Episode 5 Prof. Evangelos Pappas

In this episode we speak with Professor Evangelos Pappas, Associate Dean and Professor at University of Wollongong, where he is working on development of the Health and Wellbeing precint and commencing research into long-term outcomes from ACL injuries

His research focuses on the aetiology, prevention and treatment of athletic knee injuries

Prior to his move to the University of Wollongong he previously worked at University of Sydney where he continues to head  a large team researching ACL injuries.

In this episode we talk about his career path in researching ACL injuries,  ACL healing and how the definition of healing may be causing some widely different healing statistics. We discuss ACL repairs and reconstruction and the pros and cons of each. We delve into the gender difference in ACL injuries and try to work out why females are at much greater risk. We talk about long term outcomes post ACL injury, discussing long term participation in sports, osteoarthritis rates and what we can do to keep people active and reduce the chances of arthritis. We also talk about how we need to avoid a inter-professional turf war and what to look for in choosing a health profession to get advice from on managing ACL injuries.

Transcript

Bevan Colless  

Hello, listeners. In this episode, we speak with Professor evangelist Pappas, associate Dean and professor at the University of Wollongong, where he's working on development of a health and well-being precinct and commencing research into long term outcomes from ACL injuries. Evangelos has a Bachelor in Physiotherapy, a Master's in Orthopedic Physiotherapy, and a PhD in Orthopedic Biomechanics from New York University. His research focuses on the etiology, prevention, and treatment of athletic knee injuries by using biomechanical epidemiological and clinical research tools. Prior to his move to the University of Wollongong, he worked at the University of Sydney and he continues to head a large team researching ACL injuries there. In this episode, we talk about his career path in researching ACL injuries. And talk further about the research into ACL healing and how the definition of healing may be causing some widely different healing statistics. We discuss ACL repairs and reconstruction and the pros and cons of each. We delve into the gender difference in ACL injuries and try to work out why females are at a much greater risk of injury. We talk about long term outcomes post ACL injury, particularly participation in sports and development of osteoarthritis and what we can do to keep people active and reduce the chances of arthritis. We also talk about how we need to avoid an interprofessional turf war, and what to look for in choosing a health professional and who to get advice from on how to manage your ACL injury. I hope you enjoy this wide-ranging discussion with Professor evangelist Pappas Evangelos. 

Bevan Colless  

So can you tell us a little bit about your education and your career path? It sounds like an interesting career that you've heard.

Evangelos Pappas  

I don't know, but it I certainly have worked and studied in a few different places around the world. So I did my physiotherapy undergraduate degree in Thessaloniki in Greece. Last century, and then I moved to the United States where I did a master's in Orthopedic Physical Therapy at Quinnipiac University in Connecticut. And that was very heavily based on the Cyraix examination and manual therapy. And then I had the opportunity to do my PhD at New York University. Probably an interesting thing about me is that I really liked science, especially physics, mechanics, was something that I was really passionate about, and then find myself being a physiotherapist. I struggled a bit with reconciling these different shades of grey in the clinical diagnosis where two patients have a very identical presentation, one responds very well to the treatment, and the other does not. So my mind you was looking for concrete answers, and I found this intersection of my passion for clinical work and treating patients and their concrete answers in the world of biomechanics. So my PhD was in biomechanics, and particularly in ACL injuries. I graduated in 2005, since then, I have been working in academia, for 11 years at Long Island University, in downtown Brooklyn, in New York. Then in 2013, I moved to the University of Sydney, where I set up a large team, doing ACL research, and then for the last nine months at the University of Wollongong and again, I'm building a team that is working on ACL injuries.

Bevan Colless  

And so tell me a little bit more about this team you've got researching University of Sydney, what are they looking at? What are they researching?

Evangelos Pappas  

So we have a team of about 15. And they are doing research mainly an ACL injuries, and with a variety of different methods. We do the very basic biomechanics research where we put people in the laboratory or have the large study that we looked at people who are ACL deficient, but they had a good outcome. And we measured the way they work, as well as another number on clinical measures that we took with them. We also look at prevention of ACL injuries. So, we have Lionel Chia, leading a lot of the research on the space. And, again, there are a lot of different research topics within the broader area of ACL injury. For last few months at the University of Wollongong, we have and maybe you can talk more about this later when we speak about physical activity. But we have our work with Matt Whalen, who is the physiotherapist for the soccer was here and talented, passionate researcher and clinician looking at the prevention of ACL injuries and the treatment of ACL injuries. And with other researchers here like John Sampson, we're setting up the beginning of some really exciting projects.

Bevan Colless  

They seem like really interesting projects you've got going on, what got you interested in ACL injuries To begin with?

