in this session we're very grateful to mic for embracing this opportunity to compare contrast and cross examine the evidence and the narrative of T PLO and t ta in a way that enhances and clarifies our understanding of the reality we're also very grateful to all the attendees who responded to our survey on this debate with very thoughtful questions and comments and so we'll attempt to raise as many of those as possible and thank you also to Otto for moderating this session so with that so this is a no holds barred match the gloves are coming off so the the format is going to be we hold the audience and we have list of questions and I'm just going to start off asking some questions after Mike and Andy kind of give a five-minute spiel on why they prefer TTA or T PLO and then open it up to the audience for you guys to participate in to ask questions so I thought I'd start off with just Mike talking why he prefers a T PLO and his rationale behind the choice okay well thanks thanks Otto I really appreciate the opportunity to be here and Slobodan and everybody from Keon for inviting me so why do I choose T PLO first for me is versatility there's really no condition imaginable that you cannot treat whether it's a deformity or just the confirmation of a particular patient we have solutions for every single situation the second is reliability the planning is very easy and not only that but once you've performed your plan the execution and the result mimic your plan so it's very reliable the precision and accuracy are very high you essentially always get what you intended to which for me is very important because it's hard to hit a moving target and I want to make sure if I'm striving for a plateau angle of five and I get nine there's a problem but if I get five or a four and a half or five and a half I'm happy now based on what Slobodan was saying maybe there's a better way to plan maybe and if so if we can come up with it and change how we do the planning I'm confident we can hit that target as well it's it's a relatively straightforward if we look at outcome if we look at function for instance Ursula crow checks papers quite good and it showed that in dogs with T PLO not only did they achieve normal function sooner but they achieve normal function of both the walk and the trot and I think that's very compelling and if we consider that that was a forceplate outcome paper it's pretty good and the outcome measures are well defined and objective now slow go also mentioned meniscal tear rate as an indicator of stability and if we go back and look at a couple papers on that wolf reported about a 28% meniscal tear it with TTA and if you dig into one of Noel's papers on a thousand consecutive tea pillows in the patients with no meniscal tear and no meniscal release the tear rate was 4% and so 28% is obviously much higher than 4% complications there's a very low complication rate using today's new generation of locking implants in a paper we recently published our complication rate major complication rate was zero and that was in a handful about 80 cases it's not a huge number but the complication rate is low I think you also have to consider should you encounter a problem and need to remove implants taking off a cheap yellow plate is generally pretty easy taking out a TTA cage can be a challenge and leaves a giant hole that you need to contend with so that's another consideration for me and then the last thing is why not TGA and for me it was really the unpredictable outcome and the difficulty in planning so for instance if you have a stifle flexion angle that's not exactly correct on your x-ray your planning will change because the patellar tendon angle changes with Steiff and flexion angle if you have subluxation of the tibia in your x-ray your teller tendon angle changes and so trying to get the perfect x-ray in order to get the best possible planning is a challenge no matter what you do to the tibia if you're measuring from points on the tibia you can't change them so the planning is pretty straightforward because the bone is sitting there you measure it and there's your result so I don't know if I took up five minutes but dandy so yeah thank you for this opportunity fortunately Mike's just be on my arm reach here so I suppose the history my history of intervention for cruciate deficiency begins with the over-the-top technique which has its flaws we all know and then the lateral suture technique evolved I didn't like that I think historically I've taken more than a foot in it always seemed to give rise to a significant reaction from the joint and then we moved on to closing wedge osteotomy which i've hated with a passion controlling what you were doing and there was difficult and every morning you came in to see if the dog's foot was pointing in the right direction and you were happy if it was but it just seemed wrong so I saw a Pierre Mont upon present the very early work with TTA and I thought when that's mature when that's the technique I'm definitely going to look at that so we began using TTA and we were bowled over by the results and this met the needs of our patients where we have a significant population of very young dogs presenting with simultaneous bilateral cruciate deficiency which prior to the evolution of and thank you to Barclay Slocum for giving us some new way of managing this geometry modification we could help these dogs a very very difficult situation so the advantage of being able to apply surgery in these kind of young dogs at the beginning of the life and was significant but the TTA dogs were remarkable in the rapidity of recovery and so on and a Slobodan mentioned we then began to see that we were having this meniscal injury rate a significant rate of meniscal injury so the question was do we release or not and we decided not to and we just became better at planning I don't really accept that having a technique defined by how much effort you have to put into the plan makes one technique superior to the other I think that with experience the planning for TTA is very simple it reflects the joint that we're operating on rather than a bone that we're operating on and ignores the joint and it is repeatable you can check after surgery whether you met the criteria of your planning so by improving our cage size we are now during a late meniscal injury rate of 3% I have never in two and a half thousand cases taken a plate or a cage out I've never had two we have zero percent infection rate which historically with t PLO was a huge problem 30 or 35 percent infection rate the stainless steel plates and so on so we have never had a positive culture or a septic tt8 and we've had septic arthritis is following cruciate disease but we've never had to remove a set of implants from a single TTA and so the difficulty of doing it is negated by the fact that you shouldn't have to so the planning I think is reliable I think execution if you take your time is is repeatable I think again many people with TTA are trying to do this surgery very very quickly it's a piece of surgery that you should take your time and get it right as with all surgeries and I think that for me one of the main factors in from this kind of validation in our clinic of excellent outcome in our patients with low complication rate incredibly little complication rate means that you know you look at the the work that's out there now and you say well what the heck is going on why is the crotch check paper being touted as being some validation the TPA law is superior to TTA when actually what it shows