Jennifer
Welcome, to this evening's webinar: Orthopaedic Insights – Navigating Hip and Knee Replacement Surgery. My name is Jennifer, your RACGP representative for this evening. We are joined by our presenters, Associate Professor Sam Adie and Dr Simon Coffey, and our facilitator for this evening is Dr Tim Senior.
Before we get started, I would like to make an acknowledgement of country. We recognise the traditional custodians of the land and sea on which we live and work, and pay our respects to Elders past, present and emerging. I would also like to acknowledge any Aboriginal and Torres Strait Islander colleagues that have joined us online this evening.
Before I hand over to our presenters, I would just like to introduce them. Associate Professor Sam Adie is an orthopaedic surgeon specialising in hip and knee joint replacement surgery, sport injuries, and complex orthopaedic trauma surgery. Sam completed his orthopaedic training in Sydney in 2015, followed by primary and revision joint replacement at the University of Toronto, complex trauma and reconstruction at the University of Oxford, and a foot and ankle fellowship at Prince of Wales Hospital. Sam also underwent further training in research methods and clinical epidemiology, with a Master's in Sports Medicine in 2009 and a Master's in Public Health in 2010, and then completed a PhD in 2014. Welcome, Sam. Dr Simon Coffey is a Sydney Orthopaedic Surgeon specialising in the management of lower limb musculoskeletal problems, specifically in primary and revision hip and knee replacement, and has over 20 years' experience in specialist clinical practice, being involved in the training and supervision of many students and trainee specialists. Simon works within the medical technology industry and has been involved in the development of numerous implants and participating in collaborative research. His current research interests revolve around robot assisted joint replacement, alignment and balance in total knee arthroplasty, validation of implant positioning using RSA, and the development of robotic platform for partial knee replacements. Welcome, Simon. Last, but not the least, Dr Tim Senior is a GP at Tharawal Aboriginal Corporation in South Western Sydney. Tim is also an RACGP Medical Advisor for the National Faculty of Aboriginal and Torres Strait Islander Health, and Senior Lecturer in General Practice and Indigenous Health at UWS and an RACGP Medical Educator. I am now going to hand over to Tim to run through our learning objectives.
Dr Tim Senior
Thank you very much. Good evening, everyone. I hope you are all keeping well. These are our learning objectives for this evening. This is educational speak for what we hope to get out of this evening's activity, so that by the end of this online CPD activity, we should all be able to identify patients who should or should not have a total knee replacement, outline the management of obesity in total knee replacement, outline the current controversies and areas of clinical research, describe indications for hip replacement surgery and the role of non-operative management, and outline the likely longevity of modern hip replacement. I am going to pass straight over to our first speaker now to start us off. Thank you very much indeed.
Associate Professor Sam Adie
Thanks so much, Tim, and good evening, everyone. Thanks for joining us tonight, taking time away from your family and friends, but hopefully these talks will be worthwhile. This presentation is on who should or should not have a knee replacement. The subject matter of the talk is very much related to a paper that we published a few years ago in The Medical Journal of Australia. This is a narrative review that was invited. It is very much written for the general audience. I would urge everyone, if you do have time, to look that paper up. It does cover the topic about who is a candidate for a knee replacement, but how to approach the optimisation of these patients. What the talk is not about is the technical aspects of the surgery. All of these things are excellent and a lot of surgeons are using them. I do feel that they do improve patient outcomes in many cases. However, I do feel that the advances that have been done in this space are relatively incremental, and I think some of the major concerns that need to be addressed are not really surgical technique or technology issues. They are really related about really common things like obesity, for example, or opioid use that we will cover in a few moments.
The outline of the talk, I am going to talk about the burden of knee replacement on our society. I want to talk about the minimum requirements for a total knee replacement and then assuming that a patient is a candidate for a knee replacement, how to go about optimising them for surgery. I am going to focus on what is the evidence for the things that we can do to optimise or the lack thereof. You will find that there is a lot of evidence lacking in this space. If we do have time, then I want to address some of those controversies and some of the research that we are doing to cover those research gaps.
