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Biomechanics of Hip Replacement for Orthopaedic Exams
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Biomechanics of Hip Replacement for Orthopaedic Exams
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Language: EN.
Segment:0 .
The evening, everybody. Welcome to another Wednesday session or joint between ORUK and the FRCS mentor site. Today, we are very pleased to present Mr Mahaluxmivala.
He's a consultant orthopedic surgeon who has both affiliation with the UK and a relation with the FRC mentor group since its inception. He was a consultant. He's a consultant in Prince Alexandra Hospital in Harlow Ramsey River Hospital. He is special interest in lower limb and joint arthroplasty in revision surgery.
He's completed his original orthopedic training with the prestigious Royal National Orthopedic Hospital in Stanmore rotation, and is also spent a lot of time as a visiting fellow and world renowned, which centers all across North America. He's co-director of the park's ortho revision course at the Royal College of Surgeons England, which I strongly recommend to anybody that can attend this course as I attended it as well, and I thought it was really useful with both himself and Mr Sherman.
He's also been invited as a national speaker at international conferences, and he's on the faculty of numerous teaching courses, including in Harlow, total knee replacement course and Cambridge based science course, and as a former faculty member at the combined best instructional course with us in the FRC mentored group since inception. I have always enjoyed listening to his talks, even when I was preparing for my exams.
I look forward to when I knew he was out. Of course, I always look forward to hearing from him on a personal level. He is an amazing teacher and I'm really proud to present him today in this matter. It's a pleasure to meet you. Thank you. Thank you very much, Sean. That's very good of you.
Can you hear me? One in honey. Yes yeah, Yeah. Thanks that an excellent introduction. Thank you so much and Thanks for being there, and also to our UK to Hannah and Imogene. So just to thank everyone. Like I said, I've been involved in a war for many years and we're there for us.
Since inception, the FARC has meant a group really way beyond the pandemic that we're beyond Zoom being popular. They were in the forefront of international meetings, and I'm really glad to be part of them with which one and all the mentors who started it. In addition, like swan said, I am passionate about teaching both the Duke and Duchess of Cambridge's cause and their.
Royal college course, which is me and Mr. Sherman co-host. Now this talk is important, and I shouldn't already has done an excellent talk on free body diagram, which is on the YouTube channel. But I thought talking about biomechanics from the surgeons point of view is always easy to repeat because however much time you repeat it, it's one of the talks where you agree and you want. People don't talk about it in the coffee room, et cetera.
You agree with that. So globalization of these, this topic, I think, is important to repeat. Is that correct for both of you? Would you agree with that? Yes, absolutely. It's the basis of understanding what we're putting in and. Yes, thank you. So we all do.
The talk is let's talk about start with free body diagram. Talk about offset. Talk a bit about the loosening. And one of the questions, which always is an issue every candidate, every six months or one year as to which hip to put in. What should I say? What should I not say? So I thought, I'll just expand on that.
And I put it in the talk that because there's is an excellent format. You know, you have a lecture, then you have a case discussion. And because I was leading onto the case discussion on hips because I'm a hip surgeon as well, that I thought that the end part of this talk, I will include how to interpret complex hip X-rays. And it's not complex because it's fellowship level.
It is. You're going to be shown a complex picture in the exam, there's no doubt about it. You don't expect to know how you'll truly tackle it, but the principles of talking about it are important once again. Sean and honey, do you agree that point is there, that it's not fellowship level to tackle it, but the interpretation of the X-rays would be expected?
Would that be correct? Both of you? Absolutely, Yeah. Kurita interpretation of the X rays, especially in the yeah, exactly. So however complex it is, we have to talk about. So that's what I'll end the talk with. And then we go on to questions the tiny will ask and then we'll have the discussion in the same team.
Yes, that's the plan for everyone today. So let's talk now. Going back to basic biomechanics. What is false? This is still the examiner. There are many definitions that you can go through all the textbooks, but we're not object is pushed or pull of forces apply. Just remember that statement.
And remember to tell the examiner that force could be tangential, shear compressive, et cetera. That's what the next thing is. What is weight? So weight is the gravitational force by the Earth on object. And remember that statement? So what is weight? Weight is the gravitation force by the Earth on object. So when an object is pushed, a couple of forces applied.
Yeah, and the force could be tangential, shear or compressed. OK and what is wait, so wait, is the gravitational force by the Earth on object, so tell the examiner that I'm going to commence by knowing what is weight. So weight is the gravitational force by the Earth. On object and the magnitude of that would be a nuisance. And the way I get that would be the mass of that human being is 100 kilograms into 9.8 meters, and that gives you the nucleus.
If you just remember that part. So moving on. What is moment? So just a simple definition of moment is the bending action about a point. It's the bending action of what a point is a moment. And remember that is different from a true leader. So what I'd like to tell you is start by saying examiner, I do know what a moment is and a moment is the bending action about the point.
Now, that is a bit different from talk, which is a rude reaction about the point for the point. The important issue is start telling the examiner when you're drawing a free body diagram that I'm selecting my point. So the point I select is sent to the femoral head center off of the ankle, et cetera, and then say the movement, which I want to talk about, is the bending action about that point, which is a center of my femoral head.
So moving on, what is the movement arm? So movement arm? And this is again a repetitive, but I just repeating again, it's the perpendicular distance from the line of action of the force. This is a line of action, of course. This is the perpendicular distance, and that's your moment of that's next statement, which I which all of you all know.
