Most websites about TPLO and TTA are the sites of surgeons who are selling these high-profit surgical procedures. This page is here to provide you with the facts about TPLO and TTA that you won't find at TPLO / TTA surgeons' websites or hear from them at their offices.
Sometimes surgical procedures become more popular with surgeons than comparative results and risks justify. This is the case with TPLO, TTA, which are useful procedures in some rare circumstances, but are not the best treatment choice for most dogs with ligament injuries.  There are some honest vets who have been caught up in a faddish enthusiasm for these aggressive bone alterations as ligament injury treatment.  There are other surgeons who are simply profiteering.  They are making fortunes selling these hugely profitable procedures to people who love their dogs and accept vets' recommendations too trustingly.

This website was most recently updated in June 2015.
The information here is current and accurate. 

There are no Class I or Class II research studies supporting claims that there is any advantage to TPLO or TTA over other treatment choices. After talking with a TPLO or TTA surgeon, you may have the impression that these surgeries are universally believed to be the best possible treatment choice for all dogs with ligament injuries. That is not true. These bone-alteration surgeries are very popular with the vets who are making huge profits selling them, but there are many vets who do not agree with the excessively broad use of these bone-alteration procedures as a treatment for ligament dysfunction, and the only research supporting the use of these extremely invasive bone-alterations are low quality Class III & IV studies done by vets who sell TPLO and TTA bone-alterations for large profits. The articles which are called "research" by TPLO and TTA promoters are full of outrageously sloppy thinking which would be laughed at by anyone familiar with scientific method and the accepted norms of medical research. This sort of thing is often what you see referred to as supposedly providing proof that your dog should have bone-altering surgery. These 'proofs' are not proof to anyone who understands what scientific medical studies really involve and what methodological flaws are not acceptable in research.
---- Most TPLO / TTA surgeons claim to have wonderful success rates when they speak to potential customers. We hear of TPLO / TTA tragedies and poor outcomes daily, yet almost every TPLO surgeon tells potential customers that his record of TPLO success is near perfect. The statistics from objective research on TPLO / TTA results do not support the claims made by surgeons who sell these procedures. Someone is not telling the truth. Is it the dog owners and the objective researchers? Or is it the surgeon who wants to sell you a $3500-$4500 one-hour bone-alteration surgery?
----No oversight is done on claims made by surgeons to potential clients or on their websites. No government agency or watchdog organization is verifying those claims of high success rates. Any vet-surgeon can say anything he pleases about his results without being concerned that his misrepresentations could cause trouble for him. When a vet tells you he has a high success rate with these bone-cutting surgeries, and that he seldom sees serious complications, you should bear in mind that these are the unsupported claims of a person who will make thousands of dollars clear profit doing the one-hour procedure if he convinces you to buy.

What rates of success are really obtained with TPLO or the other bone-alteration surgeries?
--- No evidence-based objective research backs up the excessive claims made by many ortho surgeons. Only the biased opinions and pseudo-studies of other TPLO/ TTA surgeons support those claims.
--- Consider this statistic from an article published in The Journal of the American Veterinary Medical Association: This study found that only "...10.9% of the dogs treated with tibial plateau leveling osteotomy (TPLO) regained normal leg function subsequent to surgery. ..." [ Journal of the American Veterinary Medical Association, Vol. 226, No. 2, Pages 232-236doi: 10.2460/javma.2005.226.232 ]
--- This doesn't mean that the other 89.1% of dogs who have TPLOs have no use of the leg after a TPLO surgery and recuperation. While these bone-alteration surgeries can have complications resulting in ongoing pain, crippling, amputation or other very poor outcomes, many dogs do recover after these bone-alteration surgeries to the extent that they have use of the leg, but not pre-injury ability. However, other treatment options have better expectable success and less risk of severe complications than TPLO or TTA. Long-term outlook after TPLO or TTA bone alteration surgeries is especially questionable.

All dogs who have these injuries have increased risk of future arthritic changes in the joint. No surgery can prevent that. Please see the 'Arthritis Risk?' page here at this website.

