TPLO vs TTA: The Decision Your Surgeon Already Made

You have probably been comparing two procedures that were never both on offer. Most veterinary surgeons perform one osteotomy — the one they trained on, own the jig and the plate inventory for, and have done several hundred times — so the choice between a tibial plateau levelling osteotomy and a tibial tuberosity advancement is usually made before you book the consult. The published evidence says that is a defensible way for it to have been made: the systematic review that went looking for a winner concluded that "no method can be clearly preferred." Both work. What is still in your hands is everything around the cut — who performs it, whether the meniscus is inspected, and what the restricted weeks afterwards actually look like.

Why you are probably not choosing#

The way this decision reaches an owner is not the way it reads online. You search the two acronyms, find a dozen pages weighing them against each other, and arrive at a consult expecting a menu. What you usually get is a recommendation, singular, and it is the procedure that practice does.

That is not a bait and switch, and it is not laziness. Both operations are technically demanding and both need procedure-specific instrumentation — a saw blade and jig for one, a cage system and its own plates for the other — which is a real reason a practice standardises on one. A surgeon who performs the operation weekly is giving you better odds by offering you that operation, even in the hypothetical world where the other one is marginally better.

So the useful version of this article is not "which should you pick." It is: what does each one do, what does the evidence comparing them actually say, and — since the headline comparison turns out to be a wash — which questions are worth the fifteen minutes you get.

What each surgery actually does to the bone#

The cranial cruciate ligament stops the femur sliding backwards off the top of the tibia every time the dog puts weight on the leg. When it fails, that sliding — cranial tibial thrust — is what makes the knee painful and unstable. Both operations leave the torn ligament where it is and change the geometry of the joint so the thrust stops mattering. Neither replaces anything.

TPLO cuts a semicircle around the top of the tibia and rotates the plateau until it sits nearly level, then fixes it with a bone plate and screws. The American College of Veterinary Surgeons describes it as "making a semicircular cut around the top of the shin bone and rotating this to a predetermined location," stabilised "by the use of a bone plate and screws."^[1]

TTA makes a straight cut down the front of the tibia and moves the tibial crest forward, held out at its new position by a wedge or cage and a plate. The ACVS: it "requires a linear cut along the front of the shin (tibia) bone. The front of the tibia, is moved forward to neutralize forces around the knee," stabilised "by the use of a specifically designed wedge, bone plate, and screws."^[1]

Two different solutions to one equation. Both cut bone, which is why both need weeks of confinement while it knits, and why your recovery plan barely changes between them.

One thing worth holding onto before the comparison, because it changes how you read your own dog's history: the ligament almost never snaps out of nowhere. The ACVS describes rupture as "the result of subtle, slow degeneration that has been taking place over a period of time rather than the result of a sudden trauma to an otherwise healthy ligament (which is very rare)."^[1] The day he came up lame on a walk was not the day it started. It was the day the last of it went.

“Because your dog can't tell you how much pain he or she is in.”

What the comparative evidence actually found#

This is the part almost nobody publishes plainly, so here it is.

In 2022, a group at Hannover set out to answer whether one technique is superior. They identified and evaluated 72 studies on surgical management of cruciate rupture, across gait analysis, osteoarthritis, thigh circumference, goniometry, joint stability, pain and complications. Their finding on the state of the field is as important as their finding on the surgeries: 47.2% of the studies were rated low quality of evidence, and out of 72 studies there were only eleven blinded randomised clinical trials, of which five had a low overall risk of bias. Their conclusion: both techniques are successful management options, most dogs show no lameness at long-term evaluation, TTA appeared to give better osteoarthritis scores up to six months while TPLO had a lower rate of surgical site infections, and "no method can be clearly preferred, as most of the study evaluated were subpar."^[2]

Read the arithmetic underneath that. Of 72 studies on one of the most frequently performed orthopedic operations in dogs, three contained enough data to pool complication rates between the two procedures — and pooled, the review reports, "none of the surgical techniques is superior to the other."^[2]

The arthritis question has the same shape. A 2026 knowledge summary reviewed the three studies comparing postoperative radiographic osteoarthritis between the two: the first found less progression after TTA, the second found less after TPLO, neither significantly, and the third found significantly more after TTA. Its rating of the strength of that evidence is a single word — weak — and its conclusion is that there is minimal evidence either procedure reduces osteoarthritis progression relative to the other.^[3] A separate 2026 study scored osteoarthritis at 14 individual anatomic locations in the stifles of 55 dogs before surgery and six months after, and found no substantial difference between the techniques — both progressed most in the caudal tibial plateau and the lateral condyles, with the low rate of change elsewhere suggesting both procedures redistribute joint stress effectively.^[4]

An older and broader systematic review — 444 papers screened, 34 included — concluded that the evidence most strongly supports TPLO for returning dogs to normal function, and it is fair to say the weight of published opinion leans that way.^[5] It leans. It does not decide.

