Hip and knee surgery webinar transcript

Louise King

Good evening everyone, I hope you're well and welcome to our webinar on hip and knee replacements. My name is Louise and I’m your host. Our expert presenters are Mr Alex Chipperfield and Mr Matthew Oliver, our experienced Consultant Orthopaedic Surgeons at Benenden Hospital.

The presentation will be followed by a Q&A session. If you'd like to ask a question during the presentation for later on, then you can use the Q&A icon at the bottom of the screen. You can do this with or without giving your name. If you'd like to book an initial consultation following this session, our Private Patient sales team will be available until 9pm this evening and we'll be able to provide you the phone number at the end of the session.

And just to let you know this webinar is being recorded. However other attendees won't know you're taking part unless you choose to give your name during the current session.

I’ll now hand over to Mr Chipperfield and you'll hear from me again shortly.

Mr Alex Chipperfield

Thank you very much. Good evening everyone, thank you for coming along this evening. Welcome to our talk about hip and knee replacements.

My name is Alex Chipperfield I’m one of the Orthopaedic Surgeons here at Benenden.

A little bit of background. I studied medicine at Bart’s in London and qualified as a doctor in 1997. I trained around the south east of England and then, in 2009, I went on a lower limb reconstruction fellowship in Sydney, Australia.

Once I’d finished that, I came back to Kent and took up a job as a Consultant hip and knee Surgeon in east Kent, where I’ve been for the last 11 years. I’ve been a member of the Benenden Orthopaedic Consortium since we started providing a hip and knee replacement service here in 2012.

To the right of your screen there you'll see this is my page from the National Joint Registry website. I appreciate the letters are a bit small but what you can see on the pie chart there is that around half of my time I replace people's hips, and half of my time replace people's knees. I perform about 150 hip replacements and 150 knee replacements per year.

A little bit about Benenden Hospital itself. It was first opened in 1907 as a sanatorium for postal workers and, if you come along here, you'll see why: beautiful views and lots of fresh air around.

The Benenden Healthcare Society was formed around 50 or 60 years ago – 70 now - and then there was a major expansion in 2017. You can see a picture of the main entrance following the complete refurbishment of the hospital, which has left us with big, open airy spaces, state-of-the-art operating theatres and very nice pleasant wards.

It's now a Centre of Excellence for orthopaedic surgery and we perform around 900 joint replacements here every year.

Brief background on hip and knee replacement surgery. These are figures from 2019. Obviously 2020 and this year have been slightly disrupted!

Hip and knee replacements are common. Around 100,000 of each are performed in the UK every year. Generally, we tend to operate on slightly more women than men and you tend to be approaching 70 years when you have your joint replacement.

So I’m mainly going to focus on hip replacements today and the way I’ve structured my talk is (I could talk all day about hips) so what I’m going to do instead is answer some of the most frequently asked questions that I get when I see people in clinic about hip replacements.

Number one, the first commonest question I get asked, is: do I need a hip replacement? And ultimately the answer to that is “Well you tell me!”

Hip arthritis causes pain; that's the number one reason to have a hip replacement. That pain tends to be typically localised in the front of the hip, in the groin - although it can radiate to the thigh and around the back into the buttock. The pain can also travel down the leg and into the knee - and probably about once a month I will see someone who exclusively has knee pain who ends up with hip pathology and needing a hip replacement.

Now pain. In order to have a hip replacement, this needs to be pain that you can't control by any other means. So, it's when painkillers either don't work or stop working or disagree with you, or when you've tried stronger and stronger painkillers and injections and therapy - and despite all this you're struggling with the pain.

Alongside the pain, you can get other problems as well. Commonly stiffness and - typically with an arthritic hip - what we talk about is difficulty getting down to tie your shoes and socks or cut your toenails. That can also be a struggle.

Arthritic, worn-out hips can often give way as well. You no longer trust your hip, it feels unstable, you tend to lose function and that's quite easy to measure, so you can talk about how far people can walk before they have to stop - and also how often your sleep can be disturbed because of pain when you roll over in bed at night.

So, all of these things together combine to talk about the quality of life and the choice as to whether or not you have a hip replacement really depends on the effect that that worn-out hip is having on your quality of life.

Next commonest question is: what is a hip replacement made of? Hip replacements are generally made of four components.

It's a ball and a socket joint, and there are two parts to each. This here is a socket, so this has a metal semi-circular back and then the lining inside that socket. You then have a ball here and the ball sits on the metal stem. So, you tend to have a metal stem and a metal socket and the two click together to give you your moving hip replacement.

As I’ve said, the main components - the stem and the shell - are made of metal. The variability, the customisation, you tend to get in hip replacements is what you make the ball of and what you make the lining of.

