Phil Orrell

Good evening, everybody, and a very warm welcome to our webinar this evening. It's great to see so many of you signed up for this, and we'll just pause for a few moments to allow you all to join. Just bear with us.

Okay, good evening, and thank you for tuning in to our webinar this evening from Benenden Hospital on knee replacement surgery. My name's Phil, and I'll be your host for this session. I'm joined by our expert speaker, Mr Raman Thakur, and just to give you a brief overview of how the session will run, Mr Thakur's presentation will last around 20 minutes and following that there will be a question and answer session and you can submit questions anytime during the presentation or after the presentation and you can do this by using the Q and A icon at the bottom of your screen and you can submit your questions anonymously or you can give your name and at this point I should let you know that if you do give your name we are recording this webinar if you'd like to book a consultation we'll be providing contact details at the end of the session so without further ado I will hand you over to Mr Raman Thakur.

Mr Raman Thakur

Thank you very much, Phil, for having me this afternoon. As mentioned, my name is Consultant Orthopaedic Surgeon Hospital. These are the points we're going to cover during the session, based on my experience with other consultant colleagues, what we do at Benenden Hospital, and talking a bit more about knee osteoarthritis, knee replacement surgery types, surgical processes, the recovery process and risks of surgery, and patient decision support tools, followed by time for questions and answers.

So, I trained as an orthopaedic surgeon in Hyderabad, India, and came over to the UK, trained in the southeast of England, and obtained my fellowship in trauma and orthopaedics. Subsequently, I did a year's fellowship in New York, working at Lennox Hill Hospital for special surgery for a year, specializing and expanding my skills in hip and knee reconstruction.

I've been working as a consultant orthopaedic surgeon based in Kent and have worked at Benenden Hospital since 2012. I am a member of the British Orthopaedic Association and the American Academy of Orthopaedic Surgeons.

Bend Hospital is a leading provider of private hip and knee treatments in the region. It is a very pleasant atmosphere for working, and I'm sure for the people who come here to have their treatments, it is with our experienced team of orthopaedic consultants and physiotherapists who provide a good quality of care with high patient satisfaction rates that we are well engrossed and enrolled in the rapid recovery. Pathways for following hip and knee replacement, we have a team of colleagues and consultants who are doing and operating on both hip and knee replacements. I, along with another seven of our colleagues, provide both hip and knee replacement services.

It does over 400 knee replacements a year and about 500 hip replacements and is still quite a competitor to the order centre, which has been long established as a hip and knee replacement centre in the region.

Knee arthritis usually presence in the early phases as an early morning stiffness first thing in the morning when people wake up the knee feels stiff there is pain on activity particularly gardening or long walks or running and some patients may experience sensation of clicking or grinding and swelling of the knee as the arthritis in the picture here shows what actually happens within arthritis and my cursor is showing to the areas where there is denudation and damage to the covering article cartilage and gradually over a period of time then the bone gets exposed and then it becomes more advanced arthritis and then patients experience pain at night pain during rest and the knee starts getting a bit deformed so it may either go in words causing lock need or the knee may go outward causing a bow electric vomiting and walking distances significantly become reduced and become more and more intrusive level of symptoms and deteriorating function    The picture on the left shows a normal knee joint with a good cap in the bone, and the picture on the right demonstrates more advanced arthritis with a complete narrowing of joint space, particularly on the outer or lateral aspect of the knee joint.

