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Primary Hip Debate and the Anatomy of a hip replacement



Medicine professionals can enhance their prospects by attending an on-demand teaching session on the posterior approach to the hip. Not only does the session define the approach and its advantages, but it also elaborates on its potential limitations such as dislocation concerns listed in the literature. A thorough analysis of available guidelines from various medical institutions such as the B OA, BHS, and Cochrane Library is also given, offering a holistic view on the topic. The session concludes with an in-depth discussion on UK guidance and American guidance, focusing on elective primary arthroplasty and fracture care. Attendees can therefore expect to come away with a more refined understanding of where the posterior approach stands in modern-day practices.
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Learning objectives

1. Understand how to properly prepare for and present a professional medical slideshow presentation targeting peer medical professionals. 2. Understand the specifics of the posterior approach to the hip and how it compares to other procedures. 3. Gain knowledge on practices for safe surgical dissection during a hip procedure, understanding the importance of rotation and visibility. 4. Develop an understanding of the current guidance from international organizations such as the B OA and NICE on the preferred approach for primary elective hip replacements and hip fractures. 5. Evaluate and interpret research studies on different surgical approaches in order to underpin clinical decisions and ensure optimum patient outcomes.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

OK. Um II don't mind that particularly there's nothing too rude on the side of my screen. But do I just, in order to look a bit more professional, is there a way of doing that? If you just press slideshow, let's start the slideshow. It should. Yeah, I've done that. Is that encouraging it? No, if I try it the other way because you can do it two ways, can't you? Um There we go. So presumably I look like everybody else who's very short sighted doing this, right? Has that, has that made it work? Uh No, but we can see a slide so fine. OK. In which case, if everybody's happy, I'll just simply crack on cos I don't think there's anything at the um boundaries in my screen that I should be worried about. Um OK, so good afternoon everybody. Um I've just been asked to talk briefly about the posterior approach to the hip. Um So uh I've robbed a table from Miller's here. Um Just as a start point um to compare myself to the other approach. I don't think the slides are advancing when you did screen share. Did which option did you pick, did you pick, share entire screen or share window? Uh I had to share a window. Don't try to share an entire screen instead it might um sorry to disturb you flo already. No, no, no, it's um, there's no point in me rubbing to myself. Ok. Ok. I don't know. There we go. All right. Fantastic. So, um table here that I've brought from Miller just as a comparison of the different approaches. Uh One thing that I've um discovered er whilst um doing my little bit of research for this talk is that really the um lateral and anterolateral approaches to the hip. Um the terms seem to be used very interchangeably uh by different sources. Um with there being sort of more of a an anterior er box, an anterolateral boxer and then a posterior box, I'm sure a purist would tell me that's not right, but um different papers, cool things, different things and posterior is often referred to as posterior lateral er as well. So, um so for my part today interested particularly in the er posterior. So the more or southern approach, if you will um with the superficial dissection, splitting gluteus, maximus and then obviously the short external rotators when you get deep um upside to this being that it is an extensile approach and the patient that should, should recover well, hopefully without any limp. But the downside being that there has been some discussion of dislocations er in the literature So, uh I've got a couple of, er, diagrams which I just thought were too beautiful not to share. Um, first were probably all seen from Ortho bullets again, just making that nice visual comparison between the approaches with the posterior one on the far, right, they're highlighted in green and then one from Hopp Infeld, er, which is a book I er, have found that I quite like, which goes into most of the surgical approaches, er, in orthopedics. In fact, it is called surgical approaches in orthopedics. Er, with the posterior approach, obviously the left most er green arrow there. So, um just looking through the anatomy a little bit, uh I know that some people like very strict back diagrams. So on the left hand side of this screen and the next few screens is the AO diagrams from the AO Foundation Surgical Reference. And the right hand side of the diagrams from Poppen, which are a little bit more uh anatomical. Um, so uh skin incision uh obviously, er, centered over the, er, rear of the greatest tranter extending, er, depending on how uh how brave you are about sort of 6 to 8 centimeters either side, er, going through er, gluteus maximus, er, normally as laterally as you are able to and then moving to the deep, um, the deep dissection then cutting off the short external rotators. Normally after ex internally rotating the thigh, perhaps giving the fat a little bit of a, a push back um to increase your visibility of them. A lot of people use stay sutures, er, at this point uh in different places. And then obviously the deep capsulotomy, um I think uh most people um on their, on their call will, will know the approaches fairly well. So what I've tried to do instead is just think a little bit more about what uh our different masters advisors, er, in organizations such as the B OA have to say about different approaches. Uh And I was actually struck by how few of the sources that I would normally go to for information. Uh actually say very much. Uh So at this slide, er just to get out of the way it is, all the organizations that don't actually have that much to say about which surgical approach you should choose. So the B OA er the BHS uh I, I'm sure um Kate will correct me if I'm wrong. Um But there's no publicly available guidelines for those guys. And again, the National Hip Fracture Database and G on the N gr don't talk about it. Uh Don't provide judgment on it. Perhaps I should say although the Angio and data sets um do include, do ask us well, do force us to um go through which approach that we're using and the options I've got on the screen just there. Um I did also have a quick look at the Cochrane Library um which does as a as a, as an excellent place to go for, er, for reviews, cos obviously you can find anything you like on the internet, but that would be a good trusted source, but all of their um information is actually really quite old. So I'm gonna focus on um UK guidance and then for international view and the American guidance. And I know that um this month is really about elective primary arthroplasty, but I think it's also at least um relevant when considering approaches to consider um fracture care as well. So the key thing for us um is that you're probably quite familiar, nice guideline 157, which is three or four years old. Um And again, it's very open, considered a posterior or anterolateral approach for primary elective hip replacements. Uh It looked at um a series of five approaches that I've listed there. Um And it noted that 97% of the um evidence that it looked at considered only the posterior and the anterolateral approach. And therefore, during my, the remaining few slides that I've got on this presentation, I'm gonna focus as much as I'm able on the posterior and the anterolateral approach. Um because if you, if you consider it in electoral terms, I don't want you to waste too much time thinking about the Liberal Democrats, the superpath er or the anterior approach er when that's not what I think most of us are actually seeing in our practice. Um in terms of nice's advice regarding er, fracture career, it suggests that we should consider an anterolateral approach in favor of a posterior approach for hes. And what's the evidence behind these two things? So, um I was actually surprised, er, whilst looking into this by how small, if you consider the enormous number of hip replacements and having arthroplasties that were put in uh around the world. I was surprised by how small, er, the um sample sizes in the various RCT actually are. So er nice and also the A AO that I can talk about in a minute do include fairly detailed appendices on the evidence behind their guidance on their websites. And nice included 26 R CT S. Um much largest of these is one that was conducted in Korea and it still only includes uh about 100 patients in either arm, although it does follow them up for over three years, which is quite reassuring. Um Interestingly, um the one thing that I, we worry about, uh I suspect most for posterior hip replacements is that um is that they dislocate and, er, in this particular study. Uh so essentially the best evidence were being offered. Um No, the posterior hip replacements, er, dislocated, but three of the anterolateral hip replacements did. Um I do have uh uh one question um regarding the evidence there as to whether it's applicable here in the UK, because the patients are actually a lot younger than I was expecting to see, uh, in, in, in a trial, er, regarding the, um, hip fracture, er, evidence, er, that was really more focused on implant type, er, rather than approach. Er, and therefore I'm not really going to delve any deeper into that cos I don't think it is, um, very additive here. So, um, the American Association of orthopedic Surgeons also has guidelines available that are very up to date for both, um, arthritis in the first instance, last year and hip fracture in 2021 and, er, they, er, offer no um no preference as to which surgical approaches should be used in either case, er, which is obviously a AAA slightly more permissive approach even than nice have. Um, they had, they did suggest in the evidence by their guidance that er, the posterior approach did increase dislocation risk in T hr which nice didn't, er suggest. Um and that er, the anterior approach might increase your risk of wound complications. Er, and they suggested basically, er, these sort of classic shared decision making process as a result, er, for fracture. Er, they, er, suggested that the higher dislocation rate seen in some older papers, er, no longer applied. And I was quite surprised actually. And you can see that I'm not arguing this as a polemic. I know I'm not sure whether, er, M Bay wanted us particularly to, to argue in favor of a particular approach. I've, I've taken you more through my thought process, but I was interested here that um the a as seemed to be suggesting that they still have some concerns about dislocation of the posterior approach that they didn't for hip fracture, which seemed, which was the opposite way around to what I was expecting. So, the evidence behind their recommendations, um they said that there are several high quality studies, er I was quite struck by um again, the small sample sizes. Um So a lot of the evidence that's in particular recent er is largely focused around comparing um anterior approaches to a traditional approach rather than comparing the two common approaches er by that, I mean, anterior lateral and posterior. Um So there's a a good study with a long term follow up by Barrett in the states which suggested there was no difference between posterior and an approaches at 6, 12 months and indeed, five years. Um the one I thought was interesting in terms of the common approaches we use was by Rosenlund conducted 67 years ago in Denmark. Uh And um er that used largely er patient reported outcome measures and that felt that the posterior approach er was slightly preferable in terms of the fact that the anterior later approaches um had patients more likely to have a persisting limp, er which is what we would probably all expect. And then finally, um their hip fracture uh guidelines um showed that in one of the more er recent studies, there wasn't really much difference, but the two lower quality, slightly older studies did show the higher dislocation rates um that we, er, would traditionally be speaking about. So I hope that's uh at least um informed, if not argued in favor or, or against the posterior approach. Hopefully it informed questions relevant to the posterior approach. Thank you. Thanks, Nick. Um Has anyone got any questions for Nick? Just check the box. Nothing in there. Anyone you not let him off easy? Yeah, it's interesting, isn't it? I don't think any society will really be seen to dictate approach. I mean, we have, we might come to it in. No. And um talk later, obviously, there's advice about types of implants, isn't there or standards of implant to use, but I don't think anyone would necessarily commit at the end of the day. If you try to force someone that's done an anti lateral approach for 15 plus years of their career into using Posterior, there's that learning curve again, isn't there of risk to the patient? And we all are probably better doing what's good in our hands, aren't we? So I think unless there's something profound, people often won't dictate a certain ways the right way. I was surprised and I'm happy to be told otherwise if I simply didn't find it. But I was really surprised by the absence of large scale trials about this stuff, even papers that the artist are talking about as their high high impact papers that we're really talking about very small sample sizes often in patient groups where it's at least a sort of a, I'm giving slight side eye as to whether they're replicable patient groups in normal circumstances. Whereas given the amount of money that is the world we spend on this stuff. Yeah, I was just expecting there to be. I think you might see that change with time now with the changes to the N Jr. So any complication return to theater now after a joint replacement needs to be recorded, doesn't it? So you'll be more, it will be easier to pick up dislocations that are returning to theater because the approaches are recorded as well. Whereas previously registry data in the UK, it didn't capture a dislocation going back, would it, it would only capture a revision? Um So, I mean, I don't know, Kim, that might be something interesting for research day. I haven't seen a program but, you know, quality of data regards to hip replacements and how we're making our clinical decisions based on actually sometimes not the best quality data. Uh Any questions or hang on. There's something in the chat box. I think George any variation within major approach, subtypes discussed Piriformis. I've um should I follow up on that a little bit? Yeah, go ahead. II work with uh Mr Wall at the moment in Colchester and um he does a posterior pip and um he talked about doing um a sort of a piriformis sparing approach for some time and he, and he gave it a go and then sort of um drifted away from it. Um II think the initial thought is that um you're preserving some stability. Um But actually, you're probably stretching out the tendon and, and you're actually losing the stability in, in attempting it. Um So we talk about the major groups of, of approaches, but is there any um variation within these that's typically accepted? And is that worth exploring a bit more? I don't know if you want, do you want to take that Nick or do you want me to, I can tell you with confidence George that although I have looked at a number of papers and some of them have mentioned this stuff. Um I've not, I've not gone deep into the meat of that specific question. So I definitely have, thank you. There are some centers in the UK that are very pro spare approaches. Um There are some, I think the purest spare approaches have got specific retractors for doing that procedure and have a certain approach to doing it. And I think some centers have kind of adopted a spare approach and maybe then changed their minds and go back to their normal posterior approach. And I don't know if it's that they're not necessarily been and to those centers and see how they're doing it or don't necessarily have the spare specific retractors. I know, I have certainly inadvertently done spares on, on a couple of occasions and certainly the performance at the end does look a little bit floppy. Um, so, yeah, it does. You do wonder if it's better to take it and repair it. Um, I guess it, it also comes down again. We've already said good in your hands, uh, and doing what's, what's good in your hands and then, um, the anatomy. So a lot of the times when you get into these endstage hip arthritis patients, if you start looking at them in clinic, when you ask them to bend their hip up, their knee goes up in external rotation, it's obligatory, external rotation a bit like you get with a SUFI right? And they're in external rotation, you can't really get them to beyond neutral. And so when you're actually going in through the posterior approach, you're trying to get round the corner and up on yourself to get as much length of piriformis as possible. And you'll see on those ones that are kind of out in external rotation that when you come to repair, you haven't always got as much length as you want of Piriformis because you've almost amputated part of it and you end up taking a lot of it off the GT when you go to start repairing your femur. So, um I don't know how they personally, I don't know how they manage to spare in those situations when it's right. Around the corner cos