First of all, the burden of knee replacement. We are doing about 70,000 knee replacements in Australia every year. Our knee replacement rate is about twice the OECD average. You can make of that what you will. I guess we do have a very well-balanced health system with access to, for example, private surgery, so access to the surgery is perhaps better than some of the other OECD countries. There may also be an element of oversupply. Knee replacement is a very successful procedure and perhaps it is being over-serviced to an extent. I think it is really a combination of both of those things. We do have a higher knee replacement rate compared to, for example, the United Kingdom or Canada and many other places in Europe, but still lower than the United States because, again, their system is quite heavily focused on private work. Now, knee replacement is quite common. If you are a female in the audience today, your lifetime risk of having a knee replacement is about 20%, so 1 in 5 of you is likely to have a knee replacement at some point in their life. A little bit lower if you are a male, so 15%. The issue is knee replacement is excellent and it has very good outcomes, but there is some risk involved. This figure of 24% was taken from the only randomised trial that was published on knee replacement, comparing knee replacement to best non-surgical management that was published in the New England Journal of Medicine a few years ago, and that showed that about a quarter of patients can experience a serious adverse event. A lot of work is now going into how we can improve the safety or reduce the risk of having a complication after a knee replacement. The issue is knee replacement rates are rising and they are getting more and more common. This paper was actually published quite a few years ago now, but the cost of knee replacement now is about $2 billion, and that just includes the direct costs of having the surgery itself. It is projected to increase year-on-year, and it has been increasing year-on-year with a slight lull during COVID for obvious reasons, but year-on-year is increasing, and by 2030, we expect it to cost over $5 billion. That is a massive drain on our health system. It is by far the single most expensive surgical procedure in the country.
Let us talk about the minimum criteria for a knee replacement. I guess a lot of us are familiar with some of these things. To diagnose someone with symptomatic arthritis, you need to have radiological features of arthritis. Secondly, you need to have symptoms of arthritis, and they can be divided into pain, dysfunction and sometimes the deformity that results from the disease can also cause problems. Thirdly, I think this one is somewhat ignored is that patient needs to fail non-surgical management. Assuming they have x-ray features and symptoms of arthritis, there needs to be an attempt to manage their problem non-surgically, and they need to then fail that process before they are considered for surgery. What are the x-ray features, a lot of us are familiar with these? A normal-appearing x-ray on the left side. Then you have sort of mild arthritis with joint space loss in the middle over here, and then you have quite severe features of arthritis on the right with a complete loss of joint space, subchondral sclerosis, and then if it is severe enough, you can have a deformity that results. In example on the right, there is a loss of cartilage and bone leading to a varus deformity. Symptoms of arthritis are mainly pain and pain that then interferes with their activities. A lot of these can be captured by patient reported outcomes that are widely available online and routinely measured by a lot of surgeons in their practice. The Oxford, for example, is routinely collected by the Joint Replacement Registry for someone who is a candidate for surgery, and that basically asks a number of validated questions about their pain and function. You can imagine that functional needs are quite different for different patients. A younger, active male who is still working is quite markedly different to an institutionalised older lady, for example.
Failure of non-operative management is important. There are a variety of guidelines about the management of knee osteoarthritis, including the College of General Practitioners that has an excellent guideline. Now, these works are quite long. They are very much evidence-based, so they cover a lot of the data related to the recommendations in those guidelines. If I was to summarise these guidelines, it would be these three lines. Essentially, the first-line treatments are education, exercise and weight loss. Pretty much everything else is then attempting to get patients well enough or good enough symptom-wise in order to get these things, to do their exercises and to attempt to lose weight. These second-line things like TENS and bracing and massage and steroid injections, which we routinely do all the time as some sort of first line treatment really should not substitute what our discussion is with the patient, educating them about their disease, telling them about the things that may benefit them, like exercise and weight loss. There is very, very good evidence, for example, for exercise reducing the symptoms of knee arthritis.
Let us talk about how to optimise for surgery. When you think about optimising the factors that are associated with outcomes after knee replacement, there are just so many right. It is more than any other condition perhaps in surgery, perhaps some general surgical conditions that are covered in the literature., but knee replacement in particular has been associated with so many different factors in terms of a successful outcome after the surgery. I think when we discuss some of these more important and pertinent factors, I think it is important to think about what the risk of each of those comorbidities is, and then if we are thinking about optimising, what is the evidence for optimising? In other words, what evidence is there to support the interventions that I can offer that patient in order to improve their outcome postoperatively. I want to discuss the evidence and what evidence exists for a few of these more important comorbidities and factors.
