 2 cruciate ligaments in the joint – cranial and caudal. The cranial is composed of 2 bands of fibres and is the most important of the 2 ligaments. This ligament helps to stabilise the stifle, resisting twisting and forwards movements of the tibia. Rupture of the ligament leads to joint instability. Partial ruptures also occur that can cause pain and eventually will lead to a full rupture in most cases.

In addition to the cruciate there are 2 cartilage pads known as the menisci that help joint lubrication and shock absorption. An unstable joint puts the menisci at risk from tearing. Most commonly the medial (inner) meniscus is torn. This is associated with a significant degree of lameness. The joint will be uncomfortable if touched.



Making a diagnosis of a CCL rupture is based on the history, physical examination and radiographs. The history tells us information
about how the patient became lame, how long the lameness has been present for and whether it has improved or worsened.
During physical examination the vet will feel the leg and often will find a swelling and discomfort around the stifle (knee) joint. A cranial draw test can also is performed which moves the tibia relative to the femur (see animation).

Radiographs of the joint will show a swelling (effusion) and other changes such as arthritis. The ligament cannot be seen on radiographs.



There are 2 parts to the procedure. Initially the joint is inspected. The torn ends of the cruciate are removed. The menisci are examined. If the inner (medial) one is torn then it may need to be removed. In the second part of the procedure the TPLO is performed.

When walking the femur rests against the tibial plateau. This is a slope which allows the femur to fall backwards when the cruciate is ruptured. The aim of the procedure is to change the shape of the tibia to flatten this slope. This
results in what is called dynamic stability which means that the joint no longer relies on the cruciate to be stable.

A semi-circular cut is made at the top of the tibia using a specially designed saw. This section of bone is then rotated based on the pre-operative measurements. Once in position it is secured with a bone plate and screws to hold it whilst the bone heals.

Radiographs are taken at the end of the procedure to confirm that everything is in the correct position.

The surgery is intended to eliminate the thrust that pushes the tibia forwards away from the femur when the limb is loaded (i.e: walking). The TPLO procedure achieves this well and allows most patients to return to a normal or near normal level of activity.

Further radiographs are usually taken 8 weeks
following the procedure to assess healing. By this time the bone has usually healed sufficiently to allow a gradual return to off lead exercise.


Ice Packs & Physiotherapy

For the first 2 days post op we recommend applying an ice pack to the limb. Either a gel pack or bag of frozen peas wrapped in a tea towel are fine. Lay the
pack over the surgical site for 20 mins at a time. Repeat this up to 4 times a day. Passive range of motion exercises can help to keep the joints mobile. Perform 10 repetitions 2-4 times daily. Massaging the limb in gentle movements up towards the body can also help with comfort.


Exercise restriction is a very important part of post operative care. This gives time to allow the bone and joint to heal without putting them at risk. For the first 5 days post op strict rest is recommended. Please take your dog out to for toilet breaks only. This MUST be on a lead at all times for 8
weeks Please avoid steps, stairs and any jumping for
8 weeks as allowing this could lead to a fracture. Try to
avoid slippery flooring and when not attended please confine your dog to a crate or small

Lead walks can start 5 days post op and build as follows:-
Days 5-14 – 5 minutes 3 times daily in addition to toilet breaks
Weeks 2-4 – 10 minutes 3 times daily
Weeks 4-6 – 15 minutes 3 times daily
Weeks 6-8 – 20 minutes 3 times daily

This is a guide and not all pets will manage this. Be guided by how your pet is responding. Any excessive stiffness after rest or reluctance to exercise suggests they are doing too much Do not allow your pet to do more than this amount of exercise.


Sessions of hydrotherapy can be beneficial and can speed up recovery of the muscle that is lost after surgery. It is not essential to go for hydrotherapy, however 5-10 sessions is the usual amount recommended.

These can start 2 weeks post op. If you would like to arrange some of these sessions please ask your vet if there is a local facility.