Listen to Prof Ben Oliverre, Prof Fares Haddad and Prof Ed Davies in the second episode of our special podcast series, kindly sponsored by Stryker. This episode focuses predominantly on the role of robotic-arm assisted surgery in total hip replacement
Visit BJ360 here
Listen to Prof Ben Oliverre, Prof Fares Haddad and Prof Ed Davies in the second episode of our special podcast series, kindly sponsored by Stryker. This episode focuses predominantly on the role of robotic-arm assisted surgery in total hip replacement
Visit BJ360 here
[00:00:00] Welcome everybody to the BJ360 podcast. We're lucky tonight to be sponsored by Stryker. And we're talking a little bit about frontiers and hip replacement, and we're specifically going to be focusing a little bit on robotics. So thank you very much Stryker for the support. And I'm really fortunate to have two real leading experts in the hip field with me today.
My name's Ben Ollivere. I'm the editor of 360 and I'm joined tonight by Professor Fares Haddad who clearly needs no introduction. He's the editor of BJJ . He is a key opinion leader within the hip world, both nationally and internationally. And it'd be really interesting to hear what he has to say this evening.
And I'm also joined by Professor Ed Davies, who has an interest in precision hip surgery , works at The Royal Orthopaedic in Birmingham and is honorary professor at the University of Birmingham. So thank you very much, gentlemen, for joining me tonight.
Obviously we are talking a little bit about frontiers and hip replacements, I guess. And we're talking specifically about robotic-guided hips, but there's [00:01:00] potentially more to it than that. I mean, you know, obviously I'm a trauma surgeon and I do a little bit of hip replacement, but it's mostly haemiarthroplasty. I don't venture beyond that really. And I'm just interested, you know, the literature which I'm interested in and read a lot of suggests that hip replacement is basically a solved problem. You know, the majority of patients, they get their cemented taper slip stem of whatever variety you like with a polyethylene cup and a ceramic head. And then you can expect that to last for the rest of their lives. So why are we even having the conversation Ed?
Yeah, I think that's a really good point. I mean, it's the coin, the operation of the century, isn't it? And it's an incredibly successful operation and the survivorship rates are incredibly good. I suppose my challenge back to you is do you want something just to be good or do you want it to be excellent or do you want to strive for perfection? And that depends on your perspective doesn't it?
If you're a surgeon and you do hip replacements, you're gonna get a lot of patients who are very grateful and thankful for what you've done. If you're a patient, you want a [00:02:00] guarantee that it's going to be brilliant. You don't want to be okay. And you certainly don't want it to be about outlier. So for me it's striving for perfection of putting yourself in that patient's position that you want to be the one that gets the good operation. You don't want to be a bad outlier.
And I think what's particularly interesting for people like me that may do hip and knee replacements. We've talked about knee replacements not being very good for a long time and that unfavorable outcome after knee replacement, but we don't really hear that much of it in hip replacement. When you go to meetings or you see people's talks, you get people, I don't know, climbing mountains, doing all sorts of sporting activities, but if you drill down into the functional outcome, that's not really what's happening in the real world. I mean, there will be some good literature on it, about unfavorable outcomes in knee replacement. What we commonly quote, people are going to be dissatisfied about, or maybe up to one in five. If you look at hip replacements, we're still talking around maybe 10% . 10% of people being [00:03:00] dissatisfied or having continuing pain. So I agree. I think we do well with hip replacements. Should we stop and just say, yes that's okay. Or should we strive for perfection? I think there is a gap there that we need to fill.
Ben, it's not even about perfection. It's the reality is that we've allowed ourselves to be seduced by the fact that patients start with terrible pain from osteoarthritis and if we resolve some of that pain, that's regarded as a great outcome. And we've deluded ourselves with survivorship of the implant as the outcome. But actually our patients are going to be less accepting of 10 or 15 to still have pain. So if, actually, if you look at placements and that AC and proportion still have some pain. It used to be dismissed, as you know, that's just bad luck. You've got pain. It's now increasingly investigated because we've learned cross-sectional imaging with metal-on-metal. But ultimately there are lots of patients with pain because they may have altered [00:04:00] biomechanics. They may have impingement. They may have all the other things going on in their arthroplasty. But those are still patients that agree with their surgeon, that have their hip arthritis pain removed and still counts as a great success. For example, in the registry cause they may not come for another operation. So those where errors happen and we see complications through instability, through fracture, through length inequality , through secondary symptoms elsewhere because of the errors that took place, even in that population that are generally deemed to do well with a forgiving operation.
Actually, there are lots that don't do that well. And you know, the question is do we have the resource? Do we have the time? Do we have the energy to push, to improve those patients to make them better? And you know, that may be the question is whether that should be our focus right now. But if you're a hip surgeon and you want to be the best hip surgeon you can be for your population of patients, then that's the direction [00:05:00] of travel. It's the way all other industries have gone. It's towards getting real aids to planning, real aids to execute. You know at the moment we need to understand where we're going and to be able to nail it and get there. And we're very close to that in the hip. Now we weren't before. We were using surrogates.
And do you think we're missing a trick? I mean, this is what I'm sort of alluding to really, you know, we are looking at one thing and a huge amount of money has been expended in can we make it better bearing surface? I'm not even going to mention, you know, ceramic on metal, remember that a few years ago? You know, can we eke out for those few patients that are young and need those extra few years, a little bit longer at great risk relative to tried and tested technologies, be you a ceramic-on-ceramic person, a ceramic-on-poly person or, you know, metal-on-poly person.
Are we asking the right questions? You know, we look at the registry, we rely on functional outcomes in the registry, which is basically, you know, Oxford hip score that [00:06:00] a number of patients returned, but not everybody. We know there's sampling errors. Are the outcome measures correct? Can they pick up these patients who aren't quite right? Or is it just annecdote?
