Rupture of the cruciate ligament is one of the most frequent causes of lameness of the dog’s hind limbs. Of course, not all cases in which the dog limps are the result of a ruptured cruciate ligament, but since it is one of the most frequent possibilities, let’s see what it is.

The Cruciate Ligament

The dog’s knee is a rather complex joint, which is formed by the patella, cartilage and ligaments connecting the femur and tibia.

The two stabilising ligaments cross each other inside the knee: the cranial and caudal crusaders, anterior and posterior respectively. If there is an injury to even one part of the knee, this can cause discomfort and limp.

Ligament Rupture: Frequent Causes

Some owners say they heard the dog growling for several minutes when the injury occurred, but this does not always happen.

A ligament injury can be caused by various factors, including breed predisposition, obesity or simply being overweight. Sometimes it can also be the result of too much athletic effort or a wrong landing after a jump. The most susceptible razas to this type of injury are Labrador Retriever, Newfoundland, German Shepherds, Rottweiler, and Golden Retriever.

A cruciate ligament injury can be distinguished in a partial or complete rupture. The most affected is generally the cranial cruciate ligament, although the caudal ligament is more prone to rupture. Because of the injury, the tibia moves freely under the femur, resulting in pain and abnormal gait.


The diagnosis should be made by a veterinarian specialized in orthopaedics, so as to have a certain outcome and evaluate with the owner the possible solutions to the problem. In case of suspected breakage, the drawer will be tested (the tibia is moved back and forth to see if it comes out of its natural position).

In cases requiring special attention, it will also be necessary to perform X-rays of the limb or more advanced diagnostic investigations, such as arthroscopy or MRI.

Therapy And Surgery

Unfortunately, if the injury is determined, most dogs will have to undergo surgery. Only in some cases can the lesion be treated with drug therapy and a few weeks’ absolute rest (short daily walks on a leash only for physiological needs).

If, on the other hand, surgery is necessary, the techniques used are different. We mention them only for completeness, but it will be your vet to advise you at best on what to do:

Extracapsular surgery: This is the traditional surgical procedure. The damaged ligament is removed and replaced by a very strong artificial thread. It is a relatively quick and simple procedure. Less expensive than other methods.

TPLO: Tibial plate leveling osteotomy. TPLO alters the mechanism of the knee joint so that it can function properly without a cruciate ligament. A metal plate is attached to hold the bone in place. A full recovery time is quite long.

TTA: advancement of the tibial tuberosity. It is the most recent technique. Like TPLO it allows the knee to function without a cruciate ligament, but the technique to perform it is slightly different.

These three types of surgery use very different techniques in some cases and of course have different costs.

Beyond the technique used, a forced rest after the operation will be necessary to allow a full recovery of the knee function.