actually getting your access in those ones must be reasonably difficult, but I would be able to, their superior knowledge on spares for those, but certainly in knowledge at the moment, the number of end stage arthritis and the amount that are locked in this external rotation. Um, I can't imagine not taking it off personally. But I guess the other thing to add in to Nick's presentation is those end stage arthritis where everything is really contracted, everything is really tight or they've lost femoral head and everything's a bit short and there's a lot of chronicity around it is that sometimes actually dividing the glu max tendon makes a really big difference to your approach. So just remembering that you also have that advantage when you're doing posterior approach of quite a significant anterior release that you can achieve. But also taking glut max off also just makes a really big difference to your approach. So that's just a tip side of things more than the actual approach. You don't routinely take it off and you can repair it at the end. Yeah, sure, thank you. But there's always a bleeder in it. So have fine, fine forceps when you're dividing it. Is there any evidence regarding the new modern type of posterior approach, fascia sparing without incising the fascia lata? We have a couple of surgeons in Peterborough. One of them is Mr Jonathan White who to perform all his hip replacements via posterior approach. But actually I had the opportunity to be with him for a couple of his theists. And it was amazing to see that you are able to perform a hip replacement with posterior approach without actually incising without dividing the fascia pata. You just, just blunt dissection of the proximal muscular part of the fascia and you go directly to the hip without disturbing the fascia at all. Um I couldn't find any evidence. I think if you look at the level of evidence that you have for each of these approaches anyway, in a bigger sense, you trying to get any significant data in these smaller groups is I think even harder, isn't it also trying to record that in the NJ R accurately is not going to be picked up because it will get code as a posterior approach. Um I guess again, it comes down to how bad the arthritis is and what it is that you're going to need to achieve and be able to see to release. Um Of course. Yeah. As to how easy that is. Yeah. OK. Why is that? Yeah, sure. Uh Let me just see my screen. Um uh Why George is getting ready? Any final questions for Nick before we let him off the hook? Although you're back on the her, aren't you? Are you able to see my screen now? Uh Yep. But we're in the same position that we've got at slides but not a slideshow. Yet. So can I was just check in what way we're back on the hurt later on? Are you doing your journal club later? Uh Sorry. Oh, you mean in two weeks? Yeah. Are you gonna do it next time? That's fine. I thought, I thought, I thought was, was that not on the 16th? Sorry if I'm uh no, that's fine. You can do it on the 16th. It's not a problem. What are you gonna do it on then? I've got you down as doing like a VT E. Can you change your mind? I'm no, I, no, I wasn't aware of that. II thought we were, I thought we were um presenting cases like it was a sort of mock MDT. Yeah, I thought you went to a general club though. You went to a general club signed up, didn't you? Uh Yeah. Very happy to do that. Should I do that on the 16th? Then go on then spoiler. Super. Thank you. Can you see my screen now? Yes, we can. George. I'll mute myself. Excellent. Um I would, I would really like to thank you uh M space giving me the opportunity to present the anti lateral approach to the hip. So when me send the email saying saying that she is planning to do a more interactive uh hip session in May, um I took the opportunity and I was desperate to do this presentation because over the last few years working in Bedford and Luton. Currently, I'm in Peterborough. I have the opportunity to work with many different um hip surgeons. Half of them really passionate about the posterior approach, which I really admire and I really enjoy quite a lot. But I also had the opportunity to work with um surgeons who are really really big advocates of the anterolateral approach. And hopefully with this presentation, I'm going to give you the uh hot points of the anterolateral approach and try to um give you my experience working with um hip surgeons. As one of my previous bosses used to say, the anterolateral approach is going to be the old trustworthy friend. So the history of the an interlateral approach a date back in uh 74 it was s who was the first one who introduced the antila approach initially for the resection of the proximal part of the femur. Later on. It was completely revolutionized by Watson and Jones. You can see on the slide, the famous book from Watson and Jones Fractures and joint injuries published back in 95. And he was the first one to introduce the anterolateral approach for the management of neck of femur fractures, anterolateral approach. Among the posterior approach of the hip are considered to be among the oldest surgical approaches uh for the hip. And actually, the anterolateral approach is one of the approaches which has been modified by many, many uh different people. One of the most famous one is Beaker in between is back in 98. The heart approach in 1982 the Omega approach by Limo and Allen and and many others. The basic landmarks in incision we are all familiar with are the superior iliac spine, the greater trochanter, the soft of the of the femur and the vaso lateral reads. The incision for the traditional anterolateral approach is mainly centered above the tip of the trochanter and of course, the length of the varies depending mainly on surgeons preference and experience uh needs to be noted. Though that during the anterolateral approach, there is no true intra nervous plan as the two main muscles, the potential fascia lata muscle and the gluteus medias are both innervated by the superior gluteal nerve. The superficial dis is quite straight forward. After you incise the skin, you expose the fat, we incise the fat in line with the incision. And we expose the underlying fascia. At that stage, we incise the fascia along the direction of its fibers. And with this way, we create a nice interval between the tensor fascia, lata and the gluteus minimus. We identify and preserve the origin of vas lateralis. And this is one of the main modifications between the direct uh the anterior lateral and the direct lateral approach uh of the hip. The heart is the approach that we all know deep dissection and the anatomical relationships. I know during this um uh discussion uh of the anterolateral vessels, the posterior approach. One of the most common complications following anti lateral approach of the hip is the uh gait, the injury to the uh abductors. That's why during the operation, it's very important to always remember where the superior gluteal nerve lies. And hopefully this picture will make it easier for you to remember. You will see on this picture that the safe zone is considered to be five centimeters above the tip of the trochanter, deep red color. You will see the attachment and the origin of the gluteus medius and the light red color of the gluteus minimus underneath. So, during the deep dissection, after we have exposed the abductors, we detached the abductor mechanism by either detaching the anterior one third of the gluteus medius or performing trochanteric osteotomy. Having said that until uh go to Peterborough City, I've never seen an anterolateral approach. Uh uh In, I was really pleased to see Mr Parker who is a well known hip surgeon performing all of his he operations, Vienna and Steve division note, he always uh moves a small piece of GT during his primary repair. After we uh detach is underneath under the um uh glut me, the abductor minimus which is being detached and we expose the hip capsule. And at that stage, we perform the traditional capsulotomy, exposing the hip joint and the acetable rim. So as you can see the uh traditional anti uh uh hip approach is a very commonly used, we are all familiar with, we use them for our hemiarthroplasties and it's really easy and straightforward to perform this example, what we see during the deep. So the those who support people of the hip, I had this discussion with many hip uh consultants always used to say, oh George, during the the anterolateral approach, you can, you can see the aceta properly. Actually, I was quite impressed to see that even during the anti lateral approach, you can have a very good and very adequate exposure of the acetabulum. You can easily see both the anterior superior and posting of the acetabulum. You place your retractors and you are able to perform your standard acetum preparation. These are some intraoperative pictures mainly to show that always the anti lateral approach is an incision which is mainly centered above the tip of the GT two thirds below one third above or vice versa, depending on surgeon's preference. And you can have easily accessible rim and no femoral canal preparation. Now, to this note, I know that it's gonna be long discussion regarding anterolateral versus posterior approach versus direct anterior approach of the hip. That's what to say some more regarding the main hip abductor, which is the gluteus me a lot of concern regarding if there is any significant muscle damage during the anterolateral approach of hip. We have to remember some basic anatomical landmarks. The gluteus medias, as we said is the main hip abductor. The origin is the anterior posterior glue lines of the ileum. As you can see on the picture with the green color inserts uh directly onto the greater trochanter. It's really useful to remember that we have three different muscle fibers. The posterior portion of the gluteus medium medium and medius passes downwards and forwards. The middle portion pass downwards and the anterior portion pass backwards and downwards. All these fibers combined together in one attachment in the lateral part of the superior portion of the created trochanter. The function now of the gluteus minimus, we all know is the prime mover of abduction, the anterior portion of the muscle abducts and also assists in intell rotation of the femur, the posterior portion of the um uh gluteus medius, which is actually stronger than the anterior portion. And this is quite useful to remember for those who advocate mainly the posterior approach of hip assist in extension and external rotation. As published in the interesting study of, of Balas published um back in 2012, uh focusing on the structure and function of the gluteus um Medius muscle, all portions of the muscle will produce abduction regardless of of the position of the hip structures at risk. Now, in every surgical approach, there are some risks and especially for hip surgery. Every uh hip approach carries a small risk for a nerve palsy, femoral nerve palsy usually is neuropraxia and can be caused by excessive medial retraction. That's why it's so important to be careful where we position our media retractor. And it's a quite, quite common uh nerve palsy, especially if the retractor is positioned, it is positioned inside the muscle, femo artery and vein are quite uh devastating uh complications and can be caused if the anterior retractor is placed into the so muscle, that's why it's very important and make sure that we position the anterior retractor ideally under the direct vision, if possible, always on bone and always remember the golden rule, the superior gluteal nerve lies. Uh it's a safe area to dissect up to five centimeters uh from the GT. Now this question, I've been asking this question to my um uh hip consultants at least over the last few years is the anterolateral approach. The best option was. So last year I was working with Mr He's a big advocate of the anterolateral approach of the hip. He's been performing hip replacement for more than 30. He's using only the anterolateral approach. And every single time I was asking him this question, he referred me to this book. He said, George Go and read this book is the book, the traditional book written by uh The Great John, the low friction arthroplasty of the hip uh back in the fifties uh which completely revolutionized more orthopedic c especially uh in the United Kingdom. To be noted that uh John Chanley was performing his hip replacement via anterolateral approach, perforated trochanter osteotomy. So we are all familiar about the big core in 2004, which unfortunately did not give any satisfactory outcome due to insufficient quality quantity. Several studies have raised concerns over the last 30 years regarding the reportedly higher rate of dislocation using the posterior approach as very nicely. And Nick mentioned big studies published in BE J back in 1967 1995 the Swedish Joint Registry back in 2002 more, more than uh non randomized multicenter studies uh published in 2009, shown. Actually, there is no difference. The Oxford hip score is more or less the same at five years follow up. So all of your patients will be happy even to do the the prior hip replacement via anterolateral or posterior approach at five years, follow up dislocation and revision rate again, no different. This was a run to my study. Actually, I started 1000 five patients divided in two groups and significant difference. All of these though underline clearly that the posterior approach offers high uh uh fraction rate, a higher Oxford hip score at short term follow up three months and one year following posterior approach, better functional outcome in compared to the anterolateral, some more evidence. Now, many studies again, well known studies published in general for plasty, uh published in the um clinical orthopedic research journal comparing the anterolateral versus the posterior uh attempt. So higher rate for the posterior approach pigment analysis by Higgins and A big analysis by co in 2006 and 2015 respectively. Both showed again, higher dislocation of the posterior approach in comparison to the anterolateral approach, despite the use of high of bigger larger diameter fe heads. So, and a big study published in 2006, again, showed high dislocation rate of the posterior approach in to the anterolateral approach. And to that not the big study from ce all uh which focus uh on starting for uh 42,000 for 38 total hip replacements reported 2.94% dislocation rate for posterior approach versus 1.8% for the anti approach, which was found to be statistically significant. And as you can see, this was a really, really high volume study including almost 43,000 total hip replacements. So the question is, is the posterior approach then a more muscle sparing approach. So whenever I'm having this debate with some of my consultants, uh dividing them into posterior group, anterolateral group, the posterior group guys always tend to say posterior approach is a better approach more mass friendly. But I is this the case. Uh both the posterior approach and the anterolateral approach. Uh We need to say that they are not truly muscle since each of them require splitting under the gluteus maximus and salt external rotation rotators for the posterior approach group or the hip abductors for the anterolateral group. So there was a big study published in 2011 in bone. And in general and Bergen actually indicated that uh looked into the post operative serum creatinine kinase levels uh in patients divided in posterior approach versus anterior and anti lateral approach. And they found that actually patients postoperatively following a posterior approach had higher levels of serum creatinine kinase. Uh suggesting that probably posterior approach is not as muscle sparing or muscle friendly as was thought. What about knee injuries? Definitely there is no surgical um uh approach with risks and all three main approaches to the hip carry a risk for it. So these injuries are potentially devastating injuries. The direct anterior approach to the hip has been strongly associated with a lateral femoral cutaneous nerve palsy, which likely neuropraxia and usually resolves over time. Similarly, the anterolateral approach has been associated with a superior gluteal nerve palsy. Luckily 90% of them is benign, self resolving, self resolving, self limiting. But in 10% of the cases can be existing leading to tele gait. And the posterior approach has been associated with a low grade of sciatic nerve injury with heart rate from 0.1 to 1.7% in recent studies. And this is my last uh slide as an orthopedic trainee. I'm pretty sure you all share the same um uh uh worries I've been teasing to perform total hip replacements for neo feur fracture patients. And I really found find that performing a total hip replacement for a neck femur fracture. Patient is really challenge is really fascinating. And to that note, I'm always keep asking myself which surgical approach is not actually the best surgical approach. I strongly believe that and provide with a bad, very good outcome for the patient. But I'm just wondering because performing a replacement for a traumatic neck or feur patient is completely different from the elective setting, doing a hip replacement in a neck of feur fracture. It is really challenging because not only the underlying gen by mechanics of the hip is different, altered biomechanics. The cap is by definition unstable. There is underlying laxity. Patients are osteopenic, possibly osteoporotic patient presenting with the neck of femur fracture. It oftenly they do not have the the the the typical stiffness that the left hip has and also many of them do not have severe oa change. So performing a hip replacement for the acute trauma setting has always been challenging. Unfortunately, I