Cranial Cruciate Disease in Dogs

Cranial Cruciate injury in Dogs

Rupture of the cranial cruciate ligament in the hind leg is the most common orthopaedic condition we see in dogs. Seen more commonly in larger breed dogs such as Labradors and Rottweilers, we do also see this injury in dogs down to 5-10kg and even cats occasionally.

There are two cruciate ligaments in the stifle (knee) joint and they form a cross and counteract the forward and backward movement between the tibia and the femur.  In most cases it is the cranial cruciate ligament that tears and this often results in a tear in the medial meniscus inside the joint as well.  

While a lot of the time the injury occurs when your pet is exercising , sometimes it can occur just jumping out of the car or going down steps, particularly in breeds that are predisposed to this injury. In many cases we will find that the patient has had a previous partial tear some time in the past before a complete rupture occurs.  Unfortunately approximately 1/3 of dogs that tear one cruciate ligament will eventually go on to tear the cranial cruciate ligament in the other leg.

At St Lukes Veterinary Centre we perform a surgery called a TTO (Triple Tibial Osteotomy )

This procedure involves cutting the tibia bone in 3 places and removing a small wedge and then applying a surgical steel plate.  This alters how the stifle joint works in such a way that the cranial cruciate ligament is no longer required to provide stability in the joint.

On the day your pet will be admitted in the morning , and once prepped for surgery the TTO procedure will be performed.  We keep your pet in over night on intravenous pain relief to ensure they have a smooth and comfortable recovery.  They are discharged the following day and return after 24 hours to have the leg bandage removed.  Stitches are removed after 10 days and after an xray at 6 weeks to confirm the bone is healing well.  Then  a controlled return to lead exercise is started so that by 10 weeks post operatively your pet should be having up to 20 to 30 minutes walking once or twice a day.

Diagram of the stifle joint of the dog showing the normal anatomy of the stifle (knee) joint

When the Cranial Cruciate Ligament ruptures the Tibia slides forward in relation to the femur.  In a standing dog effectively the femur slides backwards off the tibia 

By making the following cuts we can close the wedge we have taken out of the tibia which has the effect of leveling the tibal plateau and eliminating the caudal slope that the femur is trying to slide down and effectively removing the forces the cruciate ligament counteracts.