Ligament injuries cause a dog's stifle joint (the canine knee) to be unstable. Most dogs can re-stabilize the stifle without surgical intervention. This is covered on the 'Recovery Without Surgery' page here at this website. But some dogs cannot and will need surgery. For most dogs with ligament injuries which need surgical intervention, the best surgical choice has always been one of the 'Conventional Stabilization Surgeries' which are described on this website's page by that name. These 'Conventional Stabilization' procedures do not alter the bones and have much less risk of serious complications and catastrophic failure than the bone-cutting surgeries TPLO, TTO & TTA. The bone-alteration surgeries do not truly stabilize the stifle joint, but instead alter the relationship between the bones of the leg as described below, shifting stresses and pressures. This can result in various problems in the joint and spine.
---- Until recent years the bone-geometry alteration of these procedures could in some cases be the best surgical choice for very large, highly energetic dogs. This was because the only materials previously available to be used in conventional stabilizations were not strong enough for the pressures a 120 pound high-energy dog would put on them. In the past, conventional stabilizations with the old materials were failing too often with that kind of dog. Newer ortho-surgical materials have changed the situation so that TPLO or TTA are no longer the best choice for the vast majority of those very large high-energy dogs. Information at the bottom of this page describes these advances in surgical treatment for very large high-energy dogs.
---- While they used to be a reasonable choice for those very big high-energy dogs, TPLO & TTA were never a good choice for most dogs with ligament injuries. For most dogs with a ligament injury, the best strategy has always been to re-establish stability at the joint, not to radically alter the dog's bone structure. But in recent years the very profitable TPLO and TTA have unjustifiably grown in popularity among surgeons. They are now widely recommended for any dog with a ligament injury. If a vet has told you your dog should have a TPLO or TTA procedure, this is probably not true. TPLO & TTA are not best for the dog in most cases where they are recommended.
---- Situations where TPLO, or TTA are the best surgical choice do exist, but these situations are rare. Bone alteration may be the best surgical choice when the Tibial Plateau Angle (the TPA)* is pathologically steep or when there is angular limb deformity or patella luxation associated with the ligament rupture. These situations are a very small minority of ligament injury cases. Yet TPLO or TTA are now recommended for nearly all canine ligament injuries by some vet ortho-surgeons.
* TPA -- The Tibial Plateau Angle is the degree of slope where the upper & lower bones of the leg meet at the stifle joint (the canine knee). A normal TPA is less than 32 degrees. There is more about TPAs lower on this page.

Question: "Does it ever happen that a surgeon misrepresents the facts about a dog's injury in order to sell a high profit procedure?"
---- Yes, that does happen. Vets are not all trustworthy. There are crooked vets who try to take advantage of your love for your dog and your trust in the vet profession. You need to be cautious. Some profiteering surgeons will tell people that their dog has some congenital bone defect or in some other way is doomed to a horrible fate of crippling arthritis unless the clients buy the surgery the surgeon is selling. You need to be cautious & skeptical.
---- While many dogs do recover at least moderately well after TPLOs and TTAs, and some have very good recoveries, these successes do not change the fact that these procedures have much more risk of very serious complications and catastrophic failure than the alternatives. TPLO & TTA have greater risk without any reasonable expectation of better results than dogs have with conventional surgery. TPLO & TTA provide a very high profit for the surgeon. That is the root of the problem. The wise choice is the one that gives the best results with the lowest risks of serious complications. That will not be TPLO or TTA in most cases.

'TPLO' stands for Tibial Plateau Leveling Osteotomy. This surgical procedure cuts off one of the bones of the dog's leg using a special kind of power saw to make an arc-shaped cut, then rotates one section of the bone through part of the arc, and re-attaches it at a different angle with a metal plate and screws. This reduces the Tibial Plateau Angle, (the TPA).
---- 'TTA' stands for Tibial Tuberosity Advancement. TTO stands for Triple Tibial Osteotomy. These are also leg-geometry-altering procedures which accomplish an effect similar to TPLO's by altering the dog's bone structure to achieve the result of lessening the TPA.
---- The idea behind all the TPA alteration surgeries is that changing the leg bones' relationship to each other in this way to decrease TPA will make stifle stability less important for joint function. This is true to an extent. Dogs will often bear weight on the leg more quickly in the time period shortly after TPLO or TTA. But longer term results are not superior and there are significant risks of catastrophic failure and severe complications with these very invasive surgeries.