What are our treatment options? If patients are having an arthritic knee initially, early arthritic changes treatment is non-surgical. First and foremost, there would be simple measures such as modifying some activities and avoiding some activities that may aggravate the condition, if possible and acceptable. If somebody is overweight then having an arthritic knee and overweight increases pressure and accelerates the progression of our parties in the knee with high BMI is a known predisposing factor for development of arthritis in the knees as well so but having already got arthritis and certainly the progression will enhance and therefore certainly weight loss would be a definite or beneficial and therapeutic value even for the longer term physiotherapy any swelling that develops as a result of arthritis gets any fluid in the knee it will rapidly weaken and base the muscles around the knee and hence physiotherapy is an important measure to keep the muscles in good conditions so that they support the joint and allow people to function it will also help with pain relief and control of pain so then going on to more intrusive measures  simple analgesics    paracetamol is a very good basic painkiller and a paracetamol is not enough usually people substitute and also add-on non-steroidal anti-inflammatories sometimes people take the non-steroidal and stop the paracetamol it usually is an additive effect if I either paracetamol or ibuprofen on their own are not helpful sometimes adding them together may actually give more relief than just carrying on with ibuprofen or even stronger medication there so more mechanical options are knee strapping or knee braces they can give a bit of proprioceptive control especially when people feel that the knee is giving way or feel unsteady then certainly the brace can give a feeling of more security by adding on some proprioception from the surface of the joint it is not something that one would want to get reliant on because it does affect the muscle bulk and muscle strength so it is not something I would recommend people use it long term and get reliant on injections are another good excellence to help with the control of pain injections either steroid injections or cortisone injections or the other alternative type of injections or hyaluronic acid and lubricant injections which we do at Benenden  What are certain injections that help with reducing inflammation, swelling, and pain? This is usually a normal hormone in the body, so one has to be careful about how many people can have over a period of time. The usual recommendation is not more than two or three injections a year, but also only if it has been working and giving good relief for a period of a few months. I tend to usually advise patients not to use them as a regular treatment but to use them particularly for severe flare-ups or occasions when people are either having a special occasion like a wedding or a function with the need to get over or a holiday to go through then certainly is having a steroid or a lubricant injection will certainly help them enable them to do that in in the early phases certainly hyaluronic acid can work and give people a much more prolonged relief of symptoms but when it is born and burned unfortunately the injections may not really lost more than a week or two so it also depends on how severe the arthritis is in terms of how well the injection may provide relief to people.

Then coming to the surgical treatment for osteoarthritis starting with the simple ones where there is deformity one can correct the alignment with an osteotomy basically cutting through the bone realigning the bone and fixing it in that position because then the weight gets transferred through the more natural part of the knee and allows the damaged area to heal itself and therefore the there are people who have had good outcomes lasting over 10 to 15 years and certainly would be something that would be recommended for the young patient arthroscopy when the arthritis is not born on burn but less severe and there are loose fragments or loose bodies in the joint which are catching causing locking or giving way or there is a significant minuscular tear which is causing catching between the bones and causing further damage all these if there are mechanical symptoms certainly an arthroscopy can help in that situation   a microfracture is a way of managing small bony defects less than one centimetre square if they are born on bone in that small area.  Sometimes we can make holes into the surface of the bone and allow bone marrow cells, which are pluripotent cells, and they can hopefully help reconstitute some cartilage-like surface and allow that need to continue performing without recourse to any replacement surgery. Unfortunately, cartilage transplantation has not been successful in osteoarthritis; it is more useful for localized traumatic defects in the surface of the joint and knee replacement surgery (we'll talk about that more in a minute), so it is a fairly common operation; over 100 000 are performed in the UK per year, and the average number of knees replaced is between 68 and 70, but the range is anywhere from 55 to 85 to 90. Over half of the patients who undergo knee replacement on the joint registry are female, and 95 percent report significant health improvement following recovery from knee replacement surgery. They also have long-term longevity in survival, and over 80 percent of these can last 25 years.

So, it is a reliable and durable solution for end-stage arthritis. Now, when a patient comes, we need to decide when it is time to have any replacement surgery. When realistically, the quality of life is affected, the symptoms are quite significant and intrusive, affecting day to day or work and also affecting rest and night. If there is a quite constable decline in function, then this would be the time to consider knee replacement surgery. Obviously, the conditions in the background could be osteoarthritis, rheumatoid arthritis, or arthritis after severe trauma involving fractures on the joint surface or ligament damage.

