Managing Instability in AA Hips (S+N Surgeon Roundtable)

Dislocation after anterior approach total hip replacement still runs around 2% in the first two years — so what actually moves that number?

Three hip surgeons work through instability prevention end to end, from the first clinic visit to the final construct.

The anterior approach has pushed dislocation rates in the right direction, but it has not solved instability — and the belief that it has is where surgeons get caught. In this roundtable, Jeff Barry, Blair Ashley, and Chance Gray work through what the database and registry literature actually show, why anterior approach hips come out the front and the back rather than predictably out the back, and how much of that risk is genuinely modifiable.

The conversation gets specific quickly. They disagree productively on whether instability risk can be optimized in the patient at all, or whether it is simply a surgeon's problem to engineer around. They cover cup targets in the setting of hip-spine mismatch, what a standing AP film really tells you, the intraoperative stability checks each of them refuses to skip, and how to escalate a construct — head size, lateralized liners, offset and length, dual mobility — without letting the most constrained option become the default.

This one is for arthroplasty surgeons, fellows, and residents building their own instability algorithm, and for anyone who has looked at a well-positioned cup on a postoperative film and wondered what they missed. It closes with each surgeon's single piece of advice for avoiding that lesson the hard way.

⏱️ Chapters:
00:00 Introduction and what the data says about dislocation
03:47 Why instability prevention starts in the clinic
05:57 Cup position first when diagnosing an unstable hip
08:30 How anterior and posterior hips dislocate differently
12:34 Instability risk after revision anterior approach surgery
14:28 Counseling patients on dislocation risk and risk factors
19:14 Why instability is a surgeon problem, not a patient problem
22:55 Planning for hip-spine mismatch in anterior approach hips
27:32 Explaining the hip-spine relationship to patients
31:48 Where CT-based planning tools fit into instability risk
35:09 Dual mobility and high offset stems for high risk patients
40:22 Non-negotiable stability checks before you close
45:32 Intraoperative red flags and navigation beyond fluoroscopy
50:04 Escalating head size, lateralized liners, and offset
56:24 Are constrained liners obsolete in the dual mobility era
1:00:43 An end-to-end instability prevention algorithm
1:07:39 Parting advice on preventing dislocation

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This podcast is intended for educational and informational purposes only.

This episode was recorded in partnership with Smith+Nephew — Life Unlimited.
Learn more at https://www.smith-nephew.com

The content discussed does not constitute medical advice and should not be used as a substitute for professional judgment. Clinicians should rely on their own training, experience, and clinical decision-making when applying information from this discussion.

#AnteriorHipFoundation #AHFPodcast

#HipInstability #HipDislocation #TotalHipArthroplasty #THA #AnteriorApproach #DualMobility #Spinopelvic #RevisionHipArthroplasty #ConstrainedLiner #JeffBarry #BlairAshley #ChanceGray

Transcript

Joseph M. Schwab 0:22

Hello and welcome to the AHF Podcast. I'm your host, Joe Schwab. Today's episode is the second in our series of six surgeon roundtables recorded in partnership with Smith+Nephew, conversations that bring together surgeons who do this work every day, peer-to-peer, with one goal: practical, reproducible techniques you can actually take back to your operating room. Last time, we took on the complex primary hip. Today, we turn to the complication every hip surgeon respects: instability. What does the data actually say about dislocation after anterior approach total hips, and how much of that risk can we actually modify? How should the hip-spine relationship change where your cup goes? What are the non-negotiable stability checks before you close? And when the risk is high, how do you escalate offset, length, dual mobility, constraint without letting the most constrained option become your default? Well, three guests join me for this conversation. Dr. Jeff Berry, who grounds us in the literature on what we know and what we only think we know about dislocation in anterior approach hips; Dr. Blair Ashley, who makes the case that instability prevention starts in the clinic long before anyone picks up a scalpel; and Dr. Chance Gray, who sees what failure looks like in the revision setting and plans every primary by working backward from it. By the end, they'll lay out a practical end-to-end algorithm for preventing instability from the first clinic visit to the final construct. And just like last time, it gets concrete fast. So let's join the conversation jeff, we read that some of your research interests include perioperative management and risk assessment, specifically managing complications around total joint replacement. So when we talk about instability in anterior approach, hips, what's one misconception maybe that you still hear that the data doesn't really support?

Jeff Barry 2:38

Yeah, that's a, that's a good question. Um, I think there's probably two misconceptions that I, I can kind of think of and, you know, the first would be that I think there's a misconception that now we have this DA approach, that that instability has been solved in the arthroplasty community. And, um, I think the data would, would strongly suggest that is not the case, at least in the general, uh, population. Um, if you look at the big database studies, you know, the rates of, uh, instability in primary hips is still probably about 2% in the first two years. So I think that misconception that now we're doing da instability fixed, I think that's probably not true. But then I think the flip side of that is the misconception that we're never gonna. Completely solve it or it's not solvable. And I think with DA Hips we can also, you know, start to see some of these centers that have been doing it for a decade are starting to show outcomes where the rates are exceedingly low when done correctly, with the right implants, with the right positioning, right? Soft tissue handling. So I think it is something that we can get to a point where it's, you know, like poly wear a thing of the past. But, um, to say that we're there now I think is, would be false.

Joseph M. Schwab 3:47

Blair, you're known for spending time with patients in a pre-op space and taking maybe a bit more of a conservative approach. From your perspective, where does instability prevention really start? Is it long before you get to the or?

Blair Ashley 4:05

Yeah, absolutely. Um, I think that patient counseling is such an important part of, um, you know, managing expectations and making sure that you're actually gonna give. Patients, um, an outcome that they're happy with. Uh, so I like to certainly understand what patient's goals are after surgery. You know, um, you know, obviously when deciding someone's a candidate for surgery, that's relatively objective. You know, that comes down to are they radiographically a candidate? Are they in enough, you know, pain, and are they functionally limited enough to be a good candidate for a hip replacement? But then it's also understanding like, what is your goal? What are you trying to get back to? Right? Are you just trying to walk and do your activities of daily living? Maybe some low impact cycling or water aerobics, things like that. Or are you trying to get back to skiing or, uh, intensive yoga or Pilates and things like that. And so, in those situations, kind of counseling patients in terms of what your expectations are and what their potential risk could be, um, is very important. Um. So, you know, there are certain complications that I like to really emphasize with patients like myself, not from my pa, not from just them reading the consent form, like coming from my own mouth and saying like, look, this is something we need to be wary of. Uh, and certainly with hip replacements, dislocation is one of those risks that I really take time to discuss with patients in terms of the fact that this is not just a, you know, your first six weeks of surgery, we worry about this and then you're out of the woods. This is a lifetime kind of almost responsibility that you're taking on. Um, and so discussing with patients that they wanna get back to some of these higher risk or higher impact activities that they are then assuming the potential that a dislocation could, you know, occur to them, whether it be three months after surgery or three years after surgery. Um, if they're not kind of being cognizant and cautious of that.

Joseph M. Schwab 5:57

Hmm, chance you've treated everything from primary, total hips to complex failed arthroplasty. When you see instability after specifically anterior approach, total hip, what's your maybe instinctive first question, was this a planning issue, an execution issue, or, or patient factors?

Chance Gray 6:19

Yeah, that's a great question, Joe. I, my instinct at this point is still, especially with anterior hips, I think, um, my gut is always to look first at the cup. Um, my, my own personal experience has just been that an anterior pro hip, uh, replacement, especially instability is almost always cup driven. Uh, so that's usually the first place I look. And, you know, I, I think we also, you, you raised a great point about patient factors. Um, you know, these cases aren't, uh, just an x-ray. You're looking at, you're, you're seeing a person. And so sometimes you do get a sense when you meet a patient that, oh, this may be driven by an neuromuscular issue. This may be driven by a, uh, you know, as Blair was talking about, certain activities that they try and do that may not be appropriate after hip replacement. I, i, is it some activity, uh, related issue? A lot of times I feel like that can still be solved for most people. And so I, I usually look first at the top. But then if the cup position looks good and looks normal, then we start going down this whole, uh, pathway of beginning to think about spinal, pelvic issues or, uh, you know, stem sided issues. But, uh, in, in my personal experience, I, I think cup driven, uh, problems are, are usually the root. Uh, I don't, I don't know if Dr. Ashley or or Dr. Barry agree, but that's been my experience.