When people take their dog to an ortho-specialist vet, they expect a consultation with an expert who will provide them with the objective facts they need to make a well-informed decision. But if the consultation is with the wrong surgeon, what they get instead may be a TPLO or TTA sales pitch. The treatment of ligament injury in general, and their own dog's condition in particular, may be described in a slanted manner intended to influence them to agree to having one of these surgeries done on their dog.

In searching for information on TPLO or TTA, when you see articles that speak highly of these surgeries, look to see who the author is and what his relationship to these surgical procedures is.  Does he sell one or both of these highly profitable procedures?  Chances are that he does.  There are many Class III and Class IV "research studies" by TPLO & TTA surgeons which claim great outcomes for the surgeries which are making them wealthy.  These articles are not true research.  They are self-serving subjective opinion.  This is explained on this website's page titled "But The Vet Said...".

The problems that can develop during and after one of these bone alteration surgeries can be very serious.
---- All surgeries have risk, but there are some especially nasty potential complications that are specific to TPLO & TTA surgeries:
-- Cracking and splintering of the bones where the metal plates are attached to bone with screws;
-- Persistent infections in the bones;
-- Failure of the patellar ligament due to increased stress on that ligament caused by altered joint geometry. 
-- Failure to heal of the saw-cut re-positioned bone segments.
-- Damage to the joint's meniscus following the 'meniscus-release' often done in association with TPLOs.  
(Please see the section on 'Meniscus Release' on the 'Meniscus Info' page here at this website.)
-- Loosening of the metal plates caused by backing-out of the screws after surgery or failure of the screws' attachment from crumbling bone or other causes . 
--Tibial tuberosity fracturing;
-- Spinal alignment problems resulting from the altered bone structure having changed stress vectors ;
-- Increased cancer rates associated with the metal implants.
-- Peroneal nerve damage
-- Popliteal artery trauma
-- And more.
With TPLO or TTA you have these risks, plus the risks that unavoidably exist in all surgeries, and all without a potential outcome superior to other treatment options. There is seldom a good reason to choose to subject your dog to these risks.

The stifle(knee) is a complex joint which interacts with many other body components in complex ways.  The vets selling TPLO & TTA like to show clients line drawings of carts on hills and use other analogies which greatly over-simplify the functioning of the stifle.   When complicated systems are subjected to major alterations in their components, unintended consequences can be expected.  There are plenty of unintended consequenses which follow TPLO & TTA. 

The most reasonable first choice when dealing with most dogs' ligament injuries is recovery without surgical intervention.
---- Any non-surgical treatment is referred to by doctors as 'Conservative Management' or 'Conservative Treatment'.  Most dogs will recover well from ligament injury without surgery. Carefully restricting a dog's activity to prevent excessive stresses to the injured leg is the best possible diagnostic tool to find out if the dog really requires surgery.  A dog who improves over the course of 8 weeks of restriction and continues to slowly improve is almost certainly not in need of surgery.  There is information on other pages here at this website about recovery without surgery.
---- For some dogs with ligament injuries, non-surgical efforts will be ineffective, and then surgery will be appropriate.  Conventional stabilization surgery, done by an experienced and skilled vet, is the best choice for most dogs when surgery is needed.  Conventional surgery aims to stabilize the injured joint without altering the dog's bone structure.  Conventional surgical procedures are much less invasive and less expensive than TPLO or TTA. While not risk-free, they do not have the horrific potential complications that are specific to the bone-alteration surgeries. There is more information on conventional surgery and non-surgical treatment on other pages of this website.

When you want to find the truth
about the qualities and reliability of a car you're thinking of buying, you look for objective evidence like that found in a 'Consumer Reports' review of the car. You don't just accept the statements of the car salesman about the car.  He will profit from your decision to buy.  He wants to convince you to buy, whether or not that is best for you.  You need to recognize that the ortho surgeon will make thousands of dollars profit on the sale if he convinces you to buy the surgery he recommends. Be skeptical of the sales-pitch.  When large profits for the provider of a service are involved you need to be cautious about accepting his description of the situation as accurate.
--- There are several websites that describe good experiences people had with their dogs' TPLOs or TTAs. On these websites you often see secondhand claims about the procedures, such as "My surgeon told me two-thirds of dogs he does TPLOs on have amazingly superior results and the other third does well too!..."  I think these are written by honest good-hearted people who are happy their dogs recovered well. They haven't looked into the subject in any depth. They are simply repeating what they have been told by the surgeons. Don't fall into the trap of accepting this kind of claim as true because you read it on a nice person's website. You need to look at the objective evidence, not the sales pitch. The sales-pitch may come directly from the surgeon or be innocently repeated secondhand by a dog-loving person you feel friendly toward.

