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To move on from there by the Gay Park group in France looked at an offset Hindu the patellar track. But what was becoming apparent by this time was that that the forces particularly the corona plane was such that this kind of thing was happening. So her but then designed a hinge with some ability to rotate and allow corona plane angulations movements. And as you might expect that the mechanics of that didn't survive very well because the forces are so high, they failed mechanically um and still no specific instrumentation for any of these. Um So putting them in was a kind of hit and miss a fair a bit, a bit, a bit on from that uh that the idea of surface replacement really was initially driven by Smith Peterson who had tried surface replacement in the hip using gas and various other things. And eventually it hit upon Cobalt chrome as, as a more useful material. So talented, tried researching just the tibia with this device that was screwed onto the front, held in pleasure to screws and fell out almost immediately. And then Platin Peppler looked at resurfacing the distal femur with these kind of mold designs against MS Peterson's talked about this in the thirties. Um Yeah, what happened to him? Ok. Sorry. Yeah, I think Gunston had a look really a more recognizable uh in contemporary terms. Anyway, Uni and I have an idea that the early ones of these um after discussions with Charlie that the polymer side, I think might have been PTFE. Um but you can see from the X ray that there's obviously big poly wear on the medial side and analytic changes in the proximal tibia such that it's actually now uh really doomed. It's have failed already, so it's loose and these didn't do very well. Um And really this is a problem with fixation and with just the mechanics of the joint that, that the materials just weren't really up to uh the standard. In fact, Polio thing at this time and even on into the nineties, the 19 nineties, polyethylene was a real problem. Um It was very crystalline when we went to the manufacturers of polyethylene. There's four big petrochemical companies really that processed the uh the powder, the raw material. And they said, how many 1000 tons a year do you want to buy? Uh Of course, they wouldn't do any research because the volumes weren't uh wouldn't justify the research. So it wasn't really until, until the late 19 nineties that Polly was being cross linked and we knew the effect of gamma sterilisation and oxygen on the long term survivorship of, of polyethylene. Sorry, you can see it. They're very clearly. Um in the U S then did the, the Djia medic link the two components to try and stabilize the fixation uh the one on the left there as you can see. Uh and then um did your Patella in 74 uh these are from, from the Brigham and uh they just linked a couple of unions with that rather strange patella flange in the front that doesn't look particularly Patella friendly, I have to say. Um but again, these were mostly short lived attempts at reconstruction and again, no instruments until this time. So it's only 75 when it started to get the rudimentary eyeball instrumentation. This is the T C one from H S S. Um It was the first true tricompartment from the three sizes uh all Politika which did surprisingly well ran a wet, published a whole series of these at 20 odd years with uh all politicians and, and they did, they did quite well. Um And the Patella button, but you can see the, that was the whole instrumentation right there that you can see. Um so alignment again, was beginning to, to, to make a periods in the discussion. And then in 79 the data instruments were created. This was for T C one and the early Insel Burstein Leagues and you had a manual distraction device which is top left. I'm sorry about the image is so old now that there's no, no original imagery left that I could find anyway. And, and this link, the tibia and femoral cuts together. So these instruments um would, would, would fit together this, um can you see my cursor? No, okay. On the right hand side, the middle instrument, they're locked the, the, the femoral cutting block above to the tibial cut. So that, that guarantee that your reflection space was, was um symmetrical. Uh The size of the space was a secondary issue at a time because you couldn't measure it. Um And then Al Burstein and uh and John Insel came with this. This is our Burstyn's design because of the, the A P and stability of the knee uh after, after the knee replacement because crucial is gone. This was criticized quite, quite powerfully in, in a lot of uh discussion's because that the feeling was that the sheer force across the spine and can mechanism because of tinea to loosen Burstein pointed out that the contact area between the femur and the tilley was very posterior. And so that tended to balance the system of force is such that they didn't all loosen. So this was this was quite successful need. Um If you got the rotations wrong, that spine would be, would be ironed into us into a cylinder or maybe there was a few that got actually broken off, which led eventually to the development of mobile bearing rotating platform. These, but this was again, a seminal um design Michael Freeman then said, well, you know, you really need to balance the gaps. And so this mechanical tensor um then then was introduced into the instrumentation and you could just crank up the pressure on, on the joint and extension. And again, this was flexion gap first. Um and then cut the distal femur to equal the gaps. And it led to some very dramatic distal femur receptions. But again, remember only three sizes of implant at this point. So it was very much and fit the patient to the implant run the other way around. Um and fairly crude instrumentation by modern standards. This is when really things really did change. This is