Blair Ashley 7:38

Yeah, I mean, if I can kind of follow up. Sorry, I didn't mean to cut you off, Joe, but I was gonna say, I, I agree with chance. I kind of, those are my first things. And then I guess my other, um, consideration is like, is is an offset problem part of this too, you know? And, and I think you generally have like a good idea that either preoperatively with your templating or postoperatively, but, um, or sorry, like intraoperatively as you're trialing. But I will say that sometimes when I'm in the operating room and I'm not happy with my stability and my leg lengths are okay, the next thing I'm thinking about is that did I adequately restore offset? And I've been known to waste the occasional liner and put in a lateralized liner. Um, and that helps me to address that issue. But I think CUP is first and foremost, um, the typical culprit. And, and then I'm also kind of thinking about Offset if there's not some other good, um, biomechanical explanation from like a spinal, pelvic relationship or something along those lines.

Joseph M. Schwab 8:31

Mm-hmm. So Jeff, based on kind of current literature, talking about dislocation patterns in anterior approach and using your clinical experience, what do we know about dislocation patterns in anterior approach hips, and maybe how it differs from other approaches? We heard some opinions from, from chance. And Blair, what do you think?

Jeff Barry 8:55

Well, I, I think that the, the dislocation pattern in general, um, I think in 2026, you can kind of say most literature, most people would agree da dislocation rates are gonna be lower than posterior hips. If you look at all the, all the papers that are put out, it's either gonna show the same dislocation rate in maybe cherry pick studies or a better dislocation weight than posterior. And I think you just need to ask our trainees if you, I, I work in a training program. If you ask the residents how many da hips they've reduced, it's gonna be pretty much zero versus posterior hips. They've all kind of done a couple, um. I'm not gonna cover lateral hips so much 'cause I think that should be outlawed. I don't think that's an appropriate surgery in 2026 in the US I think yes, you may be the most stable possible, but you've sacrificed probably the most important muscle on the hip. So that's not allowed at, at least in my practice. Um, the other thing about DA dislocations is that when they do happen, it's a little bit more of a mixed, mixed bag than, um, than posterior hips. Posterior hips almost always go out the back, right? They're going right back where they came from. DA hips. It's actually a mix. Like they, some will come out the front, but some will actually come out the back. So I, I've been referred, you know, patients that have anterior instability, quote unquote 'cause they had a DA approach and it's really actually positions that are coming out the back. So I think that leads to more of this point of the component position is a big deal, but also from a DA approach. It's soft tissue handling at the time of surgery that I think makes a big impact. And, um, patients go out the back because we are sedentary. Flexed hip position creatures, and that's just a more natural position to go out is flexed as opposed to this kind of extended external rotated leg where it needs to go to go out the front. So I think that's one nuance is trying to figure out what direction are they going if they are a da unstable person, um, that you don't have to really worry about from the back.

Joseph M. Schwab 10:49

Chance we all know.

Chance Gray 10:51

sorry, I was, can I just add one, uh, comment there? Um, to, to Jeff's response. I, I think another piece of that is you, you sort of have to know your patient population as well. So I, I completely agree with everything that, um, that Jeff just said, but I, I live in a funny part of the world where, um, we're close to the villages. So the villages is like this adult Disney world, um, where everybody starts drinking at 2:00 PM in the afternoon every day, Monday through Sunday. And they spend an incredible amount of time on bar stools. And so I, I have had, I, I can count probably, uh, of all my dislocations I've ever had, which is not a ton, but I've, I've had a few, it's been an incredible number that have been anterior dislocators. 'cause they sit on bar stools and so they end up with this funny sort of hyper extended pelvis, um, with a leg that's still, you know, externally rotated. And so, um, oddly enough we don't see very many posterior dislocations of anterior hips here, although I know the data shows that. And so, um, that's just one of these funny positions. I'm now a little more aggressive at checking because I, I worry about, I worry about my patients in that fairly unusual position that most of us

Jeff Barry 11:57

you do

Chance Gray 11:57

a lot of time in.

Jeff Barry 11:58

like a Captain Morgan test or what are you doing for that bar? Okay.

Chance Gray 12:02

Yeah, I mean, it's, it's that, uh, you know, I, I have a bump under the pelvis. I, I do not on a table, uh, anterior approach. So I, we have a bump under the pelvis, which kind of recreates that a little bit, and then that sort of hyper extension, external rotation, uh, position. But, um, but I, I take it a lot more seriously now than, than I did a few years ago, just as this, this weird group of people we see.

Joseph M. Schwab 12:23

Have you published on the bar stool simulation approach? Is that, uh.

Chance Gray 12:28

No, that's a great idea though, actually. That's, uh, yeah, I think that's my next research project. I love it.

Joseph M. Schwab 12:34

Um, staying with you for a moment. It, uh, you know, we, I think we got a good idea of some of these, um, uh, the pattern of dislocation in anterior pro hips from Jeff. When you're starting to look in revision settings, do those patterns change sort of meaningfully or are is a revision or revision kind of regardless of where they came from initially?

Chance Gray 12:57

Yeah. Um, maybe let me get a little clarity on your question. Um, Joe, so are we talking about, uh, when you're worrying about dislocations after revision anterior approach surgery? Okay. Yeah. So, you know, I, I'll specify, um, for myself, my, my typical revision approach for, um, for patients who I'm addressing, whether it's instability or, um, uh, lysis or, you know, whatever the issue is. Uh, I typically only do subsided revisions from the front. So if I'm doing any femoral sided work, I will, I'll typically still go posterior. Um. But yeah, I think the, you know, the same, the same concerns arise. We, you know, if we're talking about doing an anterior based revision, whe whether cup or, or both soft tissue handling becomes essential. Um, you, you want to, you know, you have to take away scar to appropriately visualize your, your components, but you do wanna be a little careful about preserving as much soft tissue envelope around the hip as you can. Uh, and then, you know, but I do basically the same, um, sort of provocative testing with those, those patients. I wanna arrange them in, you know, in extreme positions after I, you know, with trials in, and, uh, to my knowledge, I, I don't think that, um, instability after revision anterior approach is a, is a main, is a big issue. I know after a posterior approach, it can approach 10% in some series. But, uh, I have not seen the same with my, you know, my own experience for anterior based revisions. And, and I'm not aware of it being as, as big an issue.

Joseph M. Schwab 14:29

Yeah. And, uh, so, uh, Blair, for you, knowing that anterior approach in a revision setting, um, typically doesn't have the same instability issues that you see in posterior approach, how do you translate that information into a patient conversation without maybe sort of overpromising?

Blair Ashley 14:50

for sure. I mean, I, um, I try to give people whole numbers. You know, I find if you really get into the nuances of data that, you know, you get kind of blank stares, you're in the headlight look. So, um, you know, I tell people, you know, we're looking at about a one to 2% risk of dislocation in this particular scenario. And then, you know, if I still get funny looks, I'm like, you know. Two out of a hundred people, you know, but, um, just trying to explain that it's, it hap like, it happens. It's not zero. And I think as we've been talking about, um, during this time is that, you know, sometimes there is this idea in the kind of popular public literature that like, oh, direct anterior hip, so you don't dislocate. So some of that is just kind of reeducating people, that, that number's not zero. Um, we're looking at single digit, I say single digit risk, but the risk is there. Um, and then, and then that's kind of like the. Baseline risk for everybody. And then again, going back to kind of patient specific factors, it's like, well, do you have a lumbar spinal fusion? Do you have um, uh, si joint fusion? Do you have a history of seizures, Parkinson's disease? Do you have a connective tissue disorder? Is there anything else about that individual that makes me more concerned? And then that's a conversation I have with them where I say, okay, well maybe this one for two per one to 2% is for the general public, but for you, I'm more worried because X, Y, or Z problem. Um, and so I think it's, there's a little bit of that element too. It's just kind of giving people a baseline and then talking about them specifically to kind of make it more real for them. Then to chance's point, you know, if you're going in a revision setting, explaining to that person, like, look, I need to do a little bit more work to get the visualization that I need, um, in order to do the surgery appropriately. So, you know, uh, and even in a primary, I do a capsulectomy, I'm taking the capsule out entirely. And typically that reforms, you know, in about six weeks or so. Um, but again, kind of counseling patients that while this is a risk for your entire life, we're most concerned in those early, you know, couple of months while that those soft tissues are healing and reforming. Um, but yeah, I think as concrete as you can be about numbers and specific concerns you have with that patient, I think that's really important. Um, and then I also, that's a time when I start to talk to patients about like, well, what would I do in the OR to help mitigate your risk? Am I going to change my liner option? Am I going to make you a little bit long if I need to? And, and kind of tying in those, um, elements of like, what is my plan A, B, and C when I get in there? And I think that helps to make it a little bit more real for them.