Evangelos Pappas  

Initially that was an interest that was developed during my undergraduate physiotherapy here. I was fascinated by how an athlete would perform the same athletic maneuver 1000’s of times, like landing from a layout for a basketball player. And then this one time, they would hear this pop in their knee and the swelling and their ACL would be gone and the cascade of events that happens after that. So the unpredictability, or at least this, what we consider back then that the unpredictability of these injuries, something that I find really fascinating. So I decided to dedicate my research career on finding the cause of ACL injuries and better treatments for those who had an ACL injury. Now remember that I started my physiotherapy career in the late 90s. So, a lot of things have changed since then. But one thing that has no change is how devastating this injury is for the athletes in terms of the amount of time they have to take off from sports, and also the effect that it may have on the lives. So I would see patients as a new physiotherapist, I would see patients who had an ACL reconstruction 10 years ago, and they would keep coming back with all these recurrent knee problems. So that I find really fascinating. Now,  life has the habit of confronting us with our worst fears. As I was graduating with my PhD in 2005, just a couple of months before submitting my thesis, I tore my ACL playing basketball. So I have some personal experience, sadly, looking at the other side. And of course, they're very important and difficult decisions that patients have to make with relatively limited information. I would add, especially back then. So it was somewhat funny that I had to spend the next six months limping up on podiums, where I would present to international audiences are the results of my research and how to what causes and how to prevent ACL injuries while I just had suffered one myself, but that's life.

Bevan Colless  

I had a similar incident during my first season in Niseko, I ruptured my ACL snowboarding and, and limping up to do an assessment on a patient and talking about their ACL injury when I just suffered the previous week or month. So, it really is a fascinating injury and, and so much more being discovered about it at the moment, as you're, as you're well aware. So let's talk a little bit about ACL healing. I'm sure you're aware of the randomized control trial that's being done out of Sydney. It seems like everybody's talking about it and knows about it, but  not published yet. But I understand that they've healing rates of over 90% with the bracing and management protocol. And another Japanese study showed healing rates over 80%. But you pointed out in the debate on conservative versus surgical ACL management the other night that the Richard Frobell KANON study showed  healing rates of 4%, a really interesting discrepancy. What do you put that discrepancy down to?

Evangelos Pappas  

I think the discrepancy is based on how it is measured. So a lot of the studies that you mentioned there, the RCT that happens here in Sydney, as well as some of the other studies and the meta-analysis that was published earlier this year by the two ladies, used MRI as the outcome to demonstrate to research, whether there is any healing of the ACL. On the other hand, the KANON study on this show that only 4% of the of those who did not have an ACL reconstruction had a negative Lachman test. So the Lachman test is, in terms of the clinical examination, the gold standard for diagnosing ACL injuries, so you look for the translation, the anterior translation of the tibia compared to the other knee, that explains probably why there is this large discrepancy in injuries of the ACL. And , in terms of healing, but I think it's important to remember that non-surgical management and the expectation for the ACL to heal is not something new, it has been tried at least since the 70s, if not earlier, with very mixed outcomes, quite poor outcomes in certain occasions, I would say. So it is, it is a fascinating area, because, if we had a conservative, non-invasive, predictable way to allow the ACL to heal, everybody would be happy, almost everybody would be happy with that. And I'm really curious and excited to see the results of the RCT out of Sydney. But of course, looking at MRIs as the outcome is a good first step, I would argue that, then we need at least five year follow ups in terms of function, looking at imaging in terms of degeneration of the knee joint, which is a serious probably the most serious issue are those who suffer an ACL injury, to see if they actually hold. They do use a very unique and rather strict bracing protocol. And this may make the difference compared to the previous studies. it would be great if they do. But, I think it's a bit too early to really put all our eggs in this basket at this point, but we're watching the space very, very closely. And it would be fantastic if the results are reproducible and predictable. And as great as you said, I don't know much more about this RCT other than what was shared by Stephanie Filbay, who's leading some of this research and she did show that 54 Out of the 60 have demonstrated some healing. Now, what that does that mean, is appealing enough to allow patients to be functional and returned to pivoting sports that would be great. Is it just a few fiber some of them maybe, they're limited related to the limitations of imaging? So will time will tell. But it is important to remember the history of ACL and its management and its treatment because non-surgical treatment has been tried before and the ACL has healing capacities, we know that in the laboratory, , it's frantically trying to heal the same way the MCL does in many ways, right? But it does do this try to do this job of healing in a very harsh environment where it's bathed with synovial fluid. And it does not seem no real fluid is washing away the blood clot, if you don't have a blood clot, even if the two ends are next to each other, then it's very hard to have healing. So I am very curious. And hopefully, we'll have some good results. But I'm also quite cautious about the prospect of ACL healing at this point.

Bevan Colless  

There was an interesting point you made the other night and debate saying that, look, we've arrived at our current method of managing ACLs for a reason, it's not like we've just because we've discovered a little bit more about ACL healing. And we've discovered that more people probably than we thought can do well, without an ACL, it doesn't mean that every ACL heals, and that no one needs surgical reconstruction. And that we need to totally discard our current method of managing ACLs. 

Evangelos Pappas  

You see it's two different things, because people frequently assume that if somebody is doing well, functionally after an ACL injury that the ACL has healed. And that's not the case. People talk about the rule of thirds, which is probably an oversimplification. But again, I think that communicates the message that that substantial percentage of those athletes who suffer and a complete ACL tear, actually have good function. I know people who have suffered confirmed complete, unhealed ACL tears. And then for decades, they have been very active skiing and dancing at high level. So it can happen. These are the copers they don't necessarily have a healed ACL. But again, they, they don't need one. From what it sounds, many of them don't develop osteoarthritis. So I do think, as we understand more, because just like a COVID is probably a good example, you have people who get COVID, and they are dying or suffering really serious disease, and you have some who don't even know it. So it's not very different with ACL,  some people are coping really well. And they have good outcomes. And some people,  they have quite disastrous outcomes.

