TPLO surgery
Cranial Cruciate Ligament Injury:
Tearing of the cranial cruciate ligament (CCL) is the most common orthopedic injury that we diagnose in dogs. The CCL in dogs is equivalent to the anterior cruciate ligament (ACL) in humans, and is a primary stabilizer of the knee during weight bearing. While some dogs tear the entire ligament in one event, many dogs will experience a slow breakdown of the ligament over time which can cause the lameness to wax and wane depending upon the degree of tearing and how much scar tissue is present. Arthritis subsequently develops, and additional injury can occur via tearing of the meniscus.
Tibial Plateau Leveling Osteotomy Surgery:
In order to restore joint stability and comfort in your dog’s knee, we recommend Tibial Plateau Leveling Osteotomy (TPLO) surgery.
In humans, it is common to simply replace the ACL with a graft. By contrast in dogs, we do not have success with ligament replacement surgery to treat CCL injury. However, we do see excellent outcomes with TPLO surgery, with a success rate of 90-95%. TPLO takes into account that the top of a dog’s tibia (i.e. the plateau) has a downward slope (angle) that exacerbates the tendency for the tibia to slide forward relative to the femur when the CCL is torn (called cranial drawer or thrust movement). The TPLO procedure involves a semicircular bone cut that allows us to rotate the top of the tibia to flatten the plateau and thereby prevent cranial tibial translation, restoring stability. A plate and screws are applied to keep the bone in the new position while it is healing.
Post-op Recovery:
Activity restriction post-op is essential to a successful recovery. It is important to understand that complete bone healing can take 3-4 months, however the first 6-8 weeks post-op require the greatest adherence to activity restrictions. In general, dogs should be confined to a very small room (without furniture or stairs to climb) or large dog crate whenever they are not directly supervised during the first 6-8 weeks. If the home has slippery floors (hardwood or tile) it is a good idea to lay down some throw rugs or yoga mats to ensure good footing. Outdoors, dogs should be walked on a short leash (not an extend-a-leash). Initially the walks are brief (5-10 minutes for bathroom purposes), however after the 2 week recheck we can gradually increase the length of the walks to 10-15 minutes a few times per day. Multiple short walks are better than one long walk per day.
At the 6 week recheck your veterinarian will take x-rays of the knee to evaluate for proper bone healing and any issues with the plate/screws. If the x-rays confirm good progress and your dog is doing well, the next phase of activity restrictions can begin. At this point, we usually allow dogs to have freedom in the house, but still keep them on a short leash while outdoors. This is the time period to increase muscle strength and stamina. If your dog were allowed to take off running in the yard, they would likely pull a muscle because they have not been running full speed for the past 6 weeks (or longer). Consequently it is important to start increasing the length of the leash walks by 3-5 minutes per week, and continue with at least 2-3 walks per day. By the time your dog is 10-12 weeks post-op, it is a good idea to do some light on-leash jogging to get the running muscles ready. Transitioning to off-leash activity can be done in a fenced yard after the 10-12 week post-op period, assuming your dog is not demonstrating any ongoing lameness and can handle a 25-30 minute leash walk without any issues.
Risk/Complications:
After surgery, it is normal for the limb to experience some bruising and swelling. Sometimes the swelling will move down the leg due to gravity, and will make the ankle appear swollen. All of this is quite normal. However, if the incision is draining beyond 2 days post-op, or if something happens suddenly (i.e. your pet slips and falls and then the leg appears more swollen), please contact your veterinarian right away for a follow up visit.
We take great care in following strict aseptic technique and protocols to prevent infection in your dog’s surgery site, however as living beings, dogs can still develop infections post-operatively. The biggest risk of infection is due to your dog licking the incision, which introduces bacteria from the mouth and causes inflammation of the skin. Use of an E-collar is vital in the post-op period. Some dogs also have higher bacterial loads on their skin (due to allergies, etc.) and are more at risk of an infection. We typically send home antibiotics to help prevent infection. However infection can still occur and ultimately may require plate/screw removal once the bone is fully healed; this is an additional procedure that will incur a separate cost. (We see infections requiring plate/screw removal in less than 5% of cases).
If dogs are not restricted post-operatively and are allowed to be too active, it is possible for them to develop a seroma (fluid pocket), fracture a portion of the bone, or even break or bend the implants (rare but possible). If any of these problems occur, a second surgery may be needed to correct them; again, this will incur a separate cost.
At the time of surgery we also check the status of the meniscus (cartilage cushion in the knee) as it is often damaged as a consequence of the instability caused by the CCL tear. If the meniscus is already torn, we typically debride (remove) the damaged portion and release the remainder of the caudal medial meniscus to help prevent additional injury. Additional meniscal injury after TPLO surgery is rare but possible; in my experience we see it less than 5% of the time. If the meniscus tears at a later date, we may need to go back in to remove/release the damaged portion as a separate procedure that involves a separate cost.
FAQ’s:
What is the risk of my dog needing a TPLO on the other leg? Depending upon which study you read, the risk of a dog rupturing the CCL in the other knee within a year of it happening on the first side is 50-60%. We believe that the reasons for this are that the dog has the same genetic factors and anatomy influencing each knee.
Can my dog undergo bilateral TPLO (at the same time) if the CCL is already torn in both knees? I generally discourage bilateral same session TPLO for several reasons. When both hindlimbs undergo surgery at the same time, dogs require a lot more assistance with a sling/harness post-operatively and there is more risk of catastrophic damage if the dog slips/falls because both hindlimbs are at risk. Surgery time is inherently longer doing two legs instead of one, and this increases the risk of post-op infection (longer surgery time = greater infection risk) and anesthetic risks. So the “savings” from trying to only have one anesthetic event and one hospitalization can be quickly negated by having to spend more money managing complications.