The idea of placement is to get relief from pain. Over 85 percent of people are pleased and happy with the outcome of surgery, and over 90 percent find that replacement has been beneficial, though not completely relieving their pain. So, pain relief is one of the most important indications of pain, and that would be our primary reason to consider knee replacement surgery. Obviously, along with relief of pain, improvement of mobility, and restoration of other abilities to do other functional uses, uh, half of my patients can kneel, and half of my patients cannot kneel, so there can be a bit more normalcy restored to some of the patients, and at the same time as we are doing the knee replacement, we also aim to correct the deformity, and in most people, we have managed to get that correct. The younger patients have higher functional demands both at work and in sports, and I have greater expectations. The success rates of knee replacements have a definite distinction around the cutoff age of 55. People younger than 55 have much lower success rates, as shown in the literature, compared to people over the age of 55.

What are the options when we come to discussing knee replacement? That really depends on what or how much damage has happened within the knee. If the arthritis is localized to one part of the knee, then one could consider replacing only that compartment; it is called a unicompartmental. It could be either the medial, which is on the inside, the lateral, which is the outside, or the kneecap joint, which is the patellofemoral joint replacement, which is the joint between the kneecap and the front of the femur. A total knee replacement involves taking the cruciate ligaments out and replacing all three joint surfaces. The kneecap itself may or may not be replaced depending on the damage. There are some surgeons who will never replace it, and there are some surgeons who will routinely replace it. I usually base it on the level of damage on the surface of the burn, so if the burn is reasonably good, I would tend to leave it because there are also complications associated with doing a replacement on the kneecap. totally   replacements can be done to the conventional standard instrumentation which is over 90 percent of any replacements done in the country computer navigation has been up and down we have used them regularly in the past now people have gone away from them because there hasn't been a huge difference but we do still use them when people have got either metal work in the burns of femur and tibia or indeed they have got a deformity from a previous injury that may be preclude us to putting rods up so that we can do the knee replacement so there is still a role in a specific group of patients for computer navigation robotic surgery is taking a much more prominent role it is coming possibly to Benenden late next year or in spring of next year and hopefully there are some exciting times ahead for us again the purpose of using these tools is to give a more reliable positioning of the prosthesis ultimately it doesn't always necessarily equate to getting the best outcome out of knee replacements but we can at least ensure that technically we do as good a job as possible if the ligaments are and soft tissue envelope is damaged then there may be a more bigger knee replacement surgery called constraint knee replacement basically what it means is that we are trying to substitute for the absent ligaments so if people have got a medial collateral ligament or a lateral collateral ligament insufficiency then and even when we are doing a posterior cruciate so there are levels of constraint which are introduced and when subsequently revision surgery or severe deformity we may have to use a prosthesis which has got more constrained so that it also substitutes for the damage soft tissue envelope

The most common prosthesis we use at Benenden is the vanguard prosthesis, which is made by Zimmer-Biomet. It has an odor rating of 15a, and the 10-year survivorship rate is over 96 percent. It is one of the top three companies, and we use the processes as a semantic prosthesis. I use bone cement to hold the prosthesis in place, and, as I mentioned earlier, with or without resurfacing the patella, depending on the severity of the disease. In knee replacement surgery, we reset the diseased bone and shape the bone to fit the inner aspect of the prosthesis, so it will fit like a cap on the front and a table on top with a plastic spacer in between.

Following the knee replacement surgery Hospital stays are usually two to three days, and initially, when patients come back from the theatre, they have the knee wrapped in a large protective dressing, which is taken down after 24 hours to leave the inner sterile dressing on. Pain is managed with medication. It is important to understand that it is a painful operation, and people will be talking to you and asking you, this is physiotherapists and doctors will be asking regularly, are you in pain, and because we are expecting that you will be in pain, we want you to ask for painkillers so that you control the pain, and then you can do the exercises so that you will get a good benefit of the procedure and a successful outcome. You have daily visits from the physiotherapists around the world, and they will go through the exercises and will also tell you about exercises, how to get about at home, and how to carry on. Also essential to our care is the highly skilled team of nurses on the board, who are very experienced and look after all your needs.

