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Dr. Kim Tong, a board-certified veterinary surgeon based in the San Francisco Bay Area, frequently advises pet parents on what to expect when their dog (or cat) has hind-leg lameness and the cause is a torn or diseased knee ligament. Here are the top questions he hears, along with the key points he discusses with pet parents and vets when considering surgery.
What happens when my pet has a torn cranial cruciate ligament?
The cranial cruciate ligament, commonly referred to as the anterior cruciate ligament (ACL) in people, is a ligament within the knee joint that helps with the stability of the knee. When this ligament is torn, the knee becomes unstable, and the tibia (shin bone) will shift forward abnormally during weight bearing. This is known as tibial thrust. The abnormal shifting of the knee can lead to pain, inflammation, cartilage damage, osteoarthritis, and sometimes tears of the mensicus.
A cruciate ligament will not regenerate and does not heal on its own; therefore, a surgical procedure such as the TPLO may be warranted.
What is the TPLO?
The TPLO (Tibial Plateau Leveling Osteotomy) is a surgical procedure that stabilizes the knee by altering the biomechanics of the joint (changing the alignment of the injured knee). The cranial cruciate ligament is not replaced and is no longer needed.
How does a TPLO work?
A veterinary surgeon will make a cut to the tibia bone (“osteotomy”) with a semi-circular saw. They then rotate that segment to “level” out the joint surface (“tibial plateau”) to a specific pre-determined measurement. Hence, Tibial Plateau Leveling Osteotomy. After the cut and rotation are made, a specialized TPLO implant is fixed to the bone with medical screws to hold the osteotomy together while the bone heals over time. When the tibial plateau is leveled out like this, it counteracts the tibial thrust that was initially the cause of instability. Stable knee, happy pet!
Why the TPLO?
There are numerous options available for a torn cranial cruciate ligament. If you were to do any research online, you may come across other procedures such as the extracapsular lateral suture, tibial tuberosity advancement (TTA), tight rope, and synthetic cruciate replacements. Of all these options, the TPLO is by far the most preferred by board-certified veterinary surgeons. The TPLO has also been shown to be the most effective in getting patients back to near normal function and has a low complication rate.
What does recovery look like?
The recovery time after a TPLO depends on various factors, but is commonly considered to be around 2-3 months. This is because the osteotomy takes around 2 months to heal. Many patients are quite mobile within the first month after surgery, but most surgeons prefer that they take it easy until the bone has had adequate time to fully heal.
For optimal recovery, your veterinary surgeon may recommend the following:
- Activity modification. We recommend that your pet be confined to a small area to prevent them from wandering around the house alone. Free range in the house or outside can lead to complications.
- When on walks, recovering pets should always be on a leash, and initially their time will be limited to 10-15 minutes or so, just to eliminate. The recommended duration outside will increase as they get further out in the recovery process.
- No high-impact or strenuous activities. While the TPLO implant is a robust stabilization, we do not want to risk implant failure or delayed bone healing. Therefore, we recommend avoiding any major activities, such as running, jumping (including jumping on and off of furniture), playing with others, and/or engaging in unsupervised activity.
- Protect the incision. Please do not allow your pet to lick, chew, or scratch at the incision. This may lead to damage to the repair, opening of the incision, and/or infection of the surgical site. The most common ways to protect the incision are to use either a Lick Sleeve protective leg cover or an E-collar (cone).
- Please ensure that you administer all medications as directed by your veterinary surgeon. These medications include pain medications, joint supplements, sedatives, and sometimes antibiotics.
- It is always essential to maintain open communication with your veterinary surgeon. If you notice anything unusual, such as swelling, incisional issues, acute worsening of lameness, or obvious pain and mobility issues, please contact the surgeon. Catching small issues early may prevent more serious issues down the line.
- Physical Therapy. While formal physical therapy with a trained professional is always encouraged, at-home physical therapy and conditioning is often enough. This may include range-of-motion movements, low-impact mobility repetitions, minor strengthening exercises, and/or stretches. Your veterinary surgeon should be able to provide you with more detailed information on what they expect of you.
Final Thoughts
The key points to take away:
- The cranial cruciate ligament has some very important functions for the stability of your pet’s knee.
- The TPLO is the most commonly performed and most successful procedure for cranial cruciate ligament tears.
- In the hands of a trained veterinary surgeon, the TPLO is expected to have excellent outcomes with minimal risks.
- Adhering to the recommended post-op instructions will help ensure your pet has a smooth recovery.