is that they can't do TTA and most of these papers which are basically there are two possible two possibilities here either a procedure is inherently and intrinsically flawed in which case everyone who does it will find that there are problems with it or the surgeon is available within the context of that and so these papers that that suggests high complication rates should simply say in our clinic we cannot do tt8 and that's the only conclusion you can draw because you can't have it both ways you know so they are being incredibly honest it's unusual for surgeons to put their hand up and say they can't do something but they are which is lovely but the kind of analogy with the the crotch cheque paper I think is that if you are studying a drug a nonsteroidal anti-inflammatory and you say this drug doesn't work but you never mention your doors rate then there's no validity in that paper at all almost all of the Krawczyk patients were under dosed so if you were to use remedial at 1 milligram per kilo and say that it doesn't work then someone say that's because it should be 2 MiG's per kilo so if you use the technique appropriately that will give you a stable Stifel and preserve the meniscus and gives an excellent outcome so is that enough blood shed and that progress gloves came off earlier than expected but just to give Mike equal opportunity to address the Krawczyk paper in the comments made by nd yes so I think it's it's always easy to criticize people's work and in designing surgical procedures and implants I think it's important that we are careful not to make a procedure so difficult or demanding that the average person can't do it and so I can't imagine that the surgeons at Cornell don't know how to cut a tibia and put a cage and plate in that doesn't make sense they all took the course and they said right in their paper they used the common tangent method to plan the procedures and executed them as described in the course so either the course doesn't explain how to do it right or they didn't pay any attention and did it wrong or their paper is in fact correct and the outcome was better simple as that I mean if you know frankly if if it's so hard to do it right then maybe the procedure is no good because it's too hard or did we simply not tell them how to do it right which I find hard to believe because you know the how you do it is very well laid out in the literature so I don't think it's a question of they did the procedure wrong I think if we are gonna claim that then we ought to look at their x-rays and say exactly what did they do wrong I don't think you're gonna find anything but I don't think it's fair to say that's the case if we haven't actually looked at the x-rays I think is validated by the meniscal injury rate that they had and they have a breed range in there and a weight range of dog and their cage selection range is way too small for that weight range yeah but the planning was based on the common tangent planning not the breeding and weight and I guess that brings us to an important point you know in the literature the common tangent method of slobodan described it is the method for planning now if there's a different or superior method based on breed or weight or some other factor then we should publish that and explain it to the rest of the world because you know if the outcome can be better based on a new method of planning then we should tell everybody else what that is but as far as I know the standard method the common tangent method achieving a stifle or patellar tendon angle of ninety or slightly less than ninety so if you know is that what you're doing well I think you have your reference range so for example with the bringing down the late meniscal injury rate it was clear that if we had around about two times plate size for cage size as a minimum so five plates you get ten point five as a minimum and then that reduces the variable of subluxation of the tibia malposition of the tibia and so on I know where I'm starting from and so undersized and becomes less of an issue getting it in the right range is then correct so in some patients I will take data graphs of the uninjured contralateral limb because I'm not happy with the measurements I'm getting in the injured limb because of subluxation and positioning so and because I know what I'm expecting as a minimum and I think that that's the kind of thing that does come from experience and I think the planning is one of those things where it does have a learning curve for sure I agree they probably know how to plan but perhaps and it would be it would be valid to say that these patients were under advanced based on cage size to weight size and based on the relate meniscal injury rate within the context of that study yeah I agree that the the stifles were unstable and that explains the outcome but the question is did they do the technique as described and taught in the course and I would say yes so we can't blame them for doing it wrong if they did what they were told to do that doesn't make sense then the other thing I would say is that basing cage size on plate size which is basically tibial size is nonsensical because as Slobodan has shown the tibial plateau angle the patellar tendon angle the shape and size of the condyle it's the force that we're neutralizing the force is not related to the size of the tibia but it's related to the factors within the joint which are as he showed very elegantly in his presentation individual based on the shape of the condyles of both the tibia and the femur you're gonna find that common tangent angle and just because two patients weigh the same or have the same size tibia they may or may not have the same common tangent angle which means that if they don't have the same angle they are not they should not have the same cage because their tibial jim form the tibial geometry differs so we need to individually plan beyond just the body weight that does make sense all right totally give you that I'm not saying that we don't plan we planned that we have a floor below which it would be unlikely to go so I'm not saying don't plan and just based on body weight that's the kind of MMP technique but you do plan you do get the odd one which is a inaud outcome where it's a 5 with a 15 but I wouldn't have a 5 of the 6 and if I did do that the meniscus was intact I would know it would tear later how do you think in all these studies a couple things that are important is one and maybe Andy Mike do you agree on this as experience of the surgeon is going to be important I think everyone can relate to your first you know 5 T PLoS versus the last 5 T PLoS you did in the first 5 TTA's you did in the last 5 TTA's you did so experience definitely weighs in to that and in some of these papers it would always be nice to have pre-op and post-operative radiographs available so that anyone could interpret them and look at them and you know judge them and sometimes that is difficult given how publishes works so forth and so on one question that was brought up several times had to do and I'll ask Mike and Andy kind of individually how they handle these but it's dogs with excessive TPAs so tibial plateau angles roughly you know greater than 30 degrees how do you handle that Mike and then I'll ask Andy how they handle them another question was brought up as can you even do a TTA on dog with an excessive TPA people I've heard that no you cannot do that and so Andy maybe you can address that as well good so for the excessive TPA I think it's important to understand the individual