Bevan Colless  

It's one of the things that we see a lot of in our clinics, particularly the ski resorts, because we're doing Lachans test on patients all day, every day. And it's not uncommon to find a positive Lachman’s, but their mechanism of injury doesn't sound like an ACL. This, there's just nothing else apart from the Lachman’s that  presents as an ACL, and then you start questioning them and you find out, Oh, 15 years ago, when I was playing soccer, or money did pop and it felt a little bit funny, but it wasn't that painful. So I never went and saw anyone and you realize that this person's been living without an ACL for the last 15 years and doing pretty well. But for other people, like you say it can be can be quite debilitating. So  there seems to be quite a lot of consensus, though. It's not like everybody's totally in on opposing sides into professionally, in because there's, as you say, that there hasn't been a lot of research done and so much is so much weight has been put on the KANON study by Richard Frobell that all ACL researchers are looking at and we're still waiting for the 10 year follow up, which is a little bit overdue, but I believe the results are pretty much the same as the five year from what I hear,  maybe explain to our listeners a little bit about this KANON study.

Evangelos Pappas  

So that was the first proper randomized control trial, which is the gold standard if you want to compare two different treatments. So basically, what they did is the patients who made the criteria had a confirmed ACL tear. They were randomized into either getting surgery in the early ACL reconstruction group or getting rehabilitation with the option to have surgery when they decided later on if they decided to do that. So there is a limitation there because ethically you cannot tell people you have to stick to the straight man. Their outcomes are poor, but it is one of the better studies that was done on the big questions. And we just spent, quite some time talking about the different subgroups, for lack of a better word of those who have an ACL repair. But to me what I would really like to see moving forward, probably some selection of the patients. And as the research moves forward, hopefully, we'll have a better idea of who are those who suffered the ACL playing soccer 15 years ago, and do well and who are those who actually need some more immediate intervention. But that’s one of two RCTs. So there was another Dutch study ‘The COMPARE’ (Conservative versus Operative Methods for Patients with ACL Rupture Evaluation) that was just published a few months ago, it only has two year follow ups, which is a bit problematic, because, as we know, two years for those who had rehabilitation, ,they still didn't have to go back to sports for long enough to see if they did well, all those who had an ACL reconstruction, they’re probably still improving and rehabilitating to a certain extent. So for the COMPARE, we'll probably have to wait for the five year follow up for that. But we have the five-year KANON follow up. And as you pointed out, we are expecting the 10-year follow up from that study. So the main finding there is that, on average, these two groups, the early ACL reconstruction group versus the rehabilitation plus optional, delayed ACL reconstruction group, on average did very similarly. And then the COMPARE study actually found something similar. So there is some evidence that is coming out there that on average, one technique, one approach is not superior to the other approach. The second thing that is important to remember is that about half of both studies, about half of those patients who were randomized, and remember, these are patients who knew from the beginning what they were signing up to, so to sign an informed consent, they knew that they had a 50% chance of getting the rehabilitation group. These are not typically the patients who have set their mind in a surgical approach, otherwise, they would not sign up for the study. So half of those who were randomized into the rehabilitation approach, they ended up having surgery. To me that's not surprising, right? Because again, goes back to what you were saying before that some patients don't do well, with a rehabilitation alone approach. So it's good to see the consistency in the findings between those studies. So I do think that it is important to remember that the ACL rehabilitation approach is a bit of a trial and error, once those patients suffer through instability. So the similar mechanisms to the actual ACL tear where the lateral tibial plateau translates anteriorly. And internally  and then they have to extend their knee to pop it back in, if the patient has a couple of these episodes, to me, that's a very good indication that they need an ACL reconstruction, or  they have to change the type of sports that they do, in a combination of both changing the sports to more knee safe approach, and we may talk about this later. But also an ACL reconstruction. The ACL reconstruction is pretty good at stabilizing the knee in terms of anterior translation. So, at the hands of the experienced surgeon, it's not a particularly useful outcome, but anatomically right. The ACL graft prevents anterior translation quite well. And probably internal rotation somewhat well, we have done a series of studies with my colleagues in Greece, with Professor year release and his team there that will show that even when you put the graft in the more oblique position, which is the gold standard. Now, even when you place the drill, the femoral tunnel would be able to remediate through the anteromedial portal, which again, there's evidence to show that this is beneficial. Even then there is still a bit of deficit in internal rotation in the ACL reconstructive knees, whether this is the reason that they develop osteorthritis, we don't know, but I guess we can speculate. So I probably spoke a bit more broadly rather than the KANON study. But, I think the third thing from the KANON study the third main finding in my opinion, is that when you look at the Tegner score, which indicates the intensity of sports that they played with 10 being very high level, hard cutting and pivoting sports and zero, on the very standard theories and, the score goes from nine pre-injury so really high, intense sports that are not very safe for the knees are very challenging for the knees, down to a five to 6.5, or the two year follow on, depending on the group that you look at, and then down to four. So, a rapid decrease in the Tegner score by the five year follow up in all groups. So to me, that is another very important message there.

