Melanie Cole, MS (Host): Welcome to Better Edge, a Northwestern Medicine podcast for physicians. I'm Melanie Cole, and we have a thought leader panel for you today with two Northwestern Medicine physicians to highlight hip preservation treatment and periacetabular osteotomy.

Joining me today is Dr. Michael Stover, he's a Professor of Orthopedic Surgery; and Dr. Ryan Selley, he's an Assistant Professor of Orthopedic Surgery and a team physician for the Chicago Cubs. Doctors, thank you so much for joining us today. And Dr. Selley, I'd like to start with you. Tell us a little bit about how you came to Northwestern and how you and Dr. Stover ended up working together.

Ryan S. Selley, MD: Yeah. Thanks, Melanie. I appreciate you having us on today, excited to be here. I initially came to Northwestern in 2014 as a visiting medical student. And so, I spent a month here on an audition rotation. And Dr. Stover, Dr. Peabody were gracious enough to keep me on as a resident. So, I spent five years here in residency. Learned a lot from a lot of different people.

Dr. Stover got me interested in the open aspect of hip preservation. I was also interested in the arthroscopic side of things as well, and he encouraged me to maybe take a little bit of an atypical track where I learned to do everything inside of the hip. So, that includes arthroscopic surgery for like impingement sports-related injuries, open hip replacements, then the open hip preservation surgeries, which include periacetabular osteotomy for dysplasia as well as femoral osteotomies. So, he kind of got me interested in that during my five years here. I spent two years out at hospital for special surgery in New York, one of which was a sports fellowship. The other was a hip fellowship. I also spent a month in Switzerland during that time to learn from some of the leaders over there.

Melanie Cole, MS: Very cool. Thank you so much for sharing that with us. So Dr. Stover, to set the stage, hip preservation has become its own subspecialty as of late. Tell us a little bit about how that's evolved over the past decade or so.

Michael David Stover, MD: Yeah, I think that it started with people from multiple subspecialties that were interested in the hip. So, there are people from the trauma world, from the sports world, from arthroplasty world, that all came together to work on the preservation of the hip. And I think that was born out of the mentors that came from each of those subspecialties early on.

So, I think, today, it's evolved into its own kind of niche practice, much like some other subspecialties have focused more on a joint like shoulder and elbow as a subspecialty. I think Hip is growing as a subspecialty, and there are people like myself or like Ryan, who really focus on almost anything with regards to the hip.

I mean, I do all kinds of different things around the hip. I don't do arthroscopy as often as Dr. Selley, but I'd also do fracture work around the hip more commonly too. So, I think the two of us focus some of our practice directly on the hip. I know Ryan does some other arthroscopic sports medicine stuff too, so we all have a little bit of a niche outside of the hip itself also. But really, the focus on the hip has led us to a better understanding of it and a better thought process with regards to treatment.

Melanie Cole, MS: It's a really exciting time in your field. And Dr. Selley, what patterns are you seeing in the types of hip pathology that are referred for preservation versus arthroplasty in young adult patients? As Dr. Stover was saying, that's one of the cores of the patients that you see. So, speak a little bit about that and some of the core clinical and radiographic criteria that would make someone a good candidate for PAO.

Ryan S. Selley, MD: When a patient comes in to evaluate us, obviously, we're doing a thorough history and physical examination. The hip's a deep joint, and we rely a lot on imaging to give us some useful information of what's going on. In particular for the x-rays, those are a good initial screening tool for us. We like to look and make sure they don't have any arthritis primarily.

As an aside, a total hip performs so well that if a patient has any significant arthritis, regardless of the age, usually, that's the treatment that we'd be pursuing. So, we're using our x-rays as an initial screening tool to determine, "Okay, this patient has a lot of arthritis and they may just need a hip replacement even if they're at a younger age." But if a patient doesn't have arthritis, then we're looking at the shape of the ball in the socket, to determine if there's any mechanical abnormalities that might be causing their pain.

In general, we classify people into one or two categories. So, one would be the impinging hip. So, that's a hip that's too stable, so they have limited range of motion. Generally, they either have a hip socket that's pointed a little bit backwards or an aspherical femoral head that impinges in the front when they flex up.

And then, the other end of that spectrum is a patient that tends to have a more high range of motion hip. They generally have a nice round femoral head and a more shallow hip socket. And so, what we see with those patients is if you have a socket that doesn't cover the ball quite as well, the ball wants to slide around a little bit more. And those are the patients that we generally indicate for periacetabular osteotomy if their cartilage is appropriate and their symptoms are bad enough that it warrants an intervention.

