We discuss the etiology, exam maneuvers, diagnosis, management, and outcomes of developmental dysplasia of the hip. We are joined by Will Morris, MD, Assistant Professor of Pediatric Orthopedic Surgery at the Texas Scottish Rite Hospital for Children in Dallas and UT Southwestern.
Dr. Neeta Goli:
Welcome to Newborn News, a podcast where we discuss educational topics from medical professionals who care for newborns. I'm your host, Dr. Neeta Goli, a pediatrician in the UT Southwestern Newborn Nursery. Welcome back to the podcast. In today's episode, we will be discussing developmental dysplasia of the hip, or DDH. We are recording remotely due to the ongoing COVID pandemic. We are joined today by Dr. Will Morris, Assistant Professor of Pediatric Orthopedic Surgery at the Texas Scottish Rite Hospital for Children in Dallas and UT Southwestern.
Dr. Will Morris:
Hello.
Dr. Neeta Goli:
Hi Dr. Morris. Thanks for joining us today.
Dr. Will Morris:
Dr. Goli, thanks so much for having me on.
Dr. Neeta Goli:
Development dysplasia of the hip, or DDH, involves improper development of the femoral head in relation to the acetabulum. If untreated, it can lead to long-term sequela, such as leg length discrepancy, limp, pain, osteoarthritis, and the need for joint replacement later in life. Please can you give us a refresher on the anatomy of the area and the pathophysiology in developmental dysplasia of the hip?
Dr. Will Morris:
Absolutely. So as you mentioned DDH is a condition where the femoral head is relatively undercovered by a shallow acetabulum. And DDH is a bit of a misnomer because even though it's called a dysplasia, it's really more of a malformation of structures that develop normally during the embryologic period. And then due to a number of either intrinsic or environmental factors, the acetabulum becomes relatively shallow and underdeveloped. This can present in a broad spectrum of disease raging from physiological immaturity all the way up to a frank dislocation. It's important for us to identify and treat it early because as you mentioned, failure to recognize dysplasia at an earlier age can lead to either the need for more significant treatment such as surgery, or if it's identified very late, can lead to early osteoarthritis and need for an early joint replacement.
Dr. Neeta Goli:
How common is DDH?
Dr. Will Morris:
Well, the incidence of DDH is a little difficult to identify exactly because of differences in the definition used and different populations being studied. But generally we think that about one to maybe 2% of infants are diagnosed with a dysplastic but stable hip. However, interestingly, if we were to image all neonates immediately after birth, we would see a much higher rate of sonographic instability or dysplasia of about 15%, most of which generally normalizes without intervention. By the age of six to eight weeks, only about 1% have evidence of residual dysplasia. So most of it gets better, and that's why we have that term “physiologic immaturity” for our neonates. On the other end of the spectrum, only about 1 in 1000 have a frank hip dislocation.
Dr. Neeta Goli:
What are some of the prenatal and postnatal risk factors for an infant for DDH?
Dr. Will Morris:
Well, the most common risk factors that we think of are the four Fs. So that's female, first born, family history, and feet first, or breech presentation. Female biologic sex is present in about 80% of cases. Birth order being first-born in about 60% of cases. Family history confers about a 12-fold increased risk, so certainly, a significant risk factor. And then the literature's all over the place with regards to breech history, with some older studies suggesting a very small single digit incidence of dysplasia. But I'd say that more recent studies from San Diego and one from England quoted around 16-27% rates of at least sonographic dysplasia that required treatment, either continued observation or a Pavlik harness, a concept we'll get to a little bit later.
Dr. Will Morris:
In our institutional experience, which I just submitted for publication, is that about 25 or so percent of kids who are breech who are referred over to us actually were dysplastic. So aside from those non-modifiable risk factors, cultural or environmental factors also appear to play a role. Historically, we saw a really broad range of incidence based on geographic area. And there certainly are some studies of genetic factors which may play some contributing role. But the major punchline of seeing that broad distribution of incidences is that it's really regional or cultural differences, primarily based on the way the baby was swaddled.