variation so what we need to determine is how far can we safely rotate the plateau and if we have to rotate it further than what we consider safe then we would add a closing wedge and early on Slocum described the 34 degrees what the 24 blade was the limit but that's really not the case because individual tibial anatomy varies and so we've described as a way to calculate how far we can rotate how many degrees that achieves and whether or not we need to go further and if we need to go further then we combine it with a cranial closing wedge and that technique is extremely reliable and we've got a couple papers on it out there those papers are as otto said those are our first experiences in the complication rate mostly with loosening of K wires and cerclage wires was high in the 25 percent range we had to remove some pins but with modern locking plates and a better understanding of the sequence to do that in other words do the closing wedge put the wires and K wires first in the plate second it's extremely rare that we have to take metal out and if you think about for instance tibial tuberosity transposition with pins and K wires I have to take those pins and wires out 15 percent of the time something like that and with a cheap yellow with closing wedge we're probably around the same 10 or 15 percent of the time so it's just related to having pins and wires in the cranial part of the tibia which is a painful spot so for me again it's really reliable if we if we have a 55 degree slope and we want five we can get there very safely and the outcome is quite good I suppose there's two aspects to the question about GPA there is no in the textbook er suggestion that anything over 26 degrees needs a TPA law and the t/ta wouldn't work and I'll address that and then the other is obviously these excessive slope dogs so in terms of the first this idea that there's a prohibitive GPA beyond which TTA doesn't work there is no mechanical rationale for that and it kind of strikes me that it's a bit like someone who gives up smoking but says that they can have a cigarette Christmas and then they can have a cigar Easter and then on their birthday and then sometimes at weekends it's an excuse for people to do what they like doing and so I think the CPI law people who came from GPL or two TTA were wanting an excuse to get back to doing cheap yellow which they were good at and they had spent a lot of time in gaining that experience but at the extremes of slopes we have done TTA's and 45-degree slope dogs with excellent outcomes you have to make a bigger advancement but with certainly the carrion implants you're not gonna run into problems with you know plates breaking or forks breaking or anything like that move again had no complications in these West Highlands with 45-degree slopes six seven and a half millimeter cages we've done twenty five-plus of those dogs and so we don't measure the slope we plan for TTA and I do I don't see any basis for changing that we don't see some degradation about come in these dogs depending on their slope it's a little bit fiddly er it needs a little bit more precision in surgery but beyond that there's no issue with performing TTA in in these cases maybe 55 yeah agree perhaps at 55 you'd want to do some clothes and wedge and do something there in order to mitigate the effects of that slope but up till your standard 45 degree west see I wouldn't have any question at all about doing TTA whether it is my own dog or someone else's dog okay the next question that was commonly asked is this is probably more of a yes or no and maybe a rationale behind it is doing a municipal release and TPL OS and doing a municipal release in TTA to mitigate post-operative complications with meniscal damage sure so we don't do meniscal release I think that it's some is meniscal murder it is not allowing them to go free and range somewhere as a meniscus it is literally reducing all of your cruciate deficient patients to meniscal e deficient patients so from our point of view we would never ever offer that routinely I think that it's it the invention of meniscal release comes along with the what we know happens and within the femorotibial contact mechanics following TPA law I think if TTA had been invented first we would have simply done what we have done and improved the technique to the point where the meniscus is preserved and so from our point of view we don't do meniscal release I think meniscal release is a bad technique and should not be applied perhaps in a fifteen-year-old diabetic or something like that where you don't want to go back to theater the odd case where it's so fibrotic and chronic that you don't feel you can do an inspection and whatever perhaps under those circumstances you could make a clinical judgment argument for that but to do wholesale in every patient with cruciate deficiency I think is bad practice well I don't commit meniscal murder either common ground for other for all the same reasons and I think if you if you look at the literature and what we know what Noll reported was that four percent of the time a normal meniscus tore and so that's a poor outcome for those four out of 100 but if you think about the other 96 if you had released the meniscus in a hundred percent of cases then 96 patients would have harm because you've destroyed their miniscule function and so for me the math doesn't work out why harm 96 to help 4 and with arthroscopy it's pretty easy to remove a torn meniscus and most owners if you explain that you know your dog does not have a anymore it's never gonna have one again it could tear its meniscus and if it does we'll just scope and take that piece out the four people that come back annually to have that donor for every 100 that you do are very understanding and they say well you know you told me it might happen it did so for me that that's the most sensible way to handle it this was a I think a good question that was posed dealing with angular limb correction if they're reported been to skull damaged or latent damage is the same for both TTA and TPL oh do we really need to do anything with angular deformity more with torsion yes so I think it it's a it's really interesting to look at hidden if you will hidden deformity so the best correlation I can make would be for instance the young Labrador that has some profound femoral varus but it doesn't have a luxating patella until its cruciate ligament tears and then there's some internal tibial rotation the patella starts luxating so now that sort of silent deformity is clinically relevant and the same thing for tibial torsion tibial varus tibial valve is once we've lost one of the main stabilizers in the joint the best way to achieve the best possible stability is make the limb as straight as possible so some of these silent deformities that become expressed when the cruciate is torn have to be treated and so for that reason when we're performing TLO we're gonna check for tibial torsion tibial varus or valgus just like we would check for femoral deformity in a patient with a patellar luxation and we know very well that if we ignore the femoral deformity were likely to have a recurrence of luxation and so just like in those cases if we want the best outcome we need the straight as possible limb and so screening for those abnormalities and treating them at the same time gives us that best possible outcome yeah we the only thing we do there is use a spacer under the cranial ear we don't address those I don't otherwise the PX means straight children and you know comes from this