Expectation and satisfaction is the first one I want to talk about. This has been covered extensively in the literature. Patients that have inappropriate or expectations that are not in line with what a knee replacement is really, truly going to offer them are likely to be unsatisfied with their surgery. We have shown that in our research. It has been done many times over in other research papers that you can find elsewhere. We also try to see whether expectation or measuring expectation is actually associated with satisfaction, and it probably is. The problem is it is hard to measure something like expectations, so it is hard to replicate elsewhere. There is no clear construct for what expectation is. The best we have is to educate patients about their surgery, what to expect from the surgery during their whole journey from before, during and after their hospital admission. A lot of work has gone into decision aids, for example, providing written information. Some people have done sort of predictive models about who is going to benefit more from surgery, for example. There is no consistent evidence that any of these work, but the most common one is some sort of written information or education telling the patient about what to expect from the surgery.
This is another one. Joint disease severity. We know that worse joints before surgery probably have a worse absolute state after the surgery, but the changes or improvements that they gain are actually larger. There is a case then for trying to improve the state of that joint before they have the surgery, so the overall benefit after the surgery is going to be better. That is really the rationale for preoperative rehabilitation or so-called prehab, and that actually does have really good evidence, probably because it is a space that's run by physios and physios really do focus on high level evidence as opposed to surgeons and doctors, unfortunately. Lots of randomised trials have been published and a metaanalysis in the BMJ a few years ago shows that there is some benefit to prehabilitation, but that benefit is probably only very small. I would not ever recommend against it, but again, at the same time, I do not think it routinely should be offered and certainly should not take up any other resources otherwise.
I want to quickly run through some of these very common comorbidities. Cardiac disease definitely associated with outcome, including the risk of early mortality after surgery. There are voluminous guidelines here. These guidelines published by the European Society, for example, is like 50 pages long. From my point of view, if someone does have a history of any significant cardiac disease, then I do think that they should have at least a visit to their usual cardiologist or a referral to a cardiologist for a specialist assessment preoperatively. Respiratory disease is very similar. If someone has a significant history of respiratory disease, they should be referred early. A special mention of sleep apnoea because that is very common in our society. The anaesthetists that I work with anyway routinely ask patients the STOPBANG questionnaire that is like 3 or 4 questions that basically assess their risk of having undiagnosed sleep apnoea because there is a real risk after having surgery if you have undiagnosed sleep apnoea. If there is a significant risk or the symptoms are very, very suggestive, then they should be referred to have a formal sleep assessment. Anaemia as we know, is very, very common that should be detected in routine blood tests pre-operatively. A low haemoglobin should prompt iron studies to be done and then a clinical assessment of the cause. Now, if there is any concern for the underlying cause of their anaemia, then I would refer, if necessary to investigate bleeding for example. If it is a benign cause, then iron supplementation perioperatively has been shown to reduce the requirement of transfusion postoperatively. We know that transfusion is associated with risk itself and also affects outcome of knee replacement. Diabetes again very, very common condition. Essentially there is an increased risk across the board of all of the possible complications that you can think of with knee replacement, infection, loosening, revision, etc. There is also an increase in dysfunction after having a knee replacement. There is a rationale then for improving the HbA1c, but there is no strong rationale for a specific cutoff. Unfortunately, we searched the literature on end. There is no good rationale for deciding on a specific cutoff. What should we use? Is it 7%? Is it 8%? There is no good longitudinal or prospective data that supports a specific cutoff. There is also the case for not restricting patients for surgery if they do have symptomatic, painful arthritis, for example, and you have done your best in optimising their diabetes for whatever they can get. The best thing to do is just to attempt to optimise it for them. That means if they are self-monitoring, if their diabetic complications are being appropriately dealt with, including by specialist referral, then they can also be candidates for surgery assuming they are aware of the increased risk.
