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Summary

This one hour-long on-demand teaching session is for medical professionals who desire to learn the difference between a fully-coated stem and a meta-coated stem in the shoulder and the potential advantages and disadvantages in respective usage. The topics covered also include recommendations for stemless prosthesis, potential causes of bone resorption in the humerus, and the management of Glenoid bone loss.
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Description

Part 2

Learning objectives

Learning Objectives: 1. Describe the difference between a fully coated and a meta-coated stem for shoulder prosthesis. 2. Explain how patient selection and osteopenia/osteoporosis may contribute to prosthesis failure. 3. Discuss the advantages and challenges of stem-less prosthesis in the shoulder. 4. Compare different failure mechanisms between hips and shoulder prosthesis. 5. Identify potential management strategies for glenoid bone loss during revision total shoulder arthroplasty.
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Computer generated transcript

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

OK. So we were now you can hear me and I can hear you. We were talking, I mean, Maria, I know you've got an answer to this question because you, you've said it not once but twice. So we'll, we'll try third time, lucky with this. OK. So if you can tell me what's the difference between the two stems prosthesis there? So one of them looks like he's is coated only proximally and the other one looks like he's coated on the, on the whole surface spot on. So one is a fully coated stem. That's the one on the left and the one on the right is a meta coated stem, as you said. OK. So what are the potential advantages and disadvantages of a fully coated stem in the shoulder? And if it's good, why would it fail? The fully coated one got a diaphyseal fit. So it, it integrates with the diaphysis um uh potentially got um less stress shielding because it um there is a, an interface with a, a more surface area. OK. All right. So less, less stress shielding with a di to deal with them or more stress shielding. I would that phrase, like I would say meal fixation will have less sister shielding than dial fixation. Yeah. Yeah, that's the right way around. Yeah, exactly. So, if you have a dial fit stem, as you said, the problem with the folic stem is that you do get integration along the whole thing. So again, most people are familiar, aren't they? With hips stems? Uncemented hip stems. Ok. Um, so it's exactly the same principle. OK. Obviously, it's not weight bearing joint, the shoulder, but the biomechanics are essentially the same. It still, it still stays stress through it. So if you have a diaphyseal fit, as you said, and it's fixed a, then you are not going to load the cow car. Are you because the force, the force is transmitted down the stem and into the diaphysis rather than it being the taf seal loaded? OK. So you're quite right there. And then the meta one say somebody came up and designed a meta coated stem, which still allows some bony growth in the metastasis. But the idea being again that you're not dif ceiling. So you're right, obviously, for the humeral side, the main concern is proximal bone loss. OK. Um In terms of failure, because even with a meta loaded stem, you can still get some bone resorption, but the rates of bone resorption are much higher with a fully coated stem. OK? Um The other problem with folic stems is if you're jamming something into the diaphysis of the humerus. If you have to revise it, how much fun do you think that is not fun? Um, not fun. Yeah. So you, you've got to get the whole thing out. So if you, if you jam these up and, and round them into the deficit to get them to fit, um getting them out, you do get the bone properly grows onto them and it's incredibly difficult to get it out without completely destroying the humerus. OK. So, in terms of revision, again, if you're thinking about it, um you want to think about, if I have to advise this, what's the best way to do that? And if you use a meta seal stem, all you have to do is pop an osteotome around the outside and just break that proximal bonding. Um And it, and it should lift out if you have a fully coated stem, you're looking at AAA humeral osteotomy to get the thing out if it's wedged in. OK. So it's quite a miserable experience that, all right. Um So that's the main difference between t so what from the humeral side, bone loss is the main issue. OK. Again, as with the caveat that we've talked about infection being the thing you need to rule out in the first place as aseptic loosening. So it can also cause bone loss, but look at the type of stem that's in there um As well as a potential cause. So you, it's the same principles as a hip, as we said, as Nabil described there with the proximal bone loss and the stress shielding. OK. So there's no difference between the tea. So thinking about that and stems and things like that and jamming them in. So stem less then surely that's the answer. Can a stemless one fail? Can you get, can you get bone resorption with a stemless prosthesis? Surely not. Um Well, you, you can um I think it's a relatively more modern concept when um some people say that the humoral fixation relies mainly in the metaphyseal support. So some people suggested that there is no need for um diy stems but having said, but having said that in the literature, I think there are some numbers of failure of the stem shoulder replacements. And that is because biomechanically we are not 100% sure if just the metaphyseal stem can support all the stress that um raise along the area of the CALC and the proximal metaphyseal region. Um Yeah. So, so that's true. I think that comes down to patient selection, doesn't it? There's an element of that if the meta bone. So there's something called the thumb test, um which is basically where when you've done your cut, you get your thumb, you press on the metastasis. If your thumb goes into it, don't put a ste in. If it's sort of relatively hard, then you can put a stemi in. OK. That's that is a very crude thing. OK? For your osteopenia and osteoporosis you have in the metaphyseal bone, which can, if you, if you put in a, that ST is going to fail because there is not enough support. So it more to do with the selection of the patient that we the long term. Yeah, exactly. So the mechanism that George George is describing is basically that, that you've got insufficient meta support. So I think that's probably not an implant design issue. That's, that's more of a patient selection issue. OK. Interestingly, um the stem, this designs can fail in a similar way where you can get stress shielding. OK. Which doesn't, it sounds a bit odd, doesn't it? You think? Well, how can you, how can you get stress shielding from a meta fit stem? OK. Now, the reason for that is that you obviously these cages are sized, OK? So you can, you can have different of cages sort of come generally in about, it depends on the implant. The one this one here comes in three different sizes. OK? Um What the uh evidence is saying now is that that when you get proximal bone loss with the ST designs, it's because there's diaphyseal contact. OK. So be it with it, whether it's a thin design, a cage design because all of these have basically got fins, they're free thin designs or full fins. OK? If you've got, if you got contact or it's in with the, with the uh the cortical bone, then you're essentially uh preferentially loading that cortical bone and therefore you'll lose the meta Stal support. OK. So that's, that's again the mechanism of failure. So with stemless designs, now the the advice is to downsize them. So you're not going to the biggest one you can fit in, you go for the next one down so that you're actually making sure that those supporting fins and the cage itself is loading the meta or bone, which in theory should then not cause um stress shielding. OK. So it is still possible to get stress shielding with uh a stem. This design uh that's when you've got cortical contact, it essentially the same principle applies as what we've had earlier with the fully coated one. OK. But predominantly, that's, that's the main issue with these, these humeral stem designs, which is the same issue with, with the hip stems, isn't it? The, the design is the same issue? OK. Do you get the same thing with cement? Yeah, cement can do the same sort of thing as a fully coated stem. OK. These aren't taper slip designs. So you're not generating he stresses with these. OK. The cement in um the cement and knees are basically um stopping rotation. So they're not there to, there to support the implant per se. They're just there to stop rotation of the implant. OK. So it's a very different concept to hips and that you're essentially using it to keep the thing from rotating. Um but it's not um so you don't get the same sort of issues as you do with, you know, like composite beam designs to the hip. Er But in theory, if you were comparing it to something in a hip, this is a sort of composite beam design, really not a tape slip, so you won't get hi stress in effect. So cement, in theory, can, can cause a similar problem of stress shielding again. Um But they might show you a coated one. These were very popular then became deeply unpopular because they were very difficult to get out. Ok. But the main issue with the humerus really in terms of failure is stress shooting. OK. Or infection or? Ok. Good. That's humerus is OK. Iggy. I'll have a look for you. I think there is one that is a 10 A style. They're not many of them, relatively new stim this designs at the moment. OK. So we've done the humerus. I, I got one question. Um my um in, in, in, in case of a VN of the humerus, would that be a contraindicated for a resurfacing or a a stimulus? Are we dealing it the same as we deal with the hips or the humerus or the shoulder is more forgiving? So we can still do re and A N as an option? Yes. So recur is not something that's commonly done more in the shoulder