Dr. Will Morris:
Essentially, swaddling a baby with their hips extended can have a pretty devastating impact on early hip development. And there's actually a really neat study out of Japan, Yamamura is the first author from the 1980s. And what they looked at is they noticed that they had a rate of frank hip dislocation that was about 3.5%, which is about 30 times higher than that incidence in the US. And they identified that a swaddling diaper, which was being used prominently in Japan at that time, kept the hips in forced extension. And what's really cool about the study is it was written later, once they actually had a chance to set up a national campaign to change practices towards safe swaddling. And their rates dropped down as a result, to less than 0.2%.
Dr. Neeta Goli:
And then to get back to breech for just a second, why is it that the breech position puts babies at risk for DDH?
Dr. Will Morris:
Sure. So as I mentioned before, although it's called a dysplasia, this is theoretically an embryologically normal hip that then has some malformation that occurs, which in the case of breech presentation, is that the hip isn't resting in that normal position that it should be in slight flexion. And so the ball is not resting against the socket in a position that allows it to develop normally. And so that not only speaks to how the condition occurs, but also how we treat it. So as we manage it a little further in our talk today we'll go on to look at the way dysplasia is treated. Our main goal is to put the ball against the socket in a safe position, in slight flexion in abduction. And that allows the ball to make the socket deeper and the socket to make the ball rounder. In a patient you can imagine, like frank breech where they're in a kind of a jackknife position, that hip is not resting in a position where the ball is pushing against the socket normally, and so they end up with a shallow socket.
Dr. Neeta Goli:
How long would a baby have to spend in the breech position for this to be worrisome?
Dr. Will Morris:
That's a great question and one that we don't have the answer to, to my knowledge. I certainly see lots of little babies who are referred for varying amounts of length of time that they were breech. I saw actually a baby this morning, who was breech for a single week before they flipped. And I think conceptually, it's probably dose-dependent. The longer you're in that breech position, the more time the hip is not receiving that normal stimulation to get deeper.
Dr. Will Morris:
But that said, I would encourage all the providers that if there's a baby who has some history of breech presentation, I would still go ahead and get them screened to look for dysplasia. And I'm sure we'll talk some more about this. But I think it's just such a benign test to get that ultrasound. And we don't know what that threshold dose is with breech history that confers that increased risk of dysplasia that it's probably better if there's any history of breech presentation to go ahead and get checked out.
Dr. Neeta Goli:
All babies are screened for DDH with the physical exam in the nursery, which we'll describe a little bit later in the episode. But certain infants with risk factors should get a hip ultrasound to screen for DDH, even if they have a completely normal physical exam. Which babies do you recommend get routine imaging and what is the recommended timeframe for the imaging?
Dr. Will Morris:
Yeah, that's a that's a great point. I think a really important one because over the past 15 or 20 years, I think that the guidelines have been updated slightly. So the AAP put out guidelines in 2000 and those were updated with input from the orthopedic section of the American Academy of Pediatrics in 2016. And we currently recommend considering imaging for patients where the exam is concerning for instability. So if you're feeling that hip click or clunk in the newborn nursery or at that two week, two month checkup, to go ahead and refer them for imaging. If they have a history of breech presentation, again, now understanding that the rate of dysplasia is about 25% in breech babies, or if they have a positive family history. I think even if there is parental concern or a history of improper swaddling. If for example, for a cultural reason the baby was being swaddled with their hips extended and you're seeing them at the two month visit, it's still reasonable to consider an ultrasound for evaluation again, because it's a very benign procedure; there is no radiation involved.
Dr. Will Morris:
As far as the timeframe, I think if the indication for the imaging is purely breech history or family history and they have a rock solid stable exam, I would wait until that six to eight week mark of adjusted age, meaning including accounting for prematurity. And the idea there is to reduce the risk of false positives. Remember, I told you that studies have shown that if you imaged all neonates day one of life 15% of them would have relative physiologic immaturity of the hips; they would appear dysplastic. But then by six weeks, that number has gone from 15% to only 1%. So to reduce the weight of false positives, we generally wait if everything else seems good. However, if there's any concern for instability, I'll go ahead and get the imaging at a younger age. Because if it does seem like the hip is unstable, or one of the hips is dislocated, I'm going to initiate treatment before six weeks and so I'd like to know.
