TPLO – knee surgery
➤What is TPLO?
TPLO (Tibial Plateau Leveling Osteotomy) is an orthopedic surgery aimed at treating cranial cruciate ligament rupture in dogs.
Contrary to what one might think, this procedure does not replace the torn ligament. Instead, it modifies the shape of the tibia to make the knee stable, even in the absence of a functional ligament.
➤ Why does the knee become unstable?
The cruciate ligament acts as a “brake” to keep the dog’s knee stable. Since its leg bone (the tibia) is naturally sloped, this ligament prevents it from sliding forward with each step.
If it tears, the knee is no longer supported. With every step on the leg, the bone slides, causing pain, swelling, and promoting the development of osteoarthritis.
In most cases, this tear is not caused by an accident or a sudden movement, but by natural wear and tear (aging of the joint). A small weakness will almost always eventually turn into a complete rupture. Furthermore, since this wear affects the entire body, nearly one in two dogs will eventually have the same problem in the other knee over time.
➤Can surgery be avoided?
Non-surgical management may include:
- ✔weight management;
- ✔restriction and modification of activities;
- ✔pain and inflammation medications;
- ✔physiotherapy;
- ✔certain joint supplements.
These measures can improve comfort, but they do not repair the ligament or directly correct the mechanical instability of the knee.
Some dogs, particularly smaller ones, less active ones, or those with other significant health issues, can regain acceptable function with conservative treatment. However, the decision depends on the weight, activity level, severity of the lesion, extent of instability, and the specific needs of each animal.
For the majority of active dogs or those with significant instability, surgery offers the best chances of achieving comfortable and lasting function. Cruciate ligament rupture is generally not an immediate surgical emergency, but prolonged waiting can promote discomfort, meniscal damage, and the progression of osteoarthritis. Waiting a few weeks to make a decision, however, generally has little effect on the long-term outcome.
➤ How does TPLO work?
Rather than reconstructing the torn ligament, TPLO modifies the biomechanics of the knee.
The surgeon makes a circular cut in the upper part of the tibia to rotate the tibial plateau and decrease its slope. Once this new position is achieved, the bone is stabilized using a surgical steel plate and screws.
During the procedure, the veterinarian also inspects the menisci, two cartilage pads that absorb shocks in the knee. If a tear is present, the damaged part will be treated at the same time.
Once the tibial slope is corrected, the force that caused the tibia to slide forward disappears. The knee thus regains its stability without the need to replace the ligament.
➤Why choose TPLO?
TPLO is currently considered the gold standard surgical technique for treating cranial cruciate ligament rupture.
It generally provides better short, medium, and especially long-term results than other techniques, in both small and large dogs. It allows for faster recovery, better limb function, and limits the progression of osteoarthritis.
Other surgeries exist (TTA, TightRope, TTO, extracapsular suture, etc.), but they are generally chosen when certain patient characteristics or financial considerations make TPLO less appropriate.
This surgery is more expensive than a conventional procedure as it requires precise planning, specialized instruments, orthopedic implants (plate and screws), multiple radiographs, and advanced expertise in orthopedic surgery.
➤What to expect after surgery?
The success of TPLO depends as much on the surgery as on following the post-operative instructions.
For about 8 weeks, activities must be strictly limited to allow the bone to heal. Outings should be on a leash only, running, jumping, and stairs must be avoided, and rest must be respected.
Mild lameness is normal during healing and gradually improves. However, a sudden worsening of lameness or the appearance of significant pain warrants a prompt re-evaluation.
Two follow-up visits are usually scheduled:
- [ + ]After about 2 weeks, to check wound healing and remove stitches, if necessary.
- [ + ]After about 8 weeks, to take radiographs and confirm that the bone has healed well before a gradual return to activities.
Most dogs complete their rehabilitation around 4 months after surgery.
[!]Possible complications
Like any surgery, TPLO carries certain risks, although they are relatively uncommon.
- [ – ]Infection (3 to 5%): it can appear a few weeks or even several months after the procedure. Redness, wound discharge, pain, or new lameness should be evaluated quickly. In some cases, the plate and screws will need to be removed once the bone has completely healed.
- [ – ]Late meniscal tear (3 to 5%): despite a careful examination during surgery, a meniscus tear can appear weeks or months later. It often causes a sudden return of lameness and may require a second surgery.
- [ – ]Implant breakage (< 1%): this complication is rare and occurs mainly when resting instructions are not followed before complete bone healing.
The prognosis is excellent, and the majority of dogs regain an excellent quality of life after TPLO, particularly when the surgery is performed by an experienced surgeon and recovery recommendations are closely followed.
Source and additional information: Greg Harasen, DVM