These two are pink; they are a ceramic-bearing surface which is an incredibly hard wearing and long-lasting surface. Typically, we can use ceramics or metals or plastics or any combination of those to tailor the right kind of performance hip replacement to the patient in general.

The next thing people ask is: how are they fixed into the body? And that really depends on the quality of the bone that you're trying to implant the hip replacement into. As I’ve said, we tend to perform most hip replacements on ladies who are approaching their 70s and they can be people who suffer with weakness of the bone, or osteoporosis. So often - in order to enhance the fixation or reinforce the fixation of the implants into the bone - we use what's called a bone cement, which is an epoxy resin which acts as an interface between the bone and the metal.

In younger, stronger people we tend not to use cement. We use an uncemented implant, which typically is coated with chemicals that allows the bone to actually grow into the implant itself and make it solid.

The lifespan of a hip replacement really depends on what you do with it and how much force you put through it, but a modern hip replacement using modern materials and put in properly will last you for decades.

Next question tends to be: how long will I be in hospital for?

Your hospital journey is made up of several different steps. Typically, the first part of your journey will be an outpatient appointment. So, you will be referred up to Benenden Hospital, via your GP, and you'll meet myself - or someone like me – to talk about your problems in more detail.

From that consultation, we'll be able to take a history and look at your medical problems. I’ll also get a chance to examine your hip and the muscles and legs around it and see how everything's working. We'll also be able to investigate you with x-rays and scans. With that picture putting all those components together, we can come to a decision as to whether or not a hip replacement is the right thing for you.

If we decide to proceed with surgery, you'll then have another outpatient appointment later on, and that's called a pre-assessment appointment. In that appointment you'll discuss the anaesthetic with the anaesthetist, and you'll see that the nurses and the physios and the therapists who'll go through everything in great detail about what happens before, during and after your operation.

The hospital stay. Well, you’ll get admitted to the hospital on the day of the surgery, the operation itself will take place later on that day and, depending on the time of the operation, we try to get you up and about - fully weight bearing - on the day of the operation. If you're walking on your new hip or new knee on day zero, then that fills you with confidence for the next day that everything is strong and solid - and we get you up and get you going very quickly.

We send you home when it's safe to do so. Now, safety means lots of different things to different people. From my perspective, I need to make sure that you're medically fit. I need to make sure that I’ve seen your x-rays and I’m pleased with them, that your blood tests are okay and that your wound looks okay. From a therapist point of view, and from the nursing point of view, we need to be sure that your pain is under control and that your general mobility is to such a level that you're able to cope and look after yourself once you leave the hospital environment.

The length of stay in hospital is surprisingly brief. Typically, my patients - following a hip replacement - will go home two days later. Sometimes you stay an extra night, but it tends to be two nights in hospital.

With hip replacement surgery, we put some precautions on you in the early stages; a list of do's and don'ts while everything is knitting together and healing up. And those precautions tend to last for around six weeks.

Leading on from that, the next questions I get asked are: when can I do such and such? Here I’ve got the top eight things and people ask when they can do it. It's not in any particular order of popularity, by the way!

So, I’ll just go through these here. So, when can you walk? Well we've already said as long as your legs are awake from the anaesthetic, you'll be walking on the day of the surgery. I think that's very important.

Driving, there's no hard and fast rules as to when you can drive following a hip replacement. There are basically those three elements to it:

Firstly, you need to be able to drive a car without being under the influence of any mind-altering drugs, so strong painkillers - that kind of thing. Obviously, you can't mix that with driving.

The second thing is that you need to be able to get in and out of the car safely, so squeezing yourself into a two-seater sports car may take you longer than climbing into a normal SUV.

The third thing is that you need to be able to control the vehicle when you're in it. And that depends on which leg you've had operated. If you've had your right hip replaced, well that's the one that you need to apply the brakes and to drive the car - so you shouldn't be driving until you can safely stamp on the brakes and perform an emergency stop. With your left leg, if you have an automatic car then that left leg won't be doing very much at all. So really that's when - as long as you can sit in the car safely - then you can drive.

Typically, it tends to be somewhere between four and eight weeks when people get back behind the wheel, but that varies from person to person.

Riding a bike with a hip replacement? I replace a lot of cyclists’ hips and I see no reason why people can't get back cycling afterwards. It's not the movement of cycling that concerns me, it's the potential for causing damage if you fall off in the early stages if you're not quite as confident on your bike.

So, what I tend to suggest is that if you have a stationary bike or an indoor bike, then you can get back onto that within around three or four weeks following the operation. Outside, providing the weather is good, I tend to be a little bit more cautious and say around two to three months before you can do that.

Skiing - we have a lot of a lot of patients that like to get back to skiing following a hip replacement. Again, I have no objections to skiing - it's falling over that's the problem. So again, you need to be confident and you need to have the strength and musculature around it to be able to support yourself properly. Generally, I tell people to skip a season and then ski the next year.