this is David Hungerford, this and crane can crack out. This was the turning point really that that is the real genesis of modern day. I think tricompartmental needs. This was the poorest go down atomic PCA. And there was so many firsts in this from an engineering point of view, it was almost doomed to fail because it was the first poorest coded joints. The first titanium poor scope joint had a metal back patella which had polyethylene on its articular surface of less than two millimeters thick. And of course, it just liquefied under the pressure of the patella. Uh And then the you can see in the upper image with these two short pigs on the tibia that's not enough fixation arteria, particularly if you're looking for in gross. So you're looking for stability in the early stages of, of, of the life of the knee and of course, it was anything but stable. So eventually I had a post attached and they did at least a bit better. But I remember seeing the boxes being opened this knee and you could pour out the poorest coated beads from inside the uh inside the packaging. So these beans might stable, they came off and we're fed into the interface between the fever and uh the polyethylene. So you've got horrendous third body where but the instrumentation, there were six sizes of, of uh handed components. So they were left and right handed and was all the others were just symmetrical components. You could use an either in either knee first, I am instrumentation for the femur. Um And really the first coherent discussion around non mechanical alignment. At this time, there were two religions. It was insult. Freeman, ran a wet and co even even Scott Thornhill up in, in Boston work. We're all um proponents of mechanical alignment and hunger that said, well, you know, the joints are bleak and you should restore that applique witty. And it's interesting that that whole discussion has come around again. So that really set the scene for, for really weird today is actually to be honest, the crucial, retaining, crucial, sacrificing you have rotating platforms um by crucial retaining needs have made a reappearance. Um Gluteus tried that they've been tried a few times in the past. Um, the LCS had a, had a by cruise ship retaining, uh, knee is like a double Oxford but total knee and now the telephone re joints and, and the units units have really taken off again. And over the last 30 years, it seems to be cyclic where there's adoption and usage goes up and then there's disappointment and abandonment and you need goes down. But maybe with navigation and robotic civil, it'll be a more predictable operation. Um So really what I'd like to do now is to look at instrumentation over that period. So on the back of hunger firs work, this is Dick Scott and Tom Thornell. You have the instrumentality, femur extra medaglia, internal tibial alignment. You started to get discussion around, is it anterior down or posterior up? You know, do you make your anterior cut in the right place and sacrifice some post your offset or do you keep posting offset? So this led them to increase in the size range as well. And the discussion around rotation in the corona plane was still set at zero and three degrees. So that was that, that there were the two options um in that instrument set. And in 2006, this happened, uh somebody said that the, the, the incision need to be shorter and minimally invasive hips were getting going at that time and it's sort of leaked into the knee and I'm not sure if, when we made these, that they were an improvement and perhaps their disappearance is a measure of perhaps that they weren't very, very good. But at that time, as navigation was getting going, um, batteries in 2004 had a look at, at the post according to access alignment. And he found that about 68% of the cases you looked at were somewhere between zero and six degrees or of lateral rotation, but there was a substantial fraction that were outside of that. And his conclusion was that perhaps 30% of cases conventional wrote femoral rotation of 0 to 3 degrees lead to an unstable flexion gap in maybe 30% of cases. Um And some of the contemporary work seems to mirror that. So somewhere between 25 30% seems to be out with the expectation of, of, of that. So as a result really of, of navigation is if you look back up, if you look at the next generation of those instruments um from a company that I work for at one time historically, those those genes would allow 0 to 3 degrees of rotation, they now have 035 and seven. And that's really as a result of the data that's come back from, from uh using navigated techniques. Okay. So in 2009, the so called high performance instruments, I love, I love the names that the companies give to these, these instruments you know, they ought to, uh somebody's going to launch a set of instruments one day called the panacea instruments. Um But really, it was an exercise in, in glamorizing the instrumentation. There was no significant or meaningful innovation in terms of the work flow or the ability of the instruments to actually measure the subsidies of the alignments of the joint. And in 2019, uh that continued no change but different materials. So now, um uh and I think this is a sensible move to use polym eric uh materials uh in terms of cost. Um But the only real changes in the two instruments in the center now where they've been combined with anterior and posterior referencing and the right hand instrument is actually a tensor as well. So that that's an effort by it um an engineer to put everything into a single instrument. Um And that might be a good thing to do. I don't know. So my conclusion is in 40 years of instrument development, work flows and alignment assumptions remained largely unchanged and advances have been in changes to instrument function and manufacturing techniques. But the underlying rationale and work flow is