Bevan Colless  

I always find that a little bit sad, really, because as physios, we speak with our patients and talk about their future sporting goals. And I always think it's our job to try and help those patients achieve those goals. But I guess, we started to realize that the long-term implications for an ACL injury are that the risk of arthritis is quite high. And we probably need to caution our patients about that, and also talk at least about adapting and of future sporting goals.

Evangelos Pappas  

Absolutely. And I think at the end of the day, our job is to educate the patients and allow them to make an informed decision. Right. Agai,, you may sound somewhat surprised, but I decided on an ACL deficient knee after my injury back in 2005, to go back and play basketball. And it worked out well for a few months. But it became a disaster a bit after that. And I needed much more complicated surgeries, multiple surgeries after that. So there is that risk there, but at the end of the day, it's the patient's decision. So if, for a patient that's the, that's their life, it's very important for them, they're aware of the consequences and the reason for taking them, how the patient who had multiple ACL reconstructions, and every winter she would, practicing in New York, and every winter, she would go helicopter skiing in Canada. And, frequently she would come back with another knee injury. Again, we're not here to prohibit patients, from doing certain sports, we cannot, and we should not be doing that. But where we failed as a community from orthopedic surgeons to physiotherapist is, really setting some realistic goals and expectations. And just going back to my clinical days in New York, one of the more difficult patients to manage, were those who went to the orthopedic surgeon who very confidently convinced the patient that all they need is an ACL reconstruction and their knee will be brand new, basically, those orthopedic surgeon who somewhat arrogantly they say, ‘I've never had an ACL failure’ and the graft I will put in your knee is 170%, stronger than your original ACL’, without giving the rest of the story of what happens after you place the graft into the knee. And, the overwhelming evidence that the knee will not be back to normal. So and as physiotherapist, I find it a bit challenging that I've seen, especially on social media, some overly optimistic messages towards those patients who are considering a non-surgical approach. As we said, for some, it works really well. But creating this expectation frequently in the same breath that ACL reconstruction does not work. But conservative treatment actually will make your knee perfect. And I have multiple patients that I can show you how to do that that can provide us evidence. So that that certainly happens. But as we said, there's all these different subgroups. And we don't really know where this particular patient will fall into and what subgroup and I think we'll have to be very realistic. It's a very difficult discussion to have Bevan because,  one of the questions that came up at the debate is how exactly do you break this news to the patient,  it has to be done with a lot of empathy because having an 19 year old, who see themselves as a professional athlete, or , they live and breathe snowboarding or skiing or basketball, to be the first to tell them that hold on a second here, you keep re-injuring your knee, you're in your second or your third ACL reconstruction now, by the time you're 30, you'll have problems with activities of daily living. So telling them that is never easy, but I do think it's our responsibility to communicate very carefully some of these messages because you would  sound ethical, in my opinion, to create these very high expectations with either approach, either surgery or non surgical approach.

Bevan Colless  

For sure. And I think those conversations that you have with the patient in between the time they have their injury through to when they make a decision on how they're going to manage it, is so critical, and that's part of the reason that I've started this podcast is that they're the conversations we have in our clinics in the ski resorts in Japan every day. And we feel that heavy responsibility. And I guess the knee surgeons are having these conversations every day as well. And , the knee surgeons, as you say, shouldn't be saying, ‘Yep, all you need to do is have your operation, and you're going to be fine’. And the physios and sports scientists shouldn't be saying ‘So you don't need an ACL and we can rehab without it easily’. But it's a lot to take on for these patients who've just done a knee injury and probably haven't thought about ACLs much in the past. And all of a sudden, they're getting all these different information from different people, it can be a bit overwhelming for them, I think.

Evangelos Pappas  

Absolutely. And, I think allowing them the time to digest this information, but also knowing that we as clinicians, are right next to them to assist them to navigate the system to assist them to navigate the literature. The good thing about the ACL is that it's an elective procedure and you can take the time to do that. It's trial and error so they can try the non-surgical approach and see how it goes. The surgery is always there. So we hope in the not too distant future, is going to offer them better options and better outcomes.

Bevan Colless  

You talked a little bit about physical activity declining post ACL injury. I can't remember the exact numbers but it's quite significant in the KANON study had found that people went down from an nine to a to a four. If people have had the operation and had a really good rehab or conservative management, do you find it surprising that people are still seeing such a drop off in their physical activity?