Playing golf. Golfing in itself is an occupation that lots of people of joint replacement age do and people get back to it very quickly. Generally, what I tend to say is around about six weeks before you start on a practice screen, hitting a few putts or onto the driving range. If you are going to be playing, maybe start on a par three course or nine holes. The walking distance can get you more than the actual golf itself, so I do suggest maybe using a buggy for the first few times that you're back playing golf.

Sex again really depends on the position that you that you choose. Generally, I advise to play it safe and not put yourself in any awkward positions that could put extra stress through your hip - and generally it's something to be avoided for the first six weeks following surgery.

Travelling: lots of people travel many miles to Benenden to have their surgery and so there's nothing wrong with getting in a car at two or three days to be driven home again. We do suggest that you take a break every hour or so to stretch your legs and have a cup of coffee or tea but certainly, unlimited driving as a passenger - as long as you're sensible.

Most people tend to ask more about air travel. Hopefully one day we'll be able to get back to that! The way things are at the moment, the real risk with air travel is a risk of developing blood clots. Blood clots are a risk that are present following surgery and the risk is higher the closer to the operation that you are.

So, what we tend to recommend is that you don't travel by air for the first six weeks following a joint replacement. Between six weeks and three months we suggest that you stick to short-haul flights (so four hours or less only) and on those flights make sure that you are well hydrated - not with alcohol unfortunately - and that you get up and walk around every hour or so in the cabin. Long-haul flights - so four hours or more – I recommend three months before you do that.

Getting back to work. Recovering from a major operation like a joint replacement is something that you need time to do and you need to be able to go at your own pace to do it. What you don't want to be is be under pressure from a work environment to get back. If you try and force yourself back too soon you may run into trouble.

So, I recommend that, from the outset, you tell work that you're not going to be there for three months. If by two, two and a half months, you're feeling that you're good to go and happy to get back sooner, then that's always a nice surprise for work, rather than it being the other way around and if you're feeling you're being put under too much pressure.

What could go wrong? Again, I could talk all day about what could possibly happen during a hip replacement. There are risks associated with any kind of surgery like this - and these risks are rare, but they are real and sometimes they can be serious.

Planned hip replacement or knee replacement surgery in an environment like Benenden is an extremely safe thing to go through and we do everything that we can to mitigate any risks. If people do develop problems then we do our best to make things right as quickly as possible, but in real life sometimes bad things happen.

So, the kind of things that can happen in a hip replacement is you could lose blood, needing a blood transfusion. That's quite rare these days. About 1 in 50 people might need a blood transfusion.

Blood clots. I’ve already mentioned blood clots in relation to air travel and there's a significant risk of developing a blood clot either in your leg or in your lungs. And everything that we do in the perioperative period really is tailored to minimising the risk of blood clots.

Any wound can get infected and infection, again, is something that terrifies orthopaedic surgeons and we do everything that we can. You see there's a picture of me operating there performing a hip replacement wearing a space suit. And that is for your protection, rather than mine, to ensure that everything is as clean and sterile as possible when you're having the surgery.

Hip replacements can dislocate, they can pop out of the joint. That's a particular risk in the early stages following a hip replacement, and that's why there are certain precautions that I mentioned before. We like you to just take things easy for the first six weeks ago or so while the soft tissues and muscles are settling down around the hip.

Having a joint replacement surgery like this can alter your leg length. Again, with a planned operation that's properly thought out and properly performed, this is generally a low risk, but it can happen. You can have broken bones and you can have damage to nerves and blood vessels as well.

The other risk with the hip replacement is that an artificial joint can eventually wear out or work its way loose towards the end of its life. And that may require further surgery later down the line.

All in all, though, despite all those bad things hip replacements - joint replacements in general - are fantastic operations that have a huge benefit on your quality of life.

This is a slide that I stole from a colleague of mine. They're looking at the top ten interventions that you can have that have the biggest, longest-lasting difference to your quality of life. And - right at the top, the biggest part of that nice big blue chunk there - is reconstructive orthopaedic surgery; hip and knee replacement. A genuinely life-changing operation and overwhelmingly in a good way.

If you're undecided about whether or not to still proceed with hip replacement or knee replacement, then I recommend that you look at this website. This is jointcalc.shef.ac.uk. Sorry it's a bit of a mouthful. This is a website that is produced by the National Joint Registry. This allows you to log onto this website and you enter your individual details - so all about your symptoms, your general medical health and the surgery that you're thinking about having done - and this will tailor and quantify the risks and benefits of that procedure for you.

