A TPLO, or tibial plateau leveling osteotomy, is a surgical procedure that stabilizes a dog’s knee after a torn cruciate ligament. It’s the most commonly recommended surgery by veterinary surgeons for this injury, especially in dogs over 60 pounds. Rather than replacing the torn ligament, TPLO changes the geometry of the knee so the ligament is no longer needed for stability.
Why Dogs Need TPLO Surgery
Dogs have a ligament inside the knee called the cranial cruciate ligament, or CCL. It’s the same structure as the ACL in humans, but it fails for very different reasons. In people, ACL tears are almost always traumatic, caused by sudden twists during sports like skiing or soccer. In dogs, the ligament typically degenerates slowly over months or years due to a combination of aging, obesity, poor conditioning, genetics, and body structure. A purely traumatic CCL tear in an otherwise healthy dog is actually quite rare.
This slow-burn degeneration means many dogs show subtle signs of arthritis, stiffness, or reluctance to play long before the ligament fully gives out. When it does rupture, the shinbone (tibia) slides forward relative to the thighbone (femur) every time the dog puts weight on the leg. The muscles around the knee can’t compensate for this instability on their own, and the result is lameness that won’t resolve without intervention.
How TPLO Changes the Knee
A normal dog knee has a sloped surface at the top of the tibia, called the tibial plateau. When the dog bears weight, that slope creates a shearing force that pushes the tibia forward. In a healthy knee, the CCL resists that force. Without it, the bones shift with every step.
TPLO eliminates that forward slide by flattening the slope. The surgeon makes a curved cut in the top of the tibia, rotates the plateau to reduce the angle from its original steep slope down to about 5 degrees, then locks it in place with a metal plate and screws. Once the angle is leveled, the compressive force of weight bearing pushes straight down into the joint instead of forward. The knee becomes stable during movement without a functioning cruciate ligament at all.
This is what makes TPLO a “dynamic” procedure. It doesn’t rebuild or replace the ligament. Instead, it redesigns the forces acting on the joint so the ligament becomes unnecessary.
How Vets Diagnose a Torn CCL
Diagnosis relies on two physical tests that check whether the tibia slides forward abnormally. In the “drawer test,” the vet holds the femur steady with one hand and tries to push the tibia forward with the other. If it moves, the CCL is torn. The second test, the tibial compression test, works by flexing the ankle. In a healthy knee, the intact CCL prevents the tibia from shifting forward when the ankle bends. In a torn knee, the vet can feel the tibia push forward under their fingertip.
Some dogs with significant muscle tension or pain will tighten up during the exam, making these tests unreliable without sedation. X-rays are taken both to confirm the diagnosis and to measure the tibial plateau angle, which the surgeon needs to plan the exact degree of rotation during surgery.
TPLO Compared to Other Surgeries
Three main surgical options exist for cruciate disease in dogs: TPLO, TTA (tibial tuberosity advancement), and lateral suture stabilization (also called extracapsular repair).
- TPLO applies to the broadest range of patients. It works for dogs with steep tibial plateau angles over 30 degrees and for dogs with angular or rotational deformities in the leg, situations where the other procedures may not be appropriate.
- TTA advances a different part of the tibia to change the angle of the patellar tendon, achieving stability through a different biomechanical principle. It may cause less strain on the kneecap tendon than TPLO, but long-term studies show TPLO patients are more likely to reach full function.
- Lateral suture places a strong synthetic line outside the joint to mimic the CCL. It’s simpler and less invasive, and outcomes in smaller dogs can be comparable. For larger, more active dogs, TPLO is generally preferred because the synthetic line can stretch or fail under heavier loads.
Success Rates and Long-Term Function
TPLO has strong outcomes. In a comparative study evaluating dogs more than a year after surgery, TPLO patients recovered to about 93% of normal limb function on average, and significantly more TPLO cases reached full function compared to TTA. Owner satisfaction and veterinary assessments both favored TPLO for long-term results.
That said, TPLO does not stop arthritis. Osteoarthritis progresses in the joint after surgery, particularly in knees with a complete ligament rupture, where measurable changes appear as early as three months post-op. In dogs with only a partial tear, arthritis progression is slower and in some cases doesn’t advance at all over the study period. The important finding is that even when arthritis does progress after TPLO, it generally has only a minor effect on the dog’s ability to bear weight and move normally.
Possible Complications
The overall complication rate for TPLO ranges from 15% to 37%, though this includes minor issues like swelling at the incision site. Surgical site infection is the most discussed risk, occurring in roughly 1% to 14% of cases depending on the study, with many clinics reporting rates around 5%. Other complications include wound breakdown, bleeding from a nearby artery during or after surgery, and, rarely, fracture of the tibia near the plate or implant failure. Most complications are manageable and don’t prevent a good long-term outcome.
What Recovery Looks Like
Recovery takes about 12 weeks and follows a structured progression. The first two weeks are the most restrictive. Your dog should be touching toes to the floor within seven days of surgery, even if they’re not putting full weight on the leg yet. During this phase, walks are limited to 5 minutes on a leash, three to four times daily, just enough for bathroom breaks. No jumping on or off furniture, no stairs beyond a few steps with support, and no playing with other dogs. You’ll also do gentle massage and range-of-motion exercises two to three times a day to prevent stiffness.
Weeks three and four introduce slightly longer 10-minute leash walks and simple exercises like sit-to-stands and figure-eight walking patterns. Sutures come out during this window.
From weeks five through eight, walk times gradually increase by a few minutes each week, up to about 20 minutes per walk or 60 minutes total per day. Walking through water, snow, or tall grass adds gentle resistance. Balance exercises on unstable surfaces like a couch cushion help rebuild strength. At the eight-week mark, your vet takes follow-up X-rays to check bone healing.
If the bone has healed well, weeks eight through twelve allow off-leash activity, starting at 20 minutes a day and building up to an hour. Full return to normal activity typically happens after the 12-week period, though some dogs need a bit longer.
Cost of TPLO Surgery
TPLO typically costs between $3,500 and $7,000 per knee, though total expenses can reach $10,000 depending on your location, the surgeon’s experience, and what’s included in the quoted price. Preoperative bloodwork and X-rays, anesthesia, the surgery itself, hospitalization, and post-op medications make up the base cost. Follow-up visits, additional X-rays at eight weeks, rehabilitation therapy, and pain management are sometimes billed separately. If your dog has torn the CCL in one knee, there’s a meaningful chance the other knee will eventually need the same surgery, so it’s worth planning for that possibility financially.