Now, we always treat patients conservatively first. So, that usually is a course of physical therapy for at least three to six months. Sometimes we'll consider injections before moving on to a surgical intervention.

Melanie Cole, MS: Dr. Stover, then PAO is often described as one of the few procedures that can fundamentally change the natural history of hip disease. That's pretty cool to think about. So, what do we know now about the procedure's ability to delay possibly or even avoid a total hip arthroplasty in young adults specifically?

Michael David Stover, MD: What Ryan pointed out as very important is that, when we first started doing periacetabular osteotomies, I think we did those in patients that had maybe a little more arthritis than we would today, thinking that we could preserve the hip a little bit longer. And from the early studies on the PAO at 30 years of followup, about 35% or 30% of patients still have their native hip. So, we don't have a good natural history cohort to follow along with that. We don't understand how much better it does make it. But recent studies have shown very good preservation of the hip 17 and 20 years after the PAO in more selective patients, and we're looking at up to 90% preservation rates.

So, I think, that it does two things. I think when we have a patient with dysplasia that comes in symptomatic, I think we have two goals. One is to treat their current symptoms to improve those symptoms and to improve their functionality with their hip and to return them to some of their activities that they wish to return to. And then, the secondary gain is that hopefully we're giving that patient a hip that lasts a longer time without resulting arthritis or progressing to arthritis at an early age.

So, I don't think we can speak to the fact of how long we can make the hip last. But I do think that we do improve the longevity of the hip by improving the mechanical environment of the hip with the PAO.

Melanie Cole, MS: These are all great points. Now, Dr. Selley, when you're talking to your patients, how do you frame that conversation, especially with younger adults often in their 20s and 30s? I mean, as we think about what their longevity of life is going to be and they want to be active, how do you counsel them about—you mentioned conservative treatments. Of course, we always start with those. But when we think of recovery, getting back to their activities. Including athletes in high level activities, tell us a little bit about how you work with them, how you counsel them for other providers so that they have an idea how to work with these patients.

Ryan S. Selley, MD: Yeah. I think there's probably three important parts to any preoperative discussion. The first one is the surgery and what the proposed recovery would look like. The second being the outcomes. And then, the third being the risk of surgery, of course.

In terms of the recovery, in general, patients stay in the hospital one night, sometimes two. They are on crutches for six weeks afterwards. We give them a home exercise program to work on for the first six weeks, while we're allowing the bone to heal up. Once the bone's healed up sufficiently, then we'll get them started in formal physical therapy as an outpatient. At that point, they'll start working on getting off of crutches. Usually, most people are off of crutches by eight weeks, sometimes 10.

From there, they're progressively working on mobility, building up their strength within the hip. Most people are walking unassisted and back to most day-to-day life activities, somewhere between like eight and 12 weeks, I would say. Higher level activities like running and jumping typically are closer to around the six month mark. We will see improvements in patients even one in two years out from surgery. So, I often counsel them, you know, this isn't a surgery where we do it and you're necessarily going to feel better in two weeks. This is a very much a marathon, that it takes time for your body to accommodate to the new hip and the ability for your muscles and tendons and things to get used to it and so that you can function more normally. So, we do see improvements even one to two years out, though the majority of the recovery is probably during the first three to six months.

In terms of outcomes for surgery, in general, they're very good. We quote 92-93% of patients being significantly satisfied with the results. I think, osteotomy surgery is important to kind of pare that down a little bit too. And I think about half of those patients probably achieve what we call like a forgotten hip, meaning they don't think about their hip on a day-to-day basis. And the other half are significantly better, but they may not be perfect. They may still have some symptoms from day to day.

Michael David Stover, MD: Ryan, what about return to sport?

Ryan S. Selley, MD: Yeah. So, return to sports, one of the other considerations, a lot of these patients are younger, they're athletes. There's some early return-to-sport data. For more competitive athletes, return-to-sport's a little bit lower. It's probably in the 60-70% range. For more recreational athletes, it's more in the 80-85% range.

Return-to-sport data is a little bit challenging to interpret, because there's a lot of different definitions of that and that's been pretty well extensively studied in the sport literature. Now, you may have a competitive athlete who finished their senior year of high school and they never went back to playing their competitive sport just because they were done with their senior year, sometimes that can be challenging to interpret. But most people are doing this so they can stay active and get back to recreational sports. And I'd say we hit the mark for that for the vast majority of people.