Joseph M. Schwab 17:19

So staying with that sort of patient specific counseling, how do you, how do you separate Blair, um, a patient's sort of modifiable risk factors for instability specifically from those you simply kind of need to plan around?

Blair Ashley 17:36

Yeah, absolutely. I mean, I think going back to the, the bar stool, you know, challenge, you know, there are some kind of patient behavioral issues that you can talk to people about if they do drink a lot. I mean, that's something to talk about. That's a, a well-established risk factor is patients with excessive alcohol consumption could be an increased risk for dislocation. Uh, maybe patients that have a seizure disorder, making sure that they're well controlled on their medication. You know, some of these medical issues can be optimized and modified to some extent. There are patients who are fall risks for other reason. You know, maybe they have, um, like orthostasis again, these are medical issues that can be optimized before surgery. And kind of being cognizant of that and talking to patients about that. Uh, I also find that some of my patients, um, while the patients are not bothered by using a cane or a walker, their pa, their family members get very obsessive about like, well, I think they should be done with their walker by now. I think they should be off the cane by now. Um, and living in the northeast and operating over the winter, I'm like, please just keep the walker for an extra two weeks. Right? It's icy. There's salt on the ground. Just like manage that. So I, I consider those kind of modifiable things and talking to people about how to. Best protect themselves. But then obviously there are non-modifiable issues. So patients that already come in with a fused lumbar spine or you know, lumbopelvic spinal fusion, like that's, that is what it is. You gotta work with that. Um, or again, patients maybe with a neuromuscular disorder, it is what it is to an extent. Um, and so that's just talking to the patient that, look, you're at an elevated risk and this is what I'm gonna do to manage it. Maybe I'm automatically using A-A-M-D-M liner, for example. Like that's a situation where I'm automatically doing that and I explain that to the patient even ahead of time, so they understand that I'm doing something to try to be proactive.

Joseph M. Schwab 19:16

Jeff, which modifiable risk factors do you think are maybe the most underdressed.

Jeff Barry 19:27

so I'm, I'm gonna be a little bit contrarian maybe here. I, I don't really consider risk factors for instability to be modifiable. So you just heard a bunch of really, you know, very well established risk factors that exist, but. In my mind, there's complications that are kind of maybe more patient driven and there's complications that are more surgeon driven. And to me, instability is if, if there's an instability problem, that's a, that's, that's a me problem, not, not a you problem. So I, I need to do a hip replacement in such a way that doesn't matter if you have a seizure like that, if you have epilepsy, you, you're, you may have a seizure at some point, and it needs to be kind of bulletproof to that. So I don't really think of it so much as a like. Ahead of time optimizing as what am I gonna do in surgery to change? Or what am I gonna modify maybe to make this as, uh, optimal of a construct possible? And, and so that's where, you know, Blair mentioned kind of using or three o or some a dual mobility type construct. If there's something that's making me worried, um, I'm gonna optimize my position of components. I'm gonna be really careful with the soft tissues like I always do. Gonna make sure I restore the leg length and offset. And then even if I feel stable, if I'm worried, you know, if they have one of these risk factors, I'm gonna, I'm gonna pop in and do a mobility without hesitation.

Joseph M. Schwab 20:46

Chance, do you think about non-modifiable risks as something that still deserve a strategy or how do you look at that?

Chance Gray 20:56

Yeah, I, I actually really think, uh, both Blair and Jeff gave, uh, really insightful answers. But I, I, I agree completely with Jeff that I don't want to trust my patients to, um, I, I, I sort of wanna make an idiot proof, uh, hip here for, you know, particularly for this question of, of stability. And so, um, you know, just one other approach that I will take in addition to dual mobility is, um, you know, and, and being very careful with cup positioning and provocative testing. I'm very direct with a lot of patients upfront. If I am worried about them for, uh, instability postoperatively, I have very little hesitation to talk to people about slight lengthening, uh, or going to high offset as well. I think both of those things, you know, we always wanna match, offset to, uh, their native anatomy and, and leg length as well. But if you have that conversation upfront. A couple millimeters of offset and a couple millimeter millimeters of leg length go a long way in, in terms of improving, um, stability. And so, uh, you know, particularly in hip fracture patients, that's a group that I now am doing a lot of anterior approach hip replacement on. Um, we have, uh, a fair number of these fairly active, um, you know, 70 something year olds that come in with hip fractures. And I will tell them and their family upfront, we're gonna make the leg just a little bit longer. It's much safer for you. You know, they come to you with an injury. So I think they're very understanding of that. Um, but that's, you know, one, one additional strategy that I'll use. And I think if you counsel 'em upfront, it's incredibly useful. They're not very upset about it. They, they tolerate it quite well. But, uh, but yeah, all, all the things that, that we talked about, I, I think we've paid an incredible amount of attention in the orthopedic community in the last five years to spinal pelvic issues and, and the role of dual mobility there. Um. I, I, I think that's something we're still, uh, beginning to understand more and more and, and we still have a ways to go there, but I, I think certainly it's one of those issues that if you see somebody that you're concerned about this, you, you start to go down the dual mobility route in your head. Uh, you know, in addition to the other things we talked about.

Joseph M. Schwab 22:55

So chance, I actually wanna stay with you on that topic for a moment. 'cause obviously hip spine mismatch is sort of a big, you know, as you pointed out, something that we're thinking about, uh, we've been thinking about significantly over the last five to 10 years, at least in hip surgery. So how do you think about hip spine mismatch when planning an anter approach, especially in patients that you think are presenting for a higher risk of. Instability. Is it, is dual mobility just your option or are, are there other things you're doing to plan for sort of the hip spine relationship? I.

Chance Gray 23:32

Yeah, I, I think, you know, I will not pretend to be an expert in this space. I think there's a few people who have really carved out a niche in, um, in the spine pelvic world that are, are doing really good work there. And, and I, uh, will defer to them, you know, certainly, uh, but, um, you know, my, my sort of antenna goes up, or, or my red flag goes up with, with a couple settings. One is obviously the one where you see a huge amount of, uh, pel um, spine hardware on your AP pelvis. So you, you see the, um, the destroyed hip, but then obviously staring you in the face is the, you know, the, um, the screws that are extending down into the ileum. And those are ones I always worry about. I, I think those certainly you have to, um, begin to go down this other, uh, sort of pathway. Uh, but the other ones that can be a little subtle are, are the ones that come in that don't have hardware in their back or in their pelvis and. They have an abnormal view on their, you know, you get your traditional AP, um, pelvis and you see that it's either an inlet view or an outlet view. Um, you know, rather than being a typical ap and it, it just kind of draws, uh, your attention to the fact that they might have something abnormal in the way they carry their pelvis. Because you, if you have a radiology, uh, tech that you trust that is shooting your films regularly, you get a weird view. That's certainly somebody I start to worry about a little more. And so, um, you know, I think once you, once your antenna is up for those, you can go down the pathway of whether or not it makes sense to get sitting and standing. Um. Uh, lateral views of the spine and the um, uh, the sacrum. Um, I've found the, uh, concept, I, I forget who, who raised this, but the, um, stuck standing or stuck sitting approach is, is pretty helpful as I'm thinking about how I'm gonna approach these patients. Um, but when I identify one of those patients, my other goal is I wanna put their cup in a really good position. I want, I want to make sure I put it in a spot that's functional for them. And then I still have dual mobility as the backup, but I try and trial with Standard liner. So I will typically do a try and get a 36 neutral trial liner in, and I want to have a hip that feels stable to me with a neutral, uh, standard liner. But then I'll typically, uh, when I do my final implant, go to a dual mobility an or three O type construct.