I do want to focus on obesity because I do think that this is a major public health concern. When people think of obesity, we think about chronic diseases such as cancer and heart disease, but we forget that probably the first organ to be affected by obesity is the knee. The reason why we are seeing such a massive increase year-on-year of knee replacement rates is because obesity is becoming more and more common. As we know, a third of Australians are obese and another third or so are overweight. If you look at our joint replacement registry data, the majority of patients are overweight and obese. I think it is approximately 80% of knee replacement patients are overweight or obese. This is a major problem, especially when you consider that obesity is associated with an increased risk itself. Now, the current modus operandi of surgeons is just to go ahead and offer the surgery even if a patient is obese, sometimes even morbidly obese because we do know that you can have good gains in pain and function after the surgery, but you have to balance that with at least some sort of informed consent process telling them about their risk of these quite serious complications like deep infection and overall revision. There is a very good case then to optimise patients' weight prior to surgery if possible, so how do we do that. We know that managing patients' weight is very, very difficult, so what is the evidence in this space. The first thing that we can do is just get them to exercise a lot okay, and then even to offer the joint replacement to get rid of their pain in order for them to exercise. Now, unfortunately, that does not really work. We did that study and we measured patients weight before and after they had their joint replacement. Now, some people did lose some weight as indicated by the grey. Approximately the same proportion gained weight, but most did not have any significant changes at all. That is not really a good rationale when patients tell you, I cannot exercise or I cannot lose weight because I have got this problem, and doing the joint replacement itself is not really a solution to their weight problem. What are the other approaches that we have for weight loss before surgery? That can be diet based. It can be bariatric surgery or it can be these new kids on the block, the weight loss drugs, which have some very, very promising results. I just want to talk about very briefly some of the evidence in this space. Unfortunately, diet-based interventions are very lacking in terms of evidence. Some of the little evidence that we do have is from our own group. I have got a PhD student that is running this clinical trial of a low inflammatory, low calorie diet to improve patients' outcome after their knee replacement. There are some promising results with some people in the diet group losing a significant amount of weight and some people, in fact, withdrawing from having a joint replacement completely because of an improvement in their symptoms after losing enough weight because of their diet, but it is a pilot trial and we do need more robust data. We are submitting a grant, and I am pretty confident that grant will get in for a more robust trial assessing the role of a diet-based intervention to lose weight. What about bariatric surgery? This is a really important paper. I think everyone should look this up if you can because I think it has gone under the radar somewhat. This is a group in Melbourne led by Professor Peter Choong at St Vincent's, and they basically randomised patients to bariatric surgery before having a knee replacement or just going ahead, usual practice. They are just going ahead and straight on doing the knee replacement in these obese patients. Now there is a massive difference in complications after joint replacement in these two groups. Only 15% in the bariatric surgery group who did end up having a significant amount of weight loss, as you can imagine, after their bariatric surgery, but a 36% complication rate in the usual care group. Even more mind boggling was 30% of the bariatric group did not even end up having a knee replacement because their symptoms improved to such a significant margin versus only 5% in the usual group. Really important findings. I think this is one of the first, really the only trial that showed that. I think that needs to be replicated and I think these results are really, really important. They can be possibly addressed using drugs because these are the new, very promising treatments that we have to get people to lose weight successfully. We do know that there is very, very good clinical trial evidence for patients, for example, with diabetes, that show that they can successfully lose weight. There is not any clinical trial data, though in patients with symptomatic arthritis. Now, a grant round was recently offered specifically for those patients, we submitted a grant. Unfortunately, it was not successful, but the good news is another group was successful, so I expect there will be some clinical trial data in the context of knee arthritis using these drugs. That is a very, very promising space to watch.
Opioid dependency, brief mention of that. We do know that opioid use is very, very common with patients obviously in pain from their arthritis. The problem is being dependent on opioids also increases your risk of having complications after surgery. Now, there are quite detailed guidelines, again, including from the College of GP's about how to manage opioid use. We do know, though that a reduction in opioid use perioperatively will potentially reduce your risk of complications. We do have pilot data from our very own opioid HALT study that is being prepared for publication and has now just recently gotten $1.5 million in funding. Really, really good news, I think very excited about doing that trial. It is going to be a multicentre, randomised trial that is really going to address this question of reducing people using opioids prior to their surgery in order to improve their outcomes from knee replacement.
Smoking. I do not really want to dwell on that much. We all know how bad it is. I guess the only thing that I do want to mention is that smoking, it is not sufficient for us to just yell at them and say you have got to stop smoking and that's it. Okay, from this Cochrane review, there is a very strong suggestion that they need more help. They need help in terms of counselling, telephone services, pharmacotherapy as well as the usual advice that you give. It is not sufficient to just tell them to stop their smoking. You have just got to refer them to all of these extra services that they can they can have in order to stop the smoking. They will get a benefit if they stop at least a month before their surgery.