er, Copeland resurfacing, some places still do Copeland's but they're not, they're not terribly popular anymore. Um, mostly I think because a lot of the, um, now you've got stemless designs that are bone preserving, most people will be happy with that. I think, I think it comes down to again what the metastasis is like when you get in there, I don't think it's necessarily a contraindication. Um, because often once you've had that subchondral collapse, actually, it becomes quite sclerotic underneath when you cut it, it can be quite hard to say. Um It depends, really, doesn't it? But I think, I think again, it comes down to patient selection and what the bones actually like at the time. All right. Um So I don't think it's necessarily a contraindication to it, but I, I think you've got to take each case as you see it. OK. Right. No worries. Right. Next one. So Glenoid bone loss. So this is another issue. OK. So we're moving into revision territory now. All right. So how do you manage Glenoid bone loss? All right. So this is a case. One of the first things I did as a consultant actually. So I inherited it in this state. So you can see there that you've got a, this is an actual CT which has got a, this is a cement spacer. OK? So there's a preformed cement spacer. The bit me is in there to, to show you that on an ra where it is. OK. So what, what do you think about this glenoid? So, in context, this was a failed um uh stemless shoulder replacement that was put in by a colleague with an old poly glenoid that had been cemented in place. All right. So if at that stage, when you were taking it out, you know, how would you, what are your thoughts about managing bone loss in the glenoid? Cause obviously, if you take, when you put a uh uh an implant in uh any glenoid that you put in, you're gonna be drilling a hole in, aren't you to get some sort of peg in somewhere, right? Sometimes two holes? OK. So if you're in that context of doing this 1st, 1st stage of a revision, what are your thoughts about managing bone loss at that point? We have to consider the, the use of a, an augmented base blade uh depending on the, on the preoperative CT scanning and use of a preoperative um a surgical planning depending on the we we're gonna use. Ideally, this is going to be a very good case for a, a navigated shoulder replacement because intraoperatively, we will be able to assess the anatomy of the glenoid from the CT scan. On this axial view. It looks like there is quite significant posterior bone loss of the glenoid. And, and because I can also see the coracoid if I'm not wrong, I assume this is a case of superior and posterior glenoid bone loss, which is gonna be probably a bit more challenging. Very good. So we call it glenoid. Yes, it is. It is. And this is AM m this isn't a superior section, it's slightly high, but it's not the highest point of the shoulder. So you're right, George, I think you're thinking about the second stage. You're in the context of, of you're in there at the moment, say putting the cement space so you've ripped everything out. But is there anything at this stage that you can do to manage the glenoid bo loss? Because you inevitably gonna have glenoid bone loss right at that point because you've got two white holes where you put that thing in reconstruction like a bone graft like reconstitute that bone, bone, bone loss first and then kind of build up on a, you know, grafted glenoid here. So, yeah, I agree. You can graft it. I'm not sure about struck grafting because it, because effectively you're looking at two holes, aren't you? So, so it's, you want to start thinking. So what I'm trying to say really is at this point when you're, when you're at this point of a staged revision and you've got glenoid bone loss, you want to start thinking about how you can minimize the amount of bone you're going to have to replace or you're going to have to augment the second section. OK? Mr, you mean you mean what we can do during the first stage revision, what we have removed the previous implants? Yes, I assume probably nothing. Because if, if this is the first stage of the revision, we just need to take the previous implant out. I've seen you, you've used a cement spacer. So I assume this is an infected case. Well, that's the problem, you say so. So probably we should minimize the risk of adding any extra allograft in and screws. Because what I'm thinking is the only reason to restore the bone loss of the glenoid will be either to put some allograft and then shape the, the bone loss which is missing and secure it at the back of the glenoid er with some sort of screws. I assume. So. Are there any other options that aren't that that aren't organic in terms of grafting? No. So we're still, we're still in graft, we still in graft territory. So, yeah. So you've got, you've got organic forms of bone graft. Yes. So you had a graft or a graft? Ok. But then you have synthetic bone graft, don't you? So your calcium, you know, sulfate and your calcium tablet. All right. So there are things that you can do at this stage. You can, you can use um a combination of bone, so native bone, but you can also use things like stimulant um which can be antibiotic, impregnated. If you're worried about infection, you can impact that in. OK? Because if you can start managing if you've got two defects in there already, you're then effectively putting something very abrasive in the form of a cement spacer into a shoulder that's not going to have much in the way of containment. Ok? Because you, you, you are effectively putting a hemiarthroplasty in, aren't you at this stage? So given that the rotator cuffs probably would have probably failed in this instance, you, you're gonna have a very sort of wobbly shoulder. Um And if you have that and an abrasive thing working against something that's already got holes in, you're gonna end up in trouble, aren't you? Where you're gonna make your defect worse? So even though I accept that you're saying about the risk of infection, it's probably worth using a combination of things to impacting graft into those holes to allow you need to have something to potentially rebuild back into. Ok. So the point of this really is to illustrate that your thoughts about glenoid bay loss, don't, don't leave it all to the second stage, ok? Or, or, or to the, you know, if you're doing the first stage because if you wait for the second stage, you could be in a worse situation than you were. Ok. Impaction grafting, providing that it's loaded. So I, I did have a boss who used to for a little while because we had big glenoid defects. We put a, a kind of almost like a cap over the over the glenoid where he put the graft in to try and contain it, stop it falling out. Um But he put two screws on that. Now, the problem with that was that, is that the, the space it then loaded, the kind of cap that he put over it um run the actual bone graft. So the bone graft resorbed because it wasn't being loaded. So you can put something in just to get it to try and load it. And that's what um my colleague had done in this case, he put some stimulant into the, into the the defect already. All right, to try and try and get it to grow back. All right. So when you're coming in to talk about glenoid bone loss, you basically, it comes down to two very simple things. OK. So is the defect contained or not? OK. So by that, I mean, you know, have you essentially got the, the, the out the outline of a glenoid? So have you got the, the walls of the glenoid intact? And there's some sort of vault, albeit without any bone in it present? So it's a defect contained, yes or no. If it's a contained defect, you can impaction graft into it. OK. So that is just taking either um depending on the context in which you're doing it. If you were doing a um recut, say for a failed anatomic, you're cutting the humerus, you can take that bone that you've cut morselized it and pack it into the defect. You can use, you can use um other things that you can use. Uh you know, like your, your synthetic bone graft to help incorporate it. All right. So you can do that if it's a contained defect. If it's not, then you're looking at a structural graft. Ok. So that is something to replace it. Whereas, um I think Tom said you can use um uh you know, custom made trabecular metal implants, which are 3D printed. All right. Um If you've got massive bone loss, which is not, not um reconstruct. Now, the main thing that determines whether something's reconstruct or not is how much native glenoid have you got left. OK. So if you've got very little glenoid left, um then you can't get um sufficient prime fixation from a standard implant. Uh Then obviously, you're gonna head towards the custom. All right. But um in my practice, there's a lot of things that I can bone graft. Um because even though they look awful, there is normally enough glenoid for you to get some purchase in, but we'll talk about those as those cases come up. OK. So Glenoid bone loss, think about it early, think about ways that you can mitigate whatever you're gonna have to do at subsequent stage. Two, very simple questions. Is it contained? Yes or no. How much gleno have I got left? That's essentially decision making there. OK. So it's not, not too difficult. All right. Safe. What's happened to you? The cough finally failed. The cuff finally failed. Yeah, this cuff failed pretty rapidly actually. So this wasn't one of mine. This is one that I inherited. Um, it failed within four months of the operation. Ok. Um, so again, we come back to patient selection. Ok. This lady is in her eighties. All right. So do we, do you think a ste a stimulus anatomic is a good idea in an 80 year old? No, ultrasound under the cuff pre op. Probably not. Yeah. Ok. So cuff failure is the issue here. So, the merciful thing is that she's got a, a stemless anatomic. This is a slightly different design. Ok. Um, but it's still a stemless. So that's a lucky thing. So we've got options on the humoral side. Ok. What type of glenoid is sitting in there at the moment? It's, uh, the big, big old poly, uh glenoid. Yes. It's a polyethylene