idea of having the perfectly straight leg I don't think there's necessarily a morbidity but again there are extremes of those we're certainly with your techniques you're improving um can I ask a question actually of option like um you know based on the fact that we know that we have medial compartment Overlord from Kim and pottsy's work if I don't know whenever that's discussed it's often rejected now but given that that's what we know and given that we know that people when the scope some late T PLO is they see loss of cartilage in the medial compartment my thinking there is that actually T PLO is a contra toxic technique and if we you know we're doing a technique which is hazardous to cartilage in dogs are ten twelve months of age you know is is that a good technique you know we wouldn't use condo toxic drugs in young dogs why do we use a technique that damages cartilage in that way and so it's a good point and I think the best way to understand that is to think about the forces that slow-burn was talking about you know with the T PLO we're converting that shear force into compression so the joint load goes up but if the meniscus is there hopefully the meniscus can handle it but on the other hand if we're talking about TT a potentially allowing more tibial subluxation that's Condor toxic to because instead of squeezing the cartilage now you're sharing the cartilage and so on you know I think if we can show that TTA achieves stability in 95 or 99% of the cases I would agree with you but based on the data that's out there 60 percent or 66% of TTA's still subluxated whereas only 30 percent of TPA ellos so there's a significant number that are shearing their cartilage off which is just as bad for it as getting compressed so the ideal technique would eliminate shir but not generate compression and it's not to say that I think tea pillow is the perfect procedure but based on the best available evidence it's the best of the two that we're talking about and it's clearly written in the literature and I would say if there's a better way to do the TTA with a better outcome then we should do that study and prove it and then we won't have to argue but sheer plus compression is what you're probably gonna get in most UTP although not most 30% well will haste on the data right that the Kym paper said 30 percent of TP low subluxated but 66% of TTA's did so I guess the other outcome measure would be long term you take a hundred of those one-year-old dogs and assess their function ten years later that studies not been done the the crunch at paper was only out to a year so that's another good question what's the long-term outcome and is there a difference there but unfortunately we have zero data on a long-term outcome of either but those dogs with cartilage loss that has been shown would you say that that's a bad TPL or that's creating that situation or do you think its intrinsic within the concept of cheap ELO itself I think its intrinsic in the concept of cruciate disease and I think if we looked at the TTA cases with a meniscal tear and then Misco removal you're gonna find the same cartilage lesion because without a meniscus you're gonna have femorotibial cartilage erosion just like you would with increased compression so I think unfortunately you know the ideal joint still has a cruciate in it so any technique we're gonna do to a joint that doesn't have a cruciate and has a progression of Oh a the joints not gonna be the same ten years later there's no question about that the question is between the two is there a benefit to one over the other but long term we don't have that data but we have a suggestion that we probably would be better with the perfectly executed TT a if you provide stability and have a normal contact map after surgery then that is what TTA should offer it's true except that we've yet to see a single publication that says this is how you perfectly execute a TTA and we're gonna have less subluxation than TPL out what we know now is more than twice of the TTA is more than two times of them have more subluxation than TPL oh so until we can get over that first hurdle and say do it this way to prevent subluxation then repeat a study like Ursula's to show that the outcome at the walk and trot is the same or better than TPL oh it's a moot point because we're talking about is a lesion we see and yet function is better so function Trump's the lesion as far as I'm concerned I don't think you can't say functions better I think you can't you can't say that based on that paper because again we've no validated that these were advancing the tibial tuberosity is not a TGA stabilizing the Stifel by means of tibial tuberosity advancement is a TTA and many of these TTA's aren't hitting the goal they're not hitting the target and that comes back to my original point which is that if it's so difficult to do it right if surgeons such as yourself can do it perfectly that's great for you but what about the rest of the world right if they took the course and they did this procedure as described and now you're claiming their outcome was pork as I did it wrong why is it so hard it shouldn't be so hard so if there's a if there's a better way to plan and execute and achieve better function then it should be a simple study to do but what we know now is that at a walk only after a year the TTA becomes symmetric with the non affected limb but at the walk and trot T PLO was similar at six months which is earlier and it was at the walk and trot versus with TT it was only at the walk and at the trot it was no better than a lateral suture that's the data we have based on doing the technique as described in the course see I don't think that we can keep using that thing as described in the course I've not gone and reinvented TTA I'm doing TTA as is described in planning and by standard technique with attention to detail both in planning and execution phase and I think that that's all it takes it's not difficult it's simply that it you have to get it right but are you saying that maybe there's more margin for error and TPL oh no I'm just saying that if if we plan and execute as as we were told to in the course then why are we claiming they did it wrong they did it as they were told to in the course and this is their data if there's another more precise way to do it then we should do a study and show that if in other words if you do your study with your technique and you find that at a walk they're the same but at a trot they're not then what are we gonna say right yeah we're gonna say ersal was right but until we have that study to either show she was right or show she was wrong it's purely conjecture because there's no you don't use a force play you don't know if your patients are symmetric at a trot you simply don't know it until you measure it but I think the one difficulty that is with the paper and I think is with most TTA and T PLO papers are the experience or the person doing it and again having the data of all the preoperative and post-operative radiographs to evaluate them to make sure they were advanced enough whether TTA is harder to do than a T PLO but just to have that data I think would help as well I you know I think we can go back and forth on that paper it is published but it would be nice to have some of that information and I don't know if we're at a standstill at this point if you guys want to say anything more but I got a question here paper or you okay yeah hi my lead into the question is a little bit complicated I'm sorry but stepping back historically looking at these