Demosthenes said:
"Self-deceit comes easily. 
For what each man wishes to be true, 
he will readily accept as fact."
--- We would all like it to be true. When a surgeon recommends TPLO or TTA, we want very much to believe that there is available to us a remarkably superior, very successful surgery for our dogs.  We want to believe that if we just pay a high price for this surgery then our dogs will recover wonderfully well.  But the sales-pitch is not the truth.  TPLO & TTA success rates are not superior.  These are extremely invasive procedures which have mediocre success rates along with the potential for horrific complications.

Here's how Slocum Enterprizes, developer of the TPLO procedure, responded to an inquiry asking for information regarding problems associated with TPLO:
--- Question "...I am interested in follow-up studies regarding the type and frequency of problems encountered by surgeons while performing TPLOs, and also interested in information on post-op complications following TPLOs..."
--- Answer from Slocum Enterprises:
"...To answer your question regarding post-operative studies, there is no legal requirement between Slocum Enterprises and any veterinarian who performs the TPLO procedure to report their surgeries and/or complications to us. ..."
--- Why would Slocum Enterprises take this position when asked about complications associated with their TPLO procedure, providing no information about potential problems?  Wouldn't you expect Slocum Enterprises to be making all possible efforts to gather information on problems encountered during TPLO surgery?  Wouldn't feed-back about such problems and post-op complications make it possible to improve treatment?  Why would they decide against gathering such information?
--- Or is it possible that in fact Slocum Enterprises does compile such information, but then keeps that information private under cover of a claim that the information was not legally required to have been gathered?
---- If a tire manufacturer reacted like Slocum Enterprises when asked about problems with their tires, what would you think was the likely reason?

Slocum Enterprises quietly went out of business in the Summer of 2010.  No explanation was offered.  While the company is now defunct, there are still many vets pushing the highly profitable TPLO procedure.   

Consider what orthopedic experts who are not selling TPLOs say:
Here is a quote taken from an email written by Gail Smith, Professor of Orthopedics and Department Chairman at the University of Pennsylvania Vet School:
"... [In regard to TPLO there is a] virtual absence of research to show that this highly invasive and expensive method has any benefits whatsoever in post operative clinical function over other less invasive and expensive methods. I have taken a stand early in my career to avoid endorsing procedures that are not evidence-based ...and TPLO is a classic case of surgeons ... jumping on the bandwagon without adequate investigation to demonstrate the purported benefits of the procedure.
Sincerely, Gail"
[Gail Smith - Professor of Orthopedic Surgery; Chairman, Dept of Clinical Research, University of Pennsylvania Vet School]  
--- I think there is one main reason those vet-surgeons Professor Smith refers to "jumped on the TPLO bandwagon". That reason is money. TPLO is a very high-profit procedure. It would not be realistic to believe that this very large profit potential could not influence surgeons' treatment recommendations. Costs involved in doing the procedure are very small relative to the price charged. A few hundred dollars worth of implants and one assistant in the operating room. The TPLO procedure usually takes less than one hour. (Some vets have been known to do 6 or more a day.) Surgeons commonly charge well over $2500 and sometimes over $5000. It is not at all unusual for an ortho-surgeon vet to do over 1000 TPLOs / TTAs in a few years as part of his practice. With between $3000 and $6000 US dollars in profit for each surgery, the surgeon makes several million dollars in profit on TPLO/ TTA in a few years. These procedures have tripled the income of a bunch of ortho-specialists.
With the Slocum Enterprises patent on TPLO expired, TPLOs are being sold at a lower price by some surgeons in some locations.  This does not make TPLO a better choice.
---- When I first looked into ligament injury treatment, I assumed that a TPLO must be a very time-consuming operation which required expensive specialized equipment. Why else would it cost over $3500? But I learned that a TPLO didn't take long to do, and the equipment & training costs to the surgeon were modest. Why the high cost to dog owners then? The TPLO surgeons I talked with could offer no good explanation for the price they charge for TPLOs. In my opinion the explanation for the high price is that Slocum Enterprises originally patented the TPLO so that Slocum had control of who was legally allowed to sell TPLOs, then set up the marketing of the patented TPLO with high profits for surgeons built-in in order to attract ortho-specialists to adopt the procedure, and that pricing has been maintained (unofficially with a wink and a nod) among TPLO surgeons since the patent expired. It is easy for surgeons to market this procedure at this high price because dog owners love their dogs and are easily convinced that the high cost means it is a superior procedure. People are inclined to trust medical professionals. If an ortho-specialist vet tells them TPLO is the best, they seldom question his motives. The high price can even be a selling point. "You love your dog and want the best? The surgeon recommends TPLO and it is very expensive. TPLO must be good if it costs so much, eh?"