Your patients go home when it is safe to do so, and the main things that we expect are that patients are independently mobile with either a frame or crutches, have done safely up and down stairs, and we are happy that the wound is clean and dry. After about a week, most people can walk with sticks if the pain levels and swelling permit.

Despite the subsequent recovery over the two-week period, it is still quite a painful thing. The bruising will appear, and sometimes it can be quite dramatic, extending from all the way from the hip to the knee and sometimes down to the ankle. Some of my colleagues use staples, and they may need to come out in two weeks. Exercises are an important part of recovery. It is essential that people take the painkillers and do the exercises. Most patients find that the initial month is quite a difficult experience, but usually by six weeks their pain is significantly improved compared to even before the operation, and they can walk both at home and outside, and if they are safe to drive, they can start driving. On a general basis, if you are sitting comfortably for half an hour or your sitting tolerance is an hour, you can possibly drive for half an hour, so it is roughly about half your sitting tolerance that is the distance you can start driving. If you're planning for longer-distance driving, then you probably also need to incorporate regular breaks into your driving schedule. A follow-up appointment is at six weeks for most of our surgeons. At three months, over 90 percent of recovery has happened, and people feel the reliable benefit of surgery and start returning to normal activity. Usually, any work-related cessation of activity is followed by a return to work at three months post-surgery for most of the office and test space activities. If somebody is doing more strenuous activities, it may be the start of a phase of returning to work and continuing to follow advice and exercises as appropriate for full recovery. Full recovery may take all the way up to a year, and the swelling following a knee replacement can be there for anywhere from six months to a year. So, don’t get alarmed that, oh, my knee is still swollen, and my leg is still swollen. The most important thing is that you are swelling better than a previous week or two weeks ago, and that really is your gauge of recovery—that things are getting better. Rests after knee replacement are divided into three phases early during surgery, obviously bleeding, and if the haemoglobin drops quite low, you may need a blood transfusion and injury to the tissues. All the clockwork is around the nerves, the blood vessels, the tendon, and the burn. They're all at risk, and we take precautions to limit damage during the recovery phase. We are concerned about ongoing oozing and bleeding from the wound. We do give blood thinners to reduce the risk of blood clots in the leg, which can cause ongoing oozing and bleeding and bruising around the knee. If that is happening, it is important to let us know and sometimes to stop the blood thinners for a day or two on the advice of the doctors to ensure that the wound becomes dry. If the wound continues to leak, it could lead to infection and may require antibiotics. Occasionally, we may want to go back in sooner rather than later to wash out blood clots in the knee. DVT and blood clots can migrate to the lungs despite us giving blood thinners. If the swelling is persistent and not settling, we may need a visit to have a scan to exclude a blood clot. In the late stages of infection, long-term chronic infections can happen. Implants can fail because they can come loose or wear out and may require revision surgery. A fracture may happen because of an accident, and if it involves the prosthetic area, then it will again require revision surgery. Dislocation is less of a common problem with knee replacements compared to hip replacements, which are much more common.

Precision support tools On the NJR, which is the national joint regulator, there is certainly information regarding your surgeon's profile, the hospital profile, and how patients have rated it. There is also a private healthcare-independent network. These are all the areas where you can get more information for your due diligence, and certainly whether you as an individual can benefit from any replacement or a hip replacement, and whether it is what your risks are as an individualized calculation. If you want to do that, you can certainly use the patient precision support tool on the NJR website.

Right, Phil, over to you.

Phil Orrell

Okay, some informative points on the treatment options and the patient journey there at Benenden, and we can now start to take some questions from our attendees.

So, this person asks, I am very nervous about having a total knee replacement as I'm in my 50s. I know it's possible that I may need another replacement in my lifetime. Is it still as effective as the second time?