And patients have told me it's a very useful tool; you get a visual idea of how much better you will be following your surgery and a real idea of the potential risks and benefits. Obviously, I can only really talk in general terms about these things, but this will give you a very clear idea, personalised to you and I recommend taking a look at that if you're thinking about a joint replacement operation.

Right, I think that's enough of me for the time being. Now I’m going to hand you over to my colleague Matt Oliver who's going to talk to you about knee replacements and then I’ll see you back at the end for the Q&A session.

Mr Matt Oliver

Good evening everyone, thank you very much Alex for that excellent talk and thank you to Benenden for inviting us to perform this webinar for everyone.

I’m going to talk about total knee replacements and osteoarthritis of the knee. So, without any further ado, next slide please Alex.

So, a little bit about myself and I qualified from St George's Hospital Medical School in 1998 and completed all my surgical exams by 2009. And then, like Alex, I went abroad to the University of Calgary in 2009 for a year-long adult joint reconstruction fellowship.

Then on my return I was appointed to East Kent Hospitals as an NHS consultant with a primary interest in hip and knee surgery.

So, my talk has four parts to it. I’m going to set the scene, giving you some facts and figures about knee replacements, osteoarthritis of the knee. I’m going to talk to you about the referral process and then a little bit more detail about the different treatment options available and finally I’ll wrap things up with a conclusion or two.

So, the National Joint Registry. This was set up in 2003. Initially it was a voluntary organisation that just included the independent sector. And the National Joint Registry of England, Wales and Northern Ireland started out by recording all of the detail for hip and knee replacements initially, so the patient's details would be anonymised and the information collected would include their age at surgery, their anaesthetic status, the implant that they received, when, at what hospital and who did it.

It's got expanded significantly since its early days and, in 2014, I think it was, it became mandatory for all hospitals in England, Wales and Northern Ireland to include the data of hip and knee replacements. And they expect a compliance of about 95%.

This makes it an extremely powerful tool for health assurance purposes, to make sure that the implants used and the surgeons that do the operation are satisfactorily performing and also that a tally can be collected as to what volume is done where in the country. So, it's good for health economic planning as well.

Scotland has its own individual register. It's been expanded to also include ankles now, shoulder replacements and elbow replacements.

So, to give you a few figures about knee replacements. Up until the 31st of December 2019, between 2017 and that date, about a quarter of a million knee replacements are carried out in the National Joint Registry and a hundred thousand of those were carried out in the year 2019.

The average age of surgery requiring a knee replacement is 69 across the board and it's declining year on year.

Obesity, which is a very important factor with knee replacement surgery, is also increasing year on year. As Alex mentioned there's a female preponderance for the requirement of knee replacements with 56% of all patients being of the female sex and the overarching cause for needing a knee replacement is osteoarthritis with 98% of those operations logged into the NJR stating that is the primary pathology.

With regard to volumes, interestingly in the latest report from the NJR, the median number of total knee replacements performed per year per surgeon is 40 and the unicompartmental or partial knee replacement, the median number performed per year is just seven. And when you think there are 1.3 million total knee replacements stored in the National Joint Registry since its inception, with a long-term follow-up of 16 and three-quarter years, those two figures I’ve just mentioned don't seem to be too many.

So there's a vast spectrum of across the board with surgeons who just do hip replacements and do high volume; Surgeons who just do knee replacements and do high volumes or those who have a balanced practice like Mr Chipperfield and I, who have a practice of about 50/50. And then there’s also the occasional surgeon that does the hip or knee replacement.

The most important point though using the NJR is that it now is the largest data set of knee replacements in the world and there's a great research tool to see how different implants are performing - and also to highlight if there are any issues with survivorship. And I’ll talk a bit more about that later.

So, osteoarthritis is the most common joint disease and the knee is the most commonly affected of these joints. And it's estimated that any given time about eight million people are affected in the UK with osteoarthritis. It's a degenerative condition, at present there is no cure. These two x-rays show the degeneration in the hip and the knee.

The main risk factors for developing osteoarthritis of the knee are as follows. The number one being obesity. If you're significantly overweight, with a body mass index of over 40 - which puts you in the morbidly obese range - then studies have shown that you're 40 times more likely to require a knee replacement in your lifetime than someone with a BMI in the normal range.

Another risk factor is being over 50 years of age, having had a previous knee injury such as an ACL rupture or a significant meniscal injury or a chondral defect where the articular cartilage is damaged or previous fractures of the knee joint can precipitate osteoarthritis. Being female slightly increases the risk and there is a weak genetic link also.

The main symptoms and signs are, essentially, pain is the overarching one. With pain, you also have stiffness and with stiffness it leads to reduced function and some patients also experience crunchy, creaky knees - especially on going up and down the stairs.