So I think I will just pick you up on that one then Ben. So if you talk about metrics, so at the pre and six months PROMS that all our hips get sent. So if you look at that, we're not doing as amazing job as you would think. So if we look at the pre-op PROMS, if you look at the Oxford hip score and you ask how many patients have moderate or usually getting moderate to severe pain in their hip pre-op that's over 90% patients. Of course, that's why they are having a hip replacement. If you look at that group six months, post hip replacement, when their recovery is starting to definitely plateau, you've got about 15 to 16% of patients are still getting moderate to severe pain in their hip that they've had replaced. [00:07:00] And that's in England, you know, within the last couple of years from NHS digital. So 15% of patients are still getting moderate to severe pain in their hip post hip replacement. That isn't the utopia of hip replacement that we kind of all think about is it ?
No. And the funny thing is that that may well be below the MCID because the MCID for the Oxford Hip score is surprisingly wide. So therefore it gets reported as a success in a trial or in a cohort series, which I guess is what I'm driving at is it defined? Depends what you define your outcome has as to whether it's entirely successful.
So, you know, given that and given what you've both said which it makes a lot of sense about those patients who are outliers. The question I'd ask next is, you know, is it the case that every patient runs a risk of having a poor outcome or are there patients that you can select? What is the, you know, what is the driver of those poor outcomes? Is it poor implant position? Is it, you know, pre-existing things? I mean, [00:08:00] Fares mentioned leg-length discrepancy. I remember being taught by Keith Tucker as a registrar, and he had a massive thing about leg length discrepancy. And do you know what he was right. You know, the number of patients that you see in clinic where their leg lengths weren't quite right. Even being really careful about it because they've got tight abductors or they've got, you know, whatever it is, there's lots of causes for it. What is it that drives those patients who aren't quite right? Fares?
So I think take it a step back. I think registrar comes very useful, it's something valuable to us, but actually, you know, in your clinic, in your patient population, you will recognize that there are some problems and, you know, there are multiple factors why patients run into problems. Sometimes there are patient-related issues. There are patient selection issues. Sometimes it's the wrong implant. And sometimes it's the wrong bearing. And sometimes it is put in wrong. So I think we make the mistake quite often of trying to funnel down on one solution that solves all the problems. And it isn't one. It's a cascade of things that will determine whether that patient has a great outcome or [00:09:00] not.
So, you know, once you realize that that risk is there. Once you also then realize that there are many people doing joint replacements every day and they can have a good day, they can have a bad day. They can have the right kit or the wrong kit. They can have a scrub nurse who's experienced in hip replacement, a scrub nurse who isn't experienced in hip replacement. That adds a whole load of variables. And any technology that comes in that means that you have a number of checks along the way, checks in your planning and checks in your execution and checks in what you deliver at the end of the operation is bound to reduce that variability even for a good surgeon. So let's not even go to the people who aren't as well trained as they could be, or as diligent as they might be. Even for a good surgeon, if you give a good surgeon enhanced technology and they learn how to use it, that will help narrow you know, their outliers.
Yeah. But dare I say it, getting it right first time, that sort of Yeah. Minimising the outliers.
So what does, I mean, we are [00:10:00] kind of talking around the Mako arent we, but what does the mako, I mean you use the maker in your practice I'm guessing Fares. Do you use it for every hip? Do you use it for some? What's your general approach to it?
Yeah, and we should let Ed address this too. So no, we don't use it for every hip. I think one of the big things about Mako is that it delivers enhanced planning and delivery for the hip and the knee. And so a lot of our focus has been on the knee. So when you've got you know, we've got one robotic arm in one hospital, we've now got three at UCLH, which is fantastic. One purely for research and two for clinical delivery. In principle, we focused a lot on the knee where the gains are huge, but in the hip, so we use it in study patients, we use it in patients who have altered anatomy, where we think it might be an advantage and we're increasingly using it when we've got the capacity to use it, because it seems to deliver the biomechanics that we want and take away some of the headaches of worrying about leg length and equality.
And in your hands before we come to Ed, cause I'm sure he'll have a slightly [00:11:00] different practice in your hands. You know, timing's one of the things that worries people, you know, will I lose a joint off the list? Does it make much difference to you personally as you're going through? Do you plan a less full list if it's got robotic cases on it?
Yeah. So it's an interesting thing. Cause there's no question there's a time learning curve to this. We've published on this and collected a lot of data. So it adds a few minutes early on when you first start. You've got to get used to putting some pins in the pelvis to mount the array, and you've got to get your MPS, who's the person in theatre with you working the computer, working the robotic arm, used to your workflow and adjust it. So it probably does add 15 minutes when you first start, there or there abouts. Does that lose you a case? It probably doesn't lose you a case. And we don't do a whole day of robotic-assisted hips. We'll tend to do two or three on the list and some that aren't. Or we'll do some knees as well. So there is definitely a learning curve time-wise but that plateaus and evens up pretty quickly, but I dont know what Eds experience is.
[00:12:00] Okay. Well, if I had the chance, I'd use the robot on every single patient for sure.
Outcome driven or is that preference? As in do you prefer using the robot or do you think your patients do better?
I think it's both. So for me, it's what Fares touched on there a minute ago. It's consistency, isnt it?
So in a way human beings it doesn't matter how good you are, sometimes you'll do a better job than others. Over the last 15 years I've been using hip navigation for doing hip replacements. What that's taught me, is that despite doing a few hundred hip replacements every year, I am pretty rubbish at doing hip replacement because I get it wrong. And the amount of times hopefully is I'll just look at an assistant and say, look at that. I would've got that completely wrong had I not used the navigation and got feedback. But what it also teaches you, is giving you that instant feedback to show you that sometimes you do get it wrong and try and work out and rationalize why you get it wrong, which goes back to your question to begin with about picking those patients that might be more vulnerable and [00:13:00] might be the outliers. Which, yes. We know some patients that might be tricky, but sometimes just a routine hip replacement and you end up getting it completely wrong. So for me, I'd use it every time. That's partly because maybe I'm a little bit of a nervous surgeon and I can't stand imperfection ...