Mr Raman Thakur

Almost thing and I think you're right to be nervous about it in the 50s I would be too it is more important is it the right thing for you that would be my first question and certainly failure of the processes over time and need for revision surgery is certainly high on the agenda yes it can be redone it is not a problem but I think getting that decision right the first time and seeing if other things can help keep you going until you have to have your knee replaced it's certainly my recommendation and advice if possible to keep going as long as you can obviously it may be that the arthritis is so bad that that is the only alternative and option available so it certainly would be worth getting yourself checked by an orthopaedic surgeon and getting that advice

Phil Orrell

Okay, thank you. This attendee asks: This may sound odd, but once recovered, will I be able to do things such as jump or kneel? I often look after my grandchildren.

Mr Raman Thakur

It is interesting. I have patients ask me this, and I tend to use the analogy of a Rolls-Royce. If you buy a Rolls-Royce and drive it off the road, do you think it will last? So having said that, if you are going to do an occasional run, if you need to run for a bus or run for the train otherwise, you're going to miss it, go for it. You know if you're recovered and you're doing it, but on a regular basis, as a regular form of exercise, people are doing marathon runs. People have done it and they still do it, but that is not the recommendation that would be from my mouth. Certainly, that is not something I would recommend.

Phil Orrell

Okay, this person asks, can statins have a major effect on knee joint pain? I also appear to have muscle waste on the same leg as the painful knee.

Mr Raman Thakur

So muscle wastage is a common side effect of having a painful limb mainly because if you have particularly say arthritis in general also if you had an accident or something and you have had an injury the muscles tend to waste rapidly because you have not used it even if you spend two or three days in a bed you'll notice that there is a rapid wastage of muscle because we are not using that as commonly or as regularly so that in itself is an important thing and particularly if you're getting any swelling or fluid on the knee then muscle wastage is a common essential thing and that's the reason why it is sensible to keep exercising within the limits and constraints and comfort or finding alternative ways of exercising so that you keep your muscle conditioning then in the in the leg.

What was the other part of the question?

Phil Orrell

I think he asked about statins.

Mr Raman Thakur

Known to increase musculoskeletal pain, people do get myalgias and arthralgias, and sometimes there is pain in the muscles, pain in the joints, and pain in the tissues. It is very individualistic, and one needs to assess it on an individual basis because you need to weigh the benefits versus the side effects. It is a non-site effect, but if it is really bad, then you need to discuss with your doctor whether you need to discontinue.

Phil Orrell

Thanks. We've seen this question in previous webinars. What gap do you recommend between first and second knee replacements?

Mr Raman Thakur

So usually, we don't tend to do bilaterally needed placements at Benenden and we usually tend to stage them, and what happens is that, in practical terms, the first thing is done. You've come to see us six weeks after the surgery, and at six weeks, if you are doing well and you want to go ahead with the other side, then we can list you for surgery, which will be probably another six to eight weeks. So usually, by three months is the minimum we say to give the tab, and that is the minim but that doesn't mean you should have it at three months. You can have it anytime afterwards, depending on your own convenience, comfort, and your tolerance.

Phil Orrell

Thank you. This lady asks what types of sedation you offer?

Mr Raman Thakur

So, the anaesthetist is a person who will decide what is the best form of anaesthetic for you. Having said that, over 95 or 90 percent of my patients have a spinal anaesthetic and something to keep you under sedation.

Phil Orrell

Yes, this person asks, is there a BMI limit to being able to have surgery?

Mr Raman Thakur

So, the upper BMI limit for having surgery at Benenden Hospital for joint replacement or hip replacement is 40 and certainly, if I see anybody over that, I encourage you to certainly work and get your weight down. It is an achievable target for most people, and it will certainly make the surgery safer, reduce the risk of complications, enable us to put the processes in the best position, and hopefully give you a better outcome from surgery. So certainly, I would encourage people to get their BMI below 40. If you do need help, you can see your doctor, get to support groups, or some of our bariatric colleagues actually offer some medical treatments as well as surgical treatments, so we've got all those options for taking and seeking help for weight management. Okay, thank you.