couldn't find very significant high level of evidence um on pubmed or core, but I managed to isolate these two interesting papers. One of them is published in the journal. Both of them are really good studies that I could really say to you guys where you have time cut it on the left hand side, you will see a very interesting article published in 2022 looking to the dislocation of total hip replacements in femoral neck fracture and especially if the surgical approach or dual mob implant. And if you see closely on the results section, you will see first report high was found with a posterior approach. And when you were using single bearing prosthesis, and actually, they were so concerned that they advocate that if you want to proceed with a total hip replacement in a fracture via posterior approach, they recommend on the conclusion section, a dual mobility prosthesis for the posterior approach to are. Whereas for the lateral approach, you can easily use a single bearing hip replacement. Ideally with a large size femoral head as the dislocation rate is low using the principles of a adequate surgical um uh procedure. And on the right hand, the an interesting article published in joint looking into the association of surgical approach and bearing size and type with dislocation in total hip arthroplasty for acute hip fractures. If you see on the conclusion section, they recommend that actually when using a posterior approach for a total plastic in fractured neck of femur, the use of dual mobility cap reduces the risk of dislocation. Whereas uh there is a non significant risk reduction for dual mobility caps using the direct lateral approach. And they conclude that the direct lateral approach is protected against this location and is also associated with a lower rate of revision at three years compared to the posterior approach. Thank you. Thanks George. Any questions for George? Nothing in the chat box yet. I have to admit, Miss Pa I know uh personally, I don't have a preference. Honestly, I have to say I took the this initiative to do this anti lateral approach presentation because over the last two years, when I was Luton for one year and Bedford for one year, honestly, I'm so grateful I started my training and you know, I was always saying, oh, go ahead for hip replacements. I'm gonna see posterior approaches, posterior approaches, posterior approach. I always thought it's the gold standard. And when I was reading your the N JR um data that you sent to us on the email, it was as expected, 75% of the hip surgeons do a hip replacement with a posterior approach. This is what I understand, that's the normal thing and all this stuff. So after working one year with Mr who is a massive advocate of the anterolateral approach and we had long and long and long discussions about that. I had a look on the literature and actually, I was really impressed to see that, you know what anterolateral approach actually works. And from what I've seen so far, Miss space, I think it's the ideally if I become a surgeon and I'm really confident doing a hip replacement using both approaches. I think that's the way forward and what I've seen so far, especially for because honestly, now at this stage, I've been chasing hip replacements for neck or femur fractures as much as I can I found them really fascinating, really challenging and they are really really very good practice for us, the trainees. And I strongly believe that so far I wouldn't be impressed if at some point, there is gonna be some sort of recommendation like for neo feur fractures, consider the anterolateral approach of hip because there are so many, there are so many uh published articles, none of them with high level of evidence for sure. But it's a well nice complication. And when I have this discussion with my hip uh bosses, still to nowadays, even very experienced hip consultants always keep thinking about this hip if it's gonna dislocate or not. Uh because by definition, there is different different biomechanics in the uh traumatic setting than the elective setting. Yeah, I mean, I think it's a good point about fractured neck of femur is that if you haven't done a trauma total for a fractured neck of femur, it's a very different, I'm sorry, my other cats just now driving me if you can all hear her, it's a very different feel to a hip arthritis. So they're not tight, there isn't massive releases that need to be done and you kind of shock them and think is that right? You know, it feels a bit lax compared to other hips and your repair is very important in those kind of patients. Um You made some of the comments about dual mobility for neck of femur fractures. It's still a bit controversial to just automatically put in a dual mobility, puts a little bit more force through the bone implant interface, which obviously you've got to have some form of integration unless you're using cemented dual mobility as standard for that. Um And so there's, I guess potential risks from that point of view, I guess you have to really look at the papers in quite a bit of detail because I recognize one of the authors on the paper that was on the left as being up north and there is definitely national variation in the way people do their hips. Ok. So if you're a trainee down here, you're most likely going to be quite happy with a hybrid hip replacement. You may not leave training, seeing that many cemented hips being done, cemented sockets. I mean, you go down to Kent and London, you're going to be a trainee probably that's really used to seeing uncemented total hip replacements and you probably won't see, well, you'll see hybrids, but you probably won't see very many cemented. If you go up north, you'll see an awful lot of cemented hip replacements. You probably won't see any uncemented and you'll see the odd hybrid being done. So there's a massive variation in um, the geographical variations in the way that hip replacement or implants are being used and likewise up north. Um I say that very more that's really generalized in a certain place up north. They're very you know, using a 32 sized head that's big like they use, they put 28 in and as a suggestion of a 36 is, you know, odd. So if looking at this rates in centers rather than big registry data, that might be comparing a total hip replacement for trauma with a 28 head to a dual mobility. Whereas down here, if you have a hip fracture, um you might be having a 32 or 36 head on either a cemented or hybrid um hip replacement. So uh uh just something to bear in mind in terms of dislocation and papers, it's really difficult to tease out all the variables. Uh Of course, yeah. Uh Panos has popped something in does the late dislocation rate between posterior versus an interlateral lateral approach equalize ie after three months when soft tissues heal, I think the dislocation rate. Oh I couldn't, I couldn't find any paper focusing on this specific question. Um I think it's very, very specific to a study with safe results for something like that. Um I don't know, I'm not aware of a paper that that suggests that but a lot of the papers that eluded to the dislocation rate of posterior approaches is quite out of date now. And often they were done for people who at the time when posterior approach was starting to become trendy, people didn't repair the short external rotators, they didn't repair the capsule at the end, it was literally hip in close close fascia, right? So, actually comparing the dislocation rate of a posterior hip replacement done now, compared to then might be different. So, again, there's a bit of a pinch of salt with some of the data because you've got absolutely no idea. Did they have a repair? Did they not have a repair? Yeah. Yeah, of course. Yeah. Uh Lovely. Uh Any more questions? Looks like you're a poundy. Thank you, George. Hi, I'm just gonna share my window. Can you see that? All good. So, hi. Hi, everyone. My name's Andy. So um I've been given the direct anterior approach um for primary total hips um disclaimer before we start, I've never seen this being done. Um I do know there are some surgeons in the, in the region that do use the approach for primary total hips. Um and I'm sure if they were watching, they could give me a few more nuances or ticks and trick tricks. Um And as we've suggested before, the, the N GR data um reflects that in the UK, there's only 1% of primary total hip replacements being done in 2022 via the DAA. So the er, walking through the approach, setting them up slightly different, you put them supine. Um There's been some suggestion you can use a radiolucent table C arm and intraoperative imaging that's not done all the time. I think that's um more that I've seen from er, the American side. Um then identifying the landmarks, which is primarily the ASIS, the incision goes around two centimeters lateral and distal to the ace, avoiding the in line going just distal to it. It's an oblique excision going laterally towards the lateral thigh or fibular head um and is around 10 centimeters long. So the pictures on the right, you can see of them setting up and uh finding landmarks and preparing their incision. So, superficial dissection, you're going for that internervous interval uh between the TFL and Sartorius, er deep between rectus femoris and glute medius. Um The picture on the top right there, you can see the top green oval is um sartorius, er the er bottom green oval is uh TFL. Um and the traditional Smith Peterson um is through that yellow line, through that, er um through that interval, er, with the DAA, you go slightly more lateral. So centering over the TFL itself and that's that red line. Um So you dissect and you incise the fascia over the TFL, lift the TFL off, er, and um retract it laterally. Um This is all to try to reduce those risks of the lateral femoral cutaneous nerve, um which is lying more medially um and the neurovascular um bundle, the femoral neurovascular bundle as well. So, deep dissection again, trying to find that internervous interval superficially between TFL and sartorius and deep between the rectus fes and gluteus medius. Um the um top image shows the top green oval being er sartorius, the bottom one being TFL. So finding that interval between the middle green oval is rectus femoris. Um you incise the thin fascia over rectus femoris and and go a sort of a curved incision more proximately up to the acis. Um uh noting that there's this ascending branch of the later femoral circumflex artery, which usually needs ligating and dealing with to allow for appropriate um exposure of this acet table. So then you're down to the precapsular fat underneath it. Um Then you have your capsular release and neck cut. So you're releasing the superior aspect of the capsule um down to the GT um performing your neck cut and then allowing your um acetable exposure and femoral preparation, which I think is another talking in itself. So, these are some of the proposed advantages of um DAA reduced length of stay faster recovery. Um It's been said there's, you know, it's a muscle sparing procedure. So there's less damage to the muscles, less postoperative pain. And that makes theoretical sense to me. Um less uh muscle to damage less muscle, to repair less soft tissue healing. Um that could get you up, get you going quicker, um fewer postoperative hip precautions. Currently, a lot of there's no hip precautions told to these patients, I think in um in reality, they're told not to extend past neutral, lie prone or heavily externally rotate their um their hip, but this is one of the other um suggested advantages I've seen. And another one is um cosmetic, smaller scar, smaller incision, which can be important in some uh patient populations. Some disadvantages that I found around it. Um wound healing, there's suggestion there's more minor infection, minor superficial skin infections, um which can potentially be very serious if there's any uh deep infection. Um also obese very muscular. Uh patients might not be good candidates for it because uh because of access and exposure. And it's also been a suggestion, there's quite a steep learning curve to it. Um As we said in the N GR report, it's not standard practice in the UK. Um There's only 1% of the primary total hips being done. So looking at some of those um advantages and see if there's any research around them. So reduced uh length of stay. Uh same. Um I wanted to see if there was any sort of objective evidence that there's um er less soft tissue damage to see if they could use serum biomarkers, crp CRE and kinase to see if there's less damage following these operations. Unfortunately, there's no limited evidence on it. Um And it's of unclear value particularly, but I think it could be something which um uh more research can be looked into looking at whether um these different approaches may offer advantages in the same day discharge, which I think we're all working towards. There's a lot of low level evidence Um There's I found one which was a retrospective analysis of a single institute which suggested that there was almost double um failure to launch, which was that the patients weren't going home day one of posterior approach compared to the direct anterior approach. Um It again, it's a limited study and just noting on it as well, they also suggested there was no difference in the readmissions or uh patient outcomes or revision in that in that sample, there's a systematic review I did find of uh 42 studies comparing all the three approaches we've looked at today. Um And again, there was suggested there was no long, there was no evidence of uh reduced length of stay, there was slightly more operating time in um direct anterior approach. Um and no difference in long term outcome. One of the disadvantages I looked at was the wound healing um and its potential serious complications. Uh And again, a a systematic review uh of a couple of our randomized control trials looking at up to 25,000 hips. Um The instance in direct anterior approach was, was higher significantly. Um They're both low rates in total but um definitely higher and it makes more sense as well being close to the groin. Um patients with certain risk factors, higher body habits, you'd be more worried about infection. And as the other um two have said as well about dislocation I II think there's there's not enough high level evidence to talk about it. And I, I'd agree with, um, the space is a, I think it was a very historical, er, view that the drawback of the posterior approach was the high dislocation rates. I think that has come down and we don't really have um, enough up to date, high level uh evidence to say it's a significant difference. Uh So more research needs to be done on it, I think, and that's all I got. Uh only one question if I'm not mi if I'm not mistake, if I'm not mistaken, I think the anterior approach has been associated with a higher rate of intraoperative fractures, right? Uh Yes, the um there was a uh more interoperative fractures, periprosthetic fractures intraoperatively. Um I did see that a, a fair bit too. Yeah. Yeah. And that there a lot of the um the II they were using as well was for the implant positioning um which I found an, an interesting use of um II. Um But yeah. Um but that's mostly just the, I don't believe anyone in the UK and in the area here would use it for um primary total hips. Kim's just popped a question in the chat about positioning for DAA. Seems more complex. Um Is it practical for most hospitals in our region? I'm not actually sure how many people are doing da in our region. I know there's one in our IB. Um I don't think doing them in the NHS um from that point of view, they do take a little bit longer, but I think that's all part of that learning curve, isn't it of doing something different? And perhaps doing, you know, there's not probably many people doing pure DA approaches for their hips, there'll be some, probably DAA and some posterior depending on patient factors that they're choosing. Um And so if you think the learning curve for a DAA, I can't quite remember what the number is that you need to do as your learning curve. I'm gonna pluck it out of thin. So I won't say it, but it, it is quite a high number that you need to have done. If you think you're splitting some of your cases between two different approaches, it's gonna take you even longer to hit that number, isn't it? And I think the positioning all comes into that. Yeah, in one of the papers we were saying in one of the papers, they were saying you need at least 8080 approaches. And after the eight, your complication which dropped quite significant. There is a very high number of very high number. I've only twice. We have one surgeon in a Blanco who does occasionally approach. Oh yes, he does. It's very uh very interesting to see, but it's very complicated, to be honest with you space and actually the exposure you always struggle, uh he was really confident in doing it. No, no doubt about that. But to my mind, to my view, oh my God, it was a constant struggle. You can't see very well. To be honest, I have to admit. Yeah, I think I've, I've revised a couple that have been done through DAA S and the one thing I would say is that the amount of anterior scar tissue when you're trying to get access, I mean, I've revised them through a posterior approach, obviously, but the amount of anterior scar tissue is crazy. So, um I wouldn't have said it's a particularly, you know, it's often patients come in wanting this less invasive approach and II really don't think it is when you look at the amount of scar tissue that there is over the front. But uh yeah, the, you know, the uh smaller incision and things like that for some people uh is important, isn't it? Uh But I think again, it comes down to doing um what's good in your