Dr. Neeta Goli:
I do have one revision for our listeners: As far as the timing of breech presentation and need for screening, per the 2016 AAP Clinical Report written by Shaw et al and the AAP Section on Orthopedics, the recommendation is to considering postnatal imaging if there is any history of breech presentation in the third trimester. They do state, "There is no clear demarcation of timing of this risk; in other words, the point during pregnancy when the DDH risk is normalized by spontaneous or external version from breech to vertex position.” So basically what this means is, even if the baby was born in the cephalic position, a history of breech positioning in the third trimester should prompt you to consider screening.
Dr. Neeta Goli:
You mentioned that 25% of breech babies will have evidence of dysplasia. Was that including breech males and breech females or was it sex-specific?
Dr. Will Morris:
Sure. Well, certainly, female sex confers increased risk. And I don't think that we broke it down in our study to distinguish the rates in males and females. But certainly, female sex confers an increased risk so that 25% or 27%, I think it was in our study, is all comers, so that includes both sexes. But the rate I would expect it to be slightly higher in females.
Dr. Neeta Goli:
So is the current recommendation for even breech male infants to get the routine hip ultrasound at six weeks of age?
Dr. Will Morris:
I think that the updated article that included input from the section on orthopedics for the AAP, used recommendations like “consider imaging” rather than seeing if there's a hard stop for any of these kids. But I think for breech history for males or females, that I would go ahead and get the ultrasound to screen them. And we certainly see dysplasia in both groups, although certainly as you mentioned, female sex is an increased risk.
Dr. Neeta Goli:
And then while babies are in the nursery, the most common exam maneuvers we perform to assess for DDH are the Barlow and Ortolani maneuvers. What is their sensitivity and specificity? And then do you have any tips on performing these maneuvers correctly?
Dr. Will Morris:
Sure, well, first maybe I'll answer tips on performing the maneuvers and then we'll talk about their accuracy. So in terms of performing the exam, I think the biggest and most important tip is that the baby needs to be calm. I think we've probably all had experiences where the infant is really angry that you're there bothering them, and they're tensed up. And you're not going to be able to feel whether there's any evidence of even subtle instability, or frank instability and a dislocated hip.
Dr. Will Morris:
So on exam, if for example you're doing rounds in the newborn nursery, or if this is a patient visit and you have rooms stacked up as you're seeing patients in an outpatient setting. If I come into the room and I see that mom or dad, for example, has been waiting to give the bottle so that we could see them first and the baby is angry, I'll actually wait and come back in after they've had a chance to maybe breast or bottle feed so that the baby can calm down. Because you're not going to get a very reliable exam if the baby is tensed up. We certainly have residents and fellows who come through, and it's a stereotype about orthopedics is that much of the field can be based on brute force. But the newborn exam is a really gentle finesse exam to feel whether there's any instability. And so that's probably the first and most important tip.
Dr. Will Morris:
As far as performing the Ortolani maneuver, again, it's a gentle maneuver and I'll kind of take the baby's thigh, put my index and long finger on the greater trochanter, and my thumb around the middle side of the thigh. And then as in gently abducting that hip and providing an anteriorly directed force on the greater trochanter. And you can usually feel the hip clunking in. Now we use the term hip click, but real instability, you're probably feeling a more significant clunk as the hip's sliding in and out of the socket. I think a lot of babies have inconsequential hip clicks because there's a number of different tendons and muscles that are all running across the hip. And so frequently we feel little clicks, even though it feels and looks like a very stable hip. That said, I certainly wouldn't discount a hip click and I think it's very appropriate to look further with imaging or with the referral.
Dr. Will Morris:
The Barlow maneuver is taking a hip that is reduced at rest and is dislocatable, and attempting to dislocate it by, again, holding the hip in by the knee as you are flexing the knee somewhat as I'm flexing the hip up to 90, and then I'm adducting, or bringing that leg towards midline with a gentle posteriorly directed force. I'm not trying to overpower the baby because they're presumably pretty calm when you're doing the exam. And then you're trying to feel as you adduct and provide a posteriorly directed force actually along the femur, whether that hip is sliding out or if there seems to be increased laxity.