two procedures they were taught to the surgeons in two different ways originally Berkeley had his finger on who would teach either he taught or his people that he taught himself would teach and so the dissemination of knowledge and the procedure was completely different than that of the TTA the TTA was when I was looking into learning it there was an offer by a company that they'd have a surgeon come in and and teach me the procedure on three patients and it it was not controlled from peer or or from slobo it was more or less loosely taught not not structured and so my question is on those papers that you're referring to did you or did someone look at who taught these surgeons that did the study yeah it's a good point in and I completely agree training courses vary in quality tremendously they vary in curricula what's taught the opinion of the person teaching it but in that particular paper it states that the surgeons were all trained at the key on course yeah all but one of the faculty the everybody else was trained at the key on course sure there are four actually five studies that we're discussing here and I happen to know a little more detail about each one of those and I'd like to offer that from Boise Shawn Murphy was the one who presented t ta versus T peel-off I asked him at the time of presentation this was San Antonio because they did not show a single x-ray off either one or the other there was no x-ray presented I asked him where did he learn or the other two of the surgeons that participated t ta and this was his response he said he talked on the telephone with a surgeon a woman who was an instructor in key on courses and she told him how to do it so I know nothing particularly here but we had only one person a woman from Florida who was instructor at t ta courses at that time in she probably has never done a TTA herself she talked about suturing meniscus damage it's a very academic study isn't it so she told her friend in Boise how to do it and then he told the other two guys how to do it and they went out and did 25 TTA's I offered to Sean that time to send some x-rays to Keyon and we will put a group of maybe four or five surgeons and look at the x-rays and possibly suggest what was done wrong if it's visible on the x-rays he never did this I repeated the offer a year later in Europe he did not respond this is Boise study now Cornell it just happened as we move around and travel I happened to be at Cornell at the time when one of the residents had a question about t/ta she had an x-ray I forgot on a film or computer it was not properly done it was obviously not done right and I offered to ercel I said how about if because we were going to be there two days why don't you get a group of your residents and students let look at x-rays of TTA's planning anything that did not happen their study was finished with eight patients out to one year with a very marginal difference in the performance of TT vs. TLO it's hard to say whether that small difference makes any difference it is much smaller right it's ETA it's collected on the force plate so on so I have major doubts because again there was never an x-ray presented by aurélie in any of those papers the only thing is that they took a key on course and after taking a key on course who can go home and mess up the first ten or five 450 cases like everyone that's not a proof that it was not right now the florida is particularly interesting because they've done 30 TTA's and 30 t pillows and all of the TTA s had meniscal damage at the time of surgery why do they put them into the TT a group Antonio says because of the pre prior studies they show that TTA is better than T PLO so they're gonna give these dogs a better chance of doing okay longer term if they do TTA even though meniscus is damaged at the time surgery tibia laws were acute Thresh injuries a huge bias in the study no doubt that they've seen these chronic subluxation and I think they come because the dogs by the time they cause meniscal damage have been subluxated for many months usually six months three months whatever so that stifle is not where it needs to be that femur is sitting down quarterly right and that's what I say you need to do something else if you're gonna do TTA on a case like that to pull the femur forward with DPL are you over corrected and then you can bring it forward as I mentioned now do we need to overcorrect eta you can't because once the patella leaves the patellar groove it's not working anymore so I think that explains the difference in Florida said it's all written up it's in the paper but no one discusses the fact there was a strong bias in that study and so we were motivated to look at this basic question are there any teeth EA is out there that are not subluxation because this looked pretty bad right so me as Donnie called to just call randomly 12 here's TTA's and look at them in the same way that they down in Florida 12 dogs with intact meniscus healthy dogs versus 12 dogs that he did TTA s where meniscus was intact at the time of surgery and it was good one or two years out so dog didn't come back there was no subluxation in those dogs so at least we know that it's possible to do TTA so it doesn't stop flexing no x-ray from Antonio's group we can't judge on this I asked him can you send me x-rays we'll look at them that didn't come so now we're through Boise Cornell Florida and outcomes Leipzig I'm gonna leave Jimmy cook out yes but why really and again it's just the circumstances the two surgeons that any TTA is there took the course in Denver in 2000 one of them in 2004 the other one never took it and in 2004 we didn't know how to do TTA planning it was just you know it's either six or nine this was the discussion so at this university there was no one ever to learn how to do TTA so I really leave Jimmy Cook's study totally out and I think Conde presented that good so what we're left with is Leipzig we're on D and I went and made a big mistake coming in to the clinic which never did TTA and we're going to demonstrate how to do TTA so here's what they did they did 15 dogs with TTA on t did first two as a demo and then two others we're done next day and after quite a bit of time months and months maybe a couple of years later I finally got some x-rays from theta to look at those 15 cases there were no extended legs there they could not plan and so the best we could guess is that out of 15 11 we're not corrected under correct one was hugely over corrected a total mess and the other three were within the range now here's another very important bias in this 75% of those TTA's were not stable by you know fancy technique 75% of them had no meniscus at the time of surgery that's what Peter says so when you ask him which ones were without meniscus and which ones were unstable he cannot answer if this was 1500 patients I would say you can't keep your records for 1500 but how about 15 there was no record of which dog was a chronic case with no meniscus and thus unstable just as in Florida by all you know accounts and my only kind of positive thinking there is that it didn't make us think about possibly other problems like repair of the tendons which I think we underestimated hugely and that was prompted by light seek study so one two three four five crucial studies that claim that TTA wasn't right I wish there was a rule set up someplace somewhere that you cannot publish corrective osteotomy on bones without an x-ray somewhere in the cloud I mean how about convince your jury organize this No can anyone organize Kyoko's