glenoid and it's cemented. Yes, it's a cemented or poly. OK. Because she's got two pegs on it. Um, the head of that implant is made of ceramic. Ok. That's where you can sort of see partially for, right? That's just the type of implant that, that one is. And for Iggy, that's, that is a, that's a seven A star rated stem that, that construct? Ok. All right. So what we're going to do with this? So, do you think, uh, obviously the, the humerus bit's easy, isn't it? You're gonna whack the humerus out, put a stem, we're gonna convert to a reverse, aren't we? We don't have a choice because the cuff's gone. So, the humerus is the easy bit. But what do you, in terms of thinking that we're now talking about glenoid bone loss? What, what do you think we're gonna do to the glenoid in this instance? Exclude infection first? It fails very quickly and it's definitely not infected. Tell you that three DC P with 3D reconstruction. So do you think, and sometimes with implants in? Mhm Yeah. So if you think about the way that this has been done. So do you think a CT is going to add much to it in the system? I'm just thinking that we need to assess the bone stock of the glenoid. Um Before I think you probably would want to remove it first. Yeah. So that at the moment you cannot assess it is, it, it depends how much cement when you're going to remove the cement, how much bone is coming with it. Yeah. The CT at this point is not going to help you establish how much bone loss you're going to have after removal of the prosthesis. Yeah. Correct. So the problem at the moment is if you ct this and try and plan it on any kind of planning app, it's going to lose its mind because there's a, there's a bit of poly in there in case. So it can't work out what's going on. You get a lot of artifact anyway, off the implant. So it's quite difficult sometimes to work out exactly what's going on in there. Ok. So sometimes you have to go back to basics. All right. So this is why I teach all my registrars how to do a shoulder replacement without any fancy toys. Ok. To start with. Because you need to know how to do one without technology. Ok. So you're right. So we've got to assume that whoever put this in. Now, this is the other thing that's important about when it comes to your vision is understanding the type of implant that's in there. OK? So I know the brand of implant. This is, that's the first thing you find out is what is this? OK? So I know what it is because I put them in myself. But you, you look at it and you, that's the most important thing because you've got, once you understand what the implant is, you can understand how you're then gonna go about dressing, getting it out. So that's the most important thing with revisions. OK? Is understand the implant that's in there how you get it out is the first thing. OK? So as I said, the humoral side is really easy. You smack the head off, you put an osteotome around the fins, put a little impaction handle on it and smack it out. OK? Which is easy, the glenoid. So you've got to now think about how do I get the glenoid out? Ok. So, how do you think you go about getting this glenoid out? We can re, it can re, it, um, until we get down to bone. What I mean? That's, I'd have to be pretty desperate to do that. Um, if, if you do that, what are you going to generate loads of loads of poly debris? Yeah. And then we could second, you're going to take bone with it as well, which you don't want because the bone is now very precious. Yeah. And also you could wean those pegs off the pegs eventually fall off if you rm it far enough and you end up with two pipes stuck in there. OK? You'd be surprised actually with these, they're dead easy to it. All you do is put an osteotome between the cement interface, give it a little tap in it and they, they tend to just pop out. OK? So it's quite easy to get out. The other trick for these. For polyglycol, put a little drill hole into the poly, put a corkscrew in and pull it out like a wine cork. OK? So there's different ways, but first point is basically understand what you're gonna do. Now, let's say that we're really lucky and this just pops out, OK? In terms of the glenoid, right? You the, you need to understand how you're going to get your next implant in. So the, the implant for a reverse as most people know, whichever you're using is gonna use a base plate. Ok. Which has some sort of peg in it. Right. And then maybe some screws depending on the design. So once we've taken that Glenoid out, what's, what's the Glenoid going to look like if you're staring at it, what are you going to see? Like it, it's going to be at least the two big holes where the, the, the pegs wore in. So therefore, now you need to cover this with bone graft. Yeah. And it's more than that, you need to have screws long enough to go beyond that to fix it. Yeah. So, so you're right. Exactly right, Maria. So you hate best case scenario is it comes out, you just got two drill holes in there. OK? Without any bone that's come off with the cement. All right. But I if you have a defect there again, come back to the questions that we ask ourselves. Is this a con, is this gonna be a contained defect or an non contained defect? So it's likely to be a contained defect providing they put the drill holes in the right place. So therefore, it's as simple as bone impaction grafting as you said. Yeah. So you just impaction graft into the holes that gives you a flat surface to work off and then you just follow the normal steps of being and reversing Ok. So with this one, we don't, there's not significant where you can tell that by the fact that they've done an anatomic in the first place. Ok. So the clues are all there. They've done an anatomic. There can't have been significant, er, ization of the implant or retroversion there because they put a standard implant in this type of implant doesn't have any augments available. All right. So, so the at worst they would have reamed and, and put something in, right? So, so we know that already. So with these ones contain defects, you can bone graft and then just po pop a reverse in. All right. Which is what I did. OK. So, and there's a, there's a nice long screen, OK? Um So this is this, you can see, you can't really see it behind there, but there is into this bit here. You can't really see where the, the peg holes are, the impaction grafted into that just to try and put it in and then put a reverse stem in unspent it, right? She's delighted. Um So what do we do when we've got structural problems? OK. So this is the ones where we're talking, we've got, we're going over our 18 degrees of retroversion. All right, we've got significant medialization. OK. What we, what can we do there? OK. So what's have I lost my mind here? This is a planning software that, that comes with the shoulder replacement that we use at West Suffolk. All right. So basically what it does is it creates a 3d mesh scapula with the CT images in there as well. Um And effectively allows you to, to position the base plate, right? Which is, which will give you a preoperative plan, right? So have I lost my mind here and, and put a, put a base plate in and I'm gonna leave it hanging in fresh air or is there something else gonna happen? Are you planning to bone? Are you planning to use a bone? Yeah, under the Yeah, absolutely. So, so this scenario, there is no way this is a very unusual we wear pattern, isn't it? OK. It's massively inferiorly worn, this head's flattened off, OK? Um It is posteriorly worn as well, but you've got this, this kind of very, you know, severe um infra where OK. So effectively, there's no way that I can, I can bridge that with a, with a metallic augment. Um So I have to use a, a bone block here. Now, the indications for bone blocks are that as we said already that you can have an a you know, anything over 18 degrees, 20 degrees of retroversion. There's no way there's no augment that's recommended to correct that. But, but you bone blocks can also correct multiplanar defects. So because it's never as we've seen already when we looked at some of the x-ray images earlier, it's never a uni planar defect. Really. If it's, they're often multiplayer whether it's the classic kind of pattern is Suro posterior wear. Um where, where you get the cuff failure and it it goes up and backwards. Ok. So often with the bone blocks you're looking at trying to do a multiplanar correction, right? So software is useful in this context because you need to get your, all of your bone blockers basically worked out of where that central peg is going to go. So this design, the implant that we use here has got an offset peg, which is quite useful for revising because it's not in the middle of the glenoid. But everything I subsequently plan in terms of the bone block is is based off that peg hole. So we need to use some sort of technology to get that in place. All right. So this one here, you can see that I have got some native glenoid that I can get some of the peg into. OK. It depends on the design of the implant. This is an extended cage, all right, which is plus 10 mils on the standard. So it's about 25 mils in length that peg. All right, you need about, you know, at least 12 millimeters to 15 millimeters of cage in there to get that to hold. OK. But then basically what you can do with the software is is essentially um each slice in the CT is a millimeter. You work out where the, where the you, you get reference points off the um of the uh implant itself. So you can look to see where the holes are and you basically count back the holes and then you come up with a plan that allows you to cut a block to size. So it's all done by hand, the cutting of the block. I'll show you some examples of that. OK? So you, this is where you have effectively not really got a, a defect within the glenoid vault itself, but you have got a defect that is not correctable. So this is a different type of bone grafting. All right. So this is what the software looks like when you got it up. These guys look very jazzy. Um This is the American version because it looks very futuristic but effectively what it