Canine ACL Surgery

" Canine ACL Surgery is commonly indicated when a dog is in pain or does not have use of the knee joint. Anterior Cruciate Ligaments (ACL) are fibrous tissues, tough in nature and form bands in the knee. In a dog's knee they are responsible for preventing the tibia and femur ends from moving across each other in a to & fro motion. Usually a sudden twist in the leg, an accident or heavy weight breeds during running can experience tearing of this criss cross ligament, resulting into severe pain, lameness and swelling of the stifle joint. A surgical procedure called ACL reconstruction is usually performed to restore knee function. Complete recovery and healing usually takes 8 – 12 weeks after surgery."

Anatomy of the Knee Joint and the Anterior Cruciate Ligament:

In a dog’s knee joint, there are three bones, 1. Head of Femur; Femur is a long bone, which is extended from hip, through “Ball & Socket Joint”. 2. Head of Tibia; Tibia & Fibula are two bones collectively called Tibia – fibula which lies in between knee and ankle. This bone is smaller then femur & is richly supplied with nerve and blood supply.
3. Patella; Patella is the knee cap which protects the knee & also it prevents the movement of leg in anti – clock wise direction.
4. Knee Capsule; the knee capsule is a fibrous tissue layer, which surrounds the whole knee joint; it contains fluid, which acts as shock absorber.
5. Ligaments; The head of the femur and tibia are attached with a number of crisscrossed ligaments, known as the anterior and posterior cruciate ligaments. The term cruciate means cross, these ligaments thus exhibit a crisscross appearance. These ligaments are hard fibrous tissues and help in the to & fro movements of the knee joints and keeps the knee joint intact.

Indications for Canine ACL Surgery:

In many conditions, when a dog tries to run fast or tries to jump, it may experience extensive pressure on the knee joint. A sudden twist in the knee joint, while running or jumping can cause partial or complete rupture of anterior cruciate ligament. Dogs with that are obese or heavy are more susceptible to such twists and ruptures.

Car accidents are another main indication for canine ACL surgery. In many cases, if the legs of dog are hit by car or in any accident, it can cause twisting of leg, or extensive pressure on the knee joint, thus resulting in a rupture in the cruciate ligament.

In many cases, pathological degeneration of cruciate ligaments in the knee joint can also be a representation that indicates the need for canine ACL surgery.

Pre Surgical Requirements of Canine ACL Surgery:

Before considering surgery, ask your veterinarian about the procedure, expected results and possible consequences. Before ACL surgery a dog should not be fed 12 hours prior to surgery. As general anesthesia is being administered for canine ACL surgery, feeding should be restricted.

A veterinary surgeon may require several tests prior to surgery, including blood, immune & osteo-pathological tests. Preparation includes typing the dog's blood and making sure that blood is available if needed during surgery.

Procedures for Canine ACL Surgery:

Depending upon the diagnosis, conditions and indications, different surgical procedures can be used for canine ACL surgery, . Usually a complete ACL rupture is seen in large breeds. In such cases where a complete anterior cruciate ligament rupture is reported, the complete replacement of the ligament is surgically created. This replacement may be with a synthetic ligament which is sutured along a side of the joint. This is not a fix to the existing ligament, but a replacement. This helps the regeneration of connective tissues for the anterior cruciate ligament, which on recovery helps a dog use its leg properly.

Tibial Plateau Leveling Osteotomy (TPLO) surgery is another procedure. This surgical option is preferred in heavy breeds, where pressure on the sutures and the chances of suturing mishaps will cause irrecoverable damage to the knee joint. An osteotomy or cutting of bone at the tip of tibia is used and attached to the joint via screws and plates. This procedure is a difficult option to perform, but is a preferred approach. 

An advanced surgical technique, Tibial Tuberosity Advancement (TTA) is also used. This technique is a difficult one to perform. The technique involves the replacement of the tibial tip and then attachment of the ligament. It involves reducing the mechanical stress at the knee joint by distributing it across different angles.

Post Surgical Treatment of Canine ACL Surgery:

Once a surgical procedure is performed, a post surgical treatment plan is required. It involves series of examinations, exercises and a therapeutic plan.

Pain killers, especially Non Steroidal Anti Inflammatory Drugs (NSAID) like diclofenic sodium, buffered aspirin, and meloxicam can be administered, along with broad spectrum antibiotic therapy.

Usually recovery takes 8 – 12 weeks after surgery. The duration may increase depending upon the age, breed and option of surgery preferred. Exercises like low impact assisted walking and controlled swimming are preferred as per the veterinarian’s instructions.

Heavy breeds should be kept on a low calorie diet and should not be allowed to walk or run without assistance.

References:

K. Fedrek., Indications of Small Animal Surgery (California Press. 1997)

James McCunn. “Hobday’s Surgical Diseases of Dog & Cat” (Bailliere Tindall, London “Edited Version”)