hands, isn't it? And you know, 80 is a, a big number. That's probably a more than a year's worth of primary hip operating, isn't it? Uh in, in your numbers, if you think that people were doing knees and revisions and things like that as well. So, um and that's without a trainee. So it's, it's a big number. I think Ge George's point about, you know, if you're gonna be a hip surgeon, being able to do both is important. So I usually do most of my uh, revisions through a posterior approach. But often if somebody's had an, an anterolateral approach ready, then I often do think to myself. Mm. Ok. They might have some abductor deficiency from their previous surgery. I'm about to take off their short external rotators. Am I giving them potential instability, front and back? Should I go through the anti lateral? So there have been some occasions where I've done it um, and gone through their existing approach, but mainly put that depend on what I'm revising for. If I want to revise a socket, I'll um I'll stick to my favorite um which is posterior cos I know that I know the view I'm gonna get and that I'm familiar with it. I know what orientation I want my implants to be in. Um If you're doing something difficult, you don't wanna start doing it. This is also something I wanted to ask you miss space if you're revising a hip. And a as you said, they, you know, from the previous operative records that this patient had done anterior lateral or posterior approach, I've discussed with many people and I have two different concepts. Some people would say, you know what one part of the hip is already violated. So I will go through the same part, try to preserve the other side, pristine. Others would say, you know what one side has been already violated. So it's gonna be a complete mess. I'm not gonna be able to repair it. So let's go from the healthy side. So honestly, I don't know what is, what is wrong. II assume it depends from case to case. But yeah, I mean, I take each case on, on its own merit, my preference would normally be to go through posterior approach, regardless of what approach they've had beforehand. Unless there's other factors that are making me concerned. Um If I do end up that I've been, they've already been through the front and I'm going in through the back, my tendency is to put a dual mobility in. OK. Right. And you do get to see kind of what quality those abductors are as well. Um Even if you're going in through the back, you can see part of them so you can see has their repair failed and things like that. And actually most of the time the repair hasn't failed and actually they're probably functioning completely fine and you are just going in through new tissue which makes life a little bit easier, but definitely a lot less. Uh I don't know, I find there's a lot less scar tissue to deal with from an an interlateral approach at revision than there is with the DAA S. Mhm mhm uh Lovely. Any more questions for Andy? Let's do a quick poll if I can get its launch famous last words, what are you guys going for? What's say for arthritis? Any four people listening? I'm not shocked. Mhm. Andy. Did you just vote for yourself? No, I didn't. I actually didn't. The, the DAA was the first one. II said I'd never do. I never seen it. But, um, II also, I also voted for Posterior. By the way, I wasn't gonna ask you, George. It is too personal question. You've shown that we've roughly got an N Jr split here, haven't we? Roughly speaking 75% for so cool. All right. Why don't you take like 10 minutes or 10? Yeah, let's come back at quarter past three. Get something cold to drink and then, um, I've basically done a bit of a talk on the anatomy of a hip replacement and we'll see what else I've talked to anyway. Quarter past three guys. Yeah. Thank you. Thanks. Thank you. You guys read. Yep. Looks promising. All right. Uh Let me screen share then, Andy. Can you see the slides? Yes, perfect. All right. Uh We've got a little bit of a mix, mi mix and match as we go along. So, um, I obviously can't see you guys. So just jump in if there's any questions along the way. All right. Uh, ok. So I thought we would talk about the different types of implants and just get a rough idea of, um, and forgive me, this is probably a little bit set up to begin with, at least for more junior registrars perhaps haven't done hips yet or starting off of just the language um where you're describing x rays and knowing what implants are being used and why. So if we thought we'd start off with cups and then we'll move on to stems. So, in terms of uncemented cups, you've got solid back and clusters. So I don't know if you can see my cursor or not, but you've got a solid back cup here. It's not got any holes in for screws. OK? And then this one, you've got a few holes there uh for your screws and then your final option on your uncemented cups is gonna be a multi hole and we'll have a picture in a minute. Um Does anyone know what these cups are coated in? Hydroxy appetite? Lovely. Is that Kim? It is? Yeah. Hi, Kim. Uh Yeah, perfect hydroxy appetite. They've got a really rough surface that the bone then grows into. Yeah. So, uh sometimes questions from an Q point of view can be about what the conditions are for ingrowth. So you should uh basically be able to rattle those off. And uh if you look at Ortho bullets, they roughly all come around uh the number 50 there's 1150. So that's how I used to remember it. Um So you're looking at gap, you're looking at porosity pore size. Um And these are the kind of factors that are going to affect how easy it is for your bone to grow into an noncemented implant, whether it's a stem or a cup. Ok. So this is a multi hole. Obviously, this is probably more likely to be a complex primary or even more likely to be a revision setting. You've got lots of holes for screws to go through. But anyone think of any disadvantages, what, what happens with the more screw holes you've got less surface area for the bo growth for, on growth to occur. Exactly. So more screw holes, less hydroxy appetite. Yeah. So less surface area for the bone to grow into. And actually the more holes you've got, the more chance you've got a backside wear on your liner that goes in as well. So, there are some disadvantages and that's your reasoning behind why you wouldn't use a multihole as your standard hip replacement cup. Um But also why some people will try to go for a solid back and not have any screw hole options at all. All right. Um Just in theory, space, if we use a screw hole eliminators, we reduce the, we, yeah, we reduce the risk of uh uh polyethylene wear. Right. Absolutely. So, if you were to er, screw in eliminators, then yes, you would reduce your um risk of backside wear, but you don't improve your ingrowth because they won't have H A on the back. Correct. Yeah, but you'd have to put a lot of eliminators into a multihole. So you're probably more likely to use that in a cluster if you're going to Mhm. Uh Lovely. All right. So people talk about different fits of uncemented cups and for me, it's really dependent on the type of implant I'm using, but also the bone quality that patients got. Ok. And you'll hear people talking about press fit and you'll hear them talking about line to line. Um, Georges. Do you want to talk about it or? Sorry. Can you hear me now? What's the difference between F and going line to line? So when you're preparing the acetabulum, uh essentially in some specific type of ment caps, uh the instructor um uh suggest us to under the acetabulum rim, uh probably 1 to 2 millimeters. So when you are acetabulum C, you have the press fit function where the c really press fit inside the acetabulum cavity where as the line to line concept is you r exactly to the size of the asset of C you're gonna introduce and then you uh achieve adequate stability by having a nice confidential rim around the asset of cap. Um I think that's the, the two main concepts between the and with the press fit your hoop stresses are much higher. OK. And so if you've got someone with slightly softer bone or less, you know, not so good quality, then obviously your risk of fracture will go up. You might think you're going line to line with some of these implants because you go say you room for 50 you put a 50 cup in. Um, but actually on some of these cups, the outer diameter is a little bit bigger. Ok? Because, um, they're purposely trying to get a press fit with their coating. So it's really important that, you know what implant, the OPEC of the implant that you're using. So you'll put a 50 cup in, but it might actually be like 51.5 millimeters or something like that. So, although you might think you're going to line, line to line the implant design might have a press fit built into it. OK. So just uh whatever implants you're using, it's always really good actually to go back to the basics and look at the op tech for that implant. And actually, even now if you go back and you look at the impl er, at the optic of a DHS, you'll learn something that you didn't realize. Ok. Um I don't wanna keep picking on George. Um We remember the list of people who have picked him. Where are you gonna put your screws, Andy if you're putting screws in, actually, Panos, is there, isn't he? Panos? Uh Yeah, so we'll put it in a safe zone, which is uh in this case, in the image you have is a superior aspect. OK? Cool. Um So we're gonna go through why, um why we do the safe zone and I've got another slide in a minute. Um About what problems there are in each of those quadrants. So when you put screws in, you're trying to get primary stability from having the screws until the bony ingrowth happens on the implant. And that gives you your secondary stability. OK. Uh Sometimes that kind of question comes up in an Fr CS, if they're talking to you pushing you in an uh a, you know, a primary hip for arthritis kind of setting. So we talk about the safe zone and uh panel has already said the superior zone to put that in green and the red zone bad, OK? And this zone is in amber because it can be safe as long as you are considering. OK. So if we come over here and posterior superior quadrant, if you were to put in a long screw or you're inadvertently going in the wrong trajectory, there is some risk in theory to the sciatic nerve and superior gluteal vessels, but the risk is pretty low, ok? But actually most likely you're gonna get a nice shot straight up the fairway of the ilium. OK. In terms of the posterior inferior, these are the structures that are at risk, ok. Again, sciatic nerve, this time, the inferior gluteal vessels and possibly the uh internal pretend um bundle. But if you keep your screws short around the 20 mil mark, the likelihood of having an injury there is quite low. You don't want to ever really be putting any screws in in these anterior quadrants. Ok? There are nasty things there that you don't want to have to go looking for or ask, you know, phone for help to come if you've got significant bleeding on table. So you would avoid screws in that sitting. And even if you're ordering custom Acetabular cups, the ees that you'll have on, the custom cups will come up over into these safe zones. Then you've got a liner that you need to choose. Ok. And that might be ceramic. It might be a polyethylene predominantly. I think in the east of England, you guys are going to see polyethylene um barriers. Now, although there were quite a few ceramic on ceramics done. So you probably see those in revision settings. Um but within the poly liners, you've got your neutral liners which don't have any EV OK. And you've got elevated liners usually depending on the brands, 10 or 20 degrees of elevation. Ok. Um Who else is finding, who else likes hips or who doesn't? What's the advantage of having an elevated liner in the in the reduces the risk of dislocation? Oh, so sorry, Nick, sorry. That's right. Well done guys. Yeah. So in theory, I like that, in theory, it's reducing your dislocation risk. Yeah, depends on your component positions and depends on where you're putting your elevation. So this is what an elevated liner looks like this lip. OK? And if you're a posterior approach, you probably going to put it posterior and slightly superior. I have done as I said direct DAA revisions and they had used lip liners and put them over the front. What's the problem if I'm doing a posterior approach revision? And somebody's got an anterior ea liner that's been put in with the elevation that's anterior. What might happen? Sorry, miss space, you are revising the hip through a posterior approach, right? Yeah. So say I've done a posterior approach and they've got an elevation liner in and then it's been put anteriorly because they've had a DAA. So they've got anterior coverage. What are the problems that I might face in my revision? Um I assume it's gonna be uh more difficult and more technically demanding to remove the uh polyethene, right. Uh You can still, you can get it out and actually want if you get, take it out. Um and just change the liner. It does sort some of your problems out. If they, if I'm keeping their liner, for example, then the problem is is that I can't then have any posterior coverage for my posterior approach and the anterior will have scarred up, right? Um So I won't have any extra posterior coverage. But the second problem is is if you've got a lip that's anterior, there's possibility a little bit like if you've got massive anterior osteophyte, that your neck impinges on that lip and then your ball levers out of your socket. So just to remember that elevations are great as long as your neck doesn't engage with them because you can lever out and then dislocate. So that's why I like your comment George about in theory, they can improve your stability, but it does depend on where they are. OK. So here this picture, you can see the neck just coming into contact with the uh elevated liner. And the next step will be that if they continue to I impinge there, the hip will just leave it out. OK? And dislocate. So what are your next options? If you were worried about instability? What other options have you got on the socket side? What other types of implants? D mobility, dual mobility uh was that Nick? I don't know what else? Uh um Nick, I didn't quite hear you. Oh, sorry. Yeah, I was, I was just getting a bit further down the spectrum. I was gonna say constrained. Yeah, and constrained. So you've got Yeah, there's one other type of thing. Maybe not an uncemented cup. But so what else could you put on a cemented cup? May not have seen it done. It's quite cheap. Um And it's about a 15 minute operation. Anyone heard of a plat? No, never seen. Yeah. And it's post to your lip augmentation device. Yeah, absolutely. So it's basically a polyethylene wedge that you put at the point of which you want extra coverage. OK? And it just screws on. Um So they, they, as I say, quite cheap and a relatively quick, easy fix. Onto a cemented cup. Ok. Not a non cemented cup. So if you are talking in your exam about the full options that might be with them as well. All right, particularly in somebody that's elderly has got some instability, maybe not that fit for a full on revision but could have a relatively simple procedure done. So uh increasing your stability. So um George, so you mentioned dual mobility, how does the dual mobility cup work? So as the name mentions, it's actually a dual mobility construct, you have the um uh the a top, you have a large poly inside which rotates freely inside the cup and then articulates with the femoral head giving two pla mobility inside the cup. So one movement is the polyethylene through the acet cup. And the second movement is the femoral head inside the polyethylene liner. So, in theory increases in, in theory, increases the jump on distance provides extra stability. But of course, also dual mobility caps can dislocate because it's not a fully constrained constraint. It's a slightly more constrained contra than the conventional one. Yeah. So you do still see them dislocate but it is much less likely, all right, uh good. And then with the constrained, you have a locking ring and actually in theory, they are all coupled together. So um panos how the constrained cups fail fail uh with uh loosening. Yeah. So all of the force goes through the implant interface. And so with constrained cups often they fail on mass, ok. Uh, they become loose effectively. Um, and so in a revision setting, it might be, there's already a well fixed uncemented CPP in and you're worried about stability and you might convert that to a constrained liner. That's probably more reassuring. Yeah. But if you're having to put in an uncemented cup and you're, um, putting in a constraint in the same sitting, then it's a little bit more worrying in terms of it's more likely to loosen. OK? Because it may never get that integration that you want it. So they don't necessarily last that long. I think a a lot of, I mean, I have only used them a few times but um a lot of people say kind of fiveish years and you might start seeing loosening in them. OK. So it's not this uh you know, wonder fix that you have a dislocation. OK. Let's put a constrained cup in. Yeah, they're not that satisfying and they do have slightly stiffer hips after they've had a constrained cup. May I ask about uh the dual mobility that you mentioned? Mhm Does it not stop working as a dual mobility after a while? That's this is my understanding of the situation. Yeah. So people often talk about that with bipolar hemi heads where actually they do uh end up easing up like if you talk about like the I won't name brands, but there are some brands that uh you find they will seize up and you'll just have effectively a hemiarthroplasty head again in monopolar. Yeah. Um With the drum mobility ones though, like