To summarise, Australia has relatively high access and rates of knee replacement surgery. You should consider an individual risk and benefit profile. There are plenty of international guidelines about how to manage a lot of these co-morbidities, but some of the more common ones are lacking in data and I think more evidence is needed for how we can target those interventions. There is some high level evidence already for prehabilitation and smoking and weight loss, as we have discussed. I think I might have just another minute or so just to talk about some of these gaps in the research. I think we should be doing more randomised trials. Everyone is aware of the evidence-based pyramid. This is all about producing evidence that demonstrates clinical effectiveness. What works, what does not, what is a waste of money, what should be done because it's cost effective? This is what clinical effectiveness research is all about. We have done a few studies already. Looking, for example, about the best ways to reduce the risk of getting VTE after knee replacement, comparing aspirin versus Clexane, for example, that was recently published in JAMA, the opioid HALT study I mentioned about getting the funding for this really interesting pharmacist-led intervention to reduce patients' opioid use prior to having their surgery. Our pilot RCT showed a massive reduction in opioid use using this pharmacist-based intervention, but also very promising that it showed a reduction in complications postoperatively, which is really, really interesting, so really interested to see if that pans out with the definitive trial. Optimise is about reducing weight. This is the diet-based intervention about losing weight. Again, we have got some MRFF funding, very promising. I think that will get the funding, and hopefully we will be able to generate some data. EPIK is a massive study that we have just submitted. Again, very hopeful that we will get the funding. Results come out next month, but hopefully we will get the funding, but basically it is just about looking at patients who struggle after having the knee replacement and then identifying them very, very early through an automated system through the joint replacement registry and then having a very targeted, coordinated pathway for these patients. They get a lot of extra TLC from their surgeons, physios, GP's, psychologists, whatever that patient needs in order to get them over the line and increase their function and satisfaction and outcome after their surgery.
Dr Tim Senior
Thank you very much. That was great. We have had a few questions come through, but we will move straight over to Dr Coffey for the second part and thank you very much indeed.
Dr Simon Coffey
Thanks. Well, I can just pretty much sign off. I do not really need to add anything more. What Sam has just done, he has done a great job at really demonstrating a wide spectrum of the issues that confront joint replacement and my brief this evening is to talk a little bit about hip replacement, but a lot of the themes are very similar, so I think there is some valuable time for some questions, hopefully, at the end and I will whip through, but really just to give a little bit of a modern perspective on hip replacement.
I am not so sure we are screen sharing yet. Just to run through a couple of things, the structure of this talk is really just to give a little bit of background about hip replacement, talk a little bit about demographics and outcomes in Australia, a little bit about the hardware and how we are doing it these days, and just a few comments on what the current technology is doing, where that is moving, but I think that Sam's point early on is absolutely 100% right. It is not about the technology, it is about getting our patients in some ways better prepared for surgery, but I think the key that will hopefully come through from further discussion is about patient engagement and making sure that patients are part of that journey because if they are not engaged with whatever strategies we put in place, they are not going to enjoy the benefits that might otherwise accrue. As you know, hip replacement has been around for a while. It was described some years ago by some prominent authors as the operation of the century, and probably the outcomes have been a little bit more consistent across the board than knee replacement, which has been, in some respects, a poor cousin of hip and knee replacement. However, it is not perfect. The early days show that there were issues with a number of things, fixation, biomaterials, longevity of the implant, the morbidity of the surgery and our great bugbear, the risks of infection and this is just you can see a timeline here of an older implant that was placed and you can see that there is evidence of wearing of the implant and then subsequently loosening of that device. There was a disruptor in the 60s, a guy by the name of Charnley from Northern England, who really changed the face of hip replacement and got remarkably good results for that time. During the following 40 years, there was still some issues, though, and those issues were really about long-term outcomes being compromised largely due to wear, in particular the younger and more active patients. There was a fairly significant degree of surgical morbidity. Infection rates were unacceptably high, as were dislocation rates, but in 2023, we are very fortunate, both as surgeons and patients, to have areas of improvement over that last little while. Improvements in biomaterials, improvements in surgical technique and by that I do not just mean the actual operation, I mean the preparation for surgery, the perioperative management. We have got better quality implants and we have got better quality fixation to the point where people are just talking about this joint becoming the forgotten joint, that is the joint replacement you have when you just do not feel its presence. The hip replacements last. They do. I will refer a fair bit to our data from the National Joint Replacement Registry. When I say here 93% success rate at 22 years, that is successful in that patient has not required a revision. It does not necessarily mean that they are perfect, but it does mean for many, many patients that the benefits of hip replacement result in improved mobility and less pain for thousands of patients each year. People have looked at this, what can we expect and over 50% of patients will feel that the joint just feels normal, but others will think, oh no, I can feel it, but it does not restrict me and then a better quarter of people find that there is some minor restriction, but generally they are very functional, so it is generally successful. Just a word about demographics. In Australia, the impact of COVID was to result in less procedures than we otherwise would have expected. You can see that the numbers of hip replacements, just a little bit less than those quoted by Sam in Australia. It is about 55,000 in Australia each year, compared to 70,000. What was notable that there was a significant reduction during COVID in public hospital admissions for hip replacement and you can understand why, there were widespread lockdowns. To some extent, the private sector took up the slack there. There was a fair bit of public work in the private hospital sector being done, but it is still largely in a catch-up mode that that public sector deficiency is still trying to be caught up due to really a blocked supply for about 12 months on and off. The good news is that revisions as a percentage of the total are diminishing. That means that what we are doing today is better than it was 20 years ago in terms of the need for revision surgery and that is a good thing in terms of cost containment for the community. How do outcomes vary with age? The most common age groups for hip replacement in Australia between 65 to 74 and 75 to 84. They are the two commonest, but you can see here there is a small number of patients over 85, but there is about 10% of patients who are under 55 having hip replacement surgery and then if you look at the outcomes for that, those patients who are under 55 have a slightly higher revision rate at 22 years, but remember, if you are 75, the likelihood of you being around for your revision 25 years later is a lot less, so yes, slightly higher revision rate if you are younger, but there are a number of complex reasons for that.