gives you there is that there's a, a navigated plan which gives you you, you calibrate the um sensors, there's free sensors on there that you calibrate. It's got a reference point which is off the coracoid, it then has real time. Er it uses AC T plan that you've developed on the software just showed you, it gives you where to aim and effectively you run everything off that plan. OK? And it'll put the K to exactly where you want to. Um This is the process, there's different ways of, of grafting, OK? You can graft directly into the patient's humeral head, which is what David and I did this morning. So you can impact the base plate into the humerus because you're cutting that bone off anyway, providing it's not too cystic or, or poor quality. You can use the patient's own humerus to effectively impact the base plate inside. The other thing you can use, which is, this is an example of, is a femoral head, um, allograft. Ok. So it's difficult, you need something reasonably chunky. Um, and if you're correcting things, most of the, the sort of depth that you're looking at is somewhere in about 15 to 17 millimeters. So humeral head is quite good for this. All right. So on the top left there, what we've essentially done is impacted the, so this is like what you do on the glenoid basically, but we're doing it into a femoral head. We've impacted the glenoid base plate into a femoral head. Um And then based on a pre-optive plan, you can see that I, if you imagine that that defect there, I've, I've cut uh cut the bone to size, uh to allow me to, to correct the defect that I need to. All right, then essentially, when you drill the peg hole into the glenoid, you just impact that in. Um and then put there some peripheral squeeze as you can see from these holes here that you can press the graft into the, into the glenoid, the native glenoid done, right? And that's, that's your, that's your way of doing it. OK. Um not all shoulder replacement designs, um allow you to do sort of multiplane correction that you can see. This is quite a big bass plate, right? It's a, yes, it is a patella resurfacing gig. It's a P it's a perfect instrument for holding femoral heads. And also when I, when I bugger it up with the saw it pisses the knee surgeons off, which is an added bonus. All right. It's not the best joint anything, no way. Um So this oval uh oval base plate allows you to do more of a multiplanar correction. Some of the ones where you've just got a circular base plate, all you can do is lateralize. OK. So that will, that will save you from medial erosion but it won't, it won't correct anything posteriorly or, or um or superiorly or inferiorly. It will only allow you to lateralize off. OK. So that's another thing to bear in mind is, is the other other reason for grafting is to lateralize a very medialized um shoulder because if you're doing a reverse, you need that lateralization, as we said earlier to increase your deltoid wrap and then, and give you the stability that you need. OK. Does that make sense? So that's a, that's a bone graft there. That was uh so that's that, that I think that's an x-ray of that horrific shoulder. All right. So this one, this is another example of failure. OK. All right. So this was a uh primary shoulder that I did, um, again quite early on. All right. Very nasty. Um, and then this happened. So what's happened here? Oh, right. I mean, dislocation. Mm. Yeah. So everyone's a nightmare. Ok. Dislocation. So, er, this lady dislocated. Now what you can see there that it was a complex, primary one. You can, you, you can see if you look here, there is, there is bone graft sitting in, in there. Ok. So it was a difficult correction. So what, why, why do shoulders dislocate? Cos this is a method of failure of the shoulder replacement. It's the one that makes us all very miserable. But, but, but why do shoulders dislocate? What, what can go wrong to make them dislocate? So you can think of it that the bones and soft tissue in this case, the prosthesis alignment and also the soft tissue maintaining the alignment. So either um the initial alignment of the joint was defective or the soft tissue could not maintain that alignment because of the weakness in the and deltoid. Excellent. So I like I like that way of thinking of it. So you're essentially saying uh it's my fault either way. But um it's, it's either something I've done incorrectly with the prosthesis. So have I, have I aligned the prosthesis incorrectly? Um Or is there something to do with the soft tissue balancing that's essentially causing it not to stay in joint? Ok. Um So what, what particular positions will make shoulders, shoulder replacements dislocate. So what if you were to mow the line? Yeah. So loading is very bad. You don't like people loading it? Ok. That's, that's naughty. So no, no pushing up with your arms for the first six weeks. That's definitely one. But in terms of alignment of the prosthesis, what which direction is, is, is the biggest cause of that to dislocate the glenoid anteversion is, is um is bad. Also excessive inclination, I'm sure. Yeah. So superior in inclination is bad. OK. Uh So super inclination, anteversion being the main one of the glenoid. That is um but also if you over Antivert the stem, uh that will also cause a dislocation, right? So anteversion is generally bad in terms of positioning of implants. OK. So I doubt that I didn't ever antevert the stem in this one. OK. At least I think I did. So most um shoulder replacements go in about 20 degrees of retroversion. That's the standard. OK? You can reduce or increase the amount of retroversion you put on the stem. Now, the only benefit to that is um in terms of your rotation. OK. So you can increase, you can increase the amount of rotation you give someone um if you decrease the amount of retroversion, you give them. OK. But most shoulder replacements um are um are 20 degrees vitro so Iggy are do over retro stability but sacrifice. Yeah. Yes. So that's the compromise between the two. So if you, so 20 degrees is sort of the standard um obviously, that will affect the amount of external rotation that you then get. If you wanted to correct to give more external rotation, you'd reduce the amount of um retroversion that you, you dial in when you're, when you're positioning the implant, but there's a risk of instability. OK. So if we say that, I, so if you were gonna approach this, how would you approach this, this case? So you've got this patient. Now, unfortunately, this is in recovery, which is, which is an absolute disaster. So what are we, what are we gonna do? Identify the etiology and make plan to correct it? Yeah. OK. So what's your algorithm really for, for dislocated shoulder, uh patient factor um implant factor, surgical factor. So um I'd like to identify any like the deltoid, the dynamic stabilizers of the shoulder and she's in, she's in agony at the moment. She just wants, she, she's in a lot of pain because she's got a dis shoulder. So what are you going to do for her immediately? What's your immediate management? So, immediate management would be reducing the joint. So reducing the joint, possibly I put it in a safe position. So maybe a sling or a kind of an an abduction or possibly an induction like in a sling to protect against dislocation. And then you give me two different directions you want to put it in there inside the rotation. Yeah. Um A abduction tends to be the more the safest position. So if you put the arm up, like if you abduct them abduction, it keeps your shoulder in. OK. If you, if you abduct them, it'll come out, external rotation will come out. OK. All right. So reduce the shoulder. So where are we going to do that? We can do that in recovery we can do. So you need to screen it basically to work out. All right. So my takeaway with this one is that I took this lady back to theater and, and the literature says if you could reduce it closed, you should try and reduce it close in the first instance. OK. So this popped back in. All right. It just, it just fell back in no trouble. What about eu E was it stable in the? Yes, it was. Yeah. So I eu a it, it was stable. So under anesthesia, um it was stable in a neutral position and 90 degrees of external rotation, it was stable in 90 degrees of abduction with external rotation, which is your two points really that you're checking stability. Um I couldn't get it to dislocate, right? So I thought hooray. All right. Um She then the next day, went back to the ward. I came back to see her the next day she was in pain again. What you think it happened? Well, once you dislocated, once most likely you have taken the, the, the sups cap off. Therefore, there is no sling and therefore un stable. That's vague. I like that you've brought that up, um, is subscapularis is necessary for, er, is, is having an in subscapularis necessary for a shoulder replacement to function. No, it's not for the reverse. Right. Correct. So you don't need a subscapularis to keep a reverse shoulder in place. That shouldn't be what you're relying on. Ok. If you've got one, there's debate about whether it's worth repairing it or not, some people say if you repair it, it does reduce the rotation further because you're essentially tightening something up. Um But it's not the primary stabilizer for a shoulder. So that's a good point, Maria, I'm glad you made it because what is, what is the, what is essentially necessary to keep this thing in because this is where we're getting into now. Uh It's dislocated again. So, close reduction is not an option. Is it now? Yes, Tom Tom 10. So deltoid is the key thing. OK. So the reason I put this up is a mechanism of failure is because sometimes it's not a structural thing. It is soft tissue balancing is just as important. OK? Now, II, I, when I did this thought I'd done quite a good job. I thought, well, I've lateralized her quite sufficiently. If you look where the edge of the, the dame is. OK? Um You can see that that's, that's not, not terrible that's, if you think that this is an onlay design, it's gonna sit just under there. So I've naturalized it fine. Um, I haven't