Cruciate injuries in dogs:
Dogs can tear their cruciate ligament in their knee much like human athletes often do. In fact, the torn cranial cruciate ligament (CCL) is the one of the most common knee injuries for dogs. The good news is that we can usually repair this injury here at Cleveland Road Animal Hospital!
What are the signs?
Some dogs will suddenly become lame on the leg and may hold it in the air. Some dogs will have a mild lameness for months that will get better and worse over time. Other dogs will have the intermittent mild lameness and then suddenly become very lame.
How is it diagnosed?
Oftentimes, a veterinarian can diagnose a torn cruciate ligament with a complete physical exam. The knee will feel thickened from the bones shifting back and forth since there is no ligament holding them together, and there will be movement of the knee joint called cranial drawer which is the hallmark of a torn cruciate ligament.
The veterinarian may also do an X-ray. Although you cannot see the ligament on an X-ray, there are classic changes seen on an X-ray such as swelling and edema within the joint. Dogs do not develop arthritis in the knee for no reason, and the most common cause is cruciate tears.
How is a cruciate injury repaired?
There is not a good way to fix the actual cruciate ligament in dogs, but the most common surgeries to stabilize the knee and alleviate limping are the lateral suture and the TPLO. Today, most veterinary surgeons agree that the TPLO is the best surgery for dogs, especially large breed or more active dogs. TPLO stands for tibial plateau leveling osteotomy.
In this surgery, the surgeon cuts the back part of the tibia with a special circular saw and rotates the piece of bone so the top of the tibia is almost flat. Then the surgeon repairs the bone with a special bone plate to hold it in place while it heals. Once the bone is healed in the “flat” position, the tibia no longer thrusts forward when the dog walks and the knee is stabilized. The plate usually remains on the bone indefinitely, but it is no longer needed for support once the bone heals.
This surgery involves placing a suture, which is usually strong nylon (similar to a strong fishing line), around the outside of the joint to hold the two bones together and prevent them from shifting. The problem with this surgery in large dogs is that there is a lot of force on the nylon and it tends to break and fail. Studies have also shown dogs are in more pain after a lateral suture and develop worse long-term arthritis. Many veterinarians reserve the lateral suture for small breed dogs. Lateral suture surgeries are also less costly, so this may be a better option when trying to stay within a limited budget.
Is knee surgery painful?
Using a saw to make a bone cut is different than a trauma causing the bone to break. The TPLO surgery is usually more comfortable than the lateral suture which feels very tight around the joint. Most dogs are using the leg within a few days post operatively, and they will often be more athletic after a TPLO than a lateral suture. In both surgeries, the surgery site is treated with a therapy laser to reduce inflammation and pain and patients go home with pain medication. Often times, the surgeon can infuse the surgery site with long acting bupivacaine that will numb the surgery site for several days after surgery.
How do most dogs do after surgery?
Current studies show that 90-95% of dogs will return to their previous activity after the TPLO. All dogs develop arthritis within a few weeks of the ligament tearing due to inflammation, but once the knee is stabilized, this minimizes the arthritis. Dogs will improve up to six months after the surgery as that is how long it takes for them to build muscle strength and for the swelling to improve in the joint. Even with the arthritis, most dogs will only have occasional stiff days after strenuous play or a long rest, but quickly work out of it.
Can there be complications after knee surgery?
The two most common complications are infection and implant failure/fracture of the bone. Infection is the most common with studies showing an infection rate from 8-17%. The most common reason for infection is that dogs can lick the incision because the E-collar is removed.
If they lick the incision and an infection forms, it can move to cover the plate as there is not a lot of muscle or tissue over the plate. When that happens, it causes a slime coating over the plate that antibiotics cannot penetrate and kill permanently. If an infection forms, the bone usually heals fine, but the implant is often removed to resolve the infection. Fracture/failure of the plate and screws is possible, but this is less common if the dog is kept restricted and there is no jumping or strenuous play.
How long is recovery?
You should confine your dog to controlled leash walks for six to eight weeks post operatively while the bone heals. They are allowed to walk on the leg, but no jumping, furniture climbing, or running. They should be confined to a crate or very small room while they are healing.
Rehabilitation is recommended to build muscle strength and decrease swelling. At Cleveland Road, our veterinarians will outline some post op therapy and stretching exercises to do at home and will also recommend seeing the rehabilitation specialists in our area to help with a full return to normal activity.