Phil Orrell

This person asks what I should be doing to prepare for surgery, for example, exercises.

Mr Raman Thakur

First and foremost you need to get your diagnosis confirmed you need to find that the arthritis is severe enough and you do need the surgery and if that has been agreed to the surgeon then certainly keeping your muscles in good condition keeping active which once you're waiting for knee replacement is very essential upper body strength working on it is important coming here asking the right questions of the team making sure you're aware what is required for from you making sure that you are clear of any infections because any health issues all these can hamper your recovery and increase risk of complications and certainly having any infection increases the likelihood that your surgery might be cancelled on the day so if you have got any water or chest infection or anything get that promptly checked by your doctor get that period nearer   find out what things you need to bring to the Hospital and speak to the team about the arrangements for physiotherapy.  What are the arrangements for, you're going home, and the process, which we did discuss, and how have we at Benenden managed the same similar thing? Finding out who will arrange the physiotherapy, how it will be arranged, and who needs to arrange the physiotherapy after surgery all those things will be important considerations before and during your recovery from surgery.

Phil Orrell

Thanks. The next question is: I still have good joint space, but with patellofemoral osteoarthritis, is a total knee replacement still the best option? I'm 64 years old.

Mr Raman Thakur

I am one of the surgeons who would offer partial knee replacements, and if someone has a problem only in one part of the joint, then I'm more than happy to offer you, if that's the case, a patellofemoral joint replacement, but it needs to be properly assessed. It needs to be made sure that the rest of the knee is completely okay and that your symptoms and signs justify going down that route of surgery.

Phil Orrell

Thank you. This person asks if I don't have pain at night or sitting and walking in general, but my walking now is limited to about four miles after previously being a good walker. My x-ray shows that there's not much cushioning left. Should I leave my replacement until I'm in more pain? I'm 79 years old.

Mr Raman Thakur

I think that most people on this call will say that four miles is a very good level of activity that you're able to manage, and personally, if I were able to do that, I would try and keep going with whatever options are available. As I said, if you haven't come to the phone on burn, maybe you can have those treatments like hyaluronic acid or something to keep you going for a while until your mobility gets slightly worse and you're getting more intrusive symptoms in other aspects of your life like stair slopes or creative activities that become a more important feature.

Phil Orrell

This person asks, is swimming recommended when suffering from knee issues?

Mr Raman Thakur

Yes, it is a good exercise. The only thing that I would say with swimming is to avoid the breaststroke leg movement because that is particularly not helpful with arthritis, but if you can do the backstroke or front crawl splat movements with your legs, that is certainly a very beneficial exercise to help strengthen your knee and keep you going, and also a general exercise for your fitness. Some people can't do that; they just walk in the water again. Walking in the water, doing a bit of aqua aerobics—any of those things can help keep your muscles around the knee in good shape as well as your general health and fitness.

Phil Orrell

All right, thank you.

This person says, I hadn't had an injection at Benenden today as I always have advanced arthritis in one knee. I'm hoping that this will help in the short term and delay the need for a knee replacement. At what age should I ideally wait to have a replacement to maximize the benefit?

Mr Raman Thakur

Yeah, so if you have it once, obviously the surgeon felt that you are probably a bit too good or a bit young to or with your profile in terms of your activity and your work requirements that knee replacement may not be the right thing straight away for you, but if you find that you're getting only benefit for two to three weeks and then the pain is coming back, then injections may not be the right answer for you and whether or not other interventions such as arthroscopy are appropriate again. If it is a born-on-bone situation, then that may not be appropriate, so I think it is a bit difficult to individualize your management, but certainly trying the non-operating measures would certainly be a good thing, and if they work for you, that is brilliant and may allow you to get another couple of years. Now that you asked, we did talk about long-term survivorship and things, so even if we do surgery in the early 60s, there is always a possibility that you may need one further operation.