people are not showing their results yeah no I think those are other points but I'd go back to the point I made earlier which is that it's easy to criticize other people's work if we want to show that a well done TGA is the same or better than a TPL oh then we need to simply do that study right we've shown these studies have bias they have maybe incorrectly done procedures poor planning so on and so forth so let's do it right and show that it's better until that happens we're just stuck criticizing them with a no proof that it is the same better or worse we simply don't know so we need that information so we are going to do that study we're gonna replicate the Krawczyk having with our TTS but not with GPL oh you can do damage to another 15 I'm sorry [Laughter] it'd just be a cycle you wouldn't get achill approval for that don't think how about we use mirror here because I have seen many TTA's that are done poorly and I've seen just as many tea pillows that have done poorly so I think that there's a problem with sometimes people executing things that they have been taught how to do but one of the points that I would like to make having taught the TTA classes is that this has been a moving target in terms of planning and execution I can tell you that if you look at our first paper that was published back from Colorado as so but it's already pointed out we were under advancing those TTA's in terms of trying to get measurements I've taught a number of those classes and when we have people do the exercise to do the planning in the course guess what we got all put things all over the place we've gone from the original way of doing it to the common tangent nobody understood the common tangent I see that Slobodan in his presentation here today we're using a different circle now on the femur than we were doing when we were trying to teach the course so things have been moving that's why people can't do the technique properly and there's certainly evidence in the literature that TTA's have been under advanced for a long time Pradas paper was mentioned if you look at that paper in AHA you can see that those dogs were probably under advanced and your point about x-rays no x-rays in that paper at all they didn't even look at the x-rays postoperatively how many of you when you do tea pillows measured postoperatively most of you how many of you when you do TTA's measure postoperatively that's a bigger number than I was expecting because in the initially nobody did we just assumed that after we did the procedure we got the right advancement I can tell you that unless you do planning with some kind of interactive software or cut your x-rays whichever way you want to do it and you find out how far you need to advance it you're not going to do it right because there's high slope there's high insertion point there's low insertion point there's wider tibial tuberosity it's all over the place if you want to listen to a good lecture on some of the pitfalls here listen to Bob body and some of the problems associated with what you measure and what you actually perform are completely different unless you do some kind of virtual planning so we're all over the place with it and I you know I'm not as saying that some of these things don't happen with tea pillows as well but execution of any of these procedures is not particularly easy and I and I'm guilty as hell as anybody else because I stood up there and said TTA is easier to do than TP alone I don't think so anymore I think they're both difficult procedures to do and you need to do them correctly so I go back to what I already said which is we need to look in the mirror the other point I would like to bring up is on excessive slope you can do TTA's with excessive slope I agree with that but what you're not addressing is the flexion angle of the knee joint which i think is a mistake and then lastly I think any cruciate tear is going to lead to general arthritic changes in the joint and loss of cartilage and that's been proven in people for God's sakes anybody who has a cruciate tear whether they have an intact meniscus or not if they have an intact meniscus they'll eventually lose that meniscus and guess what they'll wind up with bone on bone and later in life granted it's a lot more years later they're gonna wind up with a total knee so we're not there yet and any cruise ship repair that we do is going to end up with with some some issues so I know you guys are arguing about well the tip below has more or less where the TTA has more or less cartilage damage they're all gonna have cartilage damage come on let's be real here and let's at least do the best job that we can with the particular technique and if we're having a problem with identifying how to do a particular procedure we need to correct it if you look at the literature and I'm biased here because I do more tea pillows or I don't do tea TAS anymore but if you look at the literature what you will see with tea pillows if people have identified how to do it more correctly hi hi cuts preserve the tibial tuberosity whereas with the TTA we've talked about all these changes in some of the courses and we've morphed along with it but where is that where is the article that describes how to do a TTA right now in the approach in the appropriate fashion maybe you should do that nd yeah I mean I think one of the aspects that hasn't been mentioned is obliquity of osteotomy so this is where you're planning I think becomes you know you can do a good plan but if you make an oblique osteotomy in surgery and don't pay attention to the plane that you're making that osteotomy in then you're not going to get the advancement you were planning for and you're going to create a whole other set of mechanics in there and I think that that's one thing that I think if you were to look at anyone's first hundred or their first thousand if they don't care about their oblique they're not correctly done and that's one thing which is difficult to control for I totally agree with you I don't think is a simple technique I think it is a technique that demands a lot of attention as I'm sure TPL orders but you you need to be aiming for the best and I think I presented before one of the problems here is that the surgeon gets away with everything with TTA you don't get broken tibias you don't get about some people do you don't get massive morbidities that would actually reflect badly in the surgeon you just create a whole set of unstable stifles because you didn't pay attention in theater to doing the job correctly and so I think that that's a loaders to do this drift towards complacency and not aiming for you know perfection with with the TTA and so I think that mediocrity is the norm for for many surgeries but for TTA and perhaps even for TPL oh you know how many people really are you know aiming for the best GP although they can do and how many are just rotating it a bit as far as they think they can and the bone heals and quite happy with that you know I think that it's as surgeons we are the fundamental variable and yet planning for TTA is is tricky you have to go out there with experience but it's not difficult to achieve and then execution is is key you know people who tell me they can do a TTA in half an hour or 40 minutes are doing it badly you need to take your time you need to get it right any other questions yes patellar tendon angles measured that were subluxation on the TTA cases they never publish that data you know they just don't and I think as Randy was saying really although it was great to see so