the ceramic and the polyethylene, I think it's a lot less likely that it happens. I think they do end up with um drum mobility for a lot longer. But ultimately, if they do seize within each other, you still have a much greater jump distance than you would if you were using a standard head. But that is obviously depends on the cup size that you've got in. So, um if you look at some of these, if they have a smaller cup, the outer diameter of your poly might be say 40 or 44. And actually, if you could get a 36 head in the difference between a 36 and a 40 is not very much, is it so, still bear that in mind when you're thinking, you're gonna choose dual mobility over a 36 head because with a 36 head, you're also gonna get to use a lit liner, aren't you? Whereas the d mobility you're not going to. So there are swings and roundabouts that it really comes back to that basic science that often people don't like. But in hips, it's quite relevant to what you do on a day to day basis. Um Whereas if you've got a guy that's got a relatively big socket and you're gonna have a nice, like quite a good outer diameter on your poly of your dual mobility. Then actually, you will get a significant advantage over a 36 head. If I, if I, if I may ask m spacey, uh the dual mobility I believe comes into a non cemented and cemented version where you can put a cemented cup. What about the, the constrained cups? Do we have this the same option on the constrained cups or is the weight bearing load through the cup to the bone interface very high to support a, a cemented version? I've personally never used a cemented constrained. I can't think of in the brands that I've used. I don't think it exists. Um I think you would have problems that your bone cement to face. Um You've got the advantage, haven't you with a non cemented cup that you're at least going to get some primary fixation with screws in the meantime. So, um, I'm not sure actually, if panels George in terms of, uh how many, if they do exist of cemented constrained cups, I certainly haven't ever seen them used because biomechanically it seems very risky to have a cemented constrained cup. Um Yeah, particularly in a revision setting. When the bone is already quite sclerotic, you may not get a great purchase in terms of your cement interface into the bone, um, with that sclerotic bone. So, um, I certainly wouldn't want to use one. I've said the constraints that I've put in have been kind of, um, if I've got any concerns of stability with APF R. Mhm. Mhm. Um, yeah, I haven't actually used a constraint for a pure revision situation yet. Thank you. I, if I just, um, pick your brains about when you would consider using lip liners for primary arthroplasty, um, is it, is it something you normally do as a, as a planned thing or is it something you do when you've, you've put your cup in and you're testing stability and you're like, um, that's not quite as good as I want. What, what the, so I think this again is another area of regional differences. So, um, the trust that I work at, I think the vast majority of people put an elevated liner into a non cemented cup at their primary hip replacements. Um, a few of the ones that I've gone through as a trainee that was also the case, um, where I've been on fellowship up north, um, neutral liners were used as routine, but then I would say that far less uncemented cups were going in, much more cemented cups were going in. So obviously you don't necessarily have that advantage of a lipped, um, a lip liner. Yeah, because they're using cemented cups. So I do think there's quite regional variation. I think the vast majority of people putting hybrid hips in are probably using some form of elevated liner. Um, but yeah, a lot of, a lot of discussion is around putting your implants in, in the right place. You know, we'll come to orientation in a moment and people are moving, some people are moving towards robotics, aren't they? Um Mainly because although we talk about where we, the orientation, we want to back up, actually, when you're in theater, knowing what that orientation should be is quite different, isn't it? Um You know what you've got to reference off of or, you know, if the patient has got um stiffness in their back and things like that. So, um for me and my primaries, if I'm putting a hybrid, do you use a 10 degree elevated liner uh standard? Um You don't necessarily have to, what I would say is that it's a relatively low risk thing to do. Uh It's usually that people are not going to get themselves into such an extreme position posteriorly that they will leave her out grab and I do find that. So I do a lot of cemented cups and when I do do a hybrid and put an elevated liner in, you do get that feeling of a lot more stability than you do uh with a cemented neutral like cup. Thank you. No worries, everyone happy so far. Yeah, I'll keep going. Uh OK. Um Kim, any thoughts on this x-ray. Um So it is a ap radiograph centered on the left hip. It shows a I would say uh uncemented total hip replacement um that is dislocated and mm I can't, there's a bit of like, um, I want to say debris but I think it's part of the implant that's around the, the neck. Um, but, uh, I don't quite know exactly what that is. Ok. Are you going to give this a pull in? A&E? No, no. Are you going to give it a pull in the? Mm. No. Um, so I think to be able to give a pull, you have to say that the implant is um, not obviously disturbed. Whereas when I'm seeing that ring, even if I get it back in there is a problem here. So that's just a short term solution. Whereas really what we should be doing is planning to see. Well, what is it since I don't know, I'll ask a senior colleague and then possibly looking into plan the revision of some sort to put a proper implant in place. So we said that constrained line, uh constrained cups can sometimes fail because they loosen the other problem sometimes is that the ring mechanism can fail. Ok. Um And so you can still potentially dislocate with a constraint. Ok. So just remember that. And yeah, so most of these require an open reduction and to have an I like some form of implant exchange, if it's one that you've got, it may be something from somewhere else and you may end up that you don't have the implants available or they're not manufactured anymore. And you have to then revise something that has clearly been a problem already. You know, this person's had multiple dislocations to have ended up with a constrained plan, uh, good. So cemented cups. Um, quite a bit of variation in their design, probably not given quite as much um, airtime in the east, in our region, I guess as uh hybrids are but a few different examples here. So the bottom right is a marathon cup. Um It's got really good registry data. It's a flanged cup. So it's got this massive plastic ring all the way around it and you can uh trim that down where you don't need it and you can leave it if there's any bone defect that you want to cover. And it just creates a bit of pressurization of the cement as you're putting the implant in. So, uh quite a nice implant to use and the top one here is uh the rim fit. So again, it has got a plastic flange on it, but it is, it is only probably like half a half a centimeter or so all the way around, whereas the marathons probably easily a centimeter all the way around. Um And this part is really hard, it's not very flexible um compared to the marathon, which is really quite uh malleable. Um So actually, when I use this cup, I actually cut all of the flange off. Um because sometimes you find that it stops you from getting the cup into the position that you want, um, looking at both of these, they are flanged cups. So, what, why have they got these Nubbins on? And the marathon doesn't seem to have that any thoughts? Do you mean the, do you mean the f the flan, do you mean the flange around the, uh, the cup or do you mean the, the inner part of the cup? So this is on the outside of the cup? So the bit that's going to be in contact with the cement. Why do you think it's, it's got these little bits that stick out on there because actually, with this way, they can uh create a better interference of the under surface of the implant with the cement mantle. So it, it, it, it gains higher um uh resi resistant forces to torsional stress. So, biomechanically the C is gonna be more stable with the um cap cement interference rather than having a flat surface if that makes sense. Yeah. So the bits of uh so these nubbins that have on is to try to get an even cement mantle around the cup. OK. So it's not actually directly related to the mange, but it is about trying to get a even cement mantle. OK. Um And sometimes you'll notice if it's a bit like these can fall off and at the end of the world if they do, but it is just trying to um a an even cement mantle and you can see that all of these have got this wiring on them and that's not structural that as purely as a marker for, on your x rays, for your orientation because obviously you can't see your cemented cups on your x rays, right? What's the difference between this cup apart from the, the ignore the rims and the, the flanes. What does this one give you at least two? Don't um any thoughts, the lip liner, right? It's got, so this is giving you 10 degrees that you could put, if you're doing your approach, you could put it slightly posterior superior. Um and it might give you a little bit more posterior coverage. Do you think that's easy to judge in theater doing a cemented cup or not very difficult dispace every single time? Um um I've been in a cemented hip replacement once you pressurize the after you prepare the acetal and you pressurize the cement, the C is really flimsy. It can go everywhere. So you have, you have to be really cautious where you're gonna have your final orientation of your cemented cup. Um We do have some of these kind of the posterior lip cemented cups still. Um We have do have some of them in Norwich. Um They have gradually kind of disappeared off. I think we've only got a few of the sizes left and they're not really used. So the problem with them is is that people then suddenly line up that posterior lip with their acetabulum. And actually, if you do that, you end up with a retroverted cup, which in a posterior approach is the last thing that you want to happen. Yeah. So, um, I think if you're using them, you have to be really careful. Um, and I certainly ii don't use them. Uh, but it's just to make you aware that they exist because if you go somewhere and they have them, it's best that you do know how to manage that posterior lip. Ok. But yeah, a quick, a quick, a quick question. I, I've used the marathon. C uh I think it's the same like the O GC which was used to be called before uh without the Flans because the flu is a very crucial part because you're pressurizing and you achieve very adequate uh implants and interferes without the flus. How can you achieve adequate pressurization with a cap on the left, on the left, on the left? Yes, which is not elevated. One. Yes. Which does not have the Flans around the cup. Um Yeah. So your pressurization comes from using a pressurizer before you put your cup in. Um, and pressure on the implant as you put it in, it doesn't have the same advantage as having the flange from a marathon. Ok. Yeah. Mhm. But you'll find that you have a much smaller cement mantle with these types of um, implants compared to the marathon. Ok. You have a much thicker cement mantle with the marathon usually. Thank you. Mm. Anyone using marathon in the region? Mr Khan uses it sometimes in uh hollow and I've seen Mr um Mr Owen use it at Cambridge before. It's a nice cup in Luton they use. Yeah, they use it in Luton. Yeah. Good. Yes. Yep. Uh lovely. All right. So um who else was signed in? Who hasn't answered yet? Anyone want to describe what this is? What angle is this? Uh It's the cup inclination angle, isn't it? Yeah. So some people call it the abduction angle. OK. What should it be? Roughly? Yeah. Should be different. People have different. So less than 45 degree is it? Yeah, roughly speaking 30 37 38 degree. Yeah. Yeah. It's difficult, isn't it in theater sometimes to judge these things? It all depends on where that pelvis is. You look at, you might be looking at to, you might be looking at the uh reference of your rim of your acid tab. You might have robotics, who knows. Um But reality is, is that it all very much depends on how you have positioned your patient, how flexible their lumbar spine is, for example. Um And even if you, you're obviously not doing these cases in people who've got normal anatomy. So you're using sometimes abnormal um anatomical reference points, aren't you to try to get these? But the implant devices have generally got some form of alignment tool on them. Which is good to use. I see sometimes people don't use them. Um I personally try to um and then it's just having that multiple reference point. So some people might just say, oh, this is what I do, I put it, I reference it to Tau. But you might find at some point that you can't see Tau or in a revision setting you don't have Tau to reference off of. So just getting used to having multiple reference points when you're doing these cases, just makes it that little bit easier and a little bit more reassuring as to where your cup is. OK. Um So that's one angle that you're going to look at. Uh what's this one? The anti, yeah, roughly what are you gonna try and make it? So if 15 degree of anti for the company, you have a combined anti version of 25 degree. OK. So uh yeah, anti version of anywhere 5 to 20. Um I if you're doing a posterior approach, you're probably going to try and be more of your more towards the later end of that, you're 10 to 20. Um If you're doing an anterolateral approach, you're probably going to be a little bit more neutral on it, aren't you? So, uh again, talking about your component positioning needs to go hand in hand with the approach properly that you're going to use as well and then thinking about the patient factors around it as well. If you're not someone with a large BMI. Do you think you're more likely to have a higher abduction angle? Meaning your cup is more open or that you're more likely to have a closed cup? I think closed cup is better. Uh, closed cup would be better. But what do you think is more likely if you've got someone with a raised BMI? So I want to keep it slightly open and then it, so in inadvertently the fatty layer of the thigh is going to push your hand up. You know, you're not gonna, it's not going to be as easy with a straight introducer to get your angle necessarily right. And you are prone to having a more open cup in someone with ABM I, that's a bit higher, which obviously makes their dislocation rate that bit higher as well, doesn't it? Um One of the ways of getting around that is actually u utilizing more of your inferior incision or even extending it. So that, that fatty tissue has the opportunity to do the right thing and move out of the way so that you can bring your hand down and close that cup slightly. Um The other things I've mentioned earlier about taking glutamax off, um the tendon off and again, it can act as a bit of a hammock where it's pushing your hand up if things are a bit tight. So again, extending that distal end of your incision, taking glut max off all kind of things that will help in somebody with a raised BMI of trying to get your cup in the right place. Better to have a bigger wound that heals side to side than having a cup that's really open and dislocates him. Uh OK, so often something that's not talked about that much, but we talk about the anteversion. We talk about how open our cups are. We don't really talk about uh what happens if you position your cup and it's very medial. So when I was training, this was actually the standard of a cup. You used to um I say when I was training back when I was at the house officer level, they used to really medialize down to the floor of the acid tab. But what effect does that have? What's the problem with doing that? Why, why do we not do that anymore? I think it can change the varus and valgus position? Sure. Offset. One is the offset. The other one is the virus and well, is it try to preserve bone stock for later revision? Yeah. So a couple of points, isn't it? So number one, whenever you do a primary, you're thinking about the next operation, aren't you? So you want to keep some bone stuck. But importantly, if you really medialize down onto that floor, you've lost offset, haven't you? So we often talk about offset on our femoral stems, but we don't really stop and talk about it. Very often on our cups. So the moment you medialize down onto the floor like that, you've lost offset. So you might end up being to try to get that back. Either that you're trying to graft to bring the cup laterally. You might use a lateralizing cup if you have them available or you might have to increase your offset on your stem. Yeah. So you can see here in this picture on the left, we've got an uncemented socket. You've lost, they've lost, lost offset, cos they're down on the, on the floor and then they've got um, a build up on their head, haven't they? So this is a skirted head. If anyone's seen them, you won't see them being used very often, but this is a, not just a plus head, but it's plus enough that it's needed a skirt. So it's a very long neck that they've put on because they've lost their offset and they're having to increase it. Yeah. Um, and we'll talk about skirted heads in a little bit. Ok. But the reason that that's there is because they've lost offset. Ok. So if you're in an exam situation and you're, they're giving you this X ray to say patients come in, they've got pain over the lateral side of their hip, they're trendelenburg