Hopefully around the 80–85-year situation, but not everybody who does have a joint survived until then requires a revision, so keep up in this crossed, give me lost you long, but yeah, I would say hold off for as long as you can, and if you can't hold off, then you need it. You need it.

Phil Orrell

Okay. The next question is: if I have issues with opioid and codeine pain relief, what are the other options that could be available for me? I'm 61, and I have chronic pain issues, and my mobility is poor. Sorry, Phil, are you breaking up in there? Can you repeat that, just about apologies? I'll repeat the question: I have issues with opioid and codeine pain relief. What are the other options that could be available to me? I'm 61, and I have chronic pain issues, and my mobility is poor.

Mr Raman Thakur

So I think what you're describing is a globally complex situation, and if you are unable to tolerate the simple coding and slightly stronger or geodes, which your doctorate prides itself on, and when you say chronic pain, it may not be just your knee; there may be other areas that are affected, so have you been referred to or have you ever had a consultation with a chronic pain consultant because they would be the appropriate people to advise you on various options? Well, from strikes from mechanical to electrical to simple heat and cold options, acupuncture, or indeed medical management of pain and discussing the various pain pathways, I would certainly recommend that if your pain is not controlled and it is significantly affecting your quality of life, then a chronic pain consultant would certainly be the person to see.

Phil Orrell

Okay, thank you. I think we have two people asking the same question here: Is there an upper age limit for knee replacement surgery? One of these people says, I'm 76 and in good health, and I've lived with osteoarthritis of the knees for 25 years.

Mr Raman Thakur

So honestly, there is no upper limit for doing any replacement. My oldest patient was 90. And my oldest hip replacement patient was 95 for osteoarthritis. I have done hip replacement on a 98-year-old who has perfectly fit after a broken hip, so I think the important determinant features are your quality of life and your health status. So, if you are in good health and your general quality of life is pretty good, and it's just the joint that's affecting you, then I think you should consider having the joint replaced. 76 is certainly the most common age for us to do knee replacements.

Phil Orrell

Thanks. Let's say an attendee asks, you mentioned the vanguard prothesis at a 10-year survivorship; how does this relate to a knee replacement lasting 25 years on average? Please, could you clarify?

Mr Raman Thakur

The thing is in general the failure rate of knee replacement long term is one in a hundred per year so at 10 years if we did 100 today 10 would fail 20 years 20 would fail 25 years 25 would fail that sort of thing so they fail over a period of time and they fail generally at that sort of rate occasionally it may be one or two more three or four less but that is the sort of average over a period of time and that is what we were talking about so when we said 10 years there is less than 10 percent failure rate it might be slightly higher later on or it may continue at that because the important things to understand is that the plastic which was used for any replacement surgery that has certainly become much more developed enhanced and we are using high quality high density polyethylene which used to fail much earlier in older prosthesis so when you're looking back in time you're not judging the same materials over a period of time so once things have failed earlier in in the past that duration and survival seems to be getting better with the newer materials

Phil Orrell

okay, thank you. I'm afraid we've run out of time to take any further questions, and I apologize to anyone who didn't receive an answer to their question, but if you've provided your name, we can answer your question via email. Raman    Uh, please, could you move to the last slide if you could?

Mr Raman Thakur

Thank you very much, everyone. I hope you found that very helpful.

Phil Orrell

Just to add as a thank you for joining the session listed on this screen, as you can see, we're offering the value of your consultation refunded upon your booking a callback from your dedicated private patient advisor, and you'll receive an email tomorrow with a recording of this session and some further information plus updates on news and future events if you would like to discuss or book your consultation. The private patient team can take your call until 8 p.m. tonight or between 8 a.m. and 6 p.m. and 6 p.m. to Friday using the number on your screen now, and we'd be grateful if you could complete the survey when this session closes. Our next webinar is on prostate enlargement, and you can visit our website to sign up for that. All that remains for me to say is on behalf of Mr Thakur and our expert team at Benenden Hospital here. I'd like to say thank you for joining us today, and we hope to hear from you very soon. Thank you, and goodbye.