So you're a hip surgeon then Ed? That's the description of a hip surgeon.
Yeah, but I've been a patient in the past. Yeah. I want perfect surgery. You know, when I had my neck done, I didn't want to be the surgeons outlier. If he could have used technology to take my discount, do my fusion. You know, then that's what I wanted. I wouldn't want to be the patient on an off day.
However, I do understand that we are doing CTS. We are affecting process. It is a very expensive technology. We haven't got the evidence at the moment about the economics of doing that. We also, I think we're probably going to work out some patients when we acquire more data, we will be able to predict the patients that might be the outliers and are [00:14:00] more at risk, which is what we touched on. Because one of the benefits of this technology is you do acquire a huge amount of information on the system. And you have pre-op CT imaging on it. So I think in the future, we'll be able to predict much better those patients that are at risk.
And teasing out from the various things that you've talked about. So, you know, it's interesting. So, so I think it's fair to say that quite a lot of orthopedic surgeons are slightly suspicious of robotics at the moment. And I'm married to a general surgeon. And they went through this process 10 years ago and pretty much every hospital in the country, if you're having colorectal surgery, GI surgery has a robot available for lots of reasons. There's lots of reasons that they do that. And we're kind of on the beginning of this journey and it's difficult to tease out the benefits. So you talked partly about navigation, I guess, so that that's potentially part of it is making sure you get it in the right place at the right time, partly about, you know outliers, not wanting to be the one that does poorly. And, you know, I've had surgery from one of my colleagues and [00:15:00] similarly was, you know, really worried about being the patient that gets the infection or... cause we've all seen that. And we've all, you know, we've all had that experience ourselves and everybody wants your patients to do the best possible.
And then the third thing, which I guess I'm not quite clear on yet in my own mind is does it let you do things that you otherwise can't do or is it just that you do each case better because one of the things in general surgery that's happened in the evolution of their own experiences is they started doing more and more robotics. They're able to do more and more complex operations because the robot is actually much more dexterous than a person. Theres no two ways about it. You know, it's a, it is a more controlled person.
I think there is a difference Ben between the robots. Whereas you say getting into the pelvis with the DaVinci is, you know, is game changing in terms of what you can do. At the moment, and I think you've got to imagine we are on a journey, we are slightly later on the journey, but at the moment we're essentially doing what we do manually just doing it more [00:16:00] reproducibly. You know, in the hip with less reaming, less bony debrief, potentially less inflammatory response from that. And all the other consequences of that. And being able to assess the position that you're putting the hip in the potential impingement, the length, the offset, all those variables that you spend your time worrying about.
So at the moment, I don't think it changes the nature of the operation or what you can do, but that's the potential. If you really, you know, you take this to the nth degree, whether you're talking about the hip or the knee, it's essentially evaluating a patient. Evaluating a patient four dimensionally, a 3d scan, plus their gate, plus, you know, how they move looking at that and then determining what that patient needs and then being able to deliver it. And we will very soon, I suspect, start seeing implants that are purely on a robotic platform in the next 10 years.
That was what I was alluding to was actually, you know, the big constraint with implant design is the fact a person's got to put it in, isnt it?
Yeah, absolutely. You know, manual instruments. And I know we're talking about the hip today, but you know, in the [00:17:00] knee, in a randomized pilot study, we've seen a differential reduction in the inflammatory response when we've used the robotic arm Mako compared to manual techniques.
Thinking about those difficult acetabular where you can now get 3d printed things. But actually the, you know, the cuts required in order to put something in precisely accurately are just beyond the person arent they? Beyond perhaps a double bubble. And that's about all you can, unless things have moved on dramatically since I was last involved in revision hip surgery, I can't believe any of these are more dextrous than they were 10 years ago. Yeah. Your thoughts Ed?
Yeah, I agree. And I think where this is going to get particularly exciting when we take it onto the revision type work for exactly what you talk about, which is burring, making complex geometries for acetabular reconstruction. I think that is interesting. What I think, just going back to the primaries, I totally agree with Fares, I think the robot just makes us better at doing the job that we were doing before. I think one interesting thing, which [00:18:00] is what I've experienced, which is the comparison of navigation to robots is the benefit of the robot controlling the reamer, particularly when you've got a deformed acetabulum, and you might have more sclerotic bone on one side than the other. And when you're trying to hold a reamer and control it you do get deviation where the reamer can be deviated off path, and you end up with an abnormal centre of rotation, but as one of the benefits of the robot is they can control the position of that reamer. So you get it right in the perfect position so it doesn't deviate so much. So I think that is one of the benefits that we will start to see, which is the whole reconstruction of centre of rotation. But yeah, I think when you want to get really excited about complex geometries, then the robot is going to come in the revision situation, which you can't use it for at the moment but I'm sure that will come.
Ben in a very practical level, all trainees, all young [00:19:00] surgeons will recognize the difficulty of getting access in an overweight patient. Our population is getting bigger, it's getting heavier. It's, you know, getting the socket right in someone where you can barely get access, can't get the angle you like, suddenly you've got a device that will put it where you want it put. And you know, people won't admit that that's difficult, but frankly it is difficult to do. And this just removes that doubt from your mind.
Does it reduce the variation in operative time associated with obesity? You know, we've gone backwards and forwards, there's lots and lots of data to show that if you are obese, you suffer more complications, whatever that is, whether it's infection, whether it's... and then some of it is to do with actually the surgery just being longer, you know, and just having bigger wounds. Do you think there's a benefit there or do you think it is that you have the same problems in terms of access and the patient's still longer on the table, but you just get a better result at the end.