Dr. Will Morris:
As far as the sensitivity and specificity, I think there is some studies that tried to look at the value of those exam findings. I think probably a more informative study actually came out very recently from a big multicenter group called the International Hip Dysplasia Institute, which our institution participates in some research too. And they had a neat study where they were looking at how good we really are at the exam. Because certainly, we consider ourselves to be experts as pediatric orthopedists at assessing the stability of the hip. And interestingly, we found that about 14% of the dislocated hips were felt to be reduced on exam by a fellowship-trained pediatric orthopedist. And so it highlights that the exam is not foolproof. I think it underscores that if you're relying on the exam alone, if there are other things that you're worried about, is not satisfactory. And that if there's other risk factors, or for example, if one person felt a click or a clunk, we'll have some concerns. And then it's not reproducible when somebody else examines them at the next visit, for example, maybe at the newborn nursery when pediatrician examined them, and you're seeing them at two weeks, and you can't reproduce it, I would have a very low threshold to go ahead and obtain imaging because we're not as good as we all think we are at assessing that stability.
Dr. Neeta Goli:
And since you mentioned the kind of clicks versus clunks, so it's really common that especially when these babies are fresh and just born, we can feel some ligamentous hip laxity. How can we determine whether something that we feel is related to just regular hip laxity or true hip dysplasia or instability?
Dr. Will Morris:
Yeah, I think that's probably a tough challenge because you guys are seeing them so fresh, that those maternal hormones are still coursing around in their body, giving them a little bit of relative laxity. And I think that the term click, again, can reflect many different findings, many of which are totally normal, like muscles and tendons that are crossing the hip. And one of the things that we learned during our training is eventually as we're testing hips, and you keep having these normal hips or these very mild clicks, that eventually you feel a clunk, you feel a real unstable hip, that's either dislocatable, or more commonly, it's a dislocated hip that's Ortolani positive, meaning you can reduce it back into the acetabulum. And you feel that it's a much more robust movement and feeling of reduction of that clunk into the socket, that you're going to appreciate the difference.
Dr. Will Morris:
But again, I think it all comes back to if it feels like it's a very minor click, and it resolves, and then everything feels very stable, and there's no other risk factors, maybe it's not somebody who necessarily needs imaging. But again, I think if there's ever any concern on the exam that you feel what seems like a significant click, and you think maybe this is a little bit more than just a little bit of soft tissue, or if maybe the patient has risk factors, they have a family history or they're a female first-born. And there was a question of whether they were breech versus transverse, some of that gives you pause. Again, I think it's so safe to go ahead and get the ultrasound. That it's a very reasonable conservative thing to do so that you have that diagnostic information to then better make sure you don't let any dislocations fall through the cracks.
Dr. Neeta Goli:
And since you mentioned this term, I wanted to just clarify what is the difference between hip dysplasia and hip instability?
Dr. Will Morris:
That's a great question. So dysplasia is a spectrum of disease, and so you can have a patient whose hips feel perfect on exam and then during the ultrasound you can see that the hips are dysplastic. And so this is one of the challenges in pediatric orthopedics is trying to identify who those kids are, what their risk factors are, so that we can screen them out. There are certainly other countries that have universal screening programs, which we don't. Except for the physical exam, we don't do universal imaging. And so trying to identify who those kids are, who are going to have dysplasia is important. But some of them will have dysplasia sonographically.
Dr. Will Morris:
And then clinically, you'll also have other findings that suggest there's some decreased stability of the hip. And so that may be a hip that is dislocatable, for example, so maybe it rests in a reduced position but you can slide the hip out with the Barlow maneuver. Which remember is when you bring the hip towards midline in flexion, you flex it, adduct it, and provide a posteriorly directed force. You may not feel a full dislocation, but you may notice that there's some increased laxity. So maybe as you're trying to push the hip down gently, you notice that it pistons a little bit, and so that pistoning is a reflection of that laxity, those are signs of instability. And then certainly if the hip is dislocated and you're able to reduce it, so it's a dislocated hip. And maybe you have a positive Galeazzi sign, which is where the hips are flexed to 90 and one leg appears to be shorter, because the hip is resting in a dissociated position, or asymmetric thigh folds, that together can build a picture of hip instability.