Joseph M. Schwab 25:49

And Jeff, how about you? Are you routinely changing your cup targets based on maybe spinal, pelvic considerations?

Jeff Barry 25:58

Yeah, I, I, I think this is a, a very, you know, we're on the tip of the iceberg in this topic, and, and I, I, I think that you could do a whole podcast on that if you wanted, but, you know, I, I, we at UCSF actually were some of the first people to write on this, and, you know, I did my whole grand rounds when I came back as faculty on this whole topic, and I, I think the. The take home message is that they are higher risk, yes. But it's not really gonna change much of what you're gonna do in surgery. And I, and I say that with the caveat that when I'm doing a hip replacement, I'm looking at their functional position of their pelvis. And to me that's a standing AP film. So a standing AP film tells me all the information I need to know about their spine from a DA approach. Um, like Chance was saying, if you get an outlet view, you know they have a flat back, right? If you get a inlet view from the standing position, you know they have hyper lordosis. And so if you put that cup in the right position in that functional plane, um, and for me that's about 20 degrees of aversion. If I can make that functional plane reproduce in the OR and I can put the cup where I want in that position, that is how I address spinal pelvic issues. I, I do go back and I fall back on that or three o the dual mobility in cases where, you know, it's a extreme, like they're an ANGs bondy patient, or they got the, the quad rods and, you know, all that stuff in there. Then, then yeah, sure, I'll, I'll maximize my stability with the doability. But I think that the cut position does not change for me based on the, the mobility of the spine or whatnot. It's where are they when they're standing?

Joseph M. Schwab 27:33

So Blair, this, this concept is complex enough for orthopedic surgeons. How do you explain it to patients in a way that maybe builds trust in what you're gonna do during their hip replacement?

Blair Ashley 27:47

Yeah, I mean I think, um, a lot of it is just trying to explain to people that, you know, the motions of transitioning from sitting to standing is a kind of a combination of the lower spine in your pelvis, in your hip, and if so, if you're fixed in like of those three places, if you're fixed in one or two of those places, you have to get, you have to compensate through the final mobile area. So if they have a lumbar spinal fusion, it's then your, the, all of your remaining motion to do your activity daily living, have to come from your. Pelvis in your hip joint or if you're again, have, you know, the, um, hardware extending into the pelvis, if you have lost complete motion in your spine and your pelvis and you're only relying now on your hip joint, you have to have a lot more, um, compensation in the hip to be able to accomplish that. So I think most people kind of understand that normally these three areas work together, but if you're knocking one or two of those areas out, um, then the remaining mobile area is doing a whole lot more in terms of its compensation, uh, in order to allow you to lead a normal life. Um, and so I think that's kind of the. Easiest way to allow people to understand that. And I'm, I myself am a visual person, and I think a lot of patients are. So I have models in the office. I have like a pelvis, like a, you know, just a sawbones pelvis. I have the, you know, kind of hip replacement models. And I think sometimes it's very helpful to kind of show people that, um, and explaining that, you know, on these X-rays, these are two dimensional images of a three dimensional problem. But then kind of going to the model and saying, this is what we're actually talking about, um, in terms of these activities of daily living. And again, it's, it's, it's hard enough, again, for surgeons to really get in the weeds. This is not an easy topic to understand and the nomenclature can be confusing and the measurements and everything else. So I'm just trying to, I think, address it to patients in terms of if these things are stiff, this last thing has to be flexible. And for it to be flexible, it needs to maybe move in places that we do not normally anticipate. Um, but, um, and, and then kind of again, going back to the, the tricks or the solutions we have in the OR to address that is, um, kind of that, you know, is a nice segue into that conversation.

Joseph M. Schwab 29:51

So,

Chance Gray 29:52

I was just gonna add Dr. Schwab's, uh, I, I think Blair's answer is really good and patients love to hear that you are thinking about that, uh, before surgery. They, I, I think it really is a nice way for them to feel that you have some expertise is that you, you kind of raise this issue and you, you show them that you're thinking through it and if you can be visual about it even better, but it really builds trust. And so if, God forbid something does happen post-op, they know that you were, you know, you weren't caught, uh, by surprise on this. They, they know you, you thought through it ahead of time and, and addressed it with them ahead of time. And it seems to, um, engender a lot more, uh, you know, easy conversations about complications then if they happen as well.

Joseph M. Schwab 31:49

any of you using tools like for instance, like a choreograph who that help you model sort of spinal pelvic mechanics that might affect your cup targets? Are any of you doing that in front of your patients and does any of that sort of meaningfully change how you plan for instability risk?

Chance Gray 32:08

You know, I, I don't, but, um, I. I will say there are some cases where I think a tool like that that was easy to execute in the OR and easy to, uh, obtain ahead of time would have a lot of value. I mean, when we get these patients that come in that have been multiply operated on elsewhere, and they're, you know, still having stability issues, if you have the ability to deliver a fairly, um, simple tool that you would be able to obtain ahead of time and you'd be able to model for yourself and then execute in surgery to match exactly what your plan is. I, I do think that's a valuable, um, uh, proposition, you know, at this point because we can plan a lot, uh, but if you can't match it to an execution in the operating room, that's, you know, that, that, uh, takes away a lot of the power for you. So, but I, I think the key is that it's gotta be something relatively simple and easy to obtain. And so something like choreograph, which, uh, is CT based and uh, allows you to get some fairly complex planning ahead of time, I think does have, does have value compared to some of the other options that are out there.

Jeff Barry 33:11

Yeah, I, I think to your, to your point there, chance, I, I think the, the, the other value of this is it gives you some confidence that you've optimized things, right? Like if you've put the components in a position that's optimized for impingement, you know, uh, implant, implant impingement, you at least can check off that box that you've done everything possible to, to make the component position aspect of the surgery perfect, right? Um, you know, you still have to worry about soft tissue. You still have to worry about abductors. You still have to worry about some of these other things, but at least gives you that peace of mind that, Hey, I've done everything I want or could do, um, from a component

Blair Ashley 33:50

I'd also, um, add that I, I, I feel like this is, I don't use this now, um, uh, but I think in terms of the world of, as we develop, you know, robotics and the kind of intraoperative guidance and planning tools, like, I have a lot of optimism for things like this. Um, I'd say as someone else, like Chance, I do an off table direct anterior, so I feel like I get really good functional testing intraoperatively, like I do, you know, I'm moving that hip through all kinds of crazy ranges of motion. And so that tends to give me, um, like relatively good confidence, I think more so than just. I think sometimes I felt in training of doing those tests on a table where I feel like you don't necessarily get as good posterior testing or, you know, you can't really get a figure of four. But, uh, even I can think of, I'm thinking of one patient in particular. Um, even with all those testing perfect in the hour, this patient who had an extensive lumbo, Publix spinal fusion did dislocate, you know, on a lesson I ultimately needed to revise. So, you know, kind of thinking of patients with those high complexity, and again, patients where you really wanna be sure, like to Jeff's point, you can check off that box that I did everything I could to optimize my physician the first go around. Um, I think that is, is eventually gonna become a very powerful tool then maybe you're not using with every patient. Um, but with these higher risk patients, um, uh, I, again, I think I'm very optimistic about, uh, how, how I could integrate that going forward.

Joseph M. Schwab 35:09

So Blair right now, um, just to kind of stay on that, those higher risk patients, patients with neuromuscular conditions or prior instability or maybe, you know, we talked about compliance concerns. Um, how do those factor right now into your initial surgical plan rather than, you know, something you might deal with after the fact?

Blair Ashley 35:30

For me, the, those patients in that category are automatically getting a, like an Oreo cup, an MDM cup, and a later a high offset stem, like automatically, basically, you know, I'm doing everything I can in, in addition, obviously to appropriate cup positioning. I think that's a given. We can all assume that. Um, but in terms of what am I doing in addition to that, those, those two things are, that's my default. I'm MDM high offset stem.

Joseph M. Schwab 35:58

Are the rest of you sort of picking kind of specific, we'll say pro stability constructs or, um, maybe chance I'll ask you at, at what point do these sort of risks push you towards maybe a different construct strategy than what you might use in a normal primary?