So it's a good question. We haven't got data to answer that, so I don't have data to answer that, but [00:20:00] you still need to get access. You still need to be able to see, you still need to be able to get the arm in. So I don't think it would be the paradigm shift there that it would be to go from open to laparoscopic with a cavitary robot. But, nevertheless, that security that you know, that you're going to get the position, right. Even though you are really struggling to get that angle is reassuring. And it's also on that, from that perspective, just to open up something else for you, you may wish to come back to is it's an unbelievably good teaching and training tool.
You've stole one of my questions. I was trying to butt in and say, can we talk about teaching and training? Cause you mentioned trainees and now you've stolen my question Fares. So again, I look like I'm following on your coattails. So there's, well, there's a couple of things I wanted to ask actually, which I guess to Ed first. So, you talked about, you know, you do your robotic surgery and you've got this volume of data that you're collecting. One of the things that was a big shift for me when I started as a consultant, which I was disastrously [00:21:00] upset to find it is nearly 10 years ago now. So I'm no longer kind of the young person in the department, which is, I guess, one of those things that we all face as we get older is that I was able to see my patients go through and some of them go through four or five years. I've got some patients now have been with me nearly a decade and you see your own results. And there's nothing, you don't get that as a trainee.
And with one of the things that I have also found is you can't quite remember what you did. You know, the ones that do well and the ones that don't do well, sometimes you can't tease out what the differences are. Is there any benefit? Do you ever find yourself going back through the system and saying actually, you know, did I do this? Is that why this patient has this result?
There's no question having the session files and having the data there is an advantage when you've got questions to ask later on, you know, if a patient's still got pain and you can't quite work out, you go back and check what you did and that's it.
I mean, there's so much more to this data that we're going to be able to use moving forward from planning to ultimately to automation. You know, you can just imagine that the sort of amount of decision-making [00:22:00] that we enjoy doing now. That ed enjoys, that I enjoy because that's part of the fun of doing things where you get lots of data. Will eventually all this data will be used, correlated with outcomes and using, you know, using AI and machine learning, we'll be able to predict who needs what. I think that that would be, that'd be really cool.
But, yes, absolutely right. On a practical level right now. And you know, we got our Mako in 2016. So we've had it for five years so far from our first Mako, when, whether it's hip or knee, if something's not quite right, we go back to the session files and try and get some feedback, try and learn.
What do you find? So when your patient comes back, right, they've got a hip that isn't quite right. And, you know, cause I've never, you know, I've seen the robot at a trade show, but I've never used one. So patient comes back, you know, they've got a painful hip or a hip that doesn't quite let them do what they want to do. They feel partly unstable. What data is available to you and Fares? What do you look at? How does it help you with your decision making?
I mean, I think you can [00:23:00] quickly go back and see, did you plan and get the centre of rotation right? Did you get the length right? Did you get the offset, right? You know, did you miss-size the implants? Cause you've basically got a haptic. You've got a plan. You can refer to that.
I mean, a practical example. So at UCLH, we've now got one of the hub centres. So we've just expanded into a new building. We've got some new surgeons coming in. They've been trained and then, you know, one of the surgeons is very worried about his post-op x-ray and in reality you know, he'd done a good job, but he'd planned to go a little bit deeper than the original plan. And therefore had suddenly noticed that he was deeper on the post-op x-ray cause what you plan is what you deliver. And it was very useful to be able to go back and say, look, dysplastic hip, in order to get it covered anteriorly, what you probably needed to do was antivert a bit more rather than medialize. And those are the things you can go back and you can educate people and people, you know, it's a great lesson learned with good data.
Ed, what do you, what's your approach?
I agree. If [00:24:00] you go back, you can see everything from your plan, as Fares said all those sort of things. You can also look at your cup orientation. So there's two other things there. I think that the robot compared to navigation, the beautiful thing about navigation is it's much more, you're doing it on the fly, whereas there's less pre-op planning. It happens during the case, and you're getting feedback. So from learning your mistakes, the navigation was much better because you actually, you put the wrong trials in, and then you take the measurements and you can see that they are the wrong trials and you can change them. The difference with a robot of course is you don't make mistakes because you plan it and then you execute the plan. So you don't experience things when they feel wrong because you've planned it right from the beginning.
And the other point here, which is really, really key, is the robot comes with the Mako product specialist. So when I walk in the room, the Mako product specialist has already [00:25:00] done a plan of what they think I want to do. So they've worked with me before they know what I like, and they have already done that. And it's already sitting on the system for me to then come in and make my final changes.
And that comes with the robot doesn't it? Everybody who has a robot, they get it? Is that uninitiated? Is that something you pay on a case by case basis or is there a sort of rental fee that includes the person, or how does that work?
They just come with it.
It's akin to your rep that that used to wandering to when you used to do your hip replacements. So that's the service that's provide. The other interesting thing is you can't turn the robot on without the Mako product specialist who holds the key. So that was what that was...
so it was a big leap for me from navigation, where I used to wheel a machine in and wipe it all down and get the dust off it and then just play around with it. And if it didn't work, then I was on my hands and knees fiddling with it. The [00:26:00] Mako product specialist is the person that sorts the robot out.
But, I think for me, it's about having that individual that you're talking to who understands what you like. So when you do have a complicated case, they're asking you, well, why have you changed that? Which then makes you think, well, have I changed it right? It stimulates the process of deep thinking as to have I got it right? Or do we need to change this? And then if I'm struggling, they'll go, well, what happens if you change your anteversion or do you think that the patient's got a different tilt there? What do you think we should do here? So it is like having another expert in the room that you can have a good discussion with.
