Cruciate Ligament Disease in the Dog

The most common orthopaedic condition in the dog is the tearing of the cranial cruciate ligament

There are two main ligaments within the knee joint, the cranial and the caudal cruciate ligaments. These ligaments are fibrous bands that have a criss-cross (hence the word cruciate) formation and have a major function in stabilising the knee joint, mainly preventing sliding of the femur (thigh bone) forwards and backwards over the tibia (shin bone).

In nearly all cases it is the cranial cruciate ligament that becomes torn or ruptured. The disruption of this ligament results in the dog exhibiting pain and lameness. Tearing or complete rupture of the cranial cruciate ligament can occur in any dog but there are some breeds in which the condition is more common, these include Rottweilers, Boxers, Labradors, Newfoundlands and West Highland white terriers and Staffordshire bull terriers.

Cruciate Ligament Disease in the Dog: image 1 In some dogs the ligament undergoes a gradual tearing process that results in the dog showing intermittent lameness of the affected hind leg. In other dogs the ligament ruptures completely and suddenly. This can be due to a traumatic incident or may be due to an underlying degeneration of the ligament. These dogs usually show a sudden non-weight bearing lameness but after a few days start touching the paw to the ground

Cruciate Ligament Disease in the Dog: image 2 If the knee is left without surgical attention signs of arthritis soon appear. The knee will feel enlarged due to thickening of the joint capsule and boney deposits will be formed. These changes are in response to the instability of the joint and are the body’s attempt at stabilising the knee. If the dog is a small breed and not very heavy then the amount of arthritis may be minimal and the lameness can resolve within several weeks. However with large breed dogs or heavier dogs the arthritic changes become extensive and cause prolonged lameness that may not resolve completely. In many cases surgery is recommended.

Currently, there a number of different surgical techniques used by veterinary orthopaedic surgeons to treat a damaged cruciate ligament. They include: the tibial plateau levelling osteotomy (TPLO), tibial wedge ostectomy (TWO), tibial tuberosity advancement (TTA), triple tibial osteotomy (TTO) and lateral suture techniques.

Until very recently the favoured technique at Ayrton has been the TTO procedure and many dogs have benefited from the operation. Since May 2011 a new technique has been introduced that involves much less dissection and fewer implants. It achieves the same forward advancement of the front of the tibia as the well-recognised TTA operation and the dogs recover very quickly. This new operation is referred to as the modified Maquet procedure (MMP) or modified Maquet technique (MMT).

The Modified Marquet Procedure (MMP) for tibial tuberosity advancement (TTA)

This is a very new technique for the treatment of CCL rupture in dogs. The procedure involves making a single cut in the bone near the front of the tibia and the edges are wedged apart using a special porous titanium wedge implant. This results in pushing the front of the tibia forwards. This is very similar to the existing techniques of TTA and TTO and therefore the principle has a well established foundation.

Cruciate Ligament Disease in the Dog img 3 The Modified Marquet Technique (MMT)

This operation is virtually identical to the MMP but instead of a wedge a titanium cage is used to push the front of the tibial forwards. This is very similar to the normal TTA operation.

Since starting the new technique in early 2011, an average of two dogs per month with cruciate ligament damage have been successfully treated using the MMP and the MMT surgical methods at Ayrton.