positive or whatever kind of story they give you and you're looking at this X ray, you can start piecing together what's going on during this case. Yeah. Um and you can say that you can say there's uh medialization of the cup offset, it's been lost. It's been an attempt to restore that with a, an extended head which is skirted and we'll talk about the problems with skirted heads in a little bit. Whereas if you see this cup on the right, actually, this is more of the kind of uh in terms of the medial uh offset position of the cup of what we try to achieve now. So you've got a lot more bone stock to work with in the future and a revision, haven't you? Um And actually this person's not lost significant offset. Yeah. Uh So something to look at on your POSTOP films here. So in terms of your stems, um the vast majority of you in this region are probably seeing cemented stems going in probably the majority of them are tapered. So things like the exeter or CPT. Yeah, but some of them will be composite beams and it's really important that you go away and you do some reading on composite beams and how they work because it's a really like a favored question in the exam. OK. It doesn't come up very often, but when it does, you want to just be able to reel it off. And I think it's something that you just need to sit down and get your head around, the difference between a tapered stem and the composite beam. It's not that difficult. But each of you are just gonna have to find a way that you find it easy to remember. OK. With the uncemented um stems, they can be either proximately coated or fully coated, which means that they've either grip blasted or they've got H A on them either at the top portion or along their full length. So the vast majority that I put in now are predominantly just proximately coated. So what's the advantage of not having a fully coated stem because you think more h a full length, more necessary? Great. That's what I want. But what's the problem with a fully coated, uncemented stem, osteolysis, reduce, reduce stress yielding. So which one do you get less stress you're doing in uh in the proximal coded uh stems? Good. So what is stress stress shielding? Uh uh So I'll try to explain as much as I can. So w whenever we have a, a cement, uh an implant which goes inside the femur every single time we are the patient loads, uh The femur, the load bearing area goes through the center of rotation of the hip down to the stem. But the difference is that the proximal coated stems load the proximal part of the femur versus the fully coated stems which load only the distal part of the femur. And as a result, the proximal part around the GT area uh gets weakened and then slowly absorbs. And then we see the typical radiolucencies on the x rays. Um good. So you end up as Georges has said, you end up with losing bone stock proximately with a fully coated stem. Because similarly to say, a spinal cord injury patient who doesn't wait, there gets osteopenia or disuse osteopenia, osteoporosis in a similar way because the bones are being loaded, the same thing happens in fully coated stem. And so when you come round to a revision point of view, you haven't got very much bone to work with. So we've moved away from these fully coated stems to proximally coated. So the weight is being um bear more evenly and predominantly through the proximal bone. Ok. There are both collared and collarless stems. So in that previous X ray, it was collar. Um and the reason behind those was well, two fold, one is that it becomes in an uncemented stem, it becomes a cow car bearing. Ok. Um And why was it? Um I don't know panels or ge um if you know, why was it that we saw a cemented cup with a collar, collar of a stem, sorry, a cemented stem with a collar because it doesn't make sense. It's not a, it's not a, a weight bearing weight bearing through the calcar. Is it correct? But it was supposed to, to, to be believed if I'm not wrong, that the uh collar will uh prevent subsidence of the stem. And in theory, fracture, fracture propagation. If a fracture on the calcar is gonna happen. And II believe the same principle also applies for the uh uncemented stems. So for in the past, for the uncemented stems, it was supposed to be a contraindication to have a fully coated stem with a color. But actually, since the last published study, uh uh describing the cai pinnacle system, uh since then, change, things have changed. And now fully coated stems come with a color because actually the color has been proven to prevent fracture propagation. Uh If I'm not mistaken. Um Yeah, good. Um So this is more to be, don't see a collar and assume that it's an uncemented implant. So you do get collared, cemented. They're not very common these days, but it was to prevent subsidence. Ok. Uh Good. Uh Lovely. Uh So I've picked the exeter because it's probably one of the more common stems that um you see around this region. Um What would anyone like to tell me about the Tron? It doesn't have to be about the exeter. What is the Trion Polish? Oh, good. Are you thinking about the Polish Nature? Uh Yeah. So Trion is polished. What different types of Trion do you get? So, if I had a picture of this and I had a picture of a CPT, what would be the difference between the trons? Could you use either company's head on them? No, you can't, sir. What's why? Why is that? Was that an awful? Yeah. Yeah. Why can't you, why can't you use the head of a CPT, the head of an A? So I'm not really sure there's something called a male, female. They, they both go and lock inside. So you should have the same, for example, uh we use uh uh in Dey, you use a 1214 taper. So that can only sit in the uh particular head, isn't it? So you can't uh put it in another company's. Absolutely. So you need the reciprocal taper in the head. Ok. So typical 1214 for many of the implants for a striker, it's V 40. But actually if you look at some of the custom made implants or even if you look at some of the older implants, they might be tapers that are like 910. So if you're revising something that is old has been in 20 plus years or has been a custom implant to begin with, you really need to know what that taper is. And if you don't know what the taper is, what options have you got in a revision setting. So, say you haven't been able to con you haven't been able to get any answer about your, um, you know, any operation notes, any stickers or anything like that, of a previous case. What, what options have you got implant wise without having to revise the stem. They're BBA adapters. Yeah. So what's that? Uh, I don't know, I think of it as being a bit like a sort of international plug adapter for electricity. You, you just have a slightly different size at either end of it, but I assume that it gives you problems of, er, increased offset. So BBA adapters, um, are pretty much like you say, um, Nick. So the first thing you do if you don't know what, what adapts, so if you don't know which one in it is, is, is that there are a couple of different sizes that you put on and you basically wait until you find one that is a fit in both planes. OK? You don't want it to sink too far down because that means that the taper is not right. You don't want there to be any side to side toggle. OK? So there's multiple tapers that you can try when you have found the one that is the right taper, you then have um to then know what it is that you're wanting to put in. So if I'm wanting to revise something to striker, I know that I need the V it, it needs to be converted to a V 40. Yeah. Um or to 1214 things like that. Yeah. So basically the inner side has one Trion taper and the outer side of the adapter has got the Trion taper that you want of the head. Yeah. Does that make sense? So it is a little bit like an international plug? I haven't thought of it. That way before Nick. Thank you. Um The other options that you've got with Vi A ball, if say you've got a really well fixed uncemented stem that you don't want to revise is, is that they then have offset changing tapers as well. So you can actually lateralize your stem, you can increase your offset. So it has got quite a few different options on it. OK? Um But yeah, basically it converts one taper to another and then you can control offset, you can control length. OK. Does that make sense? It's quite a nice option to have a read of if you are interested in revision hits? Ok. And certainly something to think about if you haven't got an operation note to have available um, and ordered in. Ok. Anyone want to talk about stem lens? What's the typical stem length of an ex primary extra hip? What length is the implant? 125 or 150? It's 150. Yeah. 150 is your kind of routine standard length? So when would you consider using a 125 Nick? Uh I imagine, um, if you've either got a very small patient or you are doing something like a cement and cement revision maybe. Yeah. Yeah, you can do that. And what other lengths does it come in? Does it stop at 150? Leading question? I suspect there are longer ones for cases where you might have, for example, problems with uh femoral lesions. But II don't know their detail. You, you said that was PT for example. Yeah. So it does come in in longer lengths as well. Any, any takers on the lengths that it might come in. I've seen 202 50 I think up to 250. Yeah. So you've got your 202 0 fives, your two twenties and then you get up to a 240. So, yeah. So it's got the advantage of say you're doing a revision and you haven't got too much proximal bones do, but you're not really in the realms of an noncemented implant. You can go longer with your cemented stem. If you're trying to, I shouldn't say this, it's recorded. But um you might choose for example to um do an ex ET O. And if you were got an anatomical reduction of either your periprosthetic fracture or an ET O, you might choose to use cement, but that's not an exam answer because what you don't want is cement getting into your et or your fracture because it won't heal. Um But you would need to bypass it so you could use the legs to stem for length. So if you have a, an anatomically reduced revision, you can do that. Um And then uh I sometimes do it from a tumor point of view. So if you're doing a hemi uh bear it for say myeloma and there's a lesion that's a few centimeters, sub trock, you could actually go along with your, um, unit tracts and bypass that lesion. Yeah. Uh So you've, you've got plenty of options with the, with the cemented stems in terms of your length? Ok. Um Any questions about stem L, they're not bowed. So the longer they get, they are still straight. Yeah. Not like when you start putting in revision on cemented implants which have got a femoral bow on them. Yeah, we'll probably cover that a little bit more next week when we talk about revision techniques. So OK. What is the centralizer for? Apart from the obvious to allow uh substance of the stent? Yeah. So a lot of people forget that the centralizer, it's not just there for its wings. OK? To give you your varus valgus control often if you're putting in si zero stem. So quite a small one, the only centralizer you get in the pack is one that doesn't have wings and it's obviously not acting as a centralizer. OK. But it allows for sub silence. So why is that important panos? How does this stem work? So this is how cement taper stems work for you. It it's about the hoop stresses. So as the patient weight bears, you expect the stent to sink uh only by 1 to 2 millimeters and that will increase the hoop stresses, stresses and the cement to implement interface. Mm. So with um the exeter you get physiological subsidence. OK. And it is intended to be like that. So when you wait there, the stem will subside, OK? It is a, the cement is a reciprocal wedge of the implant that has gone into it. OK. Um And so you need a bit of space for it to subside into otherwise it will just be up against the cement and, and it's not going anywhere to subside to if you look at an an initial POSTOP film and you look at someone a year or two years down the line. If they have another X ray, you'll see that there will be physiological subsidence by seeing slight loosening around your zone one around the shoulder. Ok. Because it will have just got a mill or so sunk down. And sometimes you can see in the, in the centralizer. Now, as you can see that you can measure the distance and see that it has subsided into the centralizer. Ok. And that might help you if you're looking at, is this physiological subsidence or is this loosing early loosening from a, um, a problem with the implant? Ok. So it is meant to subside obviously, not a lot but uh just a minute or two er, any takers for talking about the offset of an exeter or offset options if you got, comes in 37.5 44. And there is a higher offset which I've never used. There's two. So it also comes as a 50 off and it comes as a 56. So, uh, out in Norwich we do relatively frequently use the fifties. They come as a separate, um, set. So you have to ask for the 50 ras to be, um, bought out for the case. But, um, yeah, so we have quite a lot of, nor farmers who are quite tall, often end up with a 50 offset. So, um, yeah, it is something to bear in mind when you're looking at your cases. It isn't necessarily, you know, female, 37.5 male, 44. Um, but yeah, you have got other options. So you've got 5056 and I didn't get a chance to put this, a lady's x rays in who I saw last week in clinic referred to me POSTOP as a, you know, can you see this lady? She feels like she's got a leg discrepancy surgeon doesn't feel like it is just for a second opinion. And, um, petite lady, um, I looked at the note and I thought I looked at the X ray and I thought, oh, she's not got a lot of offset restored on her hip replacement and looked at the note and saw that they'd put a 50 I called up to theaters to actually check what was on all sorts. Is, is this a 50 offset, um, has a, you know, did, have, they thought they put a 50 in because it doesn't look like it's, it has restored the offset she has on the other side. And, um, it was a 50 I was like, I don't think I've ever used a 50 in a female for a start. Um, but to have a 50 it hasn't restored her offset. She's got these really various hips. Um, and I templated her up on her contralateral side and actually, you know, offset wise, she probably could have had a 56 and it's just, yeah, really, really unusual. And I spoke to some of the other guys and none of them have had to put a 50 into a female, never mind a 56. So it's just, you know, keep your, keep your wits value, uh be mindful and on these, you may not be somebody who templates. But, you know, on some occasions there are, there are good reasons, reasons to and if I remember I'll put the x-rays in for um when we do the session next time because it is quite an interesting x-ray to have a little look at, but just think about your offset. You have got your 37 fives, 40 fours, fifties and 50 sixes. There is one more offset. Any anyone there, the 35. Yeah. So you've got your 35 fives and uh you might end up using that in say um D DH type stems. Um They do start at 35 5 but they go up to 44 00. So um just bear in mind, you know, the exeter does actually cover quite a lot of different options that you might want. Um, CPT. How does anyone know how CPT works in terms of when you're trialing anyone use CPT similar Polish? They, they do it as standard extended and extra extended. Yeah. So you put your rasp in, don't you? So you might get to say a size three rasp and then you've got different trial necks. So it's quite nice in some ways because you can see the different, different extended neck without having to change your rasp over. Whereas with exeter, you need to decide what your offset is going to be and use that rasp from the get go and if you're going to change it, then you're going to take it out and put the next rasp in at the end of the world. But there's just subtle differences. Um So some of you, if you've not used X may not be so familiar with the offset. Likewise with CPT. Um There's not a number to it. It's just kind of your standard and your extended et cetera. So useful again to get in, you know, the detail of your opex to know what offset is equivalent to. Um And they do tell you that in there if you have a little look, they've got tables. Ok. Uh Good. Why is restoring offset so important? Why is, why is this lady that came to see me last week? In clinic. So upset with her hip cos she's got no leg length discrepancy. It's purely an offset, the tension of the abductors and how they will function. So, if you don't restore the offset, then they could be lax and then they don't work effectively. Mhm. Yeah. Also, go ahead. Also, it's also, it's quite important to restore the offset in order to have the less reaction force to the hip center. Uh If, if I'm not wrong, so usually uh larger offsets tend to have uh reduced um uh force in the hip, hip center rotation. So uh the hip reaction force is strongly linked to the offset that you were told to the patient. Um back to those horrible free body diagrams, doesn't it that you could have? Well, I certainly dreaded getting in the exam and luckily I didn't get that. Um Yeah, understanding the free body diagrams really helps you understand the offset and your abductive function. So I think we covered it, didn't we in basic science term last year for hips? Um But just something if you're not too certain about to start early, having a look in, say the Rami 100 basic science or whatever kind of sources you're using and try and get your head around the ba the free body diagrams for any joints because they do come up in the basic science station. And if any of you are particularly confused about it, I'm not going to put my hand up and say that I'm perfect