So, the primary care management (this is GP land) they try their best to manage the situation with lifestyle advice about weight loss, activity modification. They give advice about analgesia, they refer you to physio and some GPs that have an interest in orthopaedics will provide a steroid injection surface that keeps the pain at bay temporarily. They do also follow loose NICE guidance and, in the next slide, we'll explain that.

Once you've tried all those things for about three months, if you're going nowhere, then it's advised to be referred back into secondary care. In recent years there's been another hurdle to jump over when the patient has got to go through the musculoskeletal triaging service first, where they see an experienced or an advanced physiotherapy practitioner and have more physiotherapy, more advice, more painkillers and so on.

That can be potentially avoided by using Benenden Hospital and there are four ways to get to see us at Benenden.

Self-pay, through your membership or using your private medical insurance - and all main insurers are recognised.

The fourth way is through the NHE e-referral system at the discretion of your GP, if the waiting time in your local area is excessive - and this is nearly always the case.

And when you come to Benenden, we do our best to try and see you within two to three weeks of receiving the referral. You'll go to a dedicated hip and knee surgeon and have a detailed clinical assessment, which we've already alluded to, including history, examination and the relevant investigations.

You'll then be invited to be part of the shared decision-making process to tailor-make the treatment plan suited to what you need at that time. And that may be continued help with non-operative measures or it may be indeed the time has come to consider surgery, such as a total knee replacement.

For hip and knee replacements, Benenden has been an advocate of the Rapid Recovery Protocol now for several years and I think this is very important to emphasise. For those who haven't heard of that before, that is a multi-disciplinary approach between all of the main stakeholders in the care pathway. That includes the anaesthetist, the physiotherapists, the surgeon, the nurses on the ward and outpatient physios as well.

And it's all about optimising the patient's journey, minimising the pain and helping you recover as quickly as possible. And Benenden Hospital does this very well in my opinion.

So, a total knee replacement. Essentially it has been deemed to be a highly clinically effective and cost-effective initiative but the timing of when you have surgery of one of these is absolutely crucial. You should have at least evidence of exposed bone on bone in at least one knee compartment and some would say in at least two. We only wish to really take you to the next step when all conservative measures have been exhausted and, even then there's still more work to be done.

And it's best to try and have a good bash of pre-operative optimisation, so making sure your diabetes is sorted, trying to lose weight, getting a bit fitter. And the concept is called prehabilitation - and that will help you through the journey of recovery.

Unfortunately, especially as I found out in my time in Canada, it's becoming much more of a lifestyle choice. But it's not simply like changing a tyre on a car - it's a big procedure and it's not to be taken lightly.

This is because the revision rates at 15 years are quite significant if you have your knee replaced early in life. Sometimes you have to - there's no doubt about it - life is just too painful; you've had a significant knee injury and you need to carry on working. But it's important to understand that if you do have your knee replaced early in life, then there's a very high chance that you may need to have it revised, potentially at least once.

And an interesting fact from the latest report of the NJR that I’ve read is that they've now firmed up the calculation about when is the right age to have a knee replacement. Of course there are many other factors involved, but they say that if you have your knee replaced from 70 plus that is the ideal time because it's unlikely for the vast majority of that age group that they'll need to worry about a knee revision everything being equal, everything going to plan.

So, a partial knee replacement. This is also offered here at Benenden Hospital. There are a few of us that have a very specialist interest in this, and good outcomes are achievable. However [joint] survival is lower in most orthopaedic studies.

So patient selection and surgical technique is key, and I’d recommend that you see a surgeon that does a high volume of these. This is endorsed by the British Association of Knee Surgery and the British Orthopaedic Association. The surgeon you should see should be doing at least probably between 10 to 20 cases per year.

Again, the most popular one there that has the most usage in the NJR is the Oxford knee replacement. But again, as you see here, the revision rates are quite high compared to a total knee replacement. You know one in five at 15 years is potentially going to need to be revised. That said, the NJR is indicating that the uncemented Oxford knee (which has been around for a shorter period of time) was having some impressive results of a much lower revision rate at ten years.

The high tibial osteotomy was quite popular in the 70s and 80s and then sort of calmed down and then has risen again in recent years in vogue or popularity. But it has a high failure rate and patient selection is critical. Usually left to the younger individual to try and offload the weight-bearing part of the knee by changing its anatomy.

It is technically demanding, it requires a lot of time off work and as far as I’m aware there's no published cost-effectiveness data to say that it's a worthwhile intervention if you have established arthritis like the x-ray shows on the screen here.

Arthroscopy of the knee still a very common procedure. I’ve noticed in recent years that there has been a decrease in the use of arthroscopy in the knee for an arthritic knee and this is endorsed by several high-profile studies that have been published in important orthopaedic journals. It basically says that it's a sham procedure just to wash out the knee.