Side by side, with the receipts#

Read the rows below, but do not read them as a league table. The complication percentages come from different countries, different decades, different definitions of "complication" and — critically — different settings: one is a referral series, one is general practice, one pools many techniques. The systematic review that tried to compare them properly found three studies' worth of usable data and no difference. That is the honest comparison. Everything else is arithmetic between things that were never measured the same way.

Sources for the rows, in order: the 1,519-procedure TPLO series reporting 11.4% total and 3.1% major complications with German Shepherd Dogs at OR 3.2, plateau angle over 30° at 1.6 and heavier weight at 1.10 per 4.5 kg;^[6] 374 forkless TTAs performed by six non-specialist veterinarians in primary care, with complications in 15.2%, major in 7.5%, and postliminary meniscal injury more common when the cage-size-to-bodyweight ratio was ≤0.25 (P = .019);^[7] 670 stifles undergoing high tibial osteotomy with complications in 20.0%;^[8] the TTA-techniques systematic review reporting meniscal tears in 40.21% of stifles at surgery, late meniscal tears in 4.28%, minor complications in 33.5% and major in 10.67%;^[9] 769 TPLOs at a single institution with an overall complication rate of 19.3%, surgical site infection in 8.5% and major SSI in 6.8%;^[10] the range-of-motion cohort;^[11] and the German pricing analysis.^[12]

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The three places they genuinely differ#

Infection. The one axis where the systematic review committed to a direction: TPLO had a lower rate of surgical site infections, and the review's own conclusion says "current evidence indicates that TPLO is favorable regarding certain complications, such as SSIs."^[2] This is a difference in favour of the more expensive procedure, and it is still not large enough to overturn a surgeon's own experience. Worth knowing anyway, because infection after either operation usually means implant removal and a second anaesthetic. In the 769-TPLO series, dogs who had already had a TPLO on the other side carried twice the odds of infection (OR 2.01), and German Shepherd Dogs 4.41 times the odds.^[10]

The meniscus. Both procedures leave the meniscus in the joint, and a meniscus that tears after the surgery is a recognised reason a dog who did well at his last recheck is lame again months later. We have not found a published figure ranking the causes of late post-operative lameness, so treat "the commonest reason" — which you will read elsewhere, including in earlier drafts of this page — as unestablished. What is published is the rates. The TTA literature quantifies this better than the TPLO literature does: 40.21% of stifles had a meniscal tear already present at surgery, and 4.28% developed one afterwards.^[9] The primary-care TTA series found late meniscal injury in 3.2% and identified something practical: it was commoner when the advancement was small relative to the dog.^[7] This is the strongest argument in the article for a question you can actually ask: how will you inspect the meniscus, and what will you do if it is torn?

What the joint does in the first month. In a retrospective cohort comparing TTA, TPLO and tightrope, the one-month picture separated: dogs treated with TTA showed a significant worsening of flexion (abnormal in 69.6% before surgery, 80.4% at one month, p = 0.0208), while TPLO dogs significantly improved in extension (normal in 16.7% before, 33.3% at one month, p < 0.0001) and in flexion by six months.^[11] The finding that matters most in that paper applies to both, though: at six months, range of motion was still not normal in 100% of the stifles, even though lameness had significantly improved after every procedure. Your dog can walk soundly on a knee that has permanently lost some of its arc. That is a reason to take the rehabilitation seriously, not a reason to prefer one cut.

The number that argues against both, and what it is worth#

Here is the finding we did not expect and are printing anyway.

Seventy-one dogs with cruciate disease — 18 TPLO, 23 TTA, 30 lateral fabellotibial suture — were followed to a median of 4.6 years and scored with the Canine Orthopaedic Index. Compared with the old, cheap, extracapsular suture, the risk of stiffness and lameness was increased in the dogs who had the modern osteotomies: TPLO stiffness IRR 1.33 (p = 0.015) and lameness IRR 1.34 (p = 0.020); TTA stiffness IRR 1.26 (p = 0.035) and lameness IRR 1.31 (p = 0.026).^[13]

Now the caveats, in full, because they are load-bearing. The authors state them themselves: no follow-up veterinary examination was performed, the data came from only two university animal hospitals, and referral bias towards more complicated cases is possible — which limits generalisability. And it is very likely that the dogs sent for an osteotomy were the bigger, more active, more badly affected ones in the first place. A 4.6-year owner questionnaire cannot separate the operation from the dog who needed it.

So this is not evidence that you should ask for a lateral suture. It is evidence that the confidence with which the two osteotomies are compared to each other exceeds the confidence with which either has been compared to anything else. If you were carrying guilt about not being able to afford the expensive option, this number is the honest thing to put beside it.

The questions that do change the outcome#

Since the osteotomy choice is largely made for you, spend the consult on what is not. Our full list is in what to ask the veterinary orthopedic surgeon; these four are specific to this decision.

