Selecting and Optimising Patients for Knee Replacement

In this episode of PodMD, Orthopaedic Surgeon and Associate Professor Sam Adie will be discussing the topic of selecting and optimising patients for knee replacement surgery, including how to select the right patient, how a GP can help in optimisation, when a GP should refer and more.

  • Transcript
    Please note this is a machine generated transcription and may contain some errors.
    *As always, all in this PODMD podcast is intended for health professionals and the comments are of a general nature. Information given is not intended as specific medical advice pertaining to any given patient. If you have a clinical issue with one of your patients please seek appropriate advice from a colleague with expertise in the area.

    Today I’d like to welcome to the PodMd studio Associate Professor Sam Adie

    Assoc/Prof Adie is an Orthopaedic Surgeon located in Sydney. He specialises in surgery of the hip and knee, including total hip and knee replacement, and arthroscopic (keyhole) knee surgery.

    Today, we’ll be discussing the selecting and optimising patients for knee replacement

    *We do hope you enjoy this podcast but please remember that the advice here is of a general nature and is not intended as specific advice about a given patient. The views and opinions expressed in this podcast are those of the doctor, not PodMD.
    If you do have a patient on whom you require specific advice, then please seek advice from a colleague with appropriate expertise in that area.

    Sam, thanks for talking with us on Pod MD today.

    Sam: Thank you very much for having me today

    Question 1
    First off can you give us a quick explanation on what a knee replacement will entail?

    Sam: So, a knee replacement is essentially an operation for people with end-stage arthritis of the knee. So that’s where they’ve completely lost all of the cartilage linings of the joint. And a lot of the time the disease is advanced enough for there to be articulation of essentially bone on bone. So, when you get to that stage, uh, obviously the symptoms can be quite severe, uh, particularly in terms of pain and stiffness, and that can have far reaching effects on people’s daily activities and their, uh, function. Um, so what a knee replacement does is it essentially resurfaces those diseased areas of the bone that have all worn out with a prosthetic, um, and the boney, um, uh, uh, areas are replaced with a metal prosthesis and between the two, uh, metal prosthesis, um, which go on to the ends of the tibia and the femur.

    Uh, you have a really high-grade plastic called the polyethylene, and that tends to take the weight that that patient puts on the prosthetic knee on a day-to-day basis.And the results of that, um, sort of constant, uh, you know, uh, pressure and weight through, uh, actually, uh, quite good in the long-term. So now we’ve got results from, uh, our Australian joint replacement registry that shows that, uh, knee replacements are lasting for quite a long time for, um, you know, in about 95% of patients, uh, at the 20-year Mark, uh, not having, uh, needed a revision. So, uh, they do tend to last for quite a while. Um, so the knee replacement, as you can imagine, uh, is although a very successful surgery is quite challenging technically, um, and it’s also a major surgery, so it will require obviously an aesthetic and quite a prolonged recovery time, usually between six and 12 months.

    Question 2
    So, how do you go about selecting the right patient for a knee replacement?

    Sam: It’s really the same sorts of signs and symptoms in the older patients in the first one is largely pain. And this is where it’s essential to get an x-ray and just not assume it’s a soft tissue problem and go straight to a, an MRI as you will often pick up the problem just with an x-ray and a physical examination.

    Question 3
    Is there any subcategory of patients that a knee replacement wouldn’t suit??

    Sam: Again, Sean, this is quite a loaded question. So, um, we actually did a review on this that was published last year in the medical journal of Australia, where we explored all of these different, um, uh, characteristics that may influence, uh, patient outcomes after a knee replacement. And what we’re trying to focus on is, are there any interventions that we can offer to patients with these sorts of pathologies or co-morbidities that will eventually improve their outcomes after total knee replacement? Um, now we were quite surprised to find that there was actually quite a poor city of evidence when it comes to a lot of really, really common co-morbidities.

    I mean, think about diabetes, for example, such a common disease in the community, but what we don’t have at the moment is anything that might optimize them around the time of the surgery that might sort of modify or reduce their risk of having a bad outcome after a total knee replacement. Um, so, uh, there are some things though, and this is what I do want to focus on that we did find in that review that would clearly, I think, do have evidence for them. Um, so there are things, for example, uh, like, uh, optimizing patient expectations and outcome.

    Now the exact method of how to do that. There’s, you know, that we don’t actually know at the moment, but we do know that at the very least there needs to be a discussion, um, in terms of shared decision making with the patient about what to expect, uh, from their surgery and their recovery afterwards, um, because there has been numerous studies that have shown that, um, you know, incorrect, uh, patient expectations before the surgery do affect satisfaction rates and function after they have a knee replacement. Um, the other things are, uh, things that are, you know, can be quite obvious.

    Question 4
    How can a GP help in this optimisation??

    Sam: I see the GP as being really, uh, critical, um, figure in, uh, helping the patient through this journey. Uh, I see them as, um, being, uh, the center of, um, you know, coordinating referrals to specialists as needed, uh, as well as referral to other allied health professionals, for example. And I think it’s also important that the GPS, um, and the, and the orthopedic surgeons, um, communicate well about the patient’s current state and their co-morbidities. Um, I also think it’s important that, uh, GPS also guide patients both before surgery in that shared decision-making process about what to expect from their surgery, um, and also guide them through their rehabilitation afterwards, uh, and what to expect from that.