Chance Gray 36:17

Yeah, I think, uh, as I mentioned before, there's, there's certain patients that you, um, plan to have extra stuff on hand, but, um, I like to template my cases ahead of time as well. And so, uh, when I'm looking at, uh, you know, on my template and, and I, if I'm seeing anything out of the ordinary, then I, that's a text to the rep to say, Hey, let's make sure we have or three oh available on, you know, for, for this case. And then, um, I, I think I've also, as you know, as I've gotten a little more experience, I, uh, it's funny, I go sort of back and forth on high offset stems. I, for a while, I hated high offset stems. I tried to avoid them because I, um, I dunno, I felt like I had patients coming in complaining of troop bursitis a lot. And so I, I, I kind of stay away from 'em. Now, now I've kind of gone back to 'em because. You think, um, you know, if you take a, a modern stem, like, um, catalyst stem for instance, which has very graduated neck options, um, there's a lot more nuance now that you can achieve in offset and leg length, where, um, some of the older stems that I used to use, you would jump, uh, the high offset would be a dramatic, uh, increase in offset. I mean, sometimes on the order of, you know, 10 to 12 millimeters. And that just was too much for some folks. But, um, I think now with these graduated necks, we have a little more ability to fine tune that. And so, um, I, I will have those, uh, I I have a shorter, um, uh, sort of threshold, uh, for jumping to a slightly higher offset because it doesn't seem quite as provocative to the abductors.

Jeff Barry 37:46

I, I, I think to that, that same point you were talking earlier about, you know, telling the rep what to have. I think with the R three and the, or three o, like the transition to the, the inertia needed to switch to a dual mobility is so low, right? Like, as you were saying, you can trial with a 36 liner, like everything, and then you get the bonus of the extra head size by easily switching to a, to a dual mobility. The, the liner just goes in so easy, like it sits flush. It's easy to tell. You don't have to worry about cobalt chrome, which by the way, every cobalt chrome junction in the history of orthopedics doesn't work right. Or has had issues. So don't, don't put that in. Why are we, why are we still putting those in? Uh, but, you know, it, it just makes that decision a lot easier. The one, the one place where I will kind of still. Take pause is I, I have a lot of my, my practice is a lot of very young patients. I do still, you know, I, I will need a reason to put a dual mobility in someone under the age of kind of 40. Um, just because it is a different PO was that, well, I get a lot of teenagers, 20 year olds. We get, we get a lot of young, young, young patients. Um, but the, you know, the, the, the poly is different on a doability. So, so you need to be aware of that. It's not a fully congruent poly for any of these do abilities. So it's a little bit of a different wear mechanism. So those are the one, the one place where until we start seeing kind of 20 year data on that, I'm gonna be a little bit more cautious, but, um, older patients throw it in with without, without any hesitation.

Joseph M. Schwab 39:18

Jeff, I actually want to ask you a little bit about that young patient population. And honestly, I'm gonna go off script here a little bit, but I, uh, I, you've raised an interesting question. Um, the, is your patient population that young because of things like a VN or sickle cell disease or what, what is the, what's the genesis of that young, a patient population?

Jeff Barry 39:41

Yeah, I mean, so I'm at a tertiary care center, so we have, um, quite a, quite a range of reasons, but, but it's a, it's a mixed bag. We have a big cancer center, so a lot of it is a VN, um, after chemotherapy or stem cell transplants or, or things of that nature. Um, also a lot of dysplasia patients, right? So we get a lot of, a lot of patients with bad dysplasia. Um, uh, or, you know, I just saw a 14-year-old yesterday with a skiffy that failed, um, you know, it, a 16-year-old who had a car accident with a poster wall fracture dislocation that went on to a BN. So, you know, it's a, it, it, some of it is just. You know, we all get these little niches of patients that come to us, but it's also just being in a tertiary care center.

Joseph M. Schwab 40:23

Yeah. Um, so both, um, uh, chance and, and Blair kind of mentioned their sort of off table setup and even mentioned a little bit about what they're doing from, um, an intraoperative stability check. Jeff, I want to ask you, uh, are there. Sort of non-negotiable intraoperative stability checks that you're doing in your cases before you feel comfortable closing.

Jeff Barry 40:49

Yeah. So I, I think, um, number one, my, my number one stability check is actually just reproducing anatomy. So if I'm, if I'm happy with leg length offset and component position, um, that's my number one check, so to speak. In terms of positional checks, you know, I had, I had one surgeon one time tell me that if you've, if you've done something, you know, for, for two, 300 straight cases and never changed anything. You probably can think about if you need to keep doing it or not. And so, you know, for my first probably five years of practice, you know, a thousand plus hips, you know, many more. I was, I was doing stability testing on the H table. Um, and for me that would be externally rotating to 90 degrees and then dropping the leg halfway to the ground. If I had no subluxation in that position, I was happy with stability. Um, four or five straight years. I never changed a patient and so I have actually stopped doing that if I'm happy with my component position. I have not been burned from a DA approach yet with stability. If there, the thing that makes me more cautious, so to speak, is, um, and actually the most afraid of a dislocation is, is soft tissue issues with patients. So if you're doing a reduction, um, if they're, they're under a normal anesthetic, for me, that's a spinal. If you're doing a reduction and it's the same person doing the reduction for you on the haunted table, that usually does it, and it just kind of flies an inch away from the socket, that makes me more nervous than, than stability testing. Um, and so in those situations, um, it may be, uh, a patient where I, I would put into a mobility, or it may be a patient who, for me, I might give precautions for a few weeks. So going back to Blair's point about, you know, these early few weeks is the most high risk period. I may just, after surgery counsel that patient like, Hey, you know, I'm very happy with how everything went. You know, the stability checks were very good, but. Your soft tissues are a little lax or, or whatnot. I just wanna be extra cautious for you. Let's just do these precautions for a few weeks. And most patients are very open to that and they kind of get it and it just sets in their mind like, Hey, I gotta be a little bit careful and slow down for these first few weeks has not been an issue long-term after that, but, but those are more the the things that worthy.

Joseph M. Schwab 43:00

Blair, are there checks that you routinely do that you think maybe get rushed or skipped, maybe by other surgeons?

Blair Ashley 43:10

Um, well I'll say I think the one, the one with the DA approach, I think we all kind of take for granted that like, oh, I'm not that worried about posterior instability. You know, like it's kind of in the back of one's mind. So, um, when you do an off table da, like you can check that like, I flex the hip up to 90 and sometimes pass 90 and internally externally rotate. And I think that's probably one that's easy to kind of skip or rush through. Um, just because again, you kind of, you're like, oh well I'm doing this 'cause I can do it, but like, what is the likelihood of it's actually dislocating posteriorly? Um, and every once in a while when I'm doing that and I have my finger kind of on the articulation, I'll feel like a little osteophyte I missed or something that could be a source of impingement down the road. And I will kind of like, to Jess point, I like I'll go back and change it. So it's like, for me it's something I'm still very cognizant of, but I think it'd be an easy thing to kind of rush through. Um, but I'm very reliant on my intraoperative stability checks 'cause I don't use. Fluoro, you know, like I'm using all anatomy component positioning and I'm relying on my stability checks. So that's kind of just, again, it's a different, um, you, depending on what you're using, you're perhaps weighing the, that information differently. Um, so for me it's like kind of the figure of four because everyone's trying to put their shoes and socks on by putting your foot up on your other leg. Um, and then again, that posterior stability test in addition to just kind of leg length and um, and whatnot. But I think the posterior one's easy to, to skip 'cause we kind of take that for granted.

Joseph M. Schwab 44:35

Go ahead.

Jeff Barry 44:36

can I just make a comment as an on table person? Um, there's like early in practice, a couple of times I would take the boot out and check posterior if I was really worried. And to be honest, I didn't know what to do with it. Like, I didn't know what, what position I was gonna be. Okay. I didn't know how far it was supposed to go. Like, sometimes it would sublux and go right into the capsule. So for me, I was like, I don't know what I'm doing here. I don't know what I'm gonna change. Like what am I going towards? So for, for the on table people, don't, don't worry if you're not checking posterior. I think more important is like, make sure you're not violating posterior capsule. Make sure you're doing appropriate releases. That's, that's

Blair Ashley 45:11

and you're get, you're getting information as an ONT person that I'm not getting right. Like you get more reassurance that you've, like, you can see what your offset is and you can, you know, like, so you're getting that information elsewhere, right? So I kind of do it based on my templating and what feels appropriate than when I am, you know, testing these patients functionally. So it's just getting that information from a different place.