Dr. Will Morris:
So sometimes we see dysplasia radiographically, and we call it sonographic dysplasia. And sometimes there's other physical exam findings that have clued us into that, that maybe there may be some decreased stability. And so when the hip is more dysplastic, when maybe if it were dislocated or subluxated, you may see other findings like limited hip abduction on that side, pistoning, or positive Barlow or Ortolani sign. Those are all findings that would be more suggestive of instability than just sonographic dysplasia.
Dr. Neeta Goli:
And then since you mentioned the Galeazzi maneuver, what are some additional physical exam maneuvers or findings we might see in a baby with DDH?
Dr. Will Morris:
So as far as other findings that you might see in a baby with dysplasia, I think even if the hip is reduced, you may see that there may be some slightly asymmetric abduction. So the side that is dysplastic, whether it's dislocated or just shallow can be subluxated, you may see that side abducts less than the contralateral side. So we flex the baby's hips up to 90 and try and abduct them and see which side abducts more or if it's symmetric. That increased laxity that I mentioned, the pistoning that as you're trying your Barlow and Ortolani maneuver, as you're providing that posteriorly directed force during the Barlow maneuver, you may notice there's a little bit of increased laxity in where the leg can kind of piston up and down as opposed to the contralateral side.
Dr. Will Morris:
The Galeazzi sign is, again, when you flex the hips up to 90, you may see that one leg has an apparent limb length difference and appears shorter because the hip is resting posterosuperior to the socket, and so it makes that look a little shorter. And similarly, if you have that femoral head resting out of the socket, because it's resting posteriorly, the soft tissues of the thigh will all be accordioned down and so you end up with these asymmetric thigh folds because, again, the hip is resting out or subluxated. And so the thigh folds appear asymmetric because they're getting squished down as that femur is dropping out postero-superiorly.
Dr. Neeta Goli:
Does that mean you'd expect more or less thigh folds on the affected side?
Dr. Will Morris:
I think the key is the asymmetry. And I'll also say that asymmetric thigh folds is probably one of our least specific findings because certainly lots of babies have it without dysplasia. But if the hip is dislocated, the soft tissue is going to be squished down, so presumably you’d see more thigh folds. But I think the big point is the asymmetry. And you will probably also see other findings that would be consistent with one side being the affected side, so presumably the side with more thigh folds like limited hip abduction, and potentially a positive Galeazzi sign.
Dr. Neeta Goli:
And then if we do have a baby with an abnormal hip exam, typically here we will refer them to you all, our orthopedic colleagues, for an appointment and an ultrasound. How do you recommend we counsel these parents before the appointment with you?
Dr. Will Morris:
Well, I think the most important thing you can do is provide them some reassurance. Certainly if you're seeing them in the newborn nursery, this is a really huge event for them. I'm sure there's a lot of emotion and excitement of having a new baby, and it's probably pretty scary for mom or dad to learn that there may be something wrong with their baby. And I think you can give them some great reassurance that even if we confirm that the patient does have development dysplasia of the hip, we're incredibly successful with non-operative treatment of DDH in infants. Our institutional experience is that even with a dislocated Ortolani-positive hip, so one where it's dislocated but you kind of pop it back in manually, we’re able to get the hip reduced non-operatively with a Pavlik harness, which we're going to talk about shortly, 93% of the time in a recent study where we looked back at all of our results.
Dr. Will Morris:
So although we occasionally go to the operating room, and we will take care of the hip one way or another to make sure that the ball goes back into the socket to continue to develop normally, the vast majority of our cases are successfully treated in the clinic.
Dr. Neeta Goli:
And then so let's get to that. So if their appointment with you confirms DDH, what are your next steps in management and treatment?
Dr. Will Morris:
Well, if we see that the hip looks dysplastic, there's a couple of factors which help determine whether we're going to treat them with observation for a brief period of time, or if we're going to initiate treatment with a Pavlik harness. In some cases, we see patients who may be a little less physiologically mature, so perhaps they have an ultrasound before six weeks of age, and it shows very mild dysplasia but they're clinically stable on exam. Sometimes in those cases we talk with family about potentially just watching for four weeks, if it looks like it's a stable and mildly dysplastic hip, because frequently those will get better on their own in an additional four weeks.