What about obesity? Sam talked really well about obesity and its effect. Well, what is its effect on longevity of your implant or at least your likelihood of revision in hip replacement? There is no question if you are obese, you have a higher risk of revision surgery than if you are not obese and actually that is part of that counselling process for patients. How we deal with it is very specific to the patient, the circumstance, the sector they are having their surgery in, the impact of other reversible causes of that obesity. In most cases, it is very difficult to shift the needle in a preparatory sense, but it does open up that window of opportunity for further work to be done to see whether we can affect outcomes, and reduce obesity levels before patients actually get to surgery. Again, it is not surprising that the sicker you are, more comorbidities, the more likely you are to have complications resulting in revision surgery and a lot of marketing hype has gone into which approach is best over the last 15-20 years. The most common approaches when we do hip replacement are direct anterior, lateral and posterior approach and the direct anterior has probably grown the most in the last 10 or 15 years. What is the evidence around which one is better? It is just to make a point. The direct interior approach has some proposed benefits of being muscle sparing and apparently a quicker early recovery, and it offers a slightly lower dislocation rate. There are some disadvantages. It has a higher learning curve. It actually is demonstrated to have a slightly higher infection and fracture rate. You cannot access the associated gluteal musculature if you need to do a repair at the same time, and so not every patient is suitable for a direct anterior approach. On the other hand, the posterior approach has proposed benefits are very utilitarian. It is suitable for all patients, preserves gluteal musculature, it is an extensile approach. You can access the gluteal musculature for repair if needed and certainly modern techniques speed recovery, but its disadvantage is that there are slightly higher dislocation rates associated with that approach. What effect does the surgical approach have on revision rate? It is slightly in age, gender, body mass index and ASA adjusted figures. There is a slightly lower revision rate for the posterior approach, so you can make of that what you will. As Sam alluded to broad-based improvement in outcomes from pre-op to postop across the board, most people, most surgeons, most patients will experience significant improvements in function and pain after a successful hip replacement. How did we get to this situation where we have got better outcomes, improving outcomes for our patients? Well, it is because we have got better biomaterials, better fixation, better perioperative management, including surgical technique and enhanced recovery after surgery protocols that our anaesthetic colleagues have been instrumental in being part of. However, there are ongoing challenges and Sam alluded to some of these. Infection is our biggest concern. Dislocation and fracture are also concerns. It is worth making the point. I will make it again. Modern hip replacements rarely wear out. The materials we are using are a significant improvement on what we were using 20 years ago and so we are seeing that reflected in a diminishing rate of revision for wear. The reasons for revision predominantly are infection, fracture and dislocation. How many people get infected? It is a little bit difficult to estimate, but it is probably an incidence of around 1-2%. Sometimes it is quite hard to diagnose, sometimes it is very obvious, but infections account for 30% of revisions of hip replacements in Australia, and this is a major burden for patients, the healthcare systems and our treatment teams. Just so you are aware that a diagnosis of periprosthetic sepsis is not a benign condition. If you look at cancer survivorship rates, five-year survivorship for prostate cancer around 99%, breast cancer around 90%. If you get a periprosthetic deep joint infection, your five-year survivorship is around about 87%. This is not a benign condition. That translates to about an 8% mortality at one year compared to, say, a 3% mortality if you have had a joint replacement, if you have not had any infection, so managing the patient to avoid infection is really our number one, two and three concern.