anteverted it too much. It looks OK. I think I've put the stem in the right position. So I couldn't, I was a bit baffled as to why it kept coming out. Ok. Um, so infraspinatus too type due to actualization. No, because there is no infraspinatus. Ok? It's cuff failure. So the cuffs gone. So you have no cuff. So I can't blame the rotator cuff. All right. Um So this is all all deltoid related. All right. So what can you do? So you're not gonna reduce this closed again, you're gonna take this back to theater and open it. OK? So what, what, what, what would you do once you've got the shoulder open? What are you gonna look at to try and see where the, where the problem is? OK? You have to have some sort of strategy for trying to work out how to, how to work out where the issue is. So what are you gonna do to start with? Consider revising the poly using a thicker poly and possibly a deeper dish like a more constrained polyethylene. Yeah. So, so that's, so that's, that's the kind of I I can't get this to stay in type scenario. So when you get in there, that's definitely an option. But when you get in there, the first thing is go back to your basics again. So have a look at the, in the position of the, er, dome. OK? An easy way to check the anteversion is that these all have screws that go down the middle. So, what I did with this is I opened the shoulder up, I dislocated it. Um ironically, and then, er, put the, I just put the screwdriver on the dome to have a look to see because you can put your hand along the scapular spine and see roughly what the version is. Then co if you cos the screwdrivers lining up at the center part of the, the peg, right? So I hadn't anteverted it. So the next thing as Maria suggested is that I look at the stem, have I over anteverted the stem? Ok. So I took the poly off, OK, which is to remove it. And I put the introducing handle onto the, onto the, onto the tray because that's where you sit it on the tray when impacting it. And I looked and checked my version. Ok. So when I looked at that, I thought, hm, maybe it's a little bit, not quite perfect. All right. So what do you do then before, before considering the decision of revising the stem, uh I will probably uh go ahead with some, uh as I said, thick polyethylene trials trying to increase the offset of the prosthesis to assess if this can counterbalance the uh the more uh increased anti version of the stem and assess the arc of movement and see if it's stable or not. And also considering a more constrained polyethylene. So good shout. So what George is saying that you can, if you increase the thickness of the poly, that doesn't do anything to the later. OK? All it does is just inferior. It more so by inferiorly it, you're hopefully increasing the tension on the deltoid by pushing it further down. Right now. I did do that. I, the maximum I can go up to with this implant is a plus 2.5. So I can put 2.5 mils on the poly and then like a hip, there is a constrained version of the liner which is, which is deeper. OK? So all that does is is increase the um conformity of the joint. OK? So it, it makes it more constrained, therefore difficult to dislocate. They're not, they're not, they're not a panacea. They don't, they don't have a, they're not the sol all problem for anything because a deeper, a deeper kind of liner means that that there is a chance of impingement. OK? So because you've got a lip on it, it can, it can impinge and lever itself out. OK. So I did what you suggested George and it's still unstable. Next option, what I can think is I, I will, I before again, starting a bigger job which is going to include taking the humeral ste out because we know that this is problematic as you mentioned intraoperatively. Then my next er way of thinking will be try to consider to lateralize the glenosphere a bit more. Er So probably taking the glenosphere out and give it a trial with a more lateralized glenosphere. If I'm not wrong, I think there is some options with plus four glenosphere. Yeah. So this implant in particular. So what George is saying now is you can increase the lateralization on the glenoid side. So by lateralis off the glenoid that we should increase the rap of the deltoid, which again will increase the tension within it. OK. Bearing in mind that this is all due to due to a problem with tension in the deltoid. OK. So you can offset it. All right, you can't offset it a massive amount because the other issue I've got here is that I've I've got a bone graft sitting behind my base plate. So if you offset it further by lateralizing, you increase the arm, the arm of the, that I'm I'm potentially introducing another mechanism of failure by increasing the lever arm on, on the peg. All right. So I've got to be wary of that. What about increasing the size of the dome as well as naturalizing it? Is that is that uh does that reduce your risk of dislocation or? Sorry? What exactly did you ask? Mr this time is 38 millimeters in diameter at the time. Would that help, probably larger Glier are more stable in theory, right, where they are. But I guess the issue again comes down in this scenario to why if it's a deltoid tension problem increasing the size of the dame is not going to increase the tension in the deltoid? Does that make sense? Because all I've done is just made the thing. If anything, the issue then becomes trying to reduce the bloody thing because she's not a massive lady and then trying to reduce it. You know, where I've got four mils extra diame to try and get the thing under the dame is difficult. OK. All right. So, so we, we're gonna change the do up to plus four. I like that idea. All right. So let's say I do that. The thing still dislocates. What am I gonna do now? If you have tried everything you, we've tried with a deeper and more thick polyethylene, we've tried lateralizing the glenosphere. We've tried increasing the size of the glenosphere to increase the jump out distance of the stem. And all this combination of factors still fails. I think the only other available option would be to revise the huber stem because we know that is the base of our problem. Right. Yeah. Well, I think it is. Yeah. So, so miserably for me, that's exactly what I do. I have to take the stem out. Well, there's one more option that you can try before you have to take the stem out, which is to increase the height of the tray. So the Polys only go up in terms of by plus 2.5 but you can increase the tray up to plus 15 mils. So that's the bit that sits, that's the onlay bit that sits on top of the stem. So you can increase the height of that as well, which again increases the tension in the deltoid. All right now, sadly, for me, when I went to try and do that to get the, the, the tray off, I managed to undo the screw, tried to put an osteotome underneath and the whole bloody thing came out. Ok. Which is, which is sad for me. So I then had to get some cement out to try and get it out. She's got a tiny little humerus. Um So, you know, we said what, we can change that. So this is what ended up happening. All right. So yes, I, I mean, I did manage to crack her humerus a bit, so I had to put a cable around it, right, just to hold it. But I've managed to re cement the stem back into it. But if you look here, you can see that this tray looks deep, is bigger. Can you see the depth of the tray? So, so I've increased the, I didn't end up increasing the er offset. Ok. Uh I effectively deepened it and increased the size of the head and then reoriented my stem. Ok. Um, it stayed in hooray. All right. Um, what it actually turned out to be in this case after I'd done all of that was that she had an axillary nerve palsy. All right. So, the actual problem when I got into her shoulder was that she had her BP was run throughout the operation at about, about 70 systolic. All right. So, when she got around to recovery and woke up, she didn't have a very good, uh block and her BP went up when we went in there and I opened it to reduce it and, and have a look at all those things. There was a massive hematoma in there like huge. I was scooping out handfuls of, of blood. And as it turns out what had happened was that she got a hematoma in there which had pressed on her posterior cord, switched off her auxiliary nerve and the shoulder fell out because there's no, the delta is not firing. Which kind of makes sense. Now as to why when I was doing close reductions in e ways, it seemed stable. So this baffled me because I couldn't work out why? So I sent her off to stan more after the nerve conduction tests and it ended up that this was all due to an acc know. So it is a good case because we've talked through that stepwise approach of thinking about all the factors. We've already talked about and to how we, you know, again, when right back to the first set of slides with that, that design of shoulder replacement saying that it's all about deltoid tension. So everything we've talked about there is trying to increase the tension within the deltoid. All right, be it for later or, or inferior, which effectively to inferior more, you're increasing the height of the poly, you know, or the tray. All right. And then the later for this type of implant comes off the day. So, so your issue there is basically thinking through that in a stepwise method when you have something like this, which is a disaster, thinking about the orientation. So it comes back again to where we talked about earlier about what is it what we're trying to correct, which is the the the rotation of the implant, the version of the implant and getting the next shaft angle correct. Um And then sometimes it's just something weird, right? So don't forget about the soft tissue causes of, of disasters. All right, which is in this case, axillary nerve palsy. So the fact that that she managed to get it stable in the end is a bit of a miracle. But um but yeah, so she's, she's off it at sta having her plexus, she got some scarring basically from where the hematoma was. Um And they're releasing that and they're pretty confident that it'll be um be right now, the consequence, unfortunately, of me um