You really need to have a definite pathology, such as a loose body in the knee making the knee lock, or a significant meniscal tear on the background of osteoarthritis that has changed the usual pattern of pain. Then I think an arthroscopy in the presence of arthritis is still worthwhile.

So post-operative care after total knee replacement of Benenden, you will be seen by the physiotherapist twice daily on the ward and you'll go through a graduated exercise program with them, starting with exercises on the bed and progressing to standing and fully weight-bearing on the knee  - hopefully on the day of surgery using a frame and then progressing to crutches. And finally, you'll be shown how to safely go up and down the stairs using crutches. And the average length for stay is usually about two days after a total knee replacement.

At six weeks you'll come back to the hospital and see one of the Orthopaedic Surgeons and, for me, this is a crucial appointment because I need to make sure that the wound has healed, that the range of motion in the knee has got to at least 90 degrees and that the patient is progressing.

There will be a few backward steps but, on the whole, they're on the upward trajectory and improving.

I personally think that all patients should receive at least six sessions of targeted physiotherapy in the early post-operative period those who live locally can utilise the Benenden team post-operatively. And if there are any issues, I certainly would recommend self-funding physiotherapy because it really does put the icing on the cake and make your knee replacement an excellent one.

That brings me on to the Patient Reported Outcome Measures. These are quite topical at the moment. Hip and knee replacements are included in these and, for those who haven't heard of them before, essentially functional outcome measures and quality of life scores are taken from the patient preoperatively and then repeated again six months post-operatively and then compared. And clever people do some statistics and work out whether the intervention that has happened to you has benefited you.

In summary, with regard to knee replacements, greater than 80 percent of people have stated that they've had excellent, very good or good satisfaction of their surgery. This is at the six-month mark and I personally think it should be repeated again at the 12-month mark, because some knee replacements can take a little longer to bed in and recover from.

That said it's still being judged to be a very cost-effective intervention for the healthcare economy as a whole and, as Mr Chipperfield alluded to, it’s number one in the quality of life rankings on that pyramid that he showed earlier.

Dissatisfaction rates need a brief mention. This really does come down to getting the timing right and the age of the patient. If the patient has their knee replaced too soon, if there's not enough wear and tear, then some of the studies have shown a dissatisfaction rate of up to 20 percent and these are usually in the age group of 50 to 65. And I think the key to reducing this dissatisfaction rate is to spend quality time with the patient in managing their expectations, to make sure that they're aware of how long the recovery is going to be and what limitations and knee replacement will have upon their life.

If the prime purpose is for pain relief and function, you know, walking from A to B you're not going to really be able to play competitive sport like football. You can ski if you wish to, but there's the risk of having a fall. You can kneel on a knee replacement if you wish to but it's frowned upon because it can damage the patella. You can ride a bike, you can play golf, you can do most things but it's important to have a really good heart to heart with the patient to ensure that their expectations are managed.

So, what makes a great knee replacement? There are three factors really. The patient factors - and this includes managing expectations for patients - with resilience, their dedication to post-operative rehabilitation despite being in pain. There are surgical factors: you want to come to a unit with low infection rates, that practice enhanced recovery protocols, that have a very good physiotherapy set-up and have orthopaedic surgeons that perform this operation in high volume, such as at Benenden Hospital.

It's a team affair really and if each one of those stars align, so to speak, then a surgical result - a good surgical result - usually is the case.

These are just a few extra pictures I put in to show some of the deformities that come to our attention in the clinic. This x-ray here shows a bow-legged knee or a varus osteoarthritis knee, and every time this chap takes a step forward the knee collapses outwards and makes him unstable. And is very painful, very, very painful.

To try and correct that bow leggedness the knee replacement straightens the mechanical alignment again and here are a few scanogram pictures of that.

Then here's a quick case study. There's two osteoarthritic knees; the left knee in particular is very wobbly, unstable, and a lot of pain in the medial part of the knee and the anterior - or front part of the knee.

This is the most commonly-used knee replacement here or the prime knee replacement used here at Benenden Hospital. It’s the Zimmer Biomet Vanguard knee and there's the post-operative x-ray.

A little mention about some post-operative problems that are very important to highlight. These are things that the orthopaedic surgeon needs to know about, and we are wary of the fact that our patients come from afar and we can't always get access to them or then to us. But we could if you live down the road.

But we need to know if you have persistent wound discharge. This is very important because it is salvageable if we know about it early. If it is left to fester and the infection develops then sometimes the infection can go deep and put the implant’s longevity at risk.

The other thing to look out for is the deep vein thrombosis. The chances of that happening are minimal because of, as Alex alluded to, we take all the precautions we can, using blood thinners and so on and so forth - and getting you up, mobile, quite quickly.