    Um, but I do think it’s important for GPS be aware that they can refer, uh, patients, uh, for management in multidisciplinary teams. And these are available in most States around Australia, um, in new South Wales, for example, we do have the osteoarthritis clinical care program that is offered through the public system and in our own private practice, we have a multidisciplinary team of physiotherapists, um, sports and exercise physicians, as well as of course, orthopedic surgeons that can also, um, guide patients through, uh, their, um, their treatment journey

    Question 5
    If a patient is not suited to a knee replacement, what are their alternatives?

    Sam: There are always as you know, alternatives to having surgery. Um, the key, uh, um, evidence-based, non-operative approaches to management of arthritis are first of all, exercise and physiotherapy. Um, so think about the knee as a joint that is really made for motion. So whenever patients stop using that joint, uh, then the symptoms can get worse. So, uh, any activity, any, um, exercise is going to be quite healthy for the knee, obviously that needs to be tailored. And, uh, the patient needs to be guided as to the correct exercises to do, um, by a professional, but that has a lot of strong evidence to show that, uh, patients, even patients with quite severe arthritis can improve their symptoms. It will never reverse the arthritis as in, it will never make their x-rays look better. It can never, you know, improve the state of their cartilage for example.

    Um, but it does improve their symptoms. Uh, the other thing to do is weight loss, and we know that, uh, particularly with knee replacement, uh, that we are seeing really almost, uh, like an epidemic of knee replacements because, uh, of, uh, of the increased prevalence of overweight and obesity. And in fact about two thirds of knee replacements that have been done now are in patients that are obese or patients that have a BMI of more than 30. Uh, so we do know that reducing weight also, um, makes people, uh, opt out of having surgery, even if they’ve considered it previously. So even weight loss as little as 5% will affect, uh, their joint symptoms. Uh, so that, that is something that we’re doing a lot of work on at the moment, in terms of trying to find what the, um, you know, the optimal, uh, style of weight loss for patients with arthritis that are waiting for joint replacement surgery.

    Uh, and again, there’s lots of help out there for that, that there’s dieticians as MTT, you know, uh, teams that, um, uh, can manage that, um, sort of a patient on their weight loss journey. Um, the other are, you know, um, I guess simple things, but important things. So, uh, optimizing their pain relief, for example, uh, there’s lots of, uh, medications that can be used. And it’s just about trial and error about what works for the patient, uh, using a walking aid now in my experience, patients are not really keen on using a walking aid, but that does have an effect, um, uh, considering some intra articular injections. Again, these are not going to reverse or improve their pathology, but they do provide a temporary relief of their symptoms so that the patient can then participate in the things that matter. So think weight loss, and exercise once their symptoms settle after an injection

    Question 6
    When should a GP refer?

    Sam: So I think, um, if a patient presents with symptomatic, uh, advanced, uh, osteoarthritis, the GP should refer early, um, and that is really, um, uh, uh, done just by ordering a weight bearing x-ray, uh, as well as asking the patient about their joint symptoms. And if it appears that those symptoms are significant enough to affect their daily function. And if the, uh, you know, if you prefer, you can also do just to a bedside function scores such as a knee society score or an Oxford score. And that can also give you quite an objective measure about where this patient is symptomatically. Uh, if the patient has symptoms and they’ve got arthritis on an x-ray, then I would suggest that the patient should be referred, uh, early, because there is a lot of help out there. As I mentioned earlier, there’s MDT teams that can manage the patient’s eye Thrivers, and then also guide them on their surgical journey if there are candidates for a total knee replacement

    Concluding Question
    Thank you for your time here today in the PodMD studio. To sum up for us, could you please identify the three key take home messages from today’s podcast on the selection and optimising patients for knee replacement.

    Sam: So, I guess my take home message.
    One is a knee replacement is very, very common and it is getting, uh, more prevalent. And in fact, if you project things into the future about one in five of us is going to have a knee replacement. So, this is a really common surgery and, uh, quite a costly, um, uh, burden on our society when you think about it. So, it’s important that we get it right. Um,
    Secondly, uh, we do know that there are, um, a bunch of patient characteristics and co-morbidities that are associated with, uh, patient outcomes after they have a total knee replacement. And, um, I would suggest that, um, uh, uh, the people listening to the podcast look up the review that we actually published in this area, um, because it is, uh, quite, um, a good summary of all of those issues that I only really briefly sort of covered in this podcast. Um, and
    Thirdly, there are some things that can be optimized when it comes to those, uh, characteristics and co-morbidities, and I think the GP really plays a central role in that

    Thanks for your time and the insights you’ve provided.

    Sam: Thank you for having me

*As always, all in this PODMD podcast is intended for health professionals and the comments are of a general nature. Information given is not intended as specific medical advice pertaining to any given patient. If you have a clinical issue with one of your patients please seek appropriate advice from a colleague with expertise in the area.