I think in one of the trials that we've got running, it does come in. We have deep discussions about what is it? Does the Mako product specialist actually bring a huge advantage to the outcome of your patient, because it is like having the most experienced rep while you're doing your case, talking to you about it. So that's an [00:27:00] interesting observation that I've got is the benefit of having somebody in the room that you can talk to that challenges you, I suppose, on your plan. I'm not sure do they ever challenge you Fares or is it just me who they tell me no I have got it wrong.
No, no. We've had some, you know, we've been very lucky and we've had some great Mako product specialist, including an engineer when we first started using it, who actually, we got involved in designing some of the research questions and in what we measured and that was really incredibly valuable that feedback. I think one of the elements that's kind of coming out and which is important to stress is that this is enhanced planning as well as enhanced execution. You know, you measure twice, cut once. It's really a great challenge to people's minds to be able to truly define what they are wanting to achieve in a hip or knee operation. You know, we're kind of used to having a fairly broad target and you're narrowing of the target down to what it is, commit to exactly what you want to do [00:28:00] for this case. You don't have that.
Does it help you with the next case that you do? That isn't a robotic case. So there's a kind of Hawthorne effect here isn't there? Which is, you know, I don't subscribe to this, you know, I don't subscribe to this Fares, but there is a kind of, there is a kind of conveyor belt mentality amongst, you know, particularly managers and in fact, sadly, some of our own colleagues in terms of the way that they want to put patients through as quickly as possible in order to treat as many people as possible. And sometimes that kind of conveyor belt approach, you know, does result in people not thinking. And if you're forced to think, cause you can't do it without thinking, presumably actually some of that thought process comes across into the patients as well, particularly for trainees and people who are rotating in and out, you know and they come in and they see a couple of robot cases. And then a couple of non-robot cases. Would you let trainees do a robot case? You've got at UCLH. Is that something that they.
No, no, we do. They do. In fact, it's an ideal thing because in some respects, I know exactly what they are doing.
Cant mess it up.
It's, [00:29:00] even for my fellows, it's difficult for them to get it wrong. No no, I think there's a huge value to, you know, at a very basic, very simple level, recognizing what, let's say 40, 20 years and again and again and again, when it's actually reproduced and you know, it's right. And then when you go to do the next case then you know, it's right, again and you can adjust to that when you're doing your manual case. I think in terms of, you know, navigation taught us that you actually go back if you've navigated and get that feedback as a surgeon or as a trainer to a trainee. You come back. And so you've got that added advantage in, and that, you know, Ben, at the moment, we have a huge backlog in this country. So I think, you know, we're duty bound to do a high volume of surgery and high volume surgery makes you better. So I think this is a great wa of enhancing the patient journey. You're getting it right. And I think when you get it right, patients feel better, they move better. You know, our data is, the knees in particular feel much better than my manual knees. And I, you know, I've been in this game for a long time. [00:30:00] I thought my manual knees were pretty decent, but actually we've, you know, Ed's doing the National races study to look at that in really in more detail in the hip and the knee, but certainly in my practice, the signal's being quite significant.
So talk, just talking about function. Cause there is one thing there's something I do want to talk about. Cause it's in all of the papers. It is in every addition to the journal, pretty much you edit Fares. It is in every edition of 360 and that's the kind of, you know, the approach thing with anterior approaches to the hip. So, you know, we're talking really about improving function and there is some increasing evidence that actually muscle preserving approaches may give better function for certain patients at the cost of complications. You know, there's no doubt in the data that's out there that in fact, it is much more difficult to do an anterior hip than any other type of hip. And it does appear as an observer who avidly reads the literature that in fact people don't quite get that. And the problem happens when you end up with the occasional anterior hip [00:31:00] approacher.
How... where do you see these two things kind of colliding, I guess? I mean, you know, is there an advantage to using a robot in terms of complications and implant placement with an anterior hip? Do the two go hand in hand or is it a different approach to the same problem.
So maybe I'll start and let Ed give his perspective. So, I think that there've been a lot of minimal incision, minimally invasive type of approaches in the hip, but I think the anterior approach is likely to be here to stay. It's gained enough momentum and there is some good data out there. There are possibly some short-term advantages over the first few weeks. I doubt there are significant long-term advantages. It's probably still important to remind everybody that getting the, you know, the good fixation and durable fixation is probably the most important thing.
Having said that it's something that's still with us. It's something that we need to train people on early. Cause the problems with the anterior approach happen for the occasional user or the late adopter who tends to struggle. Now, if you take the anterior approach. You [00:32:00] know, access is difficult, you know, I've done it and I've got colleagues doing it, and I've got really good surgeons as colleagues who do it only selectively, which tells you that actually in some patients, it's very hard. So their technology can help and people tend to use the image intensifier you know, be there wearing lead, having you know, sweaty operations with radiation, whereas actually you can exactly just like a trauma surgeon and God help us as hip surgeon if we have to end up sinking to that level Ben. But, this is an opportunity to basically get the components right without necessarily needing to have a lot of radiation exposure. So I think it's the potential for Mako plus the anterior approach is massive and you know, the anterior approach is not as big in the UK as it has been in the US and elsewhere, but I'm sure it will grow. And patients come in asking you about it all the time. So I think it's an ideal combination.