What are the risk factors? Again, Sam alluded to this, if you are an overweight diabetic, you are a higher risk patient, and that is part of that informed consent process. It is very important that patients understand. Again, it was alluded to earlier. If you have a transfusion or you stay longer in hospital or you have psychiatric illness or you are male, you have a slightly higher risk of infection. Some of those are non-modifiable risk factors, but some of it is about optimisation of the modifiable risk factors before we go forward with surgery. Again, I will not dwell on optimisation. Sam has really dealt with that. It is very easy to say. It is very difficult to do all of these things and this is really the challenge of our patient preparation process, and to be honest, I think it is so multifactorial, it is such a challenge, the patient sitting in front of you in pain, asking for a solution and some of these things we can address reasonably well, but some of them are much harder to do so, and I certainly congratulate Sam and the team for doing more work, at least in terms of recognition and if we can shift the needle on that, that is going to be a great outcome. There is risk with fractures in the elderly and the osteoporotic patients and women are more at risk of this than men because their rate of osteoporosis is higher and there are a number of other risk factors, including the use of cementless implants and the specific approach that is undertaken. There are some modifications that can be made for individual patients. Hip dislocation is something that is feared by most patients and surgeons. We do a lot of work to try and minimise that risk. Prosthesis selection can affect the outcome there, but so can surgical technique and recognition of the patient who is at higher risk of a postoperative dislocation. We do some things to make those risks a little less, but that risk cannot be made zero. Most of the literature would suggest in a modern effective joint replacement practice, the risk of dislocation is somewhere around 1- 2%. You will see figures quoted up to 10% in the world's literature, which I think, that is an unacceptable level.
I know we are conscious of time, so I am just running through this reasonably quickly, but probably what has changed a little bit in terms of how we plan surgery in 2023 is that the awareness of the intimate relationship between the spine and the hip is becoming very topical at the moment. What we know is that the pelvis moves unpredictably with spinal disease, so it can flex or extend as the spine degenerates, and having some knowledge of which way that spine-pelvis relationship is going before the surgery is, we think, probably helpful. We are trying to recognise by doing some investigations, recognise high-risk individuals and make some plans for optimal alignment or common positions, so deep seated position, standing in an erect posture, and then to use a delivery system to match the plan. Example of a patient who is requiring hip replacement, you see this joint space loss. We do some analysis with CT and x-rays and do a dynamic sit-to-stand analysis with some CT. We combine that with some imaging of the spine, looking at positions of deep flexion and positions of full extension when standing, and that allows us to generate some software that allows us to try to optimise positioning of the implant based on predictive movements of the spine and the pelvis at the same time, and then we have a delivery system to put that in place. That is really just a brief snapshot of what the technology or what the current conversations we are having around trying to deliver better outcomes in terms of reducing dislocation rates.
This comes to a little bit of discussion around the differential diagnosis for hip arthritis and not everyone who says they have got hip pain has hip arthritis and every patient that we see, we consider for the differentials and then it is certainly referred pain from the spine, including radiculopathy or just simply facet joint referred pain needs to be excluded as a source of hip pain. Gluteal muscle dysfunction is extremely common in the community, particularly more common in women. It is otherwise known as trochanteric bursitis, but it is a much more complicated condition than that, and it is usually associated with gluteal tendinopathy or tendon tears and it can be isolated or coexistent with hip arthritis and does need to be considered. Other conditions around the hip, including ischial bursitis, can be troublesome, and of course, there can be abdominal causes for hip pain, so be aware of those other differentials the patients can be presenting with rather than just simply an arthritic hip.
As Sam alluded to this, how do we start the management? Well, firstly it is about patient education and having them understand what the process is, how it might develop, whether they are disabled with it or not, and whether they in fact need simple analgesia or not, and again, we would like to avoid the use of narcotics for all of the reasons which we talked about earlier, dependency and then subsequently poorer outcomes when surgery is undertaken. Initial management might be to unload the hip with a stick or other walking aid if the symptoms are relatively temporary. Once the osteoarthritis is established, the role of physiotherapy is limited. It is not zero, but it is limited. It is really a process that does continue and the natural history is for progression. We do advise the patients to modify their activity by avoiding the provocative manoeuvres such as impact loading, running, excessive movement, but we do encourage load bearing, but light load bearing exercise if at all possible. When should patients consider hip replacement? When they have got advanced arthritis radiographically, it helps. Sometimes an MRI is necessary if the radiographic changes are not so obvious and that arthritis is causing hip pain with moderate disability I talk to the patients about. The indications for surgery is when they cannot do the things that they need to do as part of a regular day-to-day lifestyle. They might be needing regular analgesia. They might be getting nocturnal pain disturbing their sleep, but they have lost their independence and that is really when joint replacement is a reasonable thing and it is important to understand that sometimes there is a natural history that is more improvement, particularly in early arthritic changes, there can be a sudden shock to patient, oh, I have got arthritis. I need to have some treatment. Sometimes it is a little bit about counselling, about what their current symptoms are, what their limitations are, and help them understand that this maybe not the end of their hip, and that they can keep working with it for some time until their symptoms become worse or more disabling. Just to summarise, hip replacements, in this day and age, it has got generally excellent outcomes and we are very lucky to have great technology and improved techniques. However, the risks remain. They are not zero infection, dislocation and fracture. They are relatively rare, but when they happen, they are a major source of morbidity and occasionally mortality, so it is important for us to try to optimise our patient profile before they get to even see their surgeon, but even once they have seen the surgeon, we try to modify those modifiable risk factors in the patient's favour, and then we have some newer technology, which is focused on trying to optimise implant alignment and hopefully reduce some of those other issues of complications such as dislocation and fracture.