at them. I'm definitely not. But the one person I know who is absolutely brilliant at free body diagrams is Mr Singh in Norwich. So if any of you um coming up to your exam and still not certain that you fully understand it, either touch base with me and I'll put you in contact with him or if you already have his contact details, just ask him, he will spend 1015 minutes going over it with you and you'll understand it. If anyone's coming up to their exam, I suggest you do that early. Yeah. Any, any questions? No. OK. Um You could be asked to draw out your femoral offset. So um I should have asked you what offset even was before we started talking about it, but it's from that center of rotation or effectively your, your tr uh to the um shaft. Ok. Um And Kim's quite right. It, it determines how your ab doctors are going to function afterwards. So this lady that's came to clinic to see me, um She's perceiving it as a leg length discrepancy. Uh But interestingly when she walks, she's got a Trendelenberg gait, but she's not Trendelenberg positive when you actually do the test. Um And she can't lie on this side at night. It's causing her a lot of discomfort and I think she's fatiguing. So initially when she starts off walking, she's ok. But once she gets towards kind of a couple of 100 yards. She starts fatiguing and starts trend down and be, yeah, where she's got some form of a deficiency occurring there. Um, but it's more of a functional deficiency as opposed to a nerve or, or muscle deficiency. Um. Ok. Who would like to describe these x rays? What kind of implants have we got in? Just keep it really simple, jo or no. Do you want to do it? What's the left hip? Yeah. So one side uh which is so the right side is cemented, the right side is sorry. No, I didn't hear you. The right side is cemented. Mhm uh uh Sorry. It's an hybrid. Yeah. And the left side is an uncemented uh D Yeah. So it's fully uncemented, isn't it? You often see when people are presenting cases in their FRCS. Um They often don't talk about all the components that are there to be seen. So it's really good uh habit to get into that, you say. Um So if you take the left, there's an uncemented um uncemented cup with an uncemented stem with a head that is either ceramic or metal. Yeah. Um You could say that it's either kind of the current generation ceramic or metal head on the right. You can say that you've got a cemented um stem with your uncemented hip consistent with your hybrid and then talk about your hair too. Um What it's interesting, isn't it? So this patient's got two different implants. What's different between the two? Which one do you think is more likely to dislocate? It doesn't have to be no fa, it might be a little bit of that. Both cup positions look all right, don't they? Yeah, you've got a reason or so, uh, patients left or, uh, my left, right. Patient's right. Patient with the uncemented, I dislocate. I think the, the offset is not restored on that side. Ok. So it's quite, quite difficult when you first look at these X rays in terms of offset because you're, well, my eye gets drawn to the fact of the child stem on the, you know, the old, um, classic on the, on the patient's left. It looks like it's got a really high offset, doesn't it? Because of this c shape that it's got this C stem? Yeah. But actually if you look at your, um, issue of femoral distance, they're not drastically off, are they, you've probably got a little bit less offset on this side. Yeah. Um, but yeah, I think sometimes this implant does make you feel like it's a really high offset. Um, ok. What other reasons do you think the right one might be, the patient's right, might be more likely to dislocate done. And it is. So, yeah, you haven't quite got the same cup position, have they as the other side? So there is a little bit of an overlap. You haven't got a kind of lateral of the c most have you. So it's either slightly retroverted or it's slightly antiverted and you can't really comment on that. Can you just on one view? But you know that it's not neutral in terms of its version on that view? Ok. So it might be protective. It may not be what makes it less likely that the patient's right hip is going to dislocate any takers. It's the size of the femoral head. So, on the patient's right side, uh most likely he has a 36 femoral head, it's a large femoral head used. Whereas on the left one, on the hybrid side, one, it's an old fashioned smaller femoral head, probably 28 or even, uh must be 28 I assume 28. Yeah. Yeah. Yeah. Good. All right. So why is femoral head size so important for your stability then? And jus it has to do with the jump out distance. So there is a nice specific diagram demonstrating that if we are using larger femoral heads, they are by definition a lot more stable because exactly the jump out distance, the distance that needs to be uh done of the femoral head to dislocate outside of the C is, is, is significantly higher using larger diameter heads versus using smaller diameter heads. Yep. So jump distance is one thing and we're gonna have got a picture to show anyone who doesn't know what jump distance is. We'll talk through it in a second. So jump distance is one aspect, what's the other aspect of having a bigger head? Why else is it stable? Um uh why else is stable? Because it gives us a greater range of movement if that's what you're trying to say. So it can give a greater range of movement. There's one other ratio that it affects. Uh do you mean the internal impingement? Um So yeah, what's it called? Oh I'm forgetting the definition sorry any take the head neck ratio? Yeah head who was that? Was that? Uh this is George George. Oh hi George sorry uh yeah so head neck ratio. Ok so um we're gonna move on and we're gonna talk through each of them in a second. Um obviously there's a wide range of sizes the very first hips. What size? Head did they have? 22.5? Very close. No but not quite so 22.8. Is it 22.22 22? 0.22? And that was because it was 7/8 of an inch because they didn't use millimeters. Ok. Uh so yeah so if you see a Charley hip implant you know that it's um 22.22. Yeah um so head size it affects your head neck ratio which we're going to come to it affects your jump distance but actually you could then say ok great. Well a bigger head is more stable I'm just gonna put a 36 on everyone that I do a hip replacement for. But obviously, the more, uh the bigger head that you have, the more surface area you've got, the more way you're gonna get. So it has got its downsides as well. Ok. So in terms of jump distance on the left of the screen, we've got a, uh, my attempts at a very big head and on the right of the screen, we've got a my attempts at say 22.2 smaller head. OK. So this is looking at the radius of the head. So if on the right, we've got our 22 then the radius is 11. Yep. If we've got a 36 on the left, we've got a radius of 18. So actually the smaller head has much less um to disengage before it can escape its cup. Yeah. So it's quite a big difference. Going from 82 to a 36 going from a 32 head to a 36 is kind of marginal gains, isn't it? OK. Everyone happy with jump distance, jump distance I would say is one element of stability, but the bigger element of the stability comes from the head neck ratio, ok? I've covered this already in a keep going. Um and this drawing is not quite so good, but I'll try. So your head neck ratio looks at the diameter of the head in comparison to the diameter of the neck. OK? And it is literally as it says head neck ratio. So if you have got um this head, you're gonna have so bigger head you've got a bigger range of movement before the neck impinges on the cup and levers out, ok? If you've got a head with a skirt on which effectively increases your neck ratio in the range of movement that you get is slightly reduced. But and you can see that because of this angle, ok? But then it levers out, ok? And that is in a situation where your head ratio is much smaller than your neck, ok? Um And that might come from having a 22 head on a on a neck and therefore there's not much difference in size or it might come from having a skirted implant, ok? So he's put an extra long neck on to deal with an issue or a leg length issue, then ends up with a stability issue, ok? So if you see those X rays, you know um that that's a potential problem, ok? You can see something wasn't quite right in that operation, ok? We've already discussed that before we start talking about surface properties and a bit of wear. I think we should have at like 5, 10 minute, 55 minute break because my batteries about to die and I just need to plug my uh laptop in. So if you wanna grab a quick drink, do so. Um I'm just gonna quickly uh plug my laptop in. Uh, so five minutes come back at 25 past. Yeah, everyone back or need a little bit longer. Yeah. All right. Let's keep going. Oh, ok. Um, obviously the answers already been up. Anybody know what wetability is and what material it's a, a unique property for or a positive property for. Isn't what ability the ability for, um, a material to be in contact with a liquid and usually refers to ceramic. Yeah. So it's a positive feature of ceramic. Uh and it affects the material ability for lubrication. All right. So people talk about the to angles um coming past that. Sorry, I've got a picture of it. Um And it's how the droplets spreads. Ok? And the angle that it forms. So you get much more lubrication for the same amount. Um So the same volume of fluid. Ok. So it's a positive feature of a ceramic. Um albeit probably one of the few um one of the few surface properties that's a positive. Um You could also talk about negative surface properties of femoral heads. Um And um you might say, well, why do we use titanium stem? Well, why do some people used to use Titanium stem? Say, but not, you can't use a titanium head. So any any negative surface properties of titanium, if it, if it was ever to be used as a head is not allowed to be used. But what's a, a bad property of titanium low resistance to abrasion. Yeah. So what's the kind of buzzword name for that? Um, Georges? Uh, it was me Panos. II. Don't know the name of it actually. Yeah. So it's called notch sensitivity. So once it's got a scratch on it, it's more likely to get a lot more. So the debris comes out, it, resistance to stress is very low. So you're actually, you're not, they're not allowed to manufacture titanium heads. ok? Um So if you're talking about what type of head you're going to use, if you're in the exam, for example, and you've had to talk about the implant choices. You have to remember that also includes your bearing surface. So you might want to be using a ceramic head, you might want to be using a metal head, but you need to have some kind of justification what you want to use. So if I was using a 36 head, I generally want to use a ceramic because the risk of tins is probably slightly less. Um Yes, I'm using a bigger head. So it's got more likely to have uh wear, but actually, I can improve its lubrication because of the wettability features. Ok? Um If it's somebody who is more elderly, then you might say, actually, I'm less worried about the wear properties. And so um I'm going to go for something that will last the patient and less likely to cause a problem and needing revisions. Um So I would use something like a metal head in those situations. OK. So some form of justification and thought process behind the type of head that you want to use, but you're probably not going to go wrong if you're wanting to use a ceramic head here. Um, ok. Anyone, er, remember what adhesive wear is? Yeah. Yeah. So the polyethylene sticks to the prosthesis and gets pulled off. So, if we've got ceramic, what are all these spiky bits? Can you remember, Andy? Any for the even the smoothest surface has got some form of asperities? OK. So the polyethylene in the gray gets stuck to the ceramic asperities and when it moves, they get, they get pulled off. OK. It produces debris. So the weak worm gets stuck to the stronger one. OK. It's probably one of the forms of wear that you're going to see in hip. What's abrasive wear. So this is more of your kind of cheese greater um effect. I guess if you've got something like a third body in there, uh you might get some abrasive wear. A trick wear is associated with the number of particles uh formed, right? If I'm not mistaken, it is the most common type of where um where the um the um how can I say? I think the, the amount of work caused is strongly associated with the number of particles inside the um uh the implant uh interface, I think. Yeah. So this relates to your head size. So basically, um the more sur there you've got the more volumetric wear you're going to have or particles you're going to produce, it determines your debri volume. OK? But when you're talking about your say 36 head wear, you're talking predominantly about volumetric wear. And what about linear wear, which are you more likely to get linear wear with a big head or a little head somewhat leading maybe? Uh So this is um how much the head penetrates the liner. So you see that over quite a long period of time, you may not see it very clearly on X rays. Um But where you've got higher force per for your surface area, you'll get more linear wear with your smaller head. Yeah. So big head volumetric wear, small head, uh more likely to get linear wear. Yeah. Um So again, diagram for your volumetric wear, your bigger head has got a bigger surface area. OK. So you're going to get more of your um debris particles um than you will with your smaller surface area. OK. Uh So that's your types of wear. And then if you get asked to talk about modes of wear, this is your numbered one. So some people, I've seen people in viva situations, we asked you to talk about different types of wear and they kind of go through the ones that we've just discussed. Um But you might want to talk, you can split that up as your modes and, and as well as the mechanisms. OK. So any take as for what type one, where is, what kind of surfaces have? Type one wear? So if I say that type one wear will occur between your femoral head and your acetabular liner, what, what kind of surfaces are they intended or unintended? It's, it's between the intended surfaces, right? It's the expected where that we are expecting to see. Yeah. So this is your volumetric wear. It's your linear wear. It's your abrasive, your adhesive. Yeah. So it's between your um intended femoral head and your intended socket or liner depending on if it's cemented or uncemented. Ok. So intended on intended. Ok. What's type two? Um If I remember correctly, it's between unexpected surface and an unexpected surface. So it's between the bearing surface from one side and the unintended from the opposite side. Yeah. Um Any example, um Georges, is it, is it the way between the, the cup and the polyethylene? Uh because that area is, are you describing back side where back side where? Yeah. Yeah. So it's not really so much of an intended surface, is it in some ways? And you could argue it? But your intended unintended might be when your femoral head sublux or you partly dislocate and your intended femoral head wears on the acetabular shell. Yeah. Ok. You, you mean eccentric wear of the polyethylene which causes uh articulation of the femoral head onto the cup So if, if this patient was to dislocate and their head gets scratched on the acetabular shell. So the metal part of the cup that would be an intended surface against an unintended surface. So you're never meant to have contact. Are you between your metal shell and your, and your femoral head? Correct. Yeah. So type three, this is the one that was slightly easier to remember and uh you always kind of hope while I was just, I hope it was the one that came up in the exam if it was gonna come. Is it when we have um uh um a particle between the, so you've got a third body. Yeah. So for example, uh a bit of cement is between your poly and your femoral head and so you get a third body. Type three. Yeah. Uh So last option anyone for type 40, it's come up anyway. Um Is your unintended surfaces? Ok. Close. So sometimes we'll see somebody who's got so much there that actually their femoral head is just in there. Um That's actually not right. Sorry, I've I've done that wrong. So that would be another example of your type two, isn't it? So it's an intended or an unintended when it's eroded right through. So, what I should have drawn in here was an example of backside wear or chinois. Yeah. So um that's when you have an unintended surface. So the back of the poly liner against uh another unintended bearing surface, your cup or the inside of your femoral head on your Trion. Ok. So where between two unintended surfaces? Again, it is a really common exam question to come up. So it's just in there for a, for a reminder from that point of view, if you uh in some ways fortunate or unlucky to get an, an arthritis in your Fr CS is a little bit like a hip fracture station. You need to do really well, cos it's kind of bread and butter, isn't it? So, in terms of getting a level eight for arthritis, you want to show evidence for the choice that you're so either any approach you're taking evidence for the implants you're using. Um And these come from being able to talk about your ba standards for arthroplasty, the nice guidelines and then talking about GF as well as the NJ R and ODP. Um And so I was going to ask for s to talk to us about their N JR report. Um But I don't think that they've covered OD. So does anyone know what ODP is? Yeah, George A I imagine you might know it's like a, a way of go ahead, Kim. It's like a way of standardizing um uh that they give a scoring to say the, how, how best to put it. So they give a, a rating for an implant to show it's