I mean, it's an interesting thing isnt it? Just before we come to Eds perspective, you know, I remember you won't [00:33:00] remember this Fares, but in, probably 2006 as a first-year registrar I went and presented The Hip Society and the session was chaired by one Fares Haddad, who gave me a really, really hard time actually. After, as I stumbled up to give my first ever public presentation, I distinctly recall it. He stood up and ripped me to pieces but there we are. So it shows that our life hasn't moved on for me. But yeah the interesting thing is, and you know, is the, actually the there's clearly a problem here because I remember, and I went to hip society every year for the fixed, I thought I wanted to be a hip surgeon before we realized I wasn't good enough. The you know, the, every hip society I went to there was symposium, it was dual incision posterior approach. I seem to recall that was trendy for a bit. And there was, you know, mini anterior, lateral, and all those things. So there's clearly a problem with muscle sparing and there's also a problem with complications associated with small incisions. And there's also clearly a problem with outliers because all those things in the, you know, the 15 intervening years haven't been solved and are still being discussed. The anterior hip seems to be here to stay. And robotics seems to be here to [00:34:00] stay as well because the things that we talked about. So, where does that fit with you Ed? You know, I understand you're not an avid anterior approacher.
No, I'm not afraid. I was hoping you werent gonna ask me cause I got quite quite firm views on it. And I suppose my views come from wanting to do no harm for the learning curve aspect of exactly what you and Fares have been talking about.
For me, I can't justify the potential harm while I learn the anterior approach for the ultimate benefits, which I think you've covered very nicely, which is possibly that the improvement in the early post-op phase and certainly no improvement once you get past that. Why would I hurt, potentially hurt some patients to get that amount of benefit?
I think also just my view on that last bit you said about there's clearly a problem, because we keep on trying to innovate. By challenging, maybe it's actually not a problem with the approach. Maybe it's just the fact that we're always trying [00:35:00] to innovate. And we're trying to come up with new stuff.
And trying to just change things around . What the difference in approach has done is probably stopped the old shark bite approaches, where you'd have an incision a foot and a half long to do a primary hip replacement. So in whatever approach you use, you've done it through a sensible sized incision rather than overly large.
Do I think the anterior approach may be improved for the use of the robot? Clearly yes. I mean, some of the complications that you're going to get in your learning curve while you're learning the anterior approach can be solved by a robot, the component orientation you're broaching to try and make sure you're broaching in the right direction of using what we call the enhanced workflow to try and reduce femoral fractures because you've planned it and then hopefully you're not going to over broach it.
So do I think there is an advantage using the robot if you were to go down the anterior approach? Absolutely. Do we have evidence yet that says that Ed should [00:36:00] start doing the anterior approach for the robot? No, I don't think we have at the moment. So I'm sticking to my posterior approach consistently trying to do it as best I can. And if we do get that evidence in the future, then yeah, maybe I'll change. I just want to point out that as well when we're talking about learning curves. I was talking to the medical student just earlier today about this, because I had a patient asked if I do it through the anterior approach. And I explained why not. And I said to him that actually, when we look at robots, we talk about a learning curve, but that's not a harm learning curve. That's just a time learning curve. So we need to be careful. Learning curves mean different things. What I'm worried about is a harm causing learning curve. If it's just, I'm going to take slightly longer than that's not such a big problem for me. Which I think is key with both navigation and robotics. It's just time, it's not harm.
Presumably that's where your man with the key comes in, because he knows all about how you should plan it. And so you can't tell the robot to do [00:37:00] something ridiculous in your first few cases.
Yeah.
I mean, having a segmented plan that somebody else has looked at is a good sort of sense check. Although I have to say, I think, you know, we look at the plan and we often do change the plan because you know, what you like to do and you know your patient and, you know, remember you've examined the patient, you know, what their spinal status is, you know, what their fixed pelvis contractors are, you know, you know what's happened to their knee or their lower leg before. So there are lots of other factors that will come in so that the clinical picture playing into that plan is quite important.
I know quite clearly. But the, I guess what I was trying to get at was that, you know, with any new technique where you've got somebody there who's familiar with it, if you're a competent hip surgeon and you know how to do a hip replacement, that seems to me to be a sensible thing.
You know, and I notice, you said past tense, Fares with many of your, many of your Mako attendees. I wonder whether they were the ones that challenged you or not, or whether they moved on elsewhere. So we've had some brilliant [00:38:00] ones when asked if they challenged you.
You know, it's a really interesting part of, I look at it as an entire process and I think you're right in terms of, as Ed was saying, in terms of the research question, Is it the CT? Is it the interaction with that person? Is it the plan? Is it the robotic execution? You know, is it the fact that there are haptic boundaries? Is it the fact that you ream less? There are lots of potential variables here that may all help to change outcome help to improve outcome.
But I think the, you know, the Mako product specialists have been amazingly helpful and, you know, challenge is always a good thing, you know, that's why we, you know, it's why we enjoy having fellows and they come and go and they really make you think harder and ask different questions. So I think, I think that is key.
Of course they do. And it's, you know, planning, isn't completely out with my area of expertise. You know, frame surgery and osteotomies and corrective lengthening, it's all about planning and it is amazing how you learn when you have to put it down on the computer. And at the end, you've got your x-ray and either looks like you [00:39:00] suggested on the computer or you didn't.
And it is a, you know, it's a really humbling experience when you get to the end of the case and you realize, in fact, you didn't do quite what you expected and perhaps you wouldn't have known if you hadn't sat down and done it to start with. So just sort of, we've got another couple of minutes, I guess, before we round up, there's a couple of things that strike me in my mind. You know, you talked about 40/20 outcome, whether it was Fares or Ed and, you know, a challenge question, I guess, cause I never like to just accept handed down wisdom.
You know, is it the case that if you can place an acetabular component more accurately, do you always need to put it the same?
Absolutely not. Absolutely not Ben. I think I'll let Ed expand on that. But the beauty is it should not always be the same. 40/20 was just an example of something you could replicate. The beauty of the modern software is that actually you can look at, you know, combine what you've got with your CT, with your spinopelvic alignment and adjust for that patient. And you know the safe zone concept is an outdated [00:40:00] concept. You can now actually look at the potential collisions, look at potential impacts in your planning and adjust. And you know, one of the things we do in hip replacements changed last few years, we do a femur first approach. We kind of look to see where the femur is going to sit, what version of the femur is going to be at before we do the socket.