Joseph M. Schwab 45:35

Uh, chance is there, I'll say maybe an intraoperative red flag that you see that tells you something isn't right, even if maybe everything else would indicate that the hip feels stable.

Chance Gray 45:51

Yeah, uh, I think there, there's a couple and, you know, they, they almost make my blood pressure rise, just sort of thinking about 'em 'cause they can be really frustrated. One is when, um, you know, I, I work with the same PA every day, and so all my hips, you know, he, I know it's him pulling on the leg. And so there are times where we go to do the reduction and like Jeff mentioned, um, you know, it's way too easy. And I, I go, oh, that was really odd. That took zero. I, I can tell that he had to pull with minimal effort and, and the cup just, or the ball just drops right in, even though all the positioning looks perfect. That to me is like, uh, I, I start second guessing and I, I, I want to go back and, and be really careful about, make sure our imaging was accurate and, and check the anatomy again. And then the second one, which I mentioned earlier is my, my bar stool test, which is, you know, the, um, and that actually, um, the, the other one I like for that is I will, um, keep the leg in sort of a neutral, um, flexion extension, but hyper ad duct, the operative side and externally rotate. So sort of bring the heel over to the other heel and then, um, try and drive the foot into extra rotation and just see if we get any posterior impingement. That's one that I think can be a subtle indicator of some over aversion of your cup or, or over combined aversion. And so, um, that's another one that I look at pretty carefully. I think that's a really important test from the front, um, at least in, in my hands. So, uh, but, uh, but yeah, that, that soft tissue, uh, question becomes a big one when, um, you know, if you're just not quite, uh, things just don't feel quite right based on your reduction tension, even though everything else looks good. I, I think you do have to think a little bit about soft tissue and, and patient anatomy in that case in terms of just their neuromuscular function.

Joseph M. Schwab 47:33

Hmm. So we've had a, a, a a nice, actually, sort of little side discussion here about, um, you know, the sort of information that you get in an on table scenario versus an off table scenario. And just thinking about that from the different perspectives that you guys have, are any of you using something like ri hip navigation, um, to help you hit your targets? Is anybody using any navigation above and beyond their anatomic guidelines or their fluoroscopic input?

Chance Gray 48:07

I'm not, but I, you know, hearing Blair talk about not using fluoro, um, is very appealing to me because I, you know, I, I I will say fluoro is easy, feels easy to get. Um, you know, we, we have good fluoro at the ready in, in the hospital, but, um, recently I, you know, I operated in an A SC and, uh, for about half my cases, and recently our radiology tech went out. She had a hip replacement. So, uh, we've been without a, a rads tech. And so I've had the nurse push in the machine, and then I'm either hitting a foot pedal or, you know, and, and the variability and quality of that imaging is, uh, high. So it would be very appealing to not have to be beholden to, to x-ray. And so, um, as I said earlier, I think if there were an easier or, or an easy, excuse me, solution, um. To, to use some kind of navigated scenario that would be easy to implement in the or. Um, not very costly, you know, especially if we're in an a SC setting. Um, and then would give me reliable information. I, I think that would be a pretty appealing thing for me, um, just to get away from being beholden to fluoro at all.

Jeff Barry 49:16

I, I, I think what you're gonna find in the, in the future is, is right now we're like right on the brink of, we can kind of navigate things, but we can't necessarily execute the preparation and the navigation together. And so, um, I, I think the next version of this is going to be the one that starts to gain more widespread adoption for the reasons Chance was just saying like, we don't love using floro, we don't love wearing lead. Um, it's another person that has to be in the or. You gotta wait for them to show up. So, um, I think once we can plan a socket, prepare a socket, and then put the socket in all through the same ecosystem, which, um, is on the verge, um, coming soon to an r near you, um, I, I think that will be the, the one that's gonna gain widespread adoption for hips.

Joseph M. Schwab 50:04

So, um, talking a little bit more about actual components and the components you might use for instability. Blair, I wanna go to you because both, um, sort of Jeff and Chance kind of mentioned this, um, being able to sort of trial with standard components, but then switching to like an or three oh, um, right at the, you know, at the point of, of actual implant placement. Um, when you've are dealing with a patient with an elevated instability risk, how do you think about escalating your construct without necessarily jumping immediately to the most constrained option? And we really haven't talked about constraint per se, but, um, you know, there's, there's very, uh, there's, um, variability in, in how one can define that. I think.

Blair Ashley 50:53

Yeah, for sure. I mean, as I mentioned, I, there are patients, I'm just planning on using an MDM, so if I'm planning on using like an R three O, I try with an R three O. I just, I like to, it's kind of just like a practice how you play thing for me. Um, but for patients who maybe aren't quite that extreme, like, or maybe that I'm not even anticipating having a stability problem, um, I do try to optimize my head size. So if I have the option to use a 40, if I'm putting in a big enough cup to use a 40 head, I'm going to a 40 head. Um, I'm, if, if the 36 is my maximum, I'm doing a 36. So I'm, you know, I, uh, I do tend to trial with the largest head size available, like even just for like a normal headliner, um, with a neutral liner. Uh, and then. Uh, I, I think I alluded to earlier, there are some patients who I sometimes worry about an offset problem based on my templating. You know, some patients have a lot of native offset or I know maybe they have some dysplasia, so I'm really medial their cup and then I'm kind of creating an offset problem. Um, and for those patients I will often, I don't typically trial my liners, but for those patients based on my template, then I'm like, Ooh, am I really, am I gonna have trouble recreating that patient's offset? I'll sometimes trial with a neutral liner first, make sure that I'm happy before putting in that neutral so that I have the option to trial with a lateralized liner if needed. Again, going back to, if I'm concerned specifically about that offset problem. Um, and then of course there are also, I mean, they're kind of just the lateralized liners, but they're also lateralized liners with an elevated lip, which is an option that exists. That's something I. I'd like to have, I like to know it's around, but I, I very rarely, very rarely use, um, I would be more likely to go to an R three oh before doing something like that, but that's another thing to have available to yourself.

Chance Gray 52:39

I was actually just gonna ask Jeff and, and Blair on that, on that very topic, Blair, I, do you guys ever use a limp or, you know, face change liner from the front? I, I don't think I ever have. Um, but I encounter it now and then, uh, when I'm revising, uh, other folks have come from elsewhere and I'm, I'm just curious what, you know, if, if you guys think there's a role for those, uh, the lateralized I, I makes total sense to me, uh, if you're trying to get pure offset, but I'm, I'm just curious about the, the lip or the face change if, if you, if either of you guys do that.

Jeff Barry 53:11

Never, never in a primer

Blair Ashley 53:12

can think

Jeff Barry 53:13

Oh, sorry.

Blair Ashley 53:14

yeah, I agree. I, it's like I can think of maybe. I can think of two patients, you know, in five years and both kind of like conversion scenarios, um, or like some kind of revision scenario that I use that in, because then you worry about like, well, what if I'm putting that elevated lip in the wrong place and I impinge and I create a problem for myself elsewhere? That's the part that I'm always worried about with that. Yeah.

Jeff Barry 53:39

Yeah. For me, it's never a primary option. It's a, there's a well fixed cup that I'm trying to salvage and it's a, it's a, revision solution. Yep.

Joseph M. Schwab 53:48

So Jeff, you also mentioned, you know, your number one sort of stability test right? Is, is anatomic reconstruction. And so talk to me a little bit about how you see offset and leg length optimization, um, in the stability sort of, uh, uh, workflow for your patients before you think about changing or escalating, maybe your constructs.