Michael David Stover, MD: And I think it's sometimes hard to measure too, because people come in very active. And some of the ways we measure their activity levels really don't change that much before and after surgery. So, it's also hard to say exactly how much better they are because they're high-performing people before, they can be high-performing people afterward too.

So, following it with like a UCLA activity index or something like that is not very granular to help us find exactly how much better they get with their activity levels. But I think return to sport is still a little bit hard to quantify.

Melanie Cole, MS: Yeah, this is really interesting. Return to play has always been an interesting thing to discuss when these athletes want to get back on, they want to get back to it. So, thank you for telling us about that. Now, Dr. Stover, as we think of PAO, it's a technically demanding operation. How important is surgical volume, team experience, the multidisciplinary aspect and approach to all of this when it comes to optimizing these outcomes?

Michael David Stover, MD: Yeah, I think it's important to have a background in doing it and having mentors and having people help you along the way and developing a practice. I know that we have literature that shows that the PAO has very low major complication rates in the hands of people who do it often. So, I think that is one of the things we try to tell the patients. It's uncommon that we have major complications after the surgery. Most of the time, it goes smoothly and they're in and out of the hospital as Ryan said in a day, two days. And what's interesting about that too is if we do a patient's right side or left side the first-time they stay two nights. And when we do their other side, they typically stay one night. So, I think there's some learning process even for the patient with regards to the impact that it has on them and whether that's more in preparation or dealing with their anxieties or whatever.

But I think that the multidisciplinary approach is very beneficial, because that also helps with our pain programs, our mobility in the hospital, getting up and getting moving right away, making sure that they have an appropriate anesthesia, pain control, and people on the floor that are knowledgeable about the symptoms that patients will have right after surgery. So, we can get these patients up, get them moving, move them beyond their concerns for injuring themselves or the pain that they have after surgery, and then moving forward on the rehabilitation plan as Ryan spelled out.

I think the other thing that we can do with regards to patients getting more mobile and more active after surgery is if they have a pretty good postoperative course or unremarkable postoperative course. Sometimes we'll get them in the water and start even with hydrotherapy by three weeks to start getting their muscles working a little bit quicker and getting them ready to start their land therapy once a six week rolls around too.

So, I think in many ways, by having surgeons that are experienced, our surgical teams that are experienced, the people on the floor, our PAs, our residents, everybody knowledgeable about the post-op protocols for the patients, and then having even physical therapists in the community that help us progress these patients are all very helpful with us achieving the outcomes that we want.

One of the things that we do with our preoperative evaluation though is sometimes get the patient more prepared for surgery to decrease the risks of surgery, and also the risks of the postoperative rehabilitation. And one of those things is sometimes crutch training that we can work with their preoperative physical therapists. They can learn to walk with crutches, how they will after surgery, and learn how to take care of their hip before.

One of the things that we commonly do is to send patients that might be a little less coordinated or a little heavier, have a higher BMI to physical therapy to help with those goals. One of the problems that we have with the surgery is that, if you do have a higher BMI or a higher body mass index or weigh a little bit more is that the complication rates do go up with the surgery. So, we also advise patients not only on the care and treatment of their hip after the surgery, but trying to get themselves into a better physical condition prior to surgery, including sometimes weight loss in order to decrease those risks of complications after the surgery.

Ryan S. Selley, MD: Yeah, I would echo that statement, Mike. I think, it is a lot easier to learn how to use crutches before you've had surgery. Then, after you've had surgery, you've had anesthesia, you know, there's blood loss, all sorts of different things going on in the hospital. If you can kind of take that one element out of it beforehand, I think the preoperative crutch training can really be beneficial for a lot of patients.

Melanie Cole, MS: Yeah, we certainly could do a whole podcast on all the studies and research about the comorbid conditions and outcomes for hip surgery, because that's really an interesting topic in itself. And, Dr. Selley, we're getting ready to wrap up and I'd love to give you each a chance for a final thought here. So, Dr. Selley, when we think of emerging technologies, AI-assisted imaging and 3D planning and biologics. There's so much going on in your field. Tell us what shows real promise. What do you see happening? What would you like to see happen?

Ryan S. Selley, MD: Yeah, I think specific for the periacetabular osteotomy would be 3D planning your correction, such that you can figure out, all right, what's the optimal position to put the socket so that we minimize the contact forces throughout the patient's normal course of motion.