tension, the shit out of her weak del deltoid is that her movements gonna be pants? Yeah, because I've effectively constrained this thing so much that she's, she's not gonna have great movement. All right. But it's kept it in joint for the time that it's being so everything you do to increase constraint. I stability has, it has its costs. So unfortunately for her, it's, it's at the, the, the stability's come at the cost of the movement that she's gonna get in the end. Does that make sense? Yeah. Yeah. Good, good case. E that, that make that upset me for several months. That, ok, this is another mechanism of failure. Don't worry, the end's in sight. We're not far off now. Ok? This is another mechanism of failure. So don't forget about trauma. All right. So this poor lady fell over. All right. What's happened to? You just go back to your hips. Hips, everyone knows hips. Yes. It's a paper prosthesis fracture. A paper prostatic fracture is a mechanism of failure of shoulder replacement. Ok. Because it's like anything, you know, you, these implants, particularly on cemented implants or cemented for that matter, but particularly uncemented implants rely on the stable bone, don't they? To, er, and a good fix to, to, for them to be stable now. So we know we're already, we've had a look at a few shoulders today. So, what type of implant is this stimulus? Yeah. Very good. How how do you, how do you think the, uh, do you think that's a stable implant or an unstable implant looks like? Wow. I was, I was hoping that as well. Um, now if you look here, can you see there's a little crack going through here? All right. Um, I couldn't get the CT images because there loads of artifact. But basically, it, it, it, it fractured up into that and around the fence. So it's basically not a stable implant anymore. Ok. All right. So how are you gonna tackle this one? The Maria and Terai crew. How are you gonna tackle this? Well, if it is not stable then is revision. Is it, it's a revision. Yeah. So it's the same principle really as hips. All right, in that if you've got the majority of per prosthetic fractures, um, in shoulder replacements tend to occur, they're like the equivalent your seeds. Yeah, your vancular seeds. So they're below the implants. Most of those can be managed non operatively. That's why you don't see a lot of, you know, pro prosthetic fracture management of shoulder replacements because a lot of the ones if they fracture at the tip of the stem can be managed non operatively and they tend to heal up. Ok. So really the indications for revision are when you've got an unstable implant. Ok. It's just, so with this one in particular, you're right, revision is the only way forward. You can plate them if they, if they need it, you have to get sort of tic fracture, plating, you can do as well if it is, if you're worried about it below the stem. But with this one, it's not a plat thing, is it? Because as you said, the main issue is really the unstable. So how would you, um how would you go about? What would you revise this to? Very grossly speaking? First, you need to remove the metal. Second, you need to reconstruct the anatomy of the proximal humerus. And then third, you need to put back a prosthesis which is longer stem and is going to bypass the defect. Like looking in very, very broad terms. No, that's fine. No principles. I like principles, Marie, you know that. So that's good. So is right in principle, that's the principle behind it now, particularly to this case. So she's got an anatomic in, as Tom says, this is a stanous anatomic. Um Are you gonna leave her with an anatomic in, I mean, probably in this mechanism of injury, the rotator cuff is gone and depending upon the age of the patient as well. Um Probably we were just better going straight to reverse now then trying to do the third operation later down. I don't know. Yeah. Yeah. So Tom's suggesting a reverse long stem. So, yeah, I think, I think we all agreed she's 80 bless her. I think if we're going to revise it, I don't really want to be revising it again again. Um So I think a reverse is definitely an option. So you've mentioned there that you want to put a long stem in now, where is most of the issue here? Where is most of the fracture? Is it, is it lower down proximal? And the cortices are very, very, um very thin and the canal is very, very big. Yes, exactly. So, so part of the problem we've got here is that I agree, if it's, if it's sort of halfway down or around the tip of the stem, then bypassing it's a no brainer, right? Because you normally have some sort of metaphyseal support at the top with this one. The issue here is that it's quite communed and it's eggshell thin, right? So, trying to get anything meaningful around that is gonna be difficult, right? So, yes, a long stem could be an option. But again, there's a chance that that might fail, but only if you can reconstruct all that, all that metaphyseal and then you are probably remaining with the proximal humerus. Yeah. Good. Right. And that is exactly what we did. So we can rebuild you with this. So this is what we did in this case. OK. So where you've got a situation where you've got massive metaphyseal bone loss, right? Um That this is a akin really to where we were talking about earlier. Remember our maids of failure on the humeral side, in fact, where you've got no meta or bone loss that you can, you can, um, reconstruct a standard stem into. Then you have to think about this as your, your kind of final option, which is your proximal humeral replacement. All right. Um, so I sort of followed your advice a little bit there. I have done a reverse with a very long stem. Ok. Um, but what we've done up here is, is remove the implant and it, and it was, as you said, Maria, it was in bits, the metaphysis, there was no way I could reconstruct that. Um So I opted for this instead. All right. Um So the, the advantage of this is basically that you don't need to worry therefore about um the bone healing up all the stability of the implant because you've effectively just chopped the broken bit out. Um This, this type of implant here has two points of fixation. So you have a cemented uh stem in there, the varying lengths that you can put in. Uh and it has AAA three pronged collar that effectively press fits around the outside of the uh outside of the bone. Um With this, the other benefit is that remember we talked earlier about stability being part of um the deltoid wrap. So the what you can do with these proximal humeral bodies because you don't have uh your GTs anymore. These are different sizes where you can increase the, the lateral offset to, to improve the deltoid wrap. OK. Uh You can also increase the height. So these are modular in that you can increase the height as required for what you've left. So somebody said what happens if it dislocates? What happens if the proximal femur dislocates ID? Yeah. So um yeah, you'd have to do that. But the whole point of doing this is that you check the stability and check it and check it on this. Um And you've got multiple things you can do to improve that as you go along, right? Um Have you checked rotation and length? OK. So it's no different really, in terms of rotation and length, you, the stem goes in and that's, that's just on top of the humerus. What you can then put on top of that is when you put the body on it, it has a retroversion rod. OK? Which screws into the body that the trial body that you put in and it will go into the actual implant that you then impact. OK? Which gives you 20 degrees of retroversion. So you can make sure that the head is, is that the body is retroverted appropriately. OK. Um Again, you just play with it really, you get the stability on. Now, the things that you can do to increase the stability when you do a proximal humerus replacement. So what's again banging this home? What is the main thing that provides stability for a reverse shoulder replacement? The tension of the and deltoid same a big advantage here is that the deltoid is insertion is maintained. Can you see that? So the deltoid comes down here and it's attaching still? OK. So in scenarios like this where you're having to do a proximal knee replacement, definitely a massive win is is having being able to preserve the deltoid attachment. OK? As you get bigger with the bits of body. So if you do want them for metastasis, say for example, where you have to do a bigger resection, um There are coated bits where you can take a sliver of bone and suture it on. That's obviously not gonna be as good as keeping your a one in. So if you can preserve deltoid, um that's ideal, right? And then that, that allows you to tension it properly, right? I may put this up as AAA kind of extreme example of what might happen, right? Um Because it's there as an option. This is your, your final bailout right? There isn't and this is the end of the line really. There isn't anything else that you can do beyond this, all right. Um Just as an extra thing because we talked about glenoid because it was a poly glenoid in there. It was a contained defect I pa and grafted into that and you can see it beautifully. You wouldn't even see that it's been impaction grafted, just a nn one. She's actually doing surprisingly well. She can um forward elevate to about 100 and 10 degrees abductions up to 90 she's externally rotating to about 50 degrees and can get her hand uh up to about L2. So it's pretty good. So, not all that bad is it? You know, so, whereas if we'd left her, I think she would have done badly. OK. So proximal humera replacement is your, your humeral bone loss solution. Ok. You will read um somewhere in the literature they do talk about sometimes using um fibular struck grafting for, for where you've lost the medial uh coca support. Um That's more in a trauma setting, I would say. Um if, if you're trying to fix something, I wouldn't, I've not really seen that used in arthroplasty because I think nowadays we've got, we've got solutions to problems that, that we didn't have before. All right. So if you had a complicated one, this is what I would go for. All