Some reasons for revision. A knee replacement, if everything goes to plan, should last 15 to 20 years, all being well. But they do eventually become loose and in the NJR 39 percent of them are revised for this reason. The polyethylene bearing can become worn as well, leading to instability. You can have a significant increase in pain if these issues happen, but to have your knee revised for unexplained pains is usually futile and should be avoided.

Sometimes mistakes are made - very rarely - and the implants can be malaligned; and sometimes infections can become deep and unable to be eradicated by wound environment and antibiotics.

Finally, just talking about the modern technologies, computer-navigated knee replacements aren't really modern anymore. They came about in the sort of early 2000s and their whole idea about them was to try and reduce the outliers, to reduce human error in the surgical cuts made and the alignment of the implants. It does do that, but medium-term studies (up to about 10 years or so) haven't really shown any significant advantages, as far as I’m aware, when compared to standard conventional techniques.

That also is the same for patient specific knee replacements, where the patient has a pre-operative MRI scan done to help design the implants - and customise the implants and the cuts on the bone to the individual.

I’ve done over 200 of these knee replacements and, anecdotally, I do see that the patients recover quicker and have less pain. The studies seem to suggest in the medium term there is no real clinical advantage when compared to conventional techniques.

Robot-assisted total knee replacements; gathering momentum. Quite an exciting thing to get involved with in the current climate, with the huge surgical waiting list caused by COVID-19. I think it will be something that will be difficult to argue in the health economy, because it takes time to build up your learning curve and to do these operations and it probably isn't a practical solution to a long waiting list.

So, to conclude, osteoarthritis of the knee is incurable at this time but they're working hard to try and regenerate cartilage using stem cells etc. If you don't wish to have an osteoarthritic knee you really should look after your body weight, because that's the prime risk factor for developing it.

Appropriate referral into secondary care is key and it should only really occur when you've exhausted all conservative efforts and patient selection timing of surgery and management of expectations of the patient is key to getting a good result.

Thank you very much.

Louise King

Great, thank you very much guys, that's really interesting. And we have some questions that have been posted already so - and if you do any other questions please do submit them - our first question is from Jeff and he says: does having the leg in a brace after knee replacement have an effect on recovery?

Mr Matt Oliver

In a brace? Usually you wouldn't need to have a brace after having a total knee replacement. It would be bandaged up with a woollen crepe the night of the operation and then we would leave it free and expect you to do the range of motion exercises. I haven't used a brace after knee replacement of anything, ever. I don't know about you, Alex?

Mr Alex Chipperfield

No, not at all. It's not something that we generally do.

Louise King

Okay, thank you. Next question is from Maria. She says: If I am suffering from regular intense, deep knee pain, cannot sleep well, have had a hip replacement on the same leg in 2016, can I consider a knee operation or investigation? She also suffers from osteoarthritis and is worried that she might have less mobility if she does have the knee replacement, and can you advise?

Mr Alex Chipperfield

Absolutely, I mean it sounds like she's someone who's in trouble, who's struggling. She knows the size of the operation involved, having been through something similar with the hip, and it sounds like she's the ideal person to come along and say hello to us - and we can take a look at her and her knee and see if her knee replacement's the right thing to do.

Louise King

Great, thank you. Okay this next question is from an anonymous person. They say: If I live a long way from the hospital, how is aftercare arranged and would I have to travel to the hospital for physio or follow-up appointments?

Mr Matt Oliver

If you're a member of Benenden, you can utilise the membership services to arrange physiotherapy in your locality postoperatively and that sometimes does occur for those who live a long distance away.

When you come back for the check up at six weeks the physiotherapy team here sometimes arrange for you to be seen on the same day with them as you would be seen by us, so you have a double appointment. I think that works out quite well actually.

But it is key to get good quality physiotherapy after a hip or knee replacement - and if you live in the north, or in Cornwall, and you come to see us I would thoroughly recommend arranging physiotherapy in your locality afterwards.

Mr Alex Chipperfield

One thing that we have noticed in the last 18 months is the advent of telemedicine, and we've been doing it for years at Benenden because we are a long way from lots of people. But, you know, for routine follow-up and aftercare we're very happy to do it either by video consultation or by telephone.

The one thing that I would echo Matt there is that I would recommend that that you see a local physiotherapist. That's the important, hands-on, post-operative care that you will need and traveling to Benenden for that - although you're very welcome to - wouldn't be the best use of your time. So, I would recommend local follow-up of physiotherapy.

The other deal that I make with my patients is - if they come from a long way away - if they say anything during the remote consultation that has me even in the slightest concern then they have to come up and see me. It's that simple. We need to know about problems, if there are any, and most of the time although we can reassure people remotely it's always best to see them face to face.

Mr Matt Oliver

I agree with that.