Now, the other aspect of that is, you know, you have to improve the contact forces, but you also have to maintain a good range of motion within the hip. So, after we're doing our correction, we're assessing the motion, both be before and afterwards. And the goal is that we maintain the same range of motion. If you're covering the hip, generally, you have to take bone away in some other areas in order to maintain the same range of motion. Typically, that's in the front, in the head and neck junction, commonly referred to as femoroplasty.

Also, we find patients will impinge on what we call the subspine region. So, that's where rectus tendon attaches on the front of the hip socket that can limit patient's hip flexion, and then we've also found through our dynamic exams that limits flexion internal rotation too. So often, we're selectively taking bone off of that region of the socket as well, with the goal being that we maintain their same range of motion, but they have a more stable hip afterwards.

So with all that being said, the holy grail of this is if we could plan beforehand where exactly we want the socket and we could map the contact forces as well as the range of motion afterwards, we could preoperatively predict where each patients need to be with regards to their correction. And that's probably a little different for everybody based on their own unique anatomy, the shape of their femur, the twist of their femur. And so, there's a lot of different things to go into that. And that's something that we've been actively working on with a few different companies in order to fine tune that.

Michael David Stover, MD: Yeah, I think that to optimize correction is probably the goal. And trying to understand where to put the socket in as well as to optimize the range of motion afterwards and limit impingement. Because impingement after periacetabular osteotomy can really mess with the results or the outcomes following that.

But I think another thing in the future is to look at how we can evaluate hips more dynamically. You know, we've relied a lot on static imaging studies in order to understand the hip and try to categorize those into what Ryan discussed, is it instability or impingement or whether they may have even contributions of both within that hip.

And I think there are some things on the horizon, whether it's dynamic ultrasounds or even maybe dynamic advanced imaging studies with MRIs or CTs or, with simulation, start to understand preoperatively what the diagnosis is or what the areas of concerns are when we go in to do any corrections. So hopefully, those are two fields that can emerge in the future to help us out and optimize our results.

Ryan S. Selley, MD: Yeah, I would echo that. You know, we're really trying to take 2D images to understand a three-dimensional problem that's really a functional range of motion impingement or instability problem. And aside from ultrasound, which has its limitations, we really don't have a great way of assessing these other than we know, based on certain shaped hips, they're more likely to have this problem or that problem. So, we have to make a lot of inferences.

I think, you know, in addition from the PAO side of understanding where to put the socket, I think, getting a better sense of what's happening, you know, with the bony congruence as well as all the muscle and tendon range of motion and functional effects after surgery will be really important as we move forward.

Melanie Cole, MS: That is really exciting to think about the future with dynamic imaging, and then being able to look at gait in real-time as you're doing what you do. That's really exciting. Dr. Stover, just last word to you. If you had to summarize this great discussion we're having today and give advice to referring physicians that are speaking to their patients about possible PAO, what would you tell them? And what would you like them to know about what we're discussing here today?

Michael David Stover, MD: One thing is I think that the PAO has evolved. I think that our understanding of the procedure, our understanding of the technique. I think the evolution of the postoperative course, including pain control and mobilization, I think has made it less impactful on the patient.

I think what people always have referred to as like this huge surgery that patients have to go through for their dysplasia, hopefully, we can tone down that communication a little bit to the patients and make it sound a little bit more common, a little bit less impactful. And that especially in the younger patient we see, patients by about two to three weeks after surgery, their pain is very well-controlled. They're actually very bored with their hip. They want to get moving forward. They're ready to put weight on it. We have to actually temper those patients back. And I think that, as we get a little older, the impact is a little bit harder on the patient and the recovery is a little bit longer.

But, I guess, what I want to say is that I think we can help a lot of these hips. I think we can help them the earlier we see them so they don't go through many different physicians or many different evaluations prior to their surgery, because that also has impacts on the patient, their mental wellbeing and other things, you know, as they try to search for an answer. And that once we get the correct diagnosis and we move forward, I think that just understanding that we can do this with a little bit of time out of their life, a little bit of discomfort, but with an outcome that's usually pretty reliable, and that most patients are very happy with.

Melanie Cole, MS: Great discussion. Thank you both for joining us today and sharing your incredible expertise for other providers. Thank you so much. And to refer your patient or for more information, please visit our website at breakthroughsforphysicians.nm.org/orthopedics to get connected with one of our providers. That concludes this episode of Better Edge, a Northwestern Medicine Podcast for physicians. I'm Melanie Cole.