right, Coke. So, because I got told off in my feedback last week for not having enough er, cases. This is all this is what you get. So you're getting more cases. This is the last thing. All right. So this is one where I just want somebody to talk through the x-rays and just to cement home what we've talked about today just wanting to talk through um how I don't need the history examination and all that. I, I'll tell you a bit of a potted history. This is a gentleman who had a um sta anatomy shoulder replacement done about three years ago. Um He came back to clinic uh for his sort of standard follow up uh and was complaining that his shoulder was painful. Uh And he had a clicking sensation in it, particularly moved it into certain positions. Ok. So how are you gonna go about managing this patient? So I just want the principles of what you're gonna do. So, describing the x-ray um I outside there is a um signs of loosening seen in the lucent lines in the um implant bone interface. Um I, I would like to uh further kind of this is aseptic loosening. However, I need to exclude any septic activities. So by history, clinical examination and blood tests, um then I would like to um plan for my um revision procedure. So um if, if these symptoms is compromising activities, blah, blah, blah, and then I need to do the revision procedure. Um The plan for revision procedure is implanting the uh the the implanted component and, and kind of do a revision procedure basically. OK. What would, what would you advise this to? Um So I would revise it to a stem um A stem, the prothesis, um uncemented stem prothesis. OK. What type of prosthesis, anatomic reverse? Um I would decide. So uh based on the rotator cuff integrity. So, clinically and MRI scan, um I would decide whether he's a candidate for anatomical or uh reverse replacement. OK. So if you look at, you've got some information there on the, on the plane film. OK. Yeah. So Tom's kind of nailed it there. So he's, he's saying if you look here on the plane film, can you see that the acromial subcranial kind of distance there? Yeah, that doesn't look normal, does it? Yeah. Um, so you, you've got that you've got that reduced space there. So I would, I would agree with Tom. I don't, I think it does look a little bit proximally migrated because you shouldn't have the, the top of the prosthesis shouldn't be there, should it? You think about your sensitive rotations there? It does look proximally migrated, doesn't it? So that's in the middle of your glenoid implant there. And you've got more of the implant above that than you have. I think. So. I think it has shot up a little bit. OK. Um You're right. It looks lucent, doesn't it? It's not just on the glenoid side. You can see this looks a bit dodgy. All right. But you've also got this kind of half moon like scalloping out of the humerus, which is a bit unusual. OK. Which implies that the actual fins of this are not, not stable, right? And it's been wobbling around. All right. So you're right. Exclude infection. As we said, that's the key. Take home message is anything that looks like it's failing, exclude infection. It's possible. It's aseptic loosening we don't know. Possibly. Ok. But infection is the main worry, the other possibility for it failing on the particular, it looks more that looks more unusual than the glenoid. You often get this kind of shabby appearance around the glenoid bit with the cemented all poly ones. But it's possible that, that we went back to patient selection, didn't we? Was his metastasis sufficient enough to support the implant in the first place and looking at the size of his brain? Do you think that was it? Do you think that's an appropriately sized implant looks a bit small to me since there is this sunken into the metastasis where it's not been big enough to, you know, the overhang from the, the actual um hemisphere is not enough to support the support the implant. Anyway, there we go. All right. So you get some advanced imaging cos obviously dead easy. No one's gonna dispute smacking out the er the, the anatomic Vicks. That's Leo, in fact, it just fell out. Um Now, what do we always have to think about managing as well? So we're gonna manage the humoral side, as you said, with a stemmed reverse. I think we've decided. Um what about the geno? So back to what we talked about summary time. So, yeah, so the Glenoid um I need to address the retro version, the Glenoid bone stock and um um this, this will require like a glenosphere. So a base blade. So I need to um address the retroversion and any kind of bone defects either by augments. Um So have a look there at the moment. So always stick specific to the case. Does this, does this look like a retroversion glenoid? It looks slightly retroverted, I would say neutral, it's a neutral glenoid. Yes. So, so it's a neutral glenoid. OK. So, so stick to your principles. So you're right, you want to correct the abnormal anatomy, but the, the version is something you'd think about. So you say I want to look at the version. Hence the CT, that's a, that's a normally retroverted. There's no signs of, of uh re excessive retroversion with this. So we can just ignore the version. All right, that's fine. The issue we've got with the glenoid is that you wanna put a reverse shoulder replacement in which needs a base play, et cetera, et cetera. But what is the issue we are gonna have because we've got normal poly G that we're pulling out. Yeah. So I need to take the pulley first out and then replace that with a base plate. Yeah. What are you gonna have when you take the pull out uh bone graft? A big hole? Thanks Tom. So you're gonna have a big hole. So then we come back to thinking about glenoid bone loss. Is it a contained or an uncontained defect? It's a contained defect. We hope so, we're gonna, you're gonna, then, as you said, bone graft, impaction graft into that to give you a surface that you can then implant onto. All right. Good. So, that's a summary basically. And that's what we did. All right. So exactly what you said. Um So I've Impaction grafted into the, the defect that was there. Um I haven't had to re re or anything like that. It's just gone straight in and then we've just uh taken the old implant out, re cut and then put a stem in, as you said. All right, good. So hopefully that last one, I'm sure you're all fed up with me now. Um But hopefully that last one just summarizes um the principles that we're talking about. Ok. So what I want you to take home from this today is basically we, the indications for shoulder replacements, we kind of touched on last week with regards to the stiff shoulder. So I'm not, I haven't labored the point on that because um, if you've got um scenarios where the patient is in pain, stiff shoulder, reduced movement, that's all kind of a nobrainer, that's your indications. I'd say the only thing to bear in mind is that inflammatory arthropathy is really not an indication to do an, an an anatomic replacement. Ok? Because it's all to do with the soft tissues as well as the bone. All right. So, so that's a contraindication, in my opinion, to an anatomic replacement, but everything else gets an anatomic if you can the evidence that you're gonna quote in the exam if you asked about anatomic versus reverse is that there is a large randomized Multicenter International trial which is blinded, which is looking at this question, no one knows the answer. Ok? I want you to hopefully take away the, um, the main point of failure on a, on a shoulder replacement is on the glenoid side. Some of that is historic. Um, but it's basically that rocker horse phenomenon that causes loosening of the glenoid. All right, but always, always, always with any pathology station you get in the exam, it's gonna be infection to rule out first and then onto your major failure. Ok. So hopefully say we've covered the mechanisms of failure on the glenoid side, which is predominantly mechanical um as well as aseptic loosening and infection. We've talked about humoral bone loss and and how um the stem itself can contribute to that. So, thinking about design elements within that, that can cause issues. We've talked about um soft tissue balancing, being a um potential mode of failure. So, inadequate soft tissue balancing and also implant malposition, which we essentially have talked about again with the the mechanisms that you can use to increase tension within the deltoid by using naturalized designs, rather the sort of medial glenoid, medial humerus and the potential risks and benefits of both of those. And then we've talked about this sort of ultimate breakout, which is the proximal human replacement Uh but again, it incorporates some of those issues that you have with balancing. OK. So hopefully that's all, that's as much as I can think of with regards to failing shoulder replacements. All right. So there's a couple of questions in there. Could I comment on briefly on hemi, do I ever use them? What do I use them for uh um for the exam? So, OK, so that's a very good question. So hemio glasses, they do have a place. All right. So for me, I tend to use them in trauma uh for a younger patient, um where I don't want to put a reverse in. Um I want to, they've got an intact rotator cuff. So when you know you fracture, um and your shoulder, uh your rotator cuff tends to be OK. Now, obviously you're relying on the Chios to heal back on for you to have a rotator cuff function. So that is a risk you run when you put a hemi in. But particularly for a younger patient, I would try not to burn all of my bridges by putting uh a reverse in straight away. Ok. So for me, I only rather really use hemiarthroplasty in that context. The other indication for a hemi is potentially somebody who is unreliable. So, if you, you know, the ones that speak to mind are people who are alcoholic, not likely to follow um, instructions and behave themselves. Um, uh that would quite easily dislocate reverse by doing the naughty things that Tom talked about earlier, like pushing themselves up and things like that. Ok. Um And also patients who have, um, you know, like uh neuromuscular conditions