Evangelos Pappas  

Probably not. I guess here, you will have to make the distinction that it's not the knee health or knee, it's not how the knee feels, and behaves that facilitates these decisions that the patients are making. Again, going back to my clinical days in New York, I would see quite commonly those patients who, in the late 20s, tore their ACL,  frequently had their ACLreconstruction tried to go back because of instability episodes, two years later, and then they realize,  what, I'm working really crazy hours at starting a family, do I really need to go for physiotherapy two to three days a week with this ongoing knee problems and seeing the surgeon once a year for a procedure. So very frequently, it's more social factors and personal factors that guide this decision. But , I also need to clarify here that the Tegner activity doesn't primarily measure the frequency of physical activity, but more the nature of physical activity. So it's not surprising that patients who had a significant injury and three quarters of them had an ACL reconstruction and their rehab that goes after that, that they make a decision to drop their intensity of the physical activity to more knee safe sports, such as cycling, swimming, and running, and so on and so forth. So that is one aspect there. And I actually think that is quite a smart decision, in many ways, switching to sports, that for those who are happy to make that decision, and naturally, a lot of them decide to make that decision to switch to sports that are less likely to predispose the athlete to future knee injury. And but then there is the sadder part for me and that is the knee that deteriorates quite rapidly. Sometimes, back in my clinical days I’ve had patients where they are, within a couple of years have serious cartilage issues. And what do you do with a 25-year-old who has the knee of an 80-year-old? To me that was the more difficult patient to treat and the real and sadly, not too uncommon after multiple knee injuries. So, the problem is that we have those patients who then cannot do any sports or any sports that allow them to keep some fitness level. And there is surprisingly and sadly, very little research in this pace. So there was a study by Bell that was published in 2017 in the American Journal of Sports Medicine, it was a very small study, I think it only 33 ACL reconstructed patients, but compared to a control group and ensure they're’s some decrease in the number of steps that the ACL reconstructed patients take the average after the reconstruction was 27 months. And also in overall physical activity levels. So that is a another sad part of this injury is that there are these patients who really want to be active in the late 20s, or in the 30s. Now, they really want to be active, they're happy to give up the sports that are more prone to  knee injuries that just cannot because they their knee cannot tolerate the impact and then the forces that even with a safer knee sports. And sadly, we know very little about this population, we actually know very little about what happens to those patients who had an ACL injury in their teens or their 20s in terms of the long-term impact to their health. But since I moved to the University of Wollongong, we have a wonderful opportunity just because it is a population of about 400,000 people in the Illawarra. And the local health district is capturing a lot of the outcomes. So we're at the beginning of some really, really exciting epidemiological projects, we can look at the long term health of those who had an ACL injury and other orthopedic injuries at some point early in their lives. I'm really excited about this project that should be coming out in the next few years. So we are recruiting for PhD students now to grow and looking to grow our team, because these are massive projects. A year hopefully, in a couple of years, I'll be back on your podcast and share some more details about what happens to them. But, until then,  I think that the patient, that 25 year old patient with an 80 year old knee is a real challenge at the clinic.

Bevan Colless  

Very sad. And just the rate of osteoarthritis post ACL is quite depressing, really, when you look at the numbers, there's six times increased chance of developing osteoarthritis. And some other people say that the diagnosis of an ACL rupture is pretty much a diagnosis of early onset osteoarthritis. 

Evangelos Pappas  

That's about right. If it's an isolated ACL injury, as opposed to those that have no meniscus and cartilage injuries that isolated ACL injuries do better in terms of low risk of developing osteo-arthritis. But, the four to six times higher risk of developing yourself  is probably where the literature would agree at this point, acknowledging that there is wide variability there. But it also depends, just from a research point of view, how do we diagnose knee osteoarthritis, is it symptomatic isn't just radiologic. Again, we know that these two don't always go hand in hand. So there's quite a few people who have really bad X rays, thinking that they will be quite disabled, but they're extremely active and happy with their knee, and vice versa, those that have very few changes in imaging, but they are very debilitated. So just to put some perspective, in the animal world, one of the more predictable ways to develop an osteoarthritis model in rats, for example, or dogs, is by severing their ACL. So, when you say that it's a ticket to knee osteoarthritis. In many ways, there's good evidence to support that. But there's quite a few things that people can do to minimize this risk.

Bevan Colless  

And what are the things people can do to avoid that? Things like avoiding sports that involve pivoting and twisting?

Evangelos Pappas  

Avoiding re-injury. So, those who are lucky enough to return to the sport that they love, but don't get another injury? That's fine. I think avoiding re injury is the key here. One way to do that is by switching to different types of sports, but not the only way. We do know that those who suffered a first ACL injury, there are 16 times more likely to which is for epidemiological terms, that's pretty huge, to suffer either a rupture of the graft or an injury to the other knee. So , biomechanically, we know that those who are suffered their non-contact ACL injury, they move quite differently. And most of my research actually is in the space. There's a lot of biomechanical risk factors that again, we there's a great opportunity for physiotherapists there to intervene in the prophylactically by with the injury prevention programs that it's on podcast, probably, but that's there's a lot of research there that they can reduce the risk of injury by almost 50% or to go for those who had an ACL injury at the very late stage rehab, and we know now that we should wait at least nine months before allowing these patients to return to sports, but at the very late stage, so looking at the biomechanics and trying to intervene there, I think is a good investment.

Bevan Colless  

It's a tricky balance to strike with patients, when you're educating them, because on one hand, we're saying, ‘this is a quite a serious injury, and we need to reassess your future sporting goals’. And the management is going to be quite in depth and require a lot of effort. But on the other hand, we don't want the patient to over-protect the knee and feel like that, all day, every day, they can't use their knee as normal. And then they start to develop, learned nonuse, like leading with the other leg all the time, and it just becomes a little bit self-fulfilling, because then, in their mind, they know that they've got a bad knee and they start to not use it and it gets weaker, and on and on it goes. So one of the mantras we have in our clinic is ‘Trust the Knee’. So while we're educating on that front,  we also want to caution that that is a serious injury. So it's hard to get that balance, right.