Dr. Will Morris:
Sometimes if it's slightly more unstable, a slightly more pronounced dysplasia, then we'll just go ahead and initiate treatment with the Pavlik harness. And this is the same treatment we use even if the hip is dislocated. A Pavlik harness is a neat orthotic or brace that is dynamic. So it allows the patient to still move around but it holds the hip overall in a position of flexion and abduction. As you remember from our discussion earlier about the concept of why breech is bad for hips, or why hip extension is bad, we know that the hip develops when it's held in a position of flexion in abduction. That puts the ball against the socket, and allows the ball to make the socket deeper and the socket to make the ball more round. And so we use those braces full-time. So depending on the situation they might be in it for 23 or 24 hours a day. And then we monitor along usually a course of about six weeks or sometimes longer, until we see those hips normalized on the ultrasound.
Dr. Will Morris:
Occasionally, we have a dislocated hip that might be refractory to that initial treatment. And we have a second-line treatment which we can use, which is abduction orthosis, that's a little more rigid brace that holds the hips and that flexed and abducted position. And if we still can't get the hip reduced, then eventually, we talk about going to the operating room to keep the baby calm, keep those muscles relaxed, and see how to get the hip in. Over the first few months, we have these findings of a positive Barlow or Ortolani maneuver, because the hip is still relatively lax and it can go from a dislocated to a reduced position.
Dr. Will Morris:
After a few months if we're not able to get the hip in, usually the patient will develop some sort of contractures of those soft tissues. And so eventually, we can't feel the hip going in and out. And at that point, we're less successful with the Pavlik harness or the abduction orthosis. And so the best way we can get the hip in is by going to the operating room, going to sleep under anesthesia, and then trying to manipulate the hip in. And if it goes in and we adjust the manipulation, we can look at it with an arthrogram and make sure it's in a great position. If so, we can treat it with a spica cast, which is kind of like a brace that you can't take off. So it holds that hip in that healthy position. And if we still can't get the hip reduced with manipulation under anesthesia, then the next step is to make an incision and clear out all those obstacles which are blocking the ball from seeing what was in the socket. And then similarly, after that procedure, we also go into a spica cast.
Dr. Will Morris:
So we have a whole algorithm of ways that we can help get that ball back into the socket. So you can provide the family reassurance that we're going to get the job done, and we'll take care of your hip. And that most of the time, we don't have to go all the way down that algorithm to the surgical reduction because we can treat it successfully with the brace.
Dr. Neeta Goli:
Is there any new research or are there any new directions in treatment that we should be aware of other than what you just mentioned?
Dr. Will Morris:
Sure. Well, I think that touching on that concept of the breech patient, there’s been growing emphasis I think over the past five years or so on the importance of not only screening breech patients but also continued surveillance. So I referenced the study that we just submitted where we looked back at all of our breech patients and saw that about a quarter of them had dysplasia. But interestingly, we also saw that there's a portion of kids who go on to develop dysplasia, even after they have a normal ultrasound at six to eight weeks. And so looking at our results, as well as a couple of other recent studies on similar subjects, or similar patient populations, it looks like about 2-10% of kids who are breech, who have no ultrasound at six to eight weeks, go on to develop some dysplasia by age two. And I think this is part of learning who we need to continue to watch to try to identify and treat dysplasia earlier in life.
Dr. Will Morris:
Dysplasia is about one in 100, maybe 1-2% of infants. But in young adults, we know that it's about 3-5%. And so trying to figure out where those other patients come from is one of our areas of interest and one of the places we need to learn more. And it looks like this is one of those populations who deserve a little more attention. And so when I see a breech baby, as opposed to just getting that screening ultrasound at six weeks, I'm now continuing to surveil them, until at this point about age two, to see whether or not they're going to be part of that minority of population who go on to develop dysplasia. But I think it's important that we recognize that this is an at-risk group that we need to keep an eye on them.