Louise King

Great! We've a question around carrying out knee and hip surgery on a 43-year-old and they appreciate they possibly need another one in their lifetime and would you do that?

Mr Alex Chipperfield

Yes, is the answer. I don't put an age limit on when. Don't wait till you're old enough to have an operation. It's all about when the timing is right for you. It's about the quality of the life that you're living and whether or not you've exhausted all other possibilities.

Both myself and Matt, although the average age for joint replacement surgery is 69, 70 we've operated on people in their 20s and in their hundreds and everywhere in between. As long as you're aware of the potential for needing further surgery in your lifetime, and also as long as you're aware of the limitations of an artificial joint.

You know, a lot of 30 or 40 year olds - when they have their knees replaced - the demands that they're going to put on those knees are much higher than your average 70 year old, and sometimes they may end up disappointed at the level of function they reach.

But absolutely, if you need it doing it's not about age it's about when the time is right.

Mr Matt Oliver

I’d just like to second that and also add that the patient themselves, in my experience, has a light bulb moment. They just know that there's nothing else that can be done and they're miserable and they're fed up with feeling miserable. They're struggling at work they're not enjoying playing with their kids in the garden, they can't keep up on a walk around the block with the wife or the husband and that to me is very important.

And it means that, you know, if they have tried everything we've just mentioned the knee replacement should very much improve their quality of life.

Louise King

That's excellent thank you. Are you able to play squash after a hip replacement?

Mr Alex Chipperfield

Personally or for the patient?! So, racket sports in general, things like tennis, squash - even badminton to a degree - they tend to just be the perfect storm really when it comes to joint replacement surgery. The combination of rapid acceleration, rapid deceleration and rapid changes of direction as well tend not to mix very well with joint replacement surgery.

So generally, patients, if you are able to still play squash or tennis, then I would probably possibly suggest that the time is not right for a hip or knee replacement. If you are unable to play because of your hip or knee, then although you may get back to playing at a low level - or more stationary – I wouldn't expect you to get back to competitive levels.

You just have to look at Andy Murray, who is surrounded by a team of people whose only job is to get him on the tennis court; and he has not been the same since a hip replacement; he's not reached that same level. So, although it is technically possible, I think you'll struggle to reach the levels that you were at your prime.

Mr Matt Oliver

I agree with that, but the caveat is, a couple of years ago, I had a man in his 50s that came to see me with a very arthritic knee, and he was the squash coach at the local private school. And he laid on my desk a magazine – I think it was called Squash Weekly or Squash Monthly – and opened it up in the centre pages and there was a spread about a 70 year old man who'd had both of his knees replaced and he is the world veteran champion. And he said can i have one of these please?

I had the perfect storm moment, like Alex has just mentioned, but I thought well yeah why not you know? This guy in the magazine has obviously managed to get back to a reasonable level, so we went for it and - as far as I’m aware - he's back coaching squash and still playing competitive squash. But he understands, just like Alex has mentioned, that it won't be quite the same.

So, you can certainly get back to playing those things because you're just aware that your knee may wear out a bit sooner.

Louise King

That makes sense. Okay our next question is from Paul. If someone is classed as obese would this mean that they could not have a knee replacement?

Mr Matt Oliver

No, but if you want to have your knee replacement at Benenden, the cut off is a BMI of 40. So elsewhere there are different criteria but the higher that your BMI is, there are perceived increased surgical risks. But certainly, I think up to about BMI of 45 a knee replacement probably can be safely performed. I think 50 and above, I have some reservations about that. I don't know what you feel about that Alex?

Mr Alex Chipperfield

Yeah, absolutely. It's down to patient safety factors. Once your BMI is over 40 the risk of developing a complication is significantly higher, so you will find that private hospitals or standalone units that don't have on-site access to critical care high dependency units, they will be more selective about BMI when it comes to surgery.

And, you know, you'll find that at Benenden if your BMI is over 40 then you wouldn't be accepted at Benenden whereas you would at a local NHS hospital that has all that critical care facilities in place, just if it's needed.

I certainly have a large cohort of patients who have a BMI between 40 and 50 who are delighted with their hip and knee replacements. You know, it's a good operation for people of all sizes but it has to be performed safely in the correct environment for them.

Louise King

Great, thank you. Right, that's all the questions we actually have time for today because then we're just hitched by time. So, I just want to say thank you both for your presentation, it's been really interesting and if anyone would like to book an initial consultation our friendly Private Patient advisor Lindsay is available until 9pm this evening on this number on your screen.

At the end of this presentation you'll receive a short survey. I’ll be really grateful if you could spare a few minutes to let us have your feedback on today's webinar. And so on behalf of Mr Chipperfield, Mr Oliver, myself and the team at Benenden Hospital I’d like to say thank you very much for joining us today and we look forward to seeing you again soon.

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