Evangelos Pappas  

That's a fantastic point, you're making them and because when we say educate, that instilsl some fear to the patient who's recovering, which again, creates this vicious cycle, they're over protecting their knee and not loading it as much. Therefore, when the time comes that they are landing on this leg, then they may be at a higher risk. So they there is this whole psychological domain for those athletes who many ways have lost their identity when they had to stay out of their sport for a long time. And then the fear of re injury, the athletes rarely forget how it felt. So then I don't have any great answers there. I think time and that's some people advocating waiting for two years after an ACL reconstruction. Because when we know that practically all the ACL ruptures happen within the first two years. So, there is a good point to make there. Now again, is it easy to tell your 19-year-old snowboarder that you have to skip a couple of seasons or potentially even three. Before returning to snowboarding, it's not an easy discussion to have. But again, if it's presented with their right sensitivities, I think it has the potential to save a lot of disability and re injuries.

Bevan Colless  

For sure. One of the other things that's interesting about ACL injuries is the gender difference with depending on what research you read, females being somewhere between four to eight times higher, you might have read some different numbers anyway, it's quite exponentially higher that females to rupture their ACLs than males. One of the common causes that have given is the hormone cycles, that females are not as strong as males in some instances, and that their hips are wider. So the Q angle of their femur, the thigh running down to the knees is wider, which predisposes them to an increased incidence of rupture. What have you found, as the reasons for this gender difference?

Evangelos Pappas  

We do know, for a long time now, probably since the 80s, to compare apples to apples. So let's say my professional basketball players, males and females, then the females are at a much higher risk of ACL injury, depending on the activity, these numbers that you mentioned, four to eight is the consensus at this point, looking at military training, for example, it can go up to 10 times higher risk. So it's a rather substantial high risk of ACL injuries for females when you expose them to the same activities. And a lot of factors may be influencing their, , I would even cite some of the work that some of the factors that have been proposed that it's the way that we are and the stereotypes that frequently society imposes on children that, girls should do certain activities and boys should do certain types of different types of activities, so they slip their multifactorial problem there, however, and I do think there is some news there. That because a lot of the work around, the hormonal cycle is very difficult to identify at what part of the cycle the athlete was at the time there after their ACL. So there's a lot of conflicting evidence there, I think it's largely theoretical at this point.

But when we look at the biomechanics, there is a clear difference there between, again, when you compare apples to apples between males and females, we published the first article on that in 2007, the clinical journal sports medicine, knee valgus is a is a reemerging rather consistently, I would say, risk factor there. So going back to the work that teams you had they back in 2005, I think, and that was a large study where you look at females at baseline very difficult and expensive studies that were funded by the NIH back then. But Tim and his team, they demonstrate it, in my opinion, quite convincingly, that excessive knee valgus. So those female athletes who learn with an excessive dynamic knee valgus position, so they allow their knees to collapse inwards, they're at the high risk of an ACL injury. This has been questioned, and there were some, , editorials that received a lot of attention, which had the advantage that, , they forced the sports medicine community to look at the research methods a bit more carefully. On the other hand, it muddied the waters a little bit, , it's about the kissing nice, is it a really predisposing risk factor. I don't know if you have followed the IOC conference in Monaco that just ended a couple of weeks ago. But one of the major messages there was a study by some of the people who questioned the importance of knee valgus that their own large corporate study actually confirmed that knee valgus moment is a predisposing risk factor for ACL injury. So , if I'm going back to the large prospective studies that looked at risk factors for ACL injuries, and females, they were Tim Hewitt and his group from Ohio that demonstrated that back in 2005, and consistently after that, there was the job ACL study, a large military study in the United States that that I don't have not seen the full paper from that. But an abstract actually confirmed that knee valgus was one of the predisposing risk factor for ACL injury. And there was in the region study that again, I've only seen the abstract and on social media that presentations from also supports trauma center that again, confirm that knee valgus moment is a predisposing risk factor. So to me, that's the evidence at this point is clearly pointing in that direction, that there's something with knee valgus, if I am to go a bit deeper there. And we published a study just a few years ago at MSC where we look at subgroups, and that was Tim Hewitt and his group where we looked at subgroups of motion profiles. And again, if any of these work, anybody would like to read a bit more carefully, especially if you do have are suffering from insomnia, please email me and share those with you lots of methodological detail. But But the message there is that 40% of high school female athletes, they are performing unanticipated cutting maneuvers in a way that is biomechanically sound. So good alignment, only 14% demonstrate excessive knee valgus angle and moment, but very high. So it was a couple of standard deviations above the mean. So there seems to be a group of females, that is probably not a very high percentage, but these seem to land with excessively valgus. And they may be the ones that are more predisposed to knee injury, while the other two groups had the combination of different biomechanical deficits in one of these groups, knee valgus also played the role, but to a lesser extent. So if I were to battle nor where we can make a difference in terms of prevention of ACL injuries, I think identifying early these group that demonstrates these knee ligament dominance deficits where the knee goes excessively to new valgus I think it's the lowest hanging fruit.

Bevan Colless  

It’s difficult to identify those in the general population on the large scale, I guess.