is really unchanged. So if you look critically at what the requirements are for from the reconstruction, you have to think about hunger, Ferd's six freedoms of movement in space and then double it because that, that there are two Cartesian reference frames that that you have to deal with, and you really have to look at all of those, those alignments. Um and then cross check those alignments with alignments in the other component of, of the, of the joint. And if you're not gonna order workflow components that you could possibly bring to that analysis, um These are just the different ways that you can construct a workflow both in terms of what you measure and how you measure. And so missing a slide. But that, that system kind of look like a linear process. The point I'm trying to make, I think here is that the way the manual instruments are designed and in fact, we used to number them, this is instrument number one, which leads to instrument number two. Then instrument number three, it looks like a linear process. Um but it isn't, it's much more like a circular process because you have to relate all of these tasks or all of these factors, they all interact. And so you really have to be able to visualize the end of the surgery before you actually start surgery. And that's very difficult with standard instrumentation because they are so prescriptive in the way that they are used. Um And then this happened, this is, this is Bellman's and Chen and we now have nine different alignment expressions these three by three matrix of, of CPAC. Um And the CPAC shows that that whilst probably 65% of both in the green side of healthy knees and, and the red side of, of knees with arthros iss that the clusters are very similar. There's a bit of a swap over of alignments, but they only represent something like 65% of cases that standard instrumentation would have any chance of addressing. And so the question I have is can this reliably and consistently deliver CPAC alignments? If once you identify CPAC alignments, you can't pretend they don't exist anymore. If that's what is being discovered, then the instrumentation has to show an ability to actually measure those and deliver those, those alignments. And I don't think that a box of assumptions like this can, can actually do that and that could be because I like robotics. I don't know. So what about robotics? Well, in the 19 sixties, this is Hollywood's idea of what robotic surgery should look like. And uh so in terms of medicine, what is the robot state currently that we have or robots fall into three categories there either active, where they autonomously perform a procedure, you just press the start button and walk away and you see that in car manufacturing plants and food processing. In various other cases, a passive robot doesn't really do the procedure, but it helps it retracts or, or it it positions and maintains position, it can be dynamic as well. So as positions change, the passive robot can actually respond to that and then semi active is where the system of ments or filters or restricts or scales, surgeons gestures. So the activities are shared with the surgeon much in the way that traction control takes care of your car. And when ice comes, the A BS braking system stops you from slamming into a tree. Um So this is uh there's everything around you is, is really Augmentin our, our, our skill sets and that's really what the ambition of should be, should be to augment what we do not substitute or take over from what we do. It's interesting in the, in the media at the moment, there's the Luddites are out with, the robots are going to take over. We're going to be killed and you know, and Arnie Schwarzenegger's coming back to kill everybody tomorrow. It's hysteria in credible. So in, in, in medicine, 1990 was when the first sort of robot doc really made an appearance in orthopedics and it was used for machining the femoral canal in the hip replacement. But it was very troublesome because if it, in order to, to try and guarantee it Stadium Bone that the engineers set up talk measures to, to measure the amount of talk that, that, that the borough was, was receiving. So you could assign a particular talk curve to bone and that was, wasn't bone. So stop. And of course, if it hit a cyst or a piece of hard bone, they didn't know what it was. So it stopped and it didn't just stop it retracted and switched off. It was a bit troublesome. Um, but now we're in, in the area where we don't, we're not using repurposed robe industrial robots now anymore. Well, not all the companies and um, the equipment is becoming very much more sophisticated, smaller and uh easier to use. Uh which is the direction that we should continue in. Uh I think it's important to keep a surgeon at the table and involved in the case as much as possible. So, the evolution of technology, well, um the kind of drivers for that smaller, faster, smarter, less expensive. Um and uh certainly in my lifetime, science fiction has become science fact, I can't remember who said that you can think that you can probably do it. But this is uh Captain Kirk's information pad that was handed to him and every episode of Star Trek that I watched avidly, um hoping that the aliens would arrive very soon. But that was in 1967 and by 2007, Steve jobs had actually made one, sir. I don't know, I guess. And he had a communicator to uh in 67 in 87 the Motorola launched a flip phone. So technology is, is real and it's moving and it's in everyday life and it's going faster and faster and that technological development threshold decreases uh in the abs Irst. So if you look at telephones now they're, they're actually handle computers. Whereas in my youth, they didn't exist or they were enormous analog, seems like like this and the same with computers. Um, these monsters, 1951 these things weighed, weighed like 13 tons and they