Dr. Neeta Goli:
What does that surveillance include?
Dr. Will Morris:
So for me, it means that if let's say, I'm screening them at six or eight weeks of age and they have a normal ultrasound, depending on what their risk factors are, I'm either going to see them at six months or at one year, and obtain an X-ray at that point. The reason for the six-month visit is that we have some good literature about six months being an opportunity to use a different brace, that more rigid brace that I mentioned that holds the hips flexed and abducted during nights and naps for a six-month period. And then we can help the hips develop during that time. So it gives us an opportunity to intervene. If maybe the hips look really great on the ultrasound and the patient has no other risk factors other than breech history, then I might push it back to one year.
Dr. Will Morris:
And then after that one year visit, we then see them at two years. And I think at that point, we don't really have all the answers yet, I don't think anybody in the country does. But if everything's looking normal at that point, then we may stop surveilling them. Because certainly there's got to be some risk-benefit balance there between bringing patients in and getting plain films, with trying to identify whether or not the hip is dysplastic.
Dr. Neeta Goli:
And then what are the long term outcomes for babies with DDH?
Dr. Will Morris:
Well, that's also a really interesting question. So I think for patients who actually have to go to the operating room, which are the ones that we tend to follow the longest, we know that even after we get the hips reduced, this is still a patient population that we're going to be following for a while, and we're going to get to watch them grow up. Because we know that if we manipulate the hip in closed, so we make them sleep and we put the ball back in the socket, there's about a 50% rate of requiring some surgery down the line for residual dysplasia. And if we have to open up the hip, we have to make that incision and remove those barriers that are obstacles to the hip reducing, then it's about a third or so. And so it's important as we counsel families, if we are getting to that point that they need to continue to follow with us and we need to watch as their baby grows up and starts playing soccer or whatever they're going to do, because there's a good chance that the hip is going to need a little more help along the way.
Dr. Will Morris:
If the baby just has dysplasia and is treated with a Pavlik harness and everything is normal, the rate of requiring further intervention is much, much lower. So yes, it was a very fortuitous question because we actually just published our study looking at those babies that we took to the operating room, where we identified this kind of higher rate of needing to perform some surgery later, having some residual dysplasia later. And one of our other areas of interest right now is looking back in general at those rates of dysplasia in the patients who were just treated with a Pavlik harness to better identify what happens with them long-term. So I think we know that it's certainly a much, much lower rate but certainly worth keeping an eye on those kids. Because we knew they had dysplasia and we know that hip development is a moving target. Just like we have height chart and weight charts, we have normative data curves for hip development, and so we keep an eye on them too.
Dr. Neeta Goli:
And then what if the DDH is not caught or not treated, what are some long term sequelae?
Dr. Will Morris:
So, even though pediatricians do an awesome job in the newborn nursery, and at those two weeks and two months visits, sometimes there's a kid, as I showed you, with even the pediatric orthopedist, we're not perfect on our exam. And sometimes kids aren't caught until a little bit later. So when kids are a little bit older, they tend to present a little bit differently. So a kid who has a dislocated hip can still get up and walk around. What you'll see though is if the hip is dislocated, that they'll walk with a limp, because the muscles around the hip are not on the appropriate tension to help them balance as they're walking. So I actually just saw in clinic today, a girl in follow up that had a hip dislocation, which was identified, I guess, around 16 months or so. So she was already walking age, and they noticed that she was limping. And she had a family history, but otherwise I don't think was breech. And she was just, unfortunately, not caught when she was younger.
Dr. Will Morris:
And so the risk there is that you're much more likely, if you're already over a year old and you're walking, that you're going to need to go to the operating room. So all those kids go to the operating room for either a closed or open reduction, meaning you go to sleep, and we are trying to manipulate that hip in, once those muscles are not as tense, or potentially we have to open up the hip joints in order to get the hip reduced. The later we see them, we're also more likely to do more procedures. So a kid who's under a year old, we're much more likely just to manipulate the hip in, over a year of age we're increasingly likely to have to make an incision to get that hip reduced. And then over two years old, we're much more likely to then have to maybe cut the femur or the pelvis to do additional procedures that help get that hip reduced and stable.