Evangelos Pappas  

Well, but that's changing, we're likely at the University of Wollongong that we're going to have a marker less system that we were successful with the grand just a couple of months ago. So the technology is rapidly evolving there. I am used so wearable sensors are rapidly developing there. So again, I'm optimistic that the next decade or so, will allow us to do that in ways that are brought less obtrusive into the activities that they do and  with a markerless system, you can pretty much do that without too much burden for the athletes. And again,  here with Matt Well I will talk about setting up some large studies to do that. So I will say watch this space? I'm quite optimistic that this will be possible.

Bevan Colless  

Great. And we know that ACL injuries can be reduced by prevention programs. But they just don't seem to be often done, even in elite sporting teams. Can you tell us a little bit about the work you've done with prevention of ACL injuries?

Evangelos Pappas  

Well, it's one of the sad things that we have an intervention that works yet it's not widely implemented. Again, my dwell on has that a lot of great work there with a Perform Plus. Where Well, it is important that we actually have moved away from this perception that the injury prevention programs are very rigid, very strict, to be done,  under the specific conditions, and if you miss an exercise, that's the end of it, there is good evidence now that the order of the different elements of the program and how you perform them, it's not as crucial as we thought it was. So it is important that we make these programs easy to implement. They're looking at how we can utilize marketing principles in order to bring the athletic community on board and increase the uptake of these programs. But as we know, it's a problem for quite some time, and we have not been moving the needle too much. I would say at this point. I do think that educating the coaches is a very important thing and selling this injury prevention programs not only for the important role, they're playing injury prevention, but also in terms of improving performance, certainly not having an adverse effect on performance. And there was some recent study that demonstrated that but even potentially being good for scoring more goals or more baskets. Because we know that's important for coaches.

Bevan Colless  

For sure. I mean, it fits right in with a preseason conditioning goals for improved performance, as well with any plyometrics you do is going to increase your power and agility and also prevent ACL. So what advice would you give people who are about looking forward to going on a ski trip or about to start their season, as to what they should be doing that reduce their chances of getting an ACL injury?

Evangelos Pappas  

My best advice is to just go there and enjoy yourself. If you are in a privileged position that you can travel at this point and go to a ski resort, I think we all need this vacation. That's right. Now in terms of prevention, ski injuries, there were some really good studies that was done a quite a while ago, out of the University of Vermont, with Bruce Bayh known and his group, I believe, where they actually showed some really good results, simply by showing an educational video to those who were at the beginning of the ski season there. So, it's probably a good opportunity for you by Avon and your team there to see if you guys are waiting to, , be transported to the top of the mountain, whether that's a good time to show them like a three minute video that very plainly and simply talks about some neat, safe procedures that they can, they can follow. But , other than that, , just make sure that your faith makes sure that you , you practice now there will always be virtual reality opportunities there. You don't have to wait once a year to perform some simulated University. And that tends to be some of the problem with skiing that you wait for a whole year and then you go in a two week vacation, and then you have to wait another year to ski again. Well, now there is some simulated activities that can be performed. That potentially , both from a motor control point of view, but also from a biomechanical point of view can reduce the risk of knee injury or I'm just hypothesizing here though. There's no studies that I know of that have done this. Take it easy. Don't be too brave. The Black Diamond, that's something that you haven't you're 45 years old, and you haven't mastered that yet. Maybe that's not the right time to try that. Or if you do, just be aware that you are taking a rather substantial risk there. So of course, be comfortable with the risk every just like every time you drive or you do any activities, you have to be aware of the risks but also comfortable and do your cost benefit analysis there.

Bevan Colless  

So just changing tack a little bit about surgery procedures. I wanted to talk a little bit about the current growth in ACL repairs over reconstructing the ligament understand you've done a little bit of work in in that area. And you were saying that the ACL repair repairs, although they're becoming more popular, they seem to be showing a higher failure rate. What do you what do you see happening in the ACL repair space moving forward?