many hands going up here but I think very few people do order their surgery afterwards with TTA whereas in CPL or i think is the norm to do that with TTA it's a cage in there the plates there and the bone will heal um so I don't think people are looking at that but that's the fundamental measure right and so I took the TTA course in 2010 and again a lot of information comes at you at once my memory of the training was you need a nine millimeter advancement he put in a nine millimeter cage in there and then shortly after that your who did it kind of advise us to make sure you're measuring you know the bottom of the cage and then very quickly started realizing you know I'd probably done 20 or 30 that while I under advanced all those yeah how many of those cases in that study were under advanced yep Provo probably yeah yeah x-ray I think it's really hard to these people Sean Murphy's cases I think the surgery was monitored or supervised by a diplomate I think this is totally irrelevant whether the surgeon is diplomate or whether he was supervised by the appointment for the outcome of these procedures I wish that publishing is done a little more seriously hungry later our frequency of surgery I think is another aspect that say in the cooked paper so study the first one was published it took about four attempts to get that paper published desura Steinberg published it he was an intern with Ray prata first 200 cases the next 300 cases showed the fantastic improvement in ray pratas hands with TTA this was gone the problem with under correction and so on not because he did very careful planning he just wouldn't put a nine-millimeter cage into a lot of though he was putting ten and a half now now the next 300 cases you cannot publish it's just impossible to get it published who's going to publish this not any of those journalists that you know people supposedly read so there is a there is a problem of getting this out and if you don't get a paper then it's not believable I mean I can talk forever here but you don't have to believe me I'm gonna play the devil's advocate here okay I do some consulting for VIN and there's at least one person who's written on there pretty vociferously that he's referring his patients for TPL owes to local surgeons in Central Ohio so the whole Columbus area so the University as well some of the private practices there his claim which i can't validate his feeling is as the general practitioner and he's seeing these dogs you know in the long term you know five seven years down the road and he feels that most of those are having terrible results that's his claim and so it's a question for all of us of course is how well do we as the surgeons get feedback on these patient's health far out are we following them I've written back to him and saying that I'm not seeing that I see a lot of these nation's back years later after both ttat pielo they're coming back for their second side they're come back with their second dog they're very happy with the results but this is one veterinarian out there eating there's a another cluster of veterinarians in his area to feel the same way that the long-term results with any of these techniques he's particularly picking on TPO are poor and obviously we know there's a lot of osteoarthritis assortment else and I've tried to get him to put up these pictures and so let's see what the x-rays look like etc but the comments here is anybody else's feelings here about long-term results in truly on led to five seven year range one thing if if there would be done such a study I think we ought oh you turn it on this in this morning it it's a major to think about all the muscles and the muscle repair which you cut it and you know which you don't cut and the thing is in those studies are not comparable if someone strips for example the blade and the other one cuts the unserious and as when when you suture is the hamstring muscles will act at the first moment and they are pulling about six hundred eight hundred Newton I have to look up in the Martin Martin spoke but then the Tenon's are even you repair it with a good suture they are elongated then you get more biceps remorse you don't you don't cut then you get an external rotation and also Papeete your muscle they some people cut them some people don't cut them the same story they are elongated and so they they will have an external rotation and there should be also in those study the closure of the wound is very very important and for me all those studies are not compare as they're doing different things they are totally doing different things no one is thinking about this huge forces of those muscles so long term outcome I think is an unknown isn't it you know I think there's no it but it is an important factor would they come back we've told them their dog may develop osteoarthritis so it does with the come back and complain probably not it's a study that would be worthy of doing how do you measure osteoarthritis obviously the degree of ossify ptosis is one way to measure it but it's a pure measure as we've discussed integrity of articular cartilage and unfunctional osteoarthritis or dysfunctional osteoarthritis is more important than some of the objective measures of an austere arthritic joint so we'd be tricky to do I mean you would have to look at range of motion comfort discomfort cartilage integrity and so on I think it would be hard to do and get any true valid data that was useful yeah those studies are incredibly incredibly difficult to do and quite expensive to do and just I mean even a short-term study to the point where the bone is healed is hard to do to do one out to a year is extremely difficult and then a ten or twelve year study is massively and difficult so that's one of the limitations it's also quite expensive but you know we don't have data we simply don't know is the long-term outcome of one superior to the other are they all the same after four years we simply have zero information about that so I must say something because I started TPL 20 years ago and then when TTA came out I was a fashion attic to start using it and I was teaching who is Randy you know in some courses at ek but after doing about 350 cases I realized that it was not so as deeply a little in outcome even a few cases were wrong and I tried to do as best as possible was in planning execution and so on but it was not always working and in few cases I had to devise a we said teepee alone and they did perfectly and the later on when I slowed down doing TTA and until I stopped at doing completely and doing all the TPA law I've been called by the several cases some colleagues at to revise the TA and doing T PLO and I solved the problem of those dogs I never had the opportunity to change a tip yellow NTTA for instance by changing TPA in the PLO it work it so in in my hand after more than three thousand kilos probably four thousand nowadays I feel I think that this is the most reliable technique and low also looking at the procedure has been described as locum more than twenty years ago is still the same while TTA is being changed theta 1 theta 2 TT a rapid that the G opposed many many different papers out of major to plan because his smart trick is not difficult to do planning to do execution while steep yellow is more standardized that is by clinical validation I think again you know TTA has evolved you're absolutely correct it has changed GPR law has changed because CB although you've got all these other innovations within the context of it and TTA has evolved but I think that it is