Cranial cruciate ligament disease is the leading cause of hindlimb lameness in dogs.1 Many owners hear of it for the first time in the consult room, worried and holding the lead, and what they take home is what you managed to make clear in a few minutes.
The explanation
This is the explanation the consult room opens with, written for the owner:
Inside the knee there are two short ligaments crossing each other that stop the joint sliding back and forward. One of them fails, usually not in one moment but by fraying over months, so the knee becomes unstable and the surfaces move against each other in a way they are not built for. That instability is what has to be fixed.
It works because it answers, in order, the three things an owner is actually wondering: what is in there, what went wrong, and why it matters. It avoids the word ‘rupture’ until they have the picture, because ‘rupture’ sounds like a single event, and in most dogs it is not one: the ligament degenerates over time.
What they ask next
“Does he need surgery?”
Usually, to make the knee stable. Osteotomy techniques, which reshape the top of the tibia so the knee is stable without the ligament, have become the standard, with TPLO the most effective.1
“Could it get better on its own?”
Management without surgery can be considered for dogs with very mild signs, for an early injury, and for small dogs and cats.1 For a larger dog with an unstable knee, the honest answer is that the instability is what causes the damage, and it needs to be addressed.
“Is anything else damaged?”
Often the meniscus, the cartilage cushion inside the joint: between 20% and 77% of dogs with a ruptured cruciate also have meniscal damage, the medial meniscus most of all.1 Telling them before surgery is kinder than telling them after.
Showing them while you talk
Owners understand a knee they can see. In the consult room, open cranial cruciate ligament disease and the dog's stifle comes up with the femur, tibia and patella labelled. Turn it so the owner is looking at the joint from the side, and point to where the ligaments run, from the femur down to the tibia, between the two bones.
Be clear about what they are looking at. The atlas says it itself: the cruciate ligaments are not modelled in this specimen, so the screen shows the joint the ligament stabilises, not the ligament or the tear. That is enough to make the instability make sense.
Then switch to the clinical register if a nurse or a second vet joins, print the handout, or send the owner a link that opens the same view at home, where the rest of the family will want to see it too.