Jeff Barry 54:16

Yeah, I, I, I think that the human body wants to go back where you found it, right? Like that's where the muscles are designed to be. That's where they're used to, their kind of range of motion to impingement. And you gotta remember the head and neck ratio of a native hip is horrible, right? So, so like they have. They're used to impinging sooner, maybe necessarily than, than your construct's gonna be. So, um, I, I think if you can reproduce those things and you haven't destroyed the soft tissues, um, you're, you're generally gonna be okay from a DA approach. Now, that said, I, I think that you have to be able, the number one, check that, so with fluoros the way I do it, or, you know, a lot of templating or navigation or whatever it is. Um, but number two, I, I think there are system based issues that make this easier to achieve, right? So, um, chance already mentioned this, like catalyst stem has. A great kind of graduated thing. Every size is a half millimeter more of length and one millimeter more of offset. It's real easy to remember that, right? If you go from the standard to the high, it's a straight lateralization. You're just getting straight offset. So it makes that kind of fine tuning in the or very easily, very easily achieved. And the other thing is when you have oxinium heads available to you, there's more options in terms of your minus and plus, um, as opposed to some of the ceramic offerings. So you, you have this kind of finetune ability, um, that doesn't exist with other systems. And the other thing is if you go to a dm, um, and, and you have an R three oh and there it's a smaller head, you get more of these 28 and 22 head options with oxinium than you would in the ceramic options. And, and you already heard what I think about cobalt chrome. So, um. I think that ability to get the target right is, is very nice with the system or with the Smith and Nephew system. Um, in terms of like, when will I add length or offset? Really, I try to avoid it. You gotta remember the people that are unstable, like these old, frail ladies with like no muscle tone. They're the ones that hate high offset the most, right? Like, they're the ones that are always complaining of bursitis. So I'm, I'm trying to avoid that. If, if, if I can.

Joseph M. Schwab 56:24

So one thing that I haven't heard anybody sort of really mention, and I'd be interested in sort of hearing the group's thoughts on this, is, is true constrained liners. Is anybody using those in any scenarios at this point or have, um, dual mobility options like the OR three Oh really made that, um, if not obsolete, extremely rare.

Blair Ashley 56:49

I mean, I guess I will say I, that is a last resort for me. You know? Um, I, I find all constrained liners annoying to put in. Um, they are obviously something where you kind of have this theoretical, like you're putting more kind of strain through your system, right? So it can accelerate the kind of, or I guess, shorten the lifespan theoretically, of your cup. So certainly if, I mean, you really wanna put it in, if there's a well fixed cup. So you're almost by. Default putting it in a revision scenario. Um, there's some literature that exists that say you could use it primarily as long as you have like five screws or, you know, a certain number of screws for good fixation. But that would give me pause. And, um, so for me, because there are, I think, so many other good options in terms of augmenting your stability with the different liner options and the dual mobility liners and, you know, hopefully you still have some ability to add leg length, you know, assuming that that scenario had not been exhausted during the primary. Um, I, I constrained to me is very much a end of the road situation. And ultimately, you know, constrained liners are a solution typically for abductor insufficiency, you know, and hopefully that is something we see less from the front. And certainly as das more popularized, that's perhaps less of a problem. But you really just have, I think it's important to still be critical of cup positioning. You don't wanna put a constrained liner into a malposition cup. That's just the wrong thing to do. Um, so I, I think it's very much a last resort situation.

Jeff Barry 58:17

Uh, I, I think for me, the only primary situation where a constraint is, is an option is, is tumors. And, and so those are a totally different ballgame, right? If you're taking out the proximal femur in their abductor. That, that may be a situation even in those I've gotten really bold with, with O three O and dual mobility constructs. If you have no abductor, the way it dislocates is usually sliding out the side and abducting, right? So take some abduction out of your cup, like really keep that cut, almost flat covering the ball. Um, and with these, you know, you put in a, you know, 50 ball, um, with the dual mobility construct, those, those will be surprisingly stable, even with no proximal femur, no abductor muscle in some of these tumor situations. And so I'm gonna let that fail before I, before I go to a constraint, um, option. Um, uh, similar to those lip liners, constraint is a, is a revision tool, not a, not a primary for me.

Joseph M. Schwab 59:13

Chance, how about you?

Chance Gray 59:17

Yeah, I agree completely with the previous comments. Um, saved for a last resort, I, I think of it, um, in case, you know, Jeff mentioned big, uh, massive resections and huge infection is another one, um, where you've already been in the hip and, and had to take away a lot of bone or tissue because of infection and, and you're concerned when you come back. Uh, but typically those are, you know, again, I do that from a posterior approach, uh, you know, if I've done a case like that. And so I think there's already a little increased instability risk, but I would rather see a dual mobility fail, um, before I would think of going to a constrained. I think you just, you're being more friendly to the, um, to the hip by staying away from constrained as long as possible.

Jeff Barry 59:58

Can I, can I just make a comment that I, I was looking at the HJRR yesterday, um, in preparation for this, and a crazy statistic to me was that in revision hips, 25% of liner choices are constrained. Like that is insane to me that revision, hip bearing option, 25% in the US were picking constraint. So I, I, I haven't seen That many, but

Chance Gray 1:00:24

that was current to like this year or, or,

Jeff Barry 1:00:26

That was 20 20, 20 22 data or whatever. It's like the 2024 report that I was looking at. So a little bit older one, but, but yeah, 20.

Chance Gray 1:00:33

yeah, Yeah. That's wild.

Joseph M. Schwab 1:00:36

I feel like we need to have those surgeons on the show to explain what they're doing. Huh.

Blair Ashley 1:00:41

Yeah, exactly.

Joseph M. Schwab 1:00:43

Um, so, uh, we're, we're getting close, uh, and I appreciate all the time that you guys have spent with us. And I, I just have a couple questions left for each of you. And, and Blair, I want to start with you. So we've talked a lot today about instability, and we've talked about it from a number of different perspectives. If you had to describe. Um, it, it sort of conceptually your sort of end to end, beginning to end maybe instability prevention algorithm. Now obviously everything's specific to each patient, but from kind of clinic visit where you're deciding to go ahead with a total hip to a final construct, let's say in a primary, uh, broad strokes, what does that look like in practice?

Blair Ashley 1:01:27

Yeah, I mean, I think, um, kinda first interaction, it's mostly like, what, what am I worried about with this patient? Is this kind of like my standard risk patient or are they a higher risk patient? Uh, not just for the conversation with them, but more for me, again, to kind of like chance and Jeff's point of what do I tell my rep that I want, right? What do I wanna have available? What's in my brain? Um, and then the next step for me is templating. And templating is very important to me because I'm not using intraoperative imaging. So, and then, so based on that template, I'm already deciding like, am I worried about my offset? Do ICOs, lateralized liners, um, am I thinking, am I leaning towards a high offset? Am I leaning towards a standard offset? What's gonna be appropriate there? Uh, and then intraoperatively, um, again, kind of, you know. Putting the parts in the right spot, right? Which is we all strive to do from the get go. Uh, and then the intraoperative assessments and, and some of the, even the choices between those two things, like if I have a very small cup size and I would only get a 32 head, that might be a situation where I would use like an or three oh, to get a bigger head size, even if it's someone's not necessarily a stability risk. So some of those, like finer tuning those decisions. And then I think, again, kind of as the point that Jeff brought up is that particularly with catalyst stem, when you have these gradual increases in terms of offset and leg length with each stem size, that might be something where as I'm trialing, if I'm getting higher from my, my, like, you know, neck length and I'm at a plus eight and thinking about going to a plus 12, at that point I'm saying to myself, look, I'm gonna upsize my stem, maybe sit it up a little bit, gain some length and offset from the stem, and then reserve myself some neck lengths. As I'm going up, if I'm trying to reestablish those things. So yeah, I think it's what am I worried about walking into the room? What is my template telling me to expect? And then how do I pivot intraoperatively? Those are are kind of my, um, biggest things. And then thinking about, heaven forbid I have to come back here, what would my next surgery look like and what options have I left for myself?

Joseph M. Schwab 1:03:24

Hmm. And so, Jeff, when you hear algorithms like that, which I, I think is a very comprehensive one, and lots of surgeons have different algorithms for, you know, uh, their instability risk, where do you see most of these algorithms breaking down in practice?