or Parkinson's something like that is another reason I would do it. Now, there are two types of hem arthroplasty that you can use. It's a standard hemi which is a short anatomical head. Ok. Which is the same that you'd use for an anatomic uh shoulder replacement. There is also something called AC T A head which the CT A bit stands for cuff tower arthropathy. So cuff to arthropathy heads are basically a bailout, ok? So if you were doing a um if you were doing a patient, um and you were trying to address the glenoid bone loss and say you had an issue, you dropped something or it was worse than you thought when you got in there using a cuff, tear arthropathy head is, is, is an option as a bailout because it's, it's a bigger head that, that effectively articulates with the chromium. Okay. So you can, you can use those in that context, but that's the only indication really I can think for, for hemi. Um they're less and less commonly done. Now, as I said, the, if you look at the NJR, more reverses are going in hemi is very low anatomic. Probably nowadays, if you look at the percentages, there's only about I'd say about 10% of all shoulder replacements are anatomic now. Ok. But that obviously varies between consultant to consultant. Um, what percentage of T cells get revised to TRSR from rotator cuff failure? Uh Good question, Nick. Er, that one is dependent. I think on the center that you're at, it's not a massive proportion. It's probably about 10 to 15% overall. Um, we have, I've done quite a few this year here but I think again, that was done partly to patient selection. And most of the ones that I'm doing are elderly. If they do fail, they tend to fail pretty early. All right. Um, but if you, if you look at the sort of a quotable number is about 10 to 15% for that one. Ok. Um Would I use what a hemi in a patient with a VN? So that would be an option? Yeah, you could use it for a VN. That would not be a bad shout. Um Piro Carbon. Interesting. So I haven't had much experience with pyro carbon as a bearing surface. So, I don't know, is the understand was in it was just because, um I think just before I was leaving Norwich, Mr Mulligan was said he had a young patient with AVM who was like in their late thirties and then he said he's going to stick a part of carbon hem in and I know I didn't get a chance to have a chat to him about, oh, is that is that the only white bearing surface that you can use in a, he, I didn't the whole time I was there. No, no, no. So there, there's so most hems are metal. Um, I guess the argument for using a pyro carbon is to do with the wear characteristics. So, not so much of the, of the actual, um, bearing surface of the hemi, but more probably it's a bit more forgiving on, on the glenoid because that's the problem with the hemi, right? You've got, you've actually got a metal surface rubbing on, on bone, so that'll eventually wear away. So, so you, that's, that's the downside of a hemi, I guess pyro carbon has probably got better wear characteristics in that. It's a bit more forgiving on the glenoid. A chromium. So Iggy said a chromium fractures. Do I leave them alone if they have a chromium deficiency? Can we reverse? Mm. Good question, Iggy. Um So yes, majority of the cro fractures. I do leave alone. Um The reason being that there isn't really a good um option for fixing them. Um There are plates, you can use K wires, you can do tension bands, you can do all sorts. Um A cranial fracture is a, a recognized complication of revered shoulder replacement. Um I don't think um in terms of deficiency, that's a very good question. I tend to. If I've got somebody who's coming in with a very thin aqua, I try to get them done sooner rather than later. Um, the other thing is that I don't, from my experience, I don't think I've really had, I don't think that correlates necessarily though, to an increased rate of fracture. Um, when they, when they do fracture it tends to the actual ones that are insufficiency. I would say I've only had one in the last year. Um, but mostly the ones that I've had tend to be traumatic, um, which is interesting, they tend to have had a fall, uh, which is probably my po selection. But there we go. Um, but re fractures are very difficult to treat if you plate them or, or try and fix them. They don't, they don't tend to heal. So it depends on what your philosophy is on it. But m my thought is that I'd rather not put additional hardware in on something that's not gonna heal. Um, most of them actually do cope reasonably well with it. Um, although you can imagine that it does then have an effect on, uh, your deltoid function because effectively you've lost that stable base at the aquarium. All right. But, um, yeah, I would tend to leave them alone. Um, you, you can still reverse. I mean, it depends when you say deficiency, it depends on, on what they, if they've got a way to thin a cranium, then I, I probably wouldn't do a reverse because you have got a very high risk of that fracturing um but that might be an indication again for uh for a Cota arthropathy head. All right. Are there any other questions at all? Mm OK. Na Na Maria. No, Tom. No. OK. La lateral or Del Petra approach? Oh Iy, you're coming out with them today. Um So advantages and disadvantages of both. So the lateral approach to the um uh to the shoulder for me, I don't use it, I use a Delta Petra approach. Now, my reason for not doing a LA, you do the advantage of a lateral approach is that you get an excellent view of the glenoid. OK? You can't, can't dispute that. It's a fantastic view. You're basically staring straight at the thing. OK? Also, you're not having to work around the corner to get, to get your instruments in, to get it to, to reimplant all of that. Now, for me, it doesn't make any sense. Um cutting into um cutting into the muscle, the sole muscle that you're relying on uh for your implant to work. So for me, I don't use a lateral approach, OK? There is a risk with the lateral approach of damaging the a damaging the axillary nerve. So I'm sure we all know it's five centimeters down from the lateral border of the Creon. So there is a risk of damaging it. Also to get in, you have to um detach the anterior aspect of the deltoid. So for me, it's you, you're, you're introducing into your shoulder replacement before you even got down to the joint and put anything in um potential mechanisms of failure. On the one thing that you're relying on for number one, it to move and number two, for it to be stable from a soft tissue point of view. All right. Um I think it comes down to what you're comfortable doing. So I think the delta pre to approach has its downsides in that it is more difficult in terms of access. But um there are ways of improving your access. Um It's also if you're more comfortable doing that for, for indications such as trauma, you're more familiar with it. So it's probably easier to do. All right. Um So there'd be proponents and opponents of both. Um But for me, my main reason for not doing lateral approach is that I think that there's too much risk of damaging a deltoid that you were then relying on. All right. Um So Tom, you've asked, is an inflammatory oop a contraindication for anatomic. Does this still stand if they're very young? Say under 50? Um Yeah, that is a pretty rare presentation. Fair enough. I think it's certainly rarer now because you've got things like the biological treatments for rheumatoid. So you don't see as bad rheumatoid disease as you used to. Shoulders. Interesting is I think I said in my last presentation last week, it's about 90% of people with rheumatoid have some sort of shoulder problem there. Ok. Um, I would still do a reverse in that age group because I'm worried you often, I don't, when you go in there and operate, I'm sure if you've operated on any, uh, patients. Um, yeah, exactly. If you don't take your medication that's, that's going to K CK them. Um, I would still do a reverse because it tends to be, the soft tissues are terrible. All right. I think that's a conversation to have with the patient. Um, as I said to you earlier, some of the evidence now is that, um, reverses in young patients are not as bad as we thought they were. Um, and I think that with, er, options now of short stemmed replacements and things like that, um, you and better designs of your glenoid components, you've got less chance of it failing. All right. Um, it's, it's a tricky one but, um, that's even 36 is not the youngest patient I've seen in Rever in, um, I think we had someone in their twenties up in Nottingham and they've done absolutely fine. So, yeah, it's a conversation for the patient but for me, I would still towards a, a reverse. Er, na, be asked, should we identify the auxiliary nerve doing primaries, revisions? Uh, I don't go looking for it. I know where it should be. I don't actively go looking for it. Um, I think if you're, if you're in a revision situation where you, it depends on what you're doing. But if you're having to do quite a, a big resection to try and get the humerus down. So you're cutting more humeral bone off. Um, I would have an idea of where it is. I don't dissect it out but you can feel it. So you, i, it's quite a chunky old thing. Um, you can feel it. Um, and just, just being aware of where it is, but no, II, I don't go dissecting it out, um, because you're at more risk of damaging it if you do that. Um, for most primaries, um, you shouldn't be anywhere near it when you're doing your cut, it's just being sensible as you're doing your subscap peel, uh, and making sure that you're sticking on bone and not drifting off too far into soft tissues. Um, revisions. Probably not again, necessarily doing a big, er, rec cut, uh, for, um, uh, you know, getting, trying to get the stem down even for proximal he replacements you. I, I've, I've not gone looking for it because you just stick on bone. If you stick on bone, you can't really get wrong. Can you, you can just strip everything off and then you shouldn't be anywhere near it. So, yeah, I don't actually look for it any other questions. Right. Right. Right. Good. Thank you.