could do very few calculations. Now, you can get a computer waste cup of kilos and it's got an internal memory of eight terabytes. So it's just astonishing that, that movement in my lifetime. I was born in 1951 and, uh, in my lifetime, that's, that, that's a dramatic change. This is my first car. That's the dashboard of the mini Cooper s so it's about data. Now, I think my point now is, is everything is about data. We have the ability now to record, manipulate, measure, interrogate data in a way that's, that's never been there before. So it's possible now to, to um to mind data and to process it. This is a modern dashboard. This is what my car looks like. Now, do I need to see all that? No, not really. But there it is. So I don't know, maybe it would take surgery that way. Um And I don't know who's, this is my final slide. I don't know who's entreaty. This is somebody said it's Elon Musk who I believe is an alien. Um But this only didn't end because the world ran out of stone, you know, so it's time and I put this as an entreaty to you as a plea as orthopods. It's time orthopedics. Um moved into the 21st century. I think so. That's it. Thank you for your patience and listening. Um I hope that was at least entertaining, if not informative. Thank you very much, Mr Frank Foley. Also very, very informative, very intriguing. It's very good to learn history and, and see where we are at, isn't it? I think in the morning, I just got one question for you. I don't think there's any questions for from the floor yet. Um We, we've moved on a lot but it seems like we're arguing about by Candler replacements now, but that is already done in the eighties. And we're arguing about kinetic kinematics alignment versus mechanical. And the next thing that we argued about this morning was single versus multi radius versus Gradus. So what's the right answer to the, I don't know, there is the right answer. I mean, with, with three D printing technology going where it is now, it, it's not beyond the bounds of mechanical reason that, that you can't print a specific knee replacement. A friend of mine is working on a polymer femur on a femur made of poly three, the ketone and that can be printed and it can, it can be structured such the bone will grow into, into it. So I don't know if, I don't know if, I don't know if it can, if you can afford to go that route. Really? That's the reality of it. Really. Who's going to pay for it. There are a number of technologies out there that that could make patient specific joints quickly accurately um the internal form of the implant. It's another thing that, that uh is like it is because it's cut with a necropsy sore. If you go down the machining route, you can machine much more subtle shapes and that might, that might deliver actually more than um than anything is to, is to look at segment reconstruction of the joint. I'm thinking particularly in the hip that it seems unreasonable to chew out the whole of the, of the remove the fastest lunata completely and put in a hemispherical implant. The the SSM is not hemisphere ng. So you know, there are areas where because of the instrumentation, the implant reflects the ability of the instruments. So if you change the instruments, you can change the design of the implants. So there might be some mileage in that, I don't know, can I ask anyone ask you a question? So I don't know whether this is more for Mr Foley or Mr Parrot who I saw was just still on the line. But how, how far back do you think we can go if we're saying that you need, sorry, total knee designs haven't really changed since 1981. It's been sort of incremental changes perhaps since then. How far back do you think we can um take seriously like survival data from total knees? So has, is essentially the same implant over the last 30 years. And therefore, we can if they've been. So, if there's a 90% survival rate over 20 years, is that still relevant to today's modern implants? And, or do we feel as though that the changes are significant enough that we'd expect the survival to be better in 20 years from now? That's interesting. I mean, I'm sure Mr Barrett will comment on the clinical side of that from, from mechanical observation site. I mean, the surgical process is so highly variable for a number of reasons. Not least because most thinking surgeons, I've never met one yet who doesn't cheat the instrumentation. Uh Fair enough. I've never made a surgeon know I should have put a comma in there. Yeah, there was a very long pause after I never met a thinking surgeon. Yeah, unfortunate. But no, I mean, you know, people like, you know what, Sauna and Scott had their own instruments, they didn't use the instruments that the company sold to the to the rump of the orthopedic uh community. So you have to wonder whose publishing the data. And I think I think the registries will go some way to actually looking at a proper data because I think historically, the proper data was put around by the mayo clinic and special surgery in these places. And I don't think that was representative of the ability of the instruments to actually deliver what they said they could do that because the guys cheated. So uh I think they didn't cheat the outcomes that, but they cheated the instruments because they ended up on the statement. Yeah. So I think, I think that the one thing that, that, that robotics and navigation will do is to bring consistency and repeatability to what is quite a variable activity at the moment. And from that, it might be, might be able to derive the way forward, you know, what, what progress actually looks like. But until you get conformity, it's difficult to draw any conclusions. Thank you very much. I don't think there's any other questions. Thank you. Thank you for your time. It's a pleasure. Thank you for the invitation. Um Yeah, I'll see you next time in, be away or something.