like um it's use and how uh how long it's been on the market and, um, uh, it's dislocate, I mean, revision rate, not dislocation rate, it's revision rate. So it kind of gives you a better view as to how good the quality of the implant is. Yeah. Absolutely. And it's also a safe way of introducing new implants. Ok. So there's something, anyone know what beyond compliance is. One heard of it is that for new implants where they can demonstrate safety, they can get an her, but it's not like um formally given, it's like a provisional rating until they've proven that they are at that standard. Yeah, so it's provisional rating and it's under really strict review. So the surgeon has to take responsibility that they've been appropriately trained on that new implant and the patient has to specifically sign a consent form that a new implant is being used for them. And there has to be data recorded from that implant. So it's a really strict way of introducing new implants. Ok. Um So an example of an OD rating might be say 10 A star. Yeah. So the 10 is the number of years of that the implant has been available and has been being implanted with recorded data. Yeah, so say 10 years of NJ R data available. The A comes from the level of evidence so it can be an A or A B. So A is good evidence. Good level B is not so good and so that might be just in house. Um You know, uh let's pick, let's pick Zimmer Zimmer have got in-house data for their implant only. So that would get them A B but the moment you get up into trials or N JR data, uh bigger numbers you get an A and then the star is your revision rate and to get a star, you have to have less than 5% revision at five years. Ok. So 10 A star is considered a good implant and uh, what we should be striving to use. Ok. Anything less than that. Uh, either poor evidence, less time or um, higher revision rate and therefore doesn't have a star is less, um, less favored for use. Ok? If you haven't been on the ODP website, you can literally go on and put in any implant and find out what his ODP score is. Ok? And it's one of the things that you need to do before your exam to know what knee replacement you're using and what hip replacement you're going to use. So you can say that you're using implants that are compliant with. Nice. Ok. So I'm gonna stop talking and I'm gonna let Jose and er, Norfolk carry on and then we will tie up any loose ends and questions that anybody's got. Uh, thank you, Jo I know you, you are on call. So thank you for, to you guys. Hi. Um, no, are you ok to run the slides for me or do you want me to? Sure, thank you. Uh Hi, good afternoon. My name is Jose and I'm John by my colleague. No, and we're hoping to take you through the N GR report and um implant choices as a consequence of it. Uh The learning objectives we're hoping to um uh have from today's session would be, I'll take you through a brief overview of what the N GR is before we decide and analyze the N GR uh uh report for last year. Talk a bit about the gi surgeon and hospital profile website. The advantages and disadvantages then try and summarize the GI I 2023 report and then try and answer the question, what hip implant would I use? Uh So, um talking a bit about the um NJ R um that that's basically a timeline of how orthopedic registries have uh uh started uh across the world. Um So the National Joint Registry is the largest in the world with about 3.7 million procedures having been recorded. It started in um 2003 with data being collected from England and Wales with Northern Ireland joining in 2013, Isle of Man in uh uh 2015 and uh Guernsey joining in 2019. Um The purpose is to collect and monitor data from hip, uh knee, ankle, elbow and shoulder arthroplasty. Um The years in the bracket basically shows when the data collection started for all of them. Um So the National Joint Registry was actually established by the Department of Health and uh the Welsh government in 2002 to capture data after the three M capital hip um plant failure, the three M uh capital Hip was actually marketed as a uh as a cheaper alternative to the Charley Hip in the uh early nineties. And by early 2000, uh there were a lot of cases of uh failure having reported where uh due to loosening uh metallosis and fracture and therefore many of these had to undergo revision. Um Then uh National Joint Registry was brought about and now uh there's been 20 years worth of data. Um submission of data to the registry has been uh mandatory for the independent sector since 2003. And for the NHS Trust from 2010, with compliance being reported approximately 95%. Uh The purpose of the NGR is to monitor outcomes for implants. Hospital and surgeons inform the patients, clinic, clinicians, industry and regulators about these evidence, any variations for best practice and try and basically have an evidence based uh uh purchasing of these implants. Um So at the uh core um of s work is keeping the patient in mind and their safety and wellbeing by engaging with the various stakeholders which are the surgeon hospital and um the industry. Um So the strategic direction and operational oversight of the registry is by the N Gr steering committee which means about uh four times in a year. Um The N GR is actually funded based on a subscription model. Uh and the money comes from the trust as well as the implant provider based on the number of cases that each uh trust um has a turnover for the previous year and approximately it's about 15 lbs per procedure. That's the approximate value for the subscription. So the uh the joint registry has an open uh access or a public access and a restricted access. The public access includes the, the annual report. The that is patient's perspective and the N gr surgeon and hospital profile website. And the restricted access is a password protected where consultants get feedback on their um data. There's a report for the hospital. Um the industry gets an implant pricing data, uh research data, uh access portal and a supplier feedback. Um So moving on just briefly touching on the ng surgeon hospital profile website again, this is part of open access. Anyone can actually just type in the name of a surgeon who is uh registered. Uh And uh then what comes up next is basically uh uh no, if you don't mind, go to the next slide is if you just type in a surgeon's name, then it basically gives um their details about their practice and um who are about the patients who are being treated and, and, and, and it's listed in a diagrammatic format for, for anyone in the public to be able to see uh and what's their 90 day mortality. Uh If you go on to the next slide, then we now coming, this is a slide which is basically more restricted data, which is available, made available to the surgeon. And this diagram may be familiar because he actually took us through this a couple of sessions ago where he talked about and I think he asked in the FRC exam as well. So if you look at the diagram there, this is a funnel plot and uh the black dot there is the is the surgeon for whom this has been provided. The Bale blue dot are all the other surgeons in the registry. So, and um I don't think the colors are very if you see what the line which is across the black, uh the black dot is the national average and then there is one standard deviation that is within 95%. And then there is two standard deviations which is within 99.8%. So if uh a a particular surgeon's uh uh outcome were to be noted to be slightly above 95% which is the alert level, then he would, then he or she would then be asked uh is recommended to review his uh his or her data and share with local colleagues. But if they were to cross over the alarm level, then uh this is then peer reviewed with within the surgical performance committee and then usually both the surgeon and his his or her unit medical director are notified. Um And if you see those red dots, those basically indicate outliers. So this is a it is more confidential. It's not uh easily accessible to the public, something similar uh is also available for each hospital in terms of how the revisions are. Um if you may go to the next slide, please. So the NJ R has advantages, numerous of them. It allows for real time and real monitoring of implant and surgical performance because of the number of years of data we have. So it allows for reporting of temporal changes, rare events which uh such as uh revision and mortality um can be better assessed. It allows for case identification as we noted in the three M capital hip and especially the metal on metal hip uh um uh issue. Uh uh for product recall and uh and for patient identification and monitoring of plate is also allowed for linkage of other data sets to uh with other patient related outcomes. But then there are disadvantages and and this is probably more um important to be aware of that. Revision is the primary endpoint for the N GR data, but revision only assesses one aspect of implant performance. Um It does not, we don't get the whole picture about implant behavior or the clinical characteristics of the patient. Again, it's an observational data set. So one cannot attribute causation or uh but can only look for association. And then there's always a question of transparency versus accountability because the N GR is funded by the NHS. And then there is politics which is involved and the politicians want all the data to be made public. But um then there is uh surgeons who they can always be tension with the surgeons who wouldn't want all the data to be uh to be available. Um So, uh I'm just gonna stop uh at that and let know if I'll take over and summarizing the N gr the 2023 report. Um Thanks. Just um so talking on top of that. So, so just a overview of the registry. So it started in April 1st 2003. So we have a huge collection of follow up about 19 years uh in the registry. So, till now we have uh more than a million. So um 14 um um we have so many primary hip replacements recorded across 484 units by 4039 consultants over the last three years alone. Um We have 16.9% of the current registry volume performed. So it's, it's a um huge volume of surgeries being performed and being monitored. Um Female to male ratio uh was 59.8 to 40. Um It was something which I noted. So females are having more hip replacements than the male. And uh oa was the main indication, uh which is about 91% and then you have the NS and then the other reasons, uh just few uh graphs. Uh it's quite uh comprehensive um report about more than 100 pages. So what I could see here uh is um these are the implants which have been recorded. So all cemented implants uh come um cemented implants about 29.8% of the primary hip operations and all cemented uncemented are 37% which is about uh 500,000 and all hybrid, about 24.9 and rest, you have the reverse hybrid resurfacing uh which are small numbers. Um And the procedure wise if you see the trend, um you have an uh unipolar uh total hip replacement um going up um from 2003 and then the resurfacing are coming down and we, we have very less amount of surgeries uh being resurfaced on total hip. And the other thing which is going up is dual mobility, total hips. Uh If you see the uh trend and uh the other thing is trends in the hip replacement. So, um this has always been a debate whether to use a cemented uh um stem or an uncemented or an hybrid. So if you see the cemented um um stems are um thr s are coming down and then there is a rise in the uncemented thr s um which peaked in 2012 13 and then peak down. But still, I think it's picking up after 2019 and then the hybrid has been uh the favorite among all of them. So it's been always been going up the trend and now 2022 suggest that it is uh more than the uncemented. Um the cemented thr bearing trend, if you see the metal on poly and the ceramic on poly are the most favorite. And uh there is an upward trend for the ceramic on poly over the years uh which has been going up and the metal on poly uh was favored, but now slowly it is coming down over the last few years. Um Then in the uncemented setting, um I think they've been using all metal and poly uh ceramic on poly. But the thing which I could see is ceramic on ceramic is coming down um quite that people are not using that instead of that, they are going for ceramic on poly, which is an upward trend and the metal on poly has always been the same and slightly it's coming down um in the hybrid uh total hip. If you see it's pretty much the same uh ceramic on poly is again going up and metal and poly is likely coming down. Uh I'm not talking about the other things because very much less. And as I said, ceramic on ceramic is again going down the trend. Um The trends in the head size if you see um as this is another good graph which shows uh um about the various head sizes. So we hardly using generally's uh head size now. So, so it's basically either 2832 and 36 are the head sizes. And um uh metal on poly and ceramic on poly, you have various trends, but I think the 28 trend is going down and uh 32 is the one which is, um, picking up in both metal on poly and uh, ceramic on poly. Um, but also there is another trend of 36 which is, uh, going up, uh, slowly but not as good as, uh, uh, 32. Um, the other slide which I found interesting was the fractured off versus oa. So if you see, um, percentage of, uh, hip operations, so you have more than 90% of being operated for a total hip for, uh, osteoarthritis and then about 10, more than 10% for fracture off. So, in that, um, it's quite, uh, um, gender wise if you see females, uh, 72% and 59% are females in osteoarthritis. And, um, if you see that, uh, male only if it's 72 the age age for fracture off having a total hip, uh, the median age is 72 years, uh, a little bit older. And then in osteoarthritis, the male age is 68 in female. It's a little bit, um, older So, the, uh, median age is 73 and then in osteoarthritis is 71. So, if you see, uh, in Fracture Off, uh, the preferred, uh, thing is all cemented in the registry and in osteoarthritis, it is 30.7. And, um, I think all hybrid is the one which is being used, uh, for fracture of 38.7. And, uh, on osteoarthritis hybrid is 24.8% among other all uncemented. Um, in fractured N is only 18%. But if you see in osteoarthritis, it's 38.8. So the uncemented thr s are going up the trend now and uh hybrid has always been like uh uh gold standard. Um Yeah. So implant choices, um if uh after seeing this data, my preference will be so, so you have different age groups but to be on the safer side when you're starting as a consultant, not to be on the outlier. Um I think 70 would be a good cut off. Obviously, you can stretch according to the bone stock, whether you want to do uh um cemented stem or an noncemented stem. So, um, hybrid thr will be a standard option, um with a, um, with a cemented stem and an uncemented cup for an osteoarthritis hip. Um um and for and off. But in osteoarthritis hip, if um, um the uncemented stem, you should be um wisely using it based on the way our nr studies are still supporting uh hybrid, but the uncemented stem thr s are going up. Um There are other registry supporting that uh the Swedish and the Australian registry all supporting the uncemented stem. And also there was a recent paper on B JJ about the uh periprosthetic fractures with the polish tapered stem um which is uh being recorded now. And um the other important thing is many periprosthetic uh fractures being fixed and DGS are not being recorded as revisions, which are again being now analyzed and they are going to come in the data soon. So if, if this trend goes on, then slowly the uncemented stem uh trend will pick up for a total hip and bearing surfaces. As I said, the ceramic and poly is being preferred over ceramic on ceramic and anger patients. And uh if the patient's age is uh old, then metallo poly is always a good option to keep in mind the head size. I think the 30 sorry, this is uh type error. So 32 is uh being preferred over 28. Uh and then 36 should be a standby. Uh If you are thinking of uh uh dislocation chances or you want to put a bigger head and the cup uh you can, and there was no uh much of that I could see whether um whether it is uh you can go for an uncemented cup, which is a preferred one but with or without the screws it depends upon how much stability you want. Uh what you want to gain in that after the operation. Uh Yeah, that's it. Well done guys. Good. Any questions for nephrologists? I always find um trauma totals quite interesting with hip fractures because often by definition, these kind of low energy falls um in patients who are, are fit enough still to have a hip replace, by definition, they've got osteoporosis, haven't they? So I do find the use of an uncemented total hip replacement in someone with osteoporosis. Quite an interesting concept. I certainly, my preference is in those patients is to actually cement them because it's more bone friendly. Um But it, yeah, it's interesting, isn't it? The variation in practice? And again, that might come down to kind of those geographical variations where people are already doing more uncemented in their, you know, in their primary practice. Um And so automatically they do that in their uh in the trauma practice as well. So, um certainly there's quite a few hybrids that go in for hip fractures, um in knowledge. Um But yeah, it's just an interesting concept, isn't it? If you know someone's got poor bone and they've had a hip fracture um to not pick something that is reliant on your bone stock? Yeah. So getting the leg length light in and uncemented is a bit tricky. So, and especially in a fractured nerve, it becomes even more trickier. So, so that's why people, yeah, so, but people who are doing uncemented, they kind of and now the data is suggesting more with the colored un.