Dr. Will Morris:
So that's why we place so much emphasis on identifying those kids early because later presented dislocation requires much more to get the hip reduced. Long term, if there's a hip that's not dislocated but just dysplastic, that may be something that's clinically silent. So we have some kids who have dysplasia and we know and we're monitoring them, for example, waiting to do surgery at a later age. Those are kids that are happy, healthy, and getting around fine keeping up with their peers. And for adolescents, dysplasia usually surfaces in your teenage years, where they may have either some groin pain, or perhaps some lateral hip pain due to fatigue of those muscles that I mentioned that are slightly out of balance when they're active. So this could be someone who's a star on the soccer team but she only notices pain kind of at the end and she starts to kind of limp a little bit when practice or the game is over.
Dr. Will Morris:
So it's not something that was just dysplasia without a dislocation, that's something that is stopping them from participating their activities, but may present as pain in teenage years. And then the reason why it's important for us to catch them too is that the patients who get on to late adolescence or early adulthood with dysplasia, can go on to develop early osteoarthritis. And this is something that I think you mentioned at the beginning of the talk, and the principle there is that with a more shallow acetabulum, you're trying to distribute your weight on less surface area. So there's more force concentration on less cartilage, which can degrade that cartilage a little bit earlier. So there's some good older studies looking at patients who had dysplasia, and there's a threshold radiographically that we know if we see this amount of dysplasia, historically, those patients went on to early hip replacements.
Dr. Will Morris:
And so that's why if we see it when they're infants, all the better, we're very successful in treating without surgery. If we meet these kids in adolescence or young adulthood, we're also very successful in treating it surgically with a specialized procedure to reorient the acetabulum. And we can still do that and help prevent them having that early hip replacement, hopefully buying them decades more with their native hip.
Dr. Neeta Goli:
To end the episode today, do you have any advice for our listeners while they take care of newborns?
Dr. Will Morris:
Sure. I think one area where we can all I think intervene and even with a very normal hip exam and a very normal history, is in teaching parents about the importance of healthy hip swaddling. So I would say that I see a lot of newborns in clinic where we're screening for dysplasia, and more than talking with parents who I'm going to treat with a Pavlik harness, I probably spend the most amount of time talking with parents about healthy hip swaddling, because we know how impactful those first couple of months are or those early stages of hip development can be if we're either putting the hips in the right position or holding them in extension where they're not going to develop well.
Dr. Will Morris:
There's a great resource at hipdysplasia.org, which is the International Hip Dysplasia Institute, which I provide to families and it shows them examples of healthy hip swaddling. But essentially, counsel families on not forcing those hips into extension. So if they're swaddling with receiving blankets, that means swaddling the arms in, but keeping the legs really loosely bound or leaving them out entirely. I think more and more parents are starting to use sleep sacks, which are great in the sense that they swaddle those arms in tightly or leave the arms out to kind of give them that swaddled sensation, but gives them a lot of room to flex their hips up and hold them that flexed and abducted position. And then likewise, with baby carriers, as patients get older and they refuse to be swaddled, parents start bringing them around in carriers. I think counseling families on looking for those carriers that hold the hips flexed and abducted where baby's legs are across your tummy or your chest or facing outward, while the hips are well-supported is also really important.
Dr. Will Morris:
So I think that's something that all pediatricians can incorporate into their anticipatory guidance as they're seeing either families in the newborn nursery, or maybe at that two week visit, because that's going to pay dividends in helping prevent dysplasia down the line.
Dr. Neeta Goli:
Thanks so much for joining us today, Dr. Morris.
Dr. Will Morris:
Thank you so much for having me. I really appreciate the opportunity to come on and chat.
Dr. Neeta Goli:
Thanks for listening to Newborn News. We hope you join us next time. If you like what you hear, make sure to subscribe and leave us a review. If you have questions, comments, feedback or suggestions for future episodes, please email me at NewbornNews@utsouthwestern.edu. As a reminder, this content is educational and is not meant to be used as medical advice. Views or opinions expressed in this podcast are those of myself and my guests and do not necessarily reflect the views of the university.