So I mean, Ed may want to expand on that, but I think that's one of the beauties of Mako 4.0, the recent software we've had is that not only are you able to have a plan and had an accurate plan, you can also adjust that plan to reduce the risk of impingement.
So when you're planning it, presumably you're not getting standing CT scans?
No we are not. We are getting a supine CT, although there is, you know, we're doing some work we're trying to get to standing CT. I think that would be really cool. The foot and ankle surgeons have got there ahead of us.
That was my thought. If you're looking at, if you're looking at, you know, pelvic inclination and how the spine moves and all that kind of thing, actually sitting and standings what you want, isn't it? You want a CT with them in the two positions of function.
So, [00:41:00] let's just say Ed, you know, you've got this difficult case. How does it change how you approach it? You know, you've got somebody with an unusual pelvic obliquity, what differences to your work flow if that patient sees you in one hospital where they can have a Mako and then the other hospital where you can't. Cause it seems like you're sort of living that kind of dual life where sometimes you get what you want and sometimes you don't.
Yeah. So that's a really good point. And I am glad you cover that because it's a MythBusters isnt it? So what I get hit with a lot of the times is this regional really expensive technology, but you dont know where you want to put the hip. So that's an excuse to not bother to adopt technology. And that's clearly not true.
As Fares said, one of the big step change is the range of movement type algorithms that we've got now. So we get the CT supine and then we get a standing and sitting lateral pelvis x-ray where we measure the inclination of the pelvis, essentially. So we can correct for that. So we put that information into the software, right.
And that's built in, so let's say that one of our hip [00:42:00] surgeons, you know, decides that he's good enough to do a Mako and you know he gets a Mako. Fares is laughing because he knows what I'm alluding to. And he gets his lateral films sitting and standing and actually just putting them into the software you don't need anything special, it's not something you're doing, especially in Birmingham. It's part of the system.
It's part of the system. You don't have to put that extra information in. You can just do your plan off your supine, CT. If you want to correct it for pelvic tilt and spinal pelvic motion, et cetera, you can put it in. And then what the software then does as Fares alluded to, is it will allow you to take the hip through a virtual range of movement. And you can look at where the hip is impinging in sitting and standing positions. And then alter your component orientation to try and minimize that. Whether it's bone-on-bone collision, whether it's implant on implant collision, it'll show you all those collision points.
And then that takes us back to the education doesn't it of when you see that the hips impinging, when you flexing up to 90 degrees and you've got five degrees of internal rotation, which [00:43:00] is awful, that then you start to sit back and think, right, okay. So how are we going to make that better? What do we need to change? Has that come from our acetabular positions? Has it come from our femeral torsions? Has it come from our offset? What do we now do? And then you rerun it and you find that you've improved that a little bit, and then you can tweak it and you can keep on getting it better. So it is truly an individualized position. It's not one size fits all. So it's ...
How often does that change your plan? You know, I remember, I remember way back when writing papers about, you know, temper putting for hips with coins that you put between the knee and, you know, really, really rudimentary things and, you'd say victoriously what it tells you plus, or minus one size, you think well theres only four sizes, but, you know, thankfully those papers got published and that helped me progress in my career. But you know how often when you do that and you put in your sitting standing xray, who sounds pretty neat actually, does it change your plan? You know, how often do you [00:44:00] find that you actually going, well, actually this isn't quite right? I'll need more offset or I need a slightly different size head. You know, what differences mean to you in real terms?
Absolutely Ben. That's a really good point. And, you can get caught up in the detail here can't you? So you can start, you can just sit there, fiddling around the plan, if you want for hours, just trying to get a few extra degrees with it. So it depends on what you're happy to achieve from the hips. And the honest answer is, we don't know at the moment. Because this technology is new and that goes back to acquiring these log files and then running, you know, running all this data through to see which of the patients and what are our tolerances? What should be our, what should we be looking for for range of movement before we get impingement? That's probably, again, going to be personalized on what the individual activities they want to get back to et cetera. But a lot of these questions, we just don't know the answer to yet, because we haven't had the ability to acquire this [00:45:00] information, but also we haven't had the ability to put the hips in, in the right position.
So we're still learning on that and you're right. It seems excessive. Doesn't it? To take standing and sitting lateral x-rays and have a CT scan on every single primary hip I'm doing.
I'm not sure it does. And, you know, this isn't, this isn't said through any, any motivation of, you know, if I was 50 and I wanted a hip replacement I was stuck with the next 20 years, you know, actually I'd rather have the x-rays thanks. You know, when I, when I do a limb reconstruction for patients with deformity or any of those things, that's really what you're talking about. You know, it is a limb reconstruction. That's what the US people call it. I often get a CT and an MRI scan. I get like measurement films. And I spend ages with the patients before I do my procedure, I think we kind of owe it to our patients. And if it was me, actually I'd want the x-rays wouldn't you?
Oh, you are converted Ben. Saying all the right things.
Im not converted. You're basically both closet limbic reconstructs. If you want to come and spend a bit of time with me on my fellowship, I can show you how to put TSFs on. It'd be wonderful, you know, you [00:46:00] wouldn't just have to do these tin hip things.
Yeah. I think, the point is that I'm sure we will have, once we acquire all this data, we will be able to reduce the number. We will be able to protect those hips that are going to be the troublesome hips that will need the extra imaging.
And again, just forgive my naivety, you know, the CT, isn't a CT, isn't a CT. So, you know, I don't get fine slice CTS for lots of my patients I do for bone infection and stuff where I want to know where the, you know, do you need a scamagram? Do you need a full CT? Do you need a four mil slice? Can you get away with a standard relatively rapid CT or do you need something that's a bit more, a bit more specialist?