---- Bone alteration procedures' profitability have fueled their popularity among vet-surgeons. The very high profit in this kind of surgery has led to a great increase in a special kind of risk for dogs. The risk of being subjected unnecessarily to a very invasive surgery which involves the possibility of horrific complications. Some dogs are maimed and crippled by these surgeries when they would have recovered well without any surgery or with a less invasive surgical procedure. This happens because there are thousands of dollars of profit in every surgery.
---- Some surgeons are truly despicable in their willingness to put dogs at risk with inappropriate surgeries.  In my email I often hear from people who have been given a sales-pitch for a clearly inappropriate surgical procedure.  For example, sometimes dogs have a limp but recover well while waiting a few weeks for an appointment with an ortho-specialist.  Quick recoveries like that indicate the dogs had minor injuries for which no honest vet would recommend surgery.  But when seen by a TPLO surgeon they may be diagnosed as needing TPLOs.  It seems that there are a number of surgeons who try to sell TPLOs or TTAs to everyone who comes through their office door.  In fact, you don't need to come through the door to get the sales pitch from some of them.  I hear of dogs diagnosed over the phone as needing bone alterations ("Limping? Needs a TPLO then. Lets set up a surgery appointment right now on the phone.")  And people write me that they have had surgeons try to frighten them into agreeing to the surgery by telling them that they must choose between TPLO and amputation.  Or in other cases that they must choose between TPLO and euthanasia.
---- All this malpractice is encouraged by the extremely high profit in each TPLO/ TTA.
Dogs' best interests are not served by their people blindly trusting that all vets have as their primary concern the welfare of dogs.  There are vets who are building fortunes on the combination of people's love for their dogs and misplaced trust.

Just look at the facts:
--- Can anyone point to real evidence that bone alteration should be preferred as a ligament injury treatment for some reason except in the rare circumstances described lower on this page? Can anyone show any reason to believe bone alteration is a generally superior treatment option for ligament injury? That is, show real evidence from objective studies, rather than opinion-piece pseudo-research articles from ortho-surgeons who have made millions doing TPLOs and TTAs?
--- Can anyone believe these surgeons are not profiteering? Does anyone think several thousand dollars is a reasonable profit for vets who do these procedure in an hour or less?
--- Can anyone believe that the excessively high profits aren't a factor in ortho-surgeon vets' recommendations?
--- Could referral fees paid by ortho surgeons to general practice vets influence them to send ligament-injured dogs to the TPLO/ TTA surgeons?
You may be thinking:
----"My vet isn't like that.  He wouldn't send Fido to a TPLO surgeon unless he believed it was best." 
---- You may be right that your vet is not someone who would do this kind of thing to dogs for money. Many honest vets mistakenly favor these surgeries.  It is true that improvement in leg use in the first few weeks after TPLO, TTO, or TTA will be better than with non-surgical treatment or conventional surgery.  Longer-term results are not superior with these very invasive procedures, and the risks of serious complications are much greater, but this rapid improvement in the short-term may have influenced your vet's opinion of the procedures.
---- Also, general-practice vets depend on specialists to be the experts in their fields. If the ortho-specialist vets they know are saying "This TPLO is a great procedure!" then many general-practice vets will just accept that as true. To see the problem with the bone alteration surgeries they would need to first recognize that greed could be effecting some ortho-specialists' views of treatment. Then they would need to dig into the professional literature with an eye to weeding out the subjective, self-interest-based articles while looking for evidence-based objective research in order to find the truth. GP vets are very busy with their patients and can't keep up with what's new in dozens of different specialized areas. They depend on ortho-specialists to be knowledgeable and objective in recommending treatment for this kind of injury. So it's easy for claims to be made by specialists and accepted by your regular vet. Your vet could honestly believe that TPLO is preferable for dogs based on what TPLO surgeons have told him.
---- The surgeons who convinced him may have tripled their incomes and become millionaires doing TPLOs.  It is not hard to understand why some ortho-specialists see bone alteration so favorably.
If a plumber working for one hour makes ten times the profit installing sink 'B' as he does installing sink 'A', which sink will he tend to think of most favorably? Which sink is he most likely to recommend? Plumbers and surgeons are equally human and equally likely to see what is best for themselves as being best overall.  When the plumber tells you "Sink 'B' is a great sink!", he may really believe it.  His opinion of sink 'B's attributes has been effected by self-interest.  Even honest surgeons' opinions may be effected by self-interest in the same way.  A TPLO takes about an hour to do and results in several thousand dollars profit for the surgeon.
"TPLO is a great procedure!"  
  Great for who?