Jeff Barry 1:03:44

Well, I think number one, you have to have an algorithm, right? So you have to have a routine that you're doing every time that, that you can address. We're we're creatures of habit, right? We do two surgeries, basically. Like you need to be, you need to have a, a routine. Um, and, and I think where they break down is, is when we, we fall out of that routine. So you crack a femur or you have trouble getting the cup to, to fit or, or you, you're having trouble with exposure or something is off from your normal workflow. That's where, where then instability kind of creeps, creeps into the, to the equation. So I, I think just being vigilant and kind of always going back to your same checks, your same, same routine, same cut positioning, like have a workflow and stick to it. I, I think that's probably the best way to avoid in the first place. And, and, you know, to Blair's point of. Do a lot of this in the, in the pre-op space, right? If you know they have a risk factor, have the or three available, like already have that planned out, ready to go, like, don't then get distracted by, you know, it's a dysplasia case and you're struggling with cuff, getting the cup right where you want, and then not think about it the end. Like have that already planned before you start the surgery.

Joseph M. Schwab 1:04:51

Chance. I, I want to hear from your perspective, 'cause we have a lot of young surgeons who listen to this, who are, uh, kind of working through what their algorithm is gonna be, what their surgical approach is like, if you were to identify a single decision point a. Regarding instability that has sort of the biggest downstream impact, meaning if you've got surgeons who need to learn. We talked about a lot of different issues today that affect instability, but what's the number one decision point that has the biggest downstream impact for patient stability after an anterior approach?

Chance Gray 1:05:31

I think there's probably a lot of viable answers to that question, Joe. Um, depending on what your workflow is. But, you know, I, I think a simple one would be, um, you know what, what, maybe starting, you know, very relevant to what we're talking about today is what family of implant am I gonna be living in for the majority of my cases? Because, um, I think, uh, breeding familiarity with your, um, with your implant system through a lot of the nuance of where surgery varies, um, it has a lot of power for you because even though, like Jeff said, we're doing the same operat, you know, one, one of a couple different operations over and over and over again, there's incredible nuance from patient to patient. What's the, you know, your exposure can be a little different based on patient, uh, muscle tension or muscle bulk or what their blood pressure was doing that day or how much, um. Uh, you know, little, little change in the position on the table or who you're working with, et cetera. And so having a, you know, having an implant system that you use all the time and that you know how to get the best results out of I, I think is really important. And you know, when things are different. So if you, you know, if you're doing the same thing all the time and using the same implants all the time, you appreciate these little differences where you may say to yourself, that was a little different than, than usual. Something's off here. I have to check that. But then also understanding where, um, you know, if you have an implant system like, uh, R three that has, you know, can run from a, um. Very standard, neutral offset liner to a, um, lateralized liner, to a face change, to a, um, dual mobility. Uh, having an implant system like that that gives you incredible versatility, I, I think is, is really valuable. And then same thing on the STEM side, um, that positions you for success because you're not gonna find yourself stuck going, oh, I wish I had the ability to, uh, do X, Y, or Z and, and dang it, I can't do that with this implant. And, uh, so, so I think that's a, uh, probably a big, simple one when you're starting practice is to say, I'm gonna get really familiar with, with this family of implant, I'm gonna use it all the time. And that way I know what I'm, I'm dealing with. I, I think would be a good place to start.

Joseph M. Schwab 1:07:40

So you've all been super generous with your time. I really appreciate it. I have kind of one closing question for each of you, sort of an opportunity to maybe provide a little philosophy or a little bit of, uh, parting wisdom to our listeners and chance I'm gonna start with you. Um, when you look back at some of the instability cases you've managed, what's one mindset shift that changed how you do anterior approach? Hips?

Chance Gray 1:08:11

I guess what I'll say for, you know, one, one big thing that I probably changed at some point early on is, um. And, and this came up earlier, I don't wanna blame the patient, uh, for, for anything, you know, uh, a mentor of mine, um, early on said, uh, he said, you know, when, when you're taking care of patients and somebody comes back with an infection, uh, you feel terrible, you wonder, what could I have done differently? Man, this really, uh, I'm really bummed out. Uh, but when they come back with a dislocation, you get. You know, you get irritated at them. And, uh, and I always thought that was an interesting remark and, um, and, and I've certainly felt that. But so a mindset shift that I've tried to adopt and, you know, as we mentioned earlier, is I, I wanna really make an idiot proof hip because I, I don't wanna find myself getting mad at my patient because they did something that I wish they hadn't done. I kind of wanna set them up that, you know, I'm, I live in the, in the world of Florida, man here, so we, we have some poor decision making that happens on a regular basis. So I, I'm gonna assume that, and I wanna leave the or with a hip that I, I trust that even if they do something pretty stupid, they're, they're not gonna get themselves into trouble. And I think that's helped keep me out of trouble for the most part, uh, especially as I've, uh, you know, in the last few years as I've gotten more experience.

Joseph M. Schwab 1:09:29

Blair, if you could help one surgeon avoid maybe learning the hard way when it comes to instability, what's the one thing you'd tell them to take seriously or to focus on from the start?

Blair Ashley 1:09:44

Yeah. Um, I mean, again, it's hard 'cause there's like, I feel like there's a rush of things that come to mind, but I, and I think this has been brought up to some extent, but I think as with all surgery, respecting the soft tissues is just so important. You know, like we're orthopods, right? We're very bone centric people. Um, but, and da hips, I think the management of the soft tissues does make a big role. Play a big role. Um, and specifically for me. I'm thinking of the femur, you know, in terms of, 'cause sometimes in, you know, bigger patients, maybe muscular males, sometimes it's really hard to elevate that femur. And for me, I know in the moment I'm like, well, I wanna see it better. I'm worried about breaking the femur. I wanna see it better. And I really wanna be able to elevate, especially for off table surgeons, you know, that's not always, that's can actually be a very challenging part of your, um, surgery. And so, uh, I think just being very cognizant of that and balancing that because if you release too much of those kind of capsular structures and you'd get into the, you know, external rotators and the abjects and things like that, you can create instability that would not have otherwise been there. So I think sometimes it's just like taking a breath only, um, doing the releases that you really need to do, uh, to see what you need to see, as opposed to giving yourself like the most amazing visual visualization possible at the ex, at the expense of these kind of protective soft tissue. Structures. I, I think that's something where initially I was just so focused on getting the best view possible of the bone. So, 'cause I was so worried about fracturing, but maybe doing almost like more than I needed to do, um, to accomplish that safely. And as I've gotten further along in my practice, I feel more comfortable, um, with starting with more minimal releases.

Joseph M. Schwab 1:11:28

Jeff with, and you kind of mentioned coming soon, you know, things like better planning tools and navigation and our implant options. Certainly the ones that are available now, but the ones that are gonna be available in the near future too. What gives you confidence about where instability management is headed and what do you think, um, is out there now or coming soon that sort of deserves some. Real respect.

Jeff Barry 1:11:59

Yeah, I, I, I mentioned this a little bit at the very beginning, but I, I do think that instability can be, um, something that we kind of look at historically, almost like poly wear, right? Like technology was the way that we solve lysis and we solve poly wear such that now we're kind of spoiled. Like that's not even a, a thing anymore. Um, I think instability can go to that same place where with the right technology that can tell you where to get the cup, tell you where to position components, achieve that target, um. Proper training, right? Like DA is now widespread in the us people are coming up learning how to do it appropriately with good soft tissue management. I, I do think this can become one of those rare to never events. Um, so I am very optimistic that this will be one of those things that we're telling trainees about. Like, Hey, remember when we used to have to reduce hips? Right? That would be really cool, right? That, that patients don't have to go to the ED and have their hips reduced. Um, so I, I, I think that, you know, this is, this is one of those places where, where it's a, it's a nice combination of implant tech surgeon, uh, ability and skill coming together and hopefully, hopefully eliminating this problem.

Joseph M. Schwab 1:13:12

Well, I, I've really appreciated this conversation and I want to thank you all for joining me today on the AHF podcast. Thank you for joining me for this episode of the AHF Podcast, and thank you to our sponsor, Smith+Nephew. As always, please take a moment to like and subscribe so we can keep the lights on and keep sharing great content and conversations just like this. Please also drop any topic ideas or feedback in the comments below. You can find the AHF Podcast on Apple Podcasts, Spotify, or in any of your favorite podcast apps, as well as in video form on YouTube/@anteriorhipfoundation, all one word. Episodes of the AHF Podcast come out on Fridays. I'm your host, Joe Schwab, asking you to keep those hips happy and healthy