It's a specific CT, it's a specific CT for them to be able to segment and give you the plan, Ben. So it is.
It's a very, it's a specific Mako CT. They come and load it onto the CT scanner and they acquire it in that, in that way. And does that, does that, we didn't really cover that when we last talked about it in the knee thing, does that, does that pose any difficulties? Can you get that on every CT scan in your [00:47:00] department or do they have to go through a specific CT? Is there. No, it just, it's a state board sequence acquisition.
Very straight forward.
Okay.
And radiation exposure is relatively minimal as Fares alluded to, we've got two studies running, one in the knee and one in the hip. And as you know, the way that we acquire CTS now reduces radiation right down, actually that the highest radiation that I worry about is getting these standing and sitting lateral x-rays. I mean, pretty high dose.
The evidence is pretty clear as the worst thing we do to patients is spinal plane films. You know, calibrated multi detector CT scan in somebody who is over the age of 50. It just, it isn't really an issue. You shouldn't do it every week, but you know, it's like going on holiday to Cornwall for a couple of days, isn't it? You know, it's not ... or taking those transatlantic flights. So, you know, I agree.
So is there anything to add? Gents we've covered an awful lot, you know, we've covered why, what, how to do it, but question for me, do you have to use a Stryker implant? Can you use any [00:48:00] kind of hip or do you have to use a Stryker implant?
So with Mako. It is a Stryker platform. And so you have to use Stryker implants with it. It's planned and done. And I think, you know, there is an issue there in that there'll be, there are other robotic platforms out there, particularly in the knee, but there will be in the hip. And I think in terms of the world we live in, we're going to have to need, we're going to have to get data on each. They're all going to be different. It's a different journey with each one and having a system that has a CT plus spine x-rays plus an MPS plus a robotic arm will be different from a system that's largely navigation based. And I think you've got to just bear that in mind, the literature will need to be looked at very carefully for all of this.
I mean, we are pretty much there with safety outcomes aren't we? It's the functional outcomes and the health economics. That's going to be a bit difficult to a bit difficult to choose and work out in you know, and it is, I don't think it necessarily requires a very large [00:49:00] randomized controlled trial, but there is that question isn't there? You know, does does data with one implant from a robot, from one manufacturer apply to a different implant from the same manufacturer, same robot or not? Or do you actually have to teach each one and to teach one in the same way that, you know, the in the same way that the Odette panel would, you know, is it the case that each acetabulum. Each stem needs its own needs its own verification with a robot or not. Presumably probably not because they're two different things aren't they? One is, does it position the implant correctly? And the second is, does the implant work? But I guess that's another question.
Does the registry, do they collect whether it was robotic now or not?
I was hoping you were going to bring that up. And I think this is really important because as we progress with technology, the technology becomes vital in how it performs. But of course it's not just the technology. It's more the software versions as well. We've just been talking about how the most upgraded, sorry, [00:50:00] most recent Stryker software has this functionality in it. I think as we move forward, it's going to be absolutely imperative that we not only collect information about the robot or the navigation system that was used to put the implant in, but also the software version. Otherwise the data's going to be meaningless. Well, we're going to draw incorrect conclusions from it. So at the moment, the registry allows us to put whether it was computer navigation or whether it was robotic. And if it's robotic, which robot . my biggest concern at the moment is we're not putting in which version of software we're using. So that there's confusion there potentially. So I think this is an interesting area that we need to be cautious on as we move forward.
And your 2016 robot Fares. Does that use the latest 4.0 version of the software. Is there any difference between your three robots? You know, if you buy one now, is it still as good as the one you buy in six years time?
So no the software [00:51:00] evolves and you can upgrade the software as you go, but you can imagine the machines. You know, the robotic arms will change in a few years' time. So I think you've got to be ready to move with that because they, you know, they get slicker, they get smaller, they get better at what they do. And you know, I can imagine what the next generation of Makos is going to look like.
Mako X in black with a silver, a silver side, because apple sets the fashion. Doesn't it?
And final question, I guess. And this is an interest for me, you know. Servicing? Do you have time when it's not available?
You know, we have this terrible problem in our place. You know, you can't get enough sets around that don't get turned around quick enough, you know, and so on. And does somebody have to come in and service this thing to make sure that it's safe and good. And do they do that on a Saturday or you probably do joint replacement on Saturday Fares? Cause you, oh you do. There you go. Probably Sunday and Sunday night as well um, you know, is that an issue? Is there a time when you can't use it?
Like all thing, you know, you have to service [00:52:00] everything. But iwe've not had any downtime. It's, it's, it's always, you know, booked in at a time that works for the unit and for everybody. So I don't know if Ed has had a problem with that, but we haven't had any problems.
Nope. Absolutely not. My only problem once was when somebody unplugged the robot. So it needs to remain in charge so that the battery has its battery backup. And then somebody came in and unplugged it and left it unplugged over the weekend, which meant we were slightly delayed in starting the case. But no. They service it whenever they can out of hours. The other thing is that the, one of the things the NPS does right at the beginning of the case is just run through the whole calibration process for you. So the robot is checked before anytime you use it. So it's fully calibrated again which is one of the benefits of the NPS kind of get a mini service and the check that everything's working before you start your case.
Thank you very much. And thank you very much, gentlemen. Is there anything to add or have we covered pretty much everything to do with robots and hips and the future and everything else?
Yeah. I think we've converted you from a trauma surgeon, to [00:53:00] someone who has a bit of understanding of the future of hips Ben, which is great.
I was going to say, we have fellowship applications at the moment. If you want to apply and let me know secretly what your application number is, I'll pull it out of the pile and you know, you could do limb recon as well in the three minutes spare you have every month.
Looking forward to it.
Thanks very much, gentlemen, have a lovely evening.
Thank you, Ben.
Thanks Ben.