What you must do to make the best decisions for your dog is to be skeptical about the expressed opinions of anyone who will profit from your acceptance of their recommendations.  When the profit will be large, your skepticism should also be large. We automatically do this in most situations where someone wants to sell us something.  But we tend to trust medical professionals more than we should.
---- The trust we place in vets and our expectation that medical professionals will not be influenced by profit help create this situation. The surgeons who recommend and do inappropriate high-profit surgeries bear the most responsibility.  But dogs' decision makers are also at fault.  Blindly trusting that a surgeon's treatment recommendation is not effected by the profit he makes on the procedure is not wise.  Dogs need their people to be more skeptical. 

"...Medical history is littered with once-popular procedures that subsequently proved ineffective or dangerous. ..."
---A quote from Consumer Reports 'On Health'

TPA --- Tibial Plateau Angle
"My 3 year old dog has been improving slowly in the weeks since his injury, but when I took him to an ortho-specialist I was told he needs TPLO.  The vet did measurements of the joint and told me the 'Tibial Plateau Angle' was too steep and that meant Fido had to have TPLO on the injured leg.  And he said that Fido should also have a TPLO on the other rear leg because the angle is too steep and Fido is bound to injure that leg the same way.  It sounded reasonable the way he explained it.  Doesn't Fido need TPLO on both legs because of those steep angles?"
---- Probably not.  A dog's Tibial Plateau Angle (TPA) is seldom a reason for surgery.  Although many TPLO/ TTA surgeons claim that the basic design of dogs' stifle(knee)joints is flawed, objective research shows that a steeper Tibial Plateau Angle (TPA) is not necessarily associated with ligament injury in dogs.  Some dogs have TPAs which are considered overly steep. This would be a TPA over 32 degrees.  But if your dog grew up from puppyhood without recurrent stifle problems and then had a stifle(knee) ligament injury as an adult, it is unlikely that steep TPAs in and of themselves are the cause, (although the steep TPAs may be a contributing factor).  When a dog does have TPA over 32 degrees, and recurrent destabilizations of his stifles, this could be an instance where bone alteration would be the appropriate surgical choice.  But it would be a mistake to think that every dog with steep TPAs must need bone alteration surgery to reduce that TPA angle. Many dogs live long active lives with steep TPA angles without ever having a ligament injury. Many dogs have a CCL/ACL ligament injury and their people are told by vets that Fido's steep TPA angle means he must have TPLO or TTA. This is not necessarily true. If Fido has recurrent destabilization injuries of his stifles and steep TPAs, those two factors together indicate that surgery altering his TPA is appropriate. If Fido just has an injury which he recovers from with activity restriction, and he does not have recurrent injuries in spite of proper activity control, he is one of the millions of dogs with steep TPAs who don't need surgical TPA alteration.
---- I need to add a warning here.  There are some TPLO surgeons who, to be blunt, are crooks pushing overpriced unneeded surgeries. They may lie about the TPA measurement or anything else in order to sell you on the TPLO or TTA or TTO.  They will say anything to frighten you into buying the surgery they are selling.  Many vets are honest, but as in all professions, there are some who are not.  A crooked vet won't appear to be crooked.  He will appear to be trustworthy and concerned that your dog receive the best treatment.  I wish I could say "Trust your vet", but that would not be a wise thing for you to do.  You need to be cautious and skeptical in making decisions for your dog.  Don't think it is best for your dog for you to close your eyes and trust a vet.  Don't think the more money you spend the better treatment your dog will get.
---- Dogs with steeper TPAs are not necessarily more likely to have ligament injuries, nor are they necessarily going to need surgical help to recover if they do tear a ligament. If your dog improves with careful restriction after the injury, and slowly continues to improve, then no surgery is needed, regardless of what a surgery salesman told you.  If your dog cannot improve when activity is properly restricted, surgery may be necessary.  
Here is the summary from a Swiss research study on this subject:
VCOT - Veterinary and Comparative Orthopaedics and Traumatology 2004 17 4: 232-0.
Tibial plateau angles with and without cranial cruciate ligament rupture
Division of Clinical Research, Department of Clinical Veterinary Medicine, University of Berne, Switzerland
"...The tibial plateau angles (TPA) of dogs with and without cranial cruciate ligament (CrCL) injuries were evaluated and further compared to the TPAs of dogs from a previous population and of wolves. Similar TPA measurements were found in all groups, suggesting that any possible changes in breeding practices, breed preferences, nutrition or other factors have not significantly influenced the TPA over time. Moreover, a difference was not found in the TPA between any group and the group affected with CrCL injury, suggesting that the TPA is not a clinically relevant predisposing factor in the development of canine CrCL rupture..."