Evangelos Pappas  

Well again, looking at the three main options that are available in terms of treatment to the athletes. So there is the non surgical treatment, that you mentioned the RCT at Sydney with a bracing protocol at this point, that would fall into this category. Then there is at the other end of the spectrum, the ACL reconstruction where the native ACL or whatever is left of it is removed. And then the free graft is taken from the hamstrings or the patellar tendon, sometimes an hour graph, and to try to refashion and reconstruct the ACL. And then there is kind of a middle of the road approach, which is the ACL repair, where the surgeon goes in arthroscopically, finds the two torn ends of the ligament try to stitch them together. More frequently, probably what they do is they drill a tunnel back into the femoral tunnel into the femur, and they try to with sutures to put the stump of the ACL, back into the femoral tunnel and allow it to heal. So there's a few different surgical technique repairs of having tried over the years. Again, it's important to remember that there's nothing new there. It has been tried it three merges every few years. One surgeon is claiming that they have superior results. I know there is one surgeon the hospital Special Surgery, which is a large specialized Hospital in New York, that is advocating for those. One thing we know now is that, again, going back to the subgroups, not everybody is a candidate for an ACL repair. So acute injuries. So capturing these early the same way we deal with the finger flexor, the finger, flexor tendon repairs, doing it very early within a few days is beneficial. an ACL tear that happened closer to the femur. So a proximal tear has better outcomes with an ACL repair. But I'm really excited and fascinated by the work that Martha Murray is doing in at Harvard University. Looking at a , probably the best case scenario for an ACL repair where they kind of have a scaffold bridge, basically, that they try to that they inject some blood into it, try to facilitate the fibrin clot formation, the fibrin clouds, they reinforce it with stitches that go through TBL and the femoral tunnel. They did that in a young population. So again, a very best case scenario. And they it was a study that was published last year, I believe, but it was a non inferiority trial. And the found that statistically, there's practically no difference between the this ACL repair ACL repair on steroids, I would, I would argue, because it is a more complex procedure. And then traditional ACL reconstruction. However, they had a 14% failure rate compared to a 6% failure rate for the ACL reconstruction. So again, not quite there, in terms of outcomes with the ACL reconstruction, but but I'm really curious to see what happens if they decrease the wait time because on average, the patients have had to wait for about a month after the ACL injury. And we do know that the ligaments feel much better at the very few days. So I think if they, if we start if we stretch our minds and treat the ACL injury more as an emergency that needs to be treated, , with not without reconstruction so much, because for that frequently, you have to wait longer for better outcomes. But for the repair, or even I would argue for the bracing protocol. If we get those patients the treatment within a few days after the injury, then I think the outcomes may be better. So I'm curious to see if that will be tried moving forward. So cutting these ACA this way times would be a crucial aspect, I would argue. So for those who are who had who suspect that they had an ACL injury and they're considering repair, I would say go to inexperienced surgeon I be prepared if it's not the approximate pair that you're not the candidate. And then if you do decide to go for the repair, it's a bit of a trial and error. You can always have the reconstruction later. And in the MRI studies show that those patients who had the reconstruction had similar outcomes to those who had the reconstruction from the beginning. And, it's worth the trial, I would say and if you have your native ACL repair then He'll then that's a good outcome.

Bevan Colless  

It's interesting, because a lot of the feedback we're getting from the KANON study, is suggesting that we should wait three months post injury, almost regardless and it should rarely be operated on so quickly. But for repair..

Evangelos Pappas  

For the construction and only for their repair, I would argue,  because by then they stumps with the torn ACL, they're started  drying out. So, an ACL repair should be performed in a rather acute stage.

Bevan Colless  

 So there's definitely some points there for early intervention. I know some of some ski resorts in the States are doing reconstructions on the same day, as the injury or repairs and the same day of injury. They've got surgical theatres, on slopes.

Evangelos Pappas  

And once I met somebody who did that in Switzerland, so there are,, I guess surgeons waiting at the base? You see, I think they and then the way it was explained to me by because I raised this with a couple of orthopedic surgeons that if you can't, if you managed your tear early within the next two to three days before the full inflammatory response, oops, then then actually, they are the outcomes are quite good. So for the reconstruction, you either get into surgery within the first couple of days, or then you wait three months until  the inflammatory response comes down. So , I think that's another very interesting area and the acute repair or reconstruction, where you actually take advantage of the blood in the joint, and then the inflammatory response after that.

Bevan Colless  

That's really interesting. Okay. All right. I think we might wind it up there for today. Evangelos. Did you have any other passing advice? We’ve covered a lot of different topics. But in general, for somebody who's listening who may have ruptured their ACL recently, and they're weighing up what to do, would you have any simple hints and advice for those people?

Evangelos Pappas  

I think there’s nothing simple about an ACL injury, sadly, but there are options there. Again,  I think it's important education is really important, finding clinicians who are well read, balanced, and become partners for the journey, because it is a bit of a journey, I think it's important going to those who see a lot of ACL injuries and specialize in those injuries, both in terms of Orthopedic Surgeons, and in terms of rehabilitation professionals, I think it's really, really key. And please, just like with everything, I would say that when it relates to your health, be aware that Facebook and Twitter are not peer reviewed, there is a lot of extreme opinions there. Some advocating for a surgical only approach and how wonderful the outcomes are with surgery, even though the evidence doesn't support these, as well as those who are saying that,  if I treat you non surgically with a rehabilitation protocol, then the outcomes will be fantastic. And you'll be able to return to your pivoting and cutting sports much faster and with very small risk of re injury. So the truth is somewhere in between. And as we said, before, it seems that we agree on that, which was wonderful to hear that there are these micro subgroups within the ACL injured patients. But probably the bigger message is for our community, for the research community to really come together to try to solve these problems, put our egos aside, look at some of these studies that we discussed today for the future in terms of finding out who is predictors of membership in in subgroup, who are those who had their ACL integral, who do really well with an ACL or whose ACL will heal, and also those who actually will do really bad with an ACL injury or a conservative approach. And identifying those early relatively early at baseline. There's very little research there barring the study by green them in the region study. But I do think, they, the future will provide some of these answers and there is some research happening that hopefully will provide better outcomes,

Bevan Colless  

Yes, be careful of anyone who's preaching that their method is going to 100% work for you. So I think that's an important message for people to hear. Well, thanks very much Evangelos. I think that's been a terrific discussion and so much more to come in the ACL space and we'll definitely stay in touch and keep an eye on that research you're doing In Wollongong as well. That sounds really interesting.

Evangelos Pappas  

It was a pleasure to do this with you Bevan. And yets, please stay in touch and thank you for investing this time to educate patients and healthcare professionals about knee injuries. So I'm looking forward to listening to the future episodes.