1. "How many of these do you do a year, and what is your own complication rate?" There is no per-surgeon registry in this field, which is precisely why the question has to be asked directly. The published range for the same operation spans practice types and decades; the number that applies to your dog is the one in that room.
2. "How will you assess the meniscus, and what do you do if it is torn?" Arthroscopy, arthrotomy, and what happens on finding a tear are all real choices, and late meniscal injury is a documented cause of a good result going bad, at 4.28% and 3.2% in the two TTA series above.
3. "What is the written rehabilitation plan, with dates?" Range of motion does not fully return on its own — 100% abnormal at six months in the cohort above. Ask for the plan on paper, with a review date, before you leave. This is the single most reliable place a recovery quietly stops.
4. "What is the plan for the other knee?" In 831 medium-to-large dogs aged eight or older at their first rupture, 19.1% ruptured the contralateral cruciate, at a median of 12.9 months.^[14] One in five is a real number to plan around. Note the population before you carry it anywhere: these were dogs already eight or older when the first side went, so they had fewer years left in which to rupture the second. It is not a figure for a five-year-old Labrador, and it is not a correction of the higher numbers you will see quoted for younger dogs.

If the conversation you are actually having is knee-versus-hip rather than knee-versus-knee, that is a different article: TPLO vs total hip replacement covers why those two are not competing options at all. And if you are not yet certain the problem is the knee, start at is my dog limping, or is it something else.

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The restricted weeks are the same either way#

This is the practical consequence of everything above: whichever osteotomy your surgeon performs, you are buying the same aftermath. A bone cut, several weeks of confinement, controlled lead walks, and a household that has to keep a large dog from doing the one thing he wants to do. Our TPLO recovery guide and the recovery gear checklist both apply to a TTA dog unchanged.

Two pieces of equipment earn their place, and both come with a caveat we would rather you had before you spend.

Start with what costs nothing. A folded bath towel under the belly is a genuine rear-support sling for a dog who needs help for a few days, and for plenty of medium dogs with a competent adult on the other end it is the whole answer. It stops working when the dog is heavy enough that your grip fails before his legs do, or when he needs support several times a day for weeks rather than days — a towel has no handle, so your wrists take the load in the worst possible geometry. Likewise, rug runners along the routes your dog will actually walk in those restricted weeks — bed to door, door to garden — cost well under $100 once and fix the floors he crosses most.

The sling is the right shape for this specific job because the job has an end date. A post-osteotomy dog needs support for the weeks of restriction his surgeon prescribes, and then progressively less; that is a different purchase from the one a dog with a progressive neurologic disease needs, where the requirement lasts years and a full body harness worn all day wins. The failure mode it prevents is the one that costs the most: a dog whose back end slides out from under him on a hard floor while an osteotomy is still healing, in the first fortnight, when the plate is doing the work the bone has not taken over yet. What it is bad at: the chest harness the maker's own guidance expects an older dog to wear is not included, and the return window is a strict 10 days clean, with a $10 restocking charge from day 11 to 30 — which means buying it the week before surgery rather than on day two, when you least want to be shopping and shipping decides whether it arrives in time.

And now the caveat that our own product page carries, because it is directly about this reader. The only trial of nail grips in exactly this population was null. Thirty dogs were randomised to nail grips or sham grips for the first two weeks after TPLO and assessed by blinded observers: no difference in visual lameness score or total pressure index at day 14 or any timepoint, and no difference on the client-specific outcome measures — including the one that asked specifically about walking on slippery flooring (p = 0.78).^[15] The authors are careful — the grips were well tolerated, the sample is small, day 14 is one early timepoint — but the honest label is that no positive trial exists, and that the manufacturer's Amazon listing markets specifically to dogs with "ACL injuries" while the only study in post-cruciate dogs found nothing (listing copy verified 2026-08-17). We still recommend them for the floors you cannot cover, on the mechanism — a rubber cleat on the nail tip where a hard nail meets a hard floor — rather than on any trial, at a running cost of $240–$480 a year that we would rather you knew before the first bag than after the fourth. Rugs first. Full detail on the ToeGrips page and in dogs slipping on hardwood floors.

We earn the same commission rate whichever of these you buy, and nothing at all if you use the towel and the rugs you already own. That last outcome is a perfectly good one.

What to do this week#

If the consult has not happened yet, stop researching the acronyms. The comparison is a wash and the fifteen minutes are not. Write down the four questions above, and add one line to the top of the page: how long has he been off this leg? The ligament degenerates over months before it fails, so the answer is almost always longer than the limp — and a surgeon who knows the leg has been sore since spring plans differently from one who is told it happened on Tuesday.

If the surgery is booked, order the sling now rather than on day two, put the runners down before he comes home, and ask for the rehabilitation plan in writing with a review date on it. The osteotomy is one morning. The weeks after it are where the leg is actually made, and they are the part nobody schedules.