Thanks very much for your attention. I do appreciate the opportunity to discuss things with you, and I would really encourage some questions if we have any. It would be a great opportunity to do so. Thanks, Tim.
Dr Tim Senior
Thank you very much. That was really good. We do have a few minutes for questions. Thanks to Sam as well, who has been answering some of them writing and some themes come through in the questions. One of them you touched on briefly there about the types of exercises that we can recommend to patients, both for preoperative preparation and also for postop recovery if we should just let physios advise or if there is any specific advice that we can give?
Dr Simon Coffey
I hesitate to call it exercise because there is a lot of fear about I am going to make my pain worse. It already hurts. I will do exercise, it will make it worse. I like to frame it in terms of activity and trying to maintain mobility and try and take the fear factor away from the pain, and that can be challenging, especially if sometimes the pain absolutely justifies getting on and going ahead with surgery, but low impact activity is a good thing. A lot of the hospitals now have pre-admission process where you will be introduced into a programme of physical therapy or sometimes hydrotherapy, it gives the patients something to focus on as part of that process. What it really does, it encourages engagement and the engaged patient will do better than if they are just here. Here is your admission form, we will see you in a year type of thing that tends to not be very effective pre-operative preparation, so engagement with the patient, educating them around the natural history of the condition, what they might expect, what analgesia options are available to them that are not going to cause them unfortunate side effects, and then having the capacity to ramp up their level of urgency if it really is needed.
Dr Tim Senior
Thank you. We have had some really helpful comments from a couple of people putting in links to exercise programmes as well for patients and I think some mentioned one that you also give out as well, which I think will be available for participants as well after the webinar if people want. I have certainly fallen into that trap myself as well, talking about exercise and people think about it as doing gym work and running and things, but actually talking about gentle stretches and activity I think can be really helpful as well, and people have said how difficult they find it, and I certainly find that adapting ways that the patient are going to enjoy and be able to do, so that doing activity in a way that fits into their routine and is fun, is much more likely to get done than saying you need to do this specific.
Dr Simon Coffey
I 100% agree. It has got to be something that the patient will do and even physiotherapy has to be something that the patient is engaged with the programme rather than going and getting treatment with an ultrasound or massage for a session a week or a fortnight, that is largely ineffective.
Dr Tim Senior
We have probably got time for one more question. The people are very interested in those trials and all the evidence that you are taking part in. They are hospital-based trials. Do we have prospective referring patients in to participate in any of those trials?
Dr Simon Coffey
Question to Sam.
Assistant Professor Sam Adie
Yeah, I answered that. Unfortunately, they are not the sort of trials that you can refer to. I am aware of a lot of trials that are like that, but they are very much hospital-based, so they are run at the centres that we recruit from, so unless your patient is getting treatment at that centre, you cannot really refer to them.
Dr Tim Senior
We love having that evidence base about what is going to work for our patients to get them better outcomes, so that is very much appreciated. We are just coming towards the end of our time now. Thank you very much both of you for those presentations. These are our learning objectives, again, so if you look through those hopefully we have achieved all of those and we can all do that. Thank you very much for your time. Jennifer will wrap us up and I think we will have the evaluation questionnaire when we close.
Jennifer
Amazing. Thank you so much, Tim, and I would also like to extend my thanks to Simon and Sam for presenting this evening and I also wanted to thank everyone who has joined us online and sending through all of your questions. We do hope that you enjoyed the session. That brings us to the end of the session. Thank you everyone and enjoy the rest of your night.
Dr Tim Senior
Thank you very much, everyone. Good night.