High-Strength Conventional Stabilization Procedures
As was mentioned near the top of this page, new developments in materials have made TPLO & TTA inappropriate for most of the large high-energy dogs for whom these procedures used to be the best choice. 
---- Conventional stabilization surgeries have always been the best surgical choice for most dogs who could not re-stabilize an injured joint non-surgically.  These surgeries are much safer and less invasive than TPLO or TTA, and do not alter the dog's bone's natural relationship to each other as TPLO & TTA do.  But large, highly active dogs have had a higher risk of failure of conventional stabilization surgeries since the orthosuture used to stabilize the joints in these conventional surgical procedures sometimes could not withstand the pressures from big active dogs during the months of post-surgical recovery.  So with large highly energetic dogs, when the ligament injury was severe, and non-surgical recovery was not successful, it was appropriate to have one of the bone-geometry-altering procedures in preference to conventional stabilization surgery.   However,advances in orthosuture and other materials available for conventional stabilization now make it possible for conventional stabilization surgeries to be several times stronger and more resistant to breaking/stretching/abrasion than previously. 
---- Advanced ortho-sutures* are much stronger and more resistant to stretching and abrasion when used in stifle stabilizations than the standard nylon ortho-suture monofilament material.  Other advances in hardware as well as improved methods of securing the suture material also add to the overall increase in the capacity of the stabilization to resist failure.  These new materials make possible a stabilization that is several times stronger than one done with the old conventional surgical materials.
---- In light of these developments, the TPLOs and TTAs which have been considered the best choice for large, high-energy dogs will no longer be appropriate in most circumstances.
-- The Arthrex company markets a surgical kit which uses their 'FiberTape' in a high-strength conventional procedure they developed which they call 'TightRope CCL'
-- The Securos company markets a similar surgical kit which uses their products in a high-strength conventional procedure they call 'XGEN CCR'.
There is more information about advances in high-strength stabilization procedures on the 'Conventional Stabilizing Surgeries' page linked on the column at the upper left of this page. Please understand that the vast majority of dogs with this kind of injury do not need any surgery; and that among those who do require surgery the best surgical choice is a conventional stabilization using nylon monofilament rather than the advanced high-strength materials, and that the high-strength materials have inherent disadvantages and are only appropriate for very large high-energy dogs. This is all covered on other pages here at this website.
*-- Examples of advanced suture include Ethibond [Ethicon, Somerville, NJ], FiberTape and FiberWire [Arthrex, Naples, FL], Orthocord [DePuy-Mitek, Norwood, MA], OrthoFiber [Securos, Fiskdale, MA], Hi-Fi [ConMed Linvatec, Largo, FL], Ultrabraid [Smith & Nephew, Andover, MA], ForceFiber [Stryker Endoscopy, San Jose, CA], MagnumWire [ArthroCare, Sunnyvale, CA], MaxBraid PE [Arthrotek, Warsaw, IN]