now a pain wielding member of society rather than the stone-throwing one that was probably around when you were doing TTA although you know I think that it is a mature technique is when executed well delivers exactly what it should those cases where you've revised from at TTA and improved them at EPA log were clearly unstable if they were unstable or under advance if they're under advance the surgeon didn't do a good job so yeah that's great you know maybe that's where T PLO should come in is is only to be used for you know revising for surgeons TTA's yeah that's it's indication I think we found the reason to do T PLO excellent I think it all that brings up a good point and it may be that all the not all but many of the the bugs and the TPL were worked out by Berkeley and his group before it was launched into the public whereas with TTA the bugs were worked out in the public realm and so I think that may be a difference I'm not sure John D would know how long T PLO was being done by Berkeley and his friends before they started offering courses I would guess it was at least 10 years which is about the history where we are with TTA right now Berkeley did a large number of cases before he mentored anybody so that may have been a big factor and so that that learning curve was an internal learning curve before it was launched out into the group yeah I mean there's been so modification so even after Slocum released everything there's been some for sure and I think one you know the preoperative planning that was mentioned about doing it on either Horace you know to do the virtual planning before I think is helpful as well because it is to advancing it what you measure and what cage you use sometimes is different and using Horace and other preoperative planning for both T PLO and TTA is very beneficial as a comment I'm a general practitioner and I've come here for several courses and several of the symposiums and the only comment I have to make is if it wasn't the speakers mentioned that a procedure should be published and so that anybody can do it my feeling is there are a lot of people out there that are not capable of doing certain procedures I know what I'm not capable of doing and if you're not producing good results then maybe you shouldn't be doing those cases period we all have our limitations we're all not perfect at everything and if we can't do a good job whether it's t PL o-- or TTA we should be letting the people do it who can do a good job just one to support slow-dance theory as we did we did the long term results of T PLO I think there was two thousand six or seven as a study a thesis and we found out that less austere thrivers on in the stocks were when when we had a plateauing in between nine and eleven degree it was not five or six we had the rock back in nearly one and but those dogs after five years which had this lower angle showed less or stealth riders and perhaps lower than is right it doesn't matter whether it's six degrees 11 degrees or zero the number is wrong it should not be used for any comparison because it's reference to a wrong line so we can't discuss whether five or eleven is better we should just not use this we should measure the right thing and then discuss this and we should measure the right thing and then do the procedure and then see what happens this way I think Mike you mentioned this in Barcelona that it would be really nice if we could plan TPA law for the patient for that one we can do this it's it's straightforward right rather than making the wrong reference the wrong line the wrong angle it's all off now it's consistent but it's consistently wrong and I can't believe that Slocum would have come up with release of meniscal of meniscus if he didn't see a good number of cases coming back he must have seen 20 30 percent and that's when he came up with meniscal release if he saw one or two percent he wouldn't cut meniscus so in his time his first drawings he is way down distal with his center of rotation and that is under correcting by whatever you know you get less so that's why he was turning tonight and he's still had problem so TPA law has evolved I think Slocum was not accepted for a long long time it took years before people in schools started talking about Slocum as a person he was not part of the academia right we all know this so he had time to practice and make mistakes on his own Pierre and I took three years before we came out with TTA so it wasn't three months it was three years and the uptake in 2004 was fantastic the first year out everyone was happy with TTA and the second year everyone was happy we had really no planning at that time he was either six or nine that was the discussion and then I like nine and then I like ten and a half but I think both techniques are actually fairly forgiving that's the point that's why they survived 20 30 years and million dogs are running around but I think we can improve I think we can improve both TPO and we can improve TTA but these people that publish these studies it's their responsibility I keep asking them you messed it up you fix it do another study properly rather than just saying well here it is it's in the vet surgery or whatever it is there is responsibility on publishing bad stuff as well I think that's a really good point that the individual planning in other words is 5° necessary for every dark we simply don't know my concern with what you showed though was that in the Kim and Potsie study 30% subluxated but with your calculation for the 20 dogs you did only 10% were under-rotated with the T PLO planning as it exists which still leaves 20% how do we explain those so I think I'm I completely agree there's probably a better way to plan and on an individual basis so that the dogs that only need eight degrees get aid and the ones that need three degrees get three or however you want to make the measurement but just like with any of these techniques we need to come up with the idea and then validate that in fact it's working at least as good or better than what we're doing now and that's that's the work for the future it kind of directly stems off of what you're just saying about doing some of the measurements and could it be more individualized and just kind of to throw another concept in there is how a lot of orthopedic radiographs and human medicine are done in standing positions and how there's been a lot of at least unpublished commentary because of the kora based leveling osteotomy coming about that should we actually be looking at the standing light angle of the stifle and be utilizing that for our determinations for Corrections it's just an interesting time especially with the level of recurve autumn in certain species and how they hold their particular stifles different from a shepherd to a Yorkie to a Great Dane right yeah it's a really good point the standing angle is important but standing is different than limb strike and so really we would want to know what's the geometry of the limb when the paw strikes the ground so we prevent that initial subluxation and how you would determine that from either a standing or a recumbent radiograph that's another challenge that we face because we do a lot of our planning at a Stifel angle of 135 or 145 whichever number you like but the dog doesn't have his foot hit the ground at that angle and then what about if it's laying down and it stands up and it stifles really flexed so there's a lot of variability and a lot of unknowns okay so thank you very much to the panel and to everyone who contribute in this session