But I would like to say that again. Moving on, what is the movement, therefore? Is the force into the perpendicular distance, the force we need to know and the perpendicular distance from the point? And that gives you the movement. Now, direction of movement is something which every one of you will argue with your colleagues as to what is the direction of movement.
One would say this one or the other. The best way to remember this is it's the right hand thumbs up rule. So you put your hand. Yeah, everyone can use. Can anyone? See me now, can you see my hand, right hand and you put it a thumbs up your direction of finger as your brain is anti-clockwise?
So anti-clockwise is positive. That's one physical way of annoying. And I got this from a physics book, so. So the anti-clockwise is positive. Just remember that. So moving on, verbalize to the examiner that I do know and I want to know when I'm drawing you my free body diagram that I need to know the magnitude of my force. And that is the length.
So tell the examiner, the magnitude of my force is the length of the arrow, which I'm drawing, then say I need to know the line of action. I remember one word either use the word line of action or use the word line of orientation, so that could be either vertical. It could be. It could be horizontal, it could be vertical, it could be oblique.
So that's your line of action. And the third thing that the examiner, I will draw the arrow, which gives me my sense of the direction. So the three statements when you start drawing the first arrow is a magnitude is the length. The orientation is the angle. And the third is the direction, which is a set. And then say that we can now calculate forces by drawing to scale, which is the typical method.
That's your next statement. And then say, I do know that, I want to introduce a topic called couple. And what is a couple? Couple is a pair of horses, but in opposite direction. And I do know the resultant force of a couple is zero. So just going back again, this is the statement which I want you to give for drawing any free diagram. Whether it's the hip, the ankle, the spine is using these words, which is magnitude, orientation and sense.
Saying that I will calculate it by the tail method, then saying I need to know what is a couple that a pair of forces with opposite sense and the result of that force is zero? So moving on, we have the attachment of muscles, so can everyone see this? Yeah, so this is your attachment of your abductors, you agree at this. So we agree this is the magnitude, which is the length.
You agree that this is the body weight. Correct and this is the resultant force of the hit. Now one of the statements, which always confuses him and I ask or Sean or Henry when we are wavering, everyone puts the arrow or the sense down to the weight because that's no confusion. You agree. But when we draw the abductors, the abductor arrow is downwards and some people put it up where they can't understand why we are putting it downwards.
And the best way of explaining this is that imagine and once again try and just see where they can see my hands above me. So imagine that as a person, I am in the middle of the femoral head and I am trying to get my head out from the head. So and the right hand pulling down is your wit. OK now, imagine if there was no force pulling this way. You agree that if this pull down, I would just stumble across and go spinning, spinning, spinning.
So the way the body is up is going to neutralize that is. That's the reason why this is downwards and the abductor has to be in the same direction. And you as the head inside is coming out trying to get out through the head, and that's your result with force. So that's the best way I can explain it, rather than trying to argue with people as to why the arrows down rather than up.
OK, so this is just one simple way. But remember, the Arrowhead of both is going to be downwards. And the resultant force, of course, is here. And so once again, when you're telling the examiner, tell him, I'm going to draw your free body diagram, this is my type. I picked the center of the femoral head. This is the way downwards. This is the abductor force. And then moving on.
You have to ask the question, what are the common questions, what is the joint reaction force on the hit in single stance and opposite hand? Other question is tell me what happens when you swing your body over the affected hip? And tell me what happened? Do you agree? Five questions are the common ones asked. I don't have time to do all, but I just tell you how I want you to verbalize straightforward and simply as to what we do.
Tell me the joint reaction force in the hip in single stance, which is the common one asked. So for that, tell the examiner and verbalize that I do know that this is my magnitude and the arrow of pointing downwards. Yeah, that's. And that's five six. What do you eat? And that's when someone is standing on the left lower limb.
Right so that's downwards. Then say when in equilibrium, the known clockwise movement, you agree that this is clockwise and you agree by my convention of the off the thumbs up rule. You agree it's minus everyone. That's what we had said. This clockwise movement, which is downwards, has to be balanced by the unknown black-white anti-clockwise movement, which is here around the center of the femoral head.
Therefore, the first thing I want to know is what is the adductor muscle force? So the way I get that is I do know that it is 5 centimeters before that. We know B is 15 centimeters. So that's how we know the distances. We know until examiners, the forces or the couple is zero. And therefore, this force, which at the moment is unknown to me, this is unknown to me at the moment force into a which is this that's 5 plus.
Remember, we agree that coming down is minus for the body weight and to b, which I know this level 0. And by that calculation, I get 2.5. Body weight is my adductor force, and that's the direction of my arrow. Do you agree everyone? Now I want to know what is my joint reaction force? Now I know that this arrow downwards is 5 six body weight.
I know this arrow in this angle. And with the arrow down is 2.5 body weight. So therefore, when I do my. Dipped to Dale method. We agree this is 2.5 in this direction down. 5.6 there. And therefore the joint reaction force is 3.3. I believe that everyone gets confused because without knowing the abductors, they try to get this diagram.
But I'm trying to say is that you need to get to the force abductor first, which is on this slide right? You have to get my abductor force first and then you get the joint reaction force. So that's the simpler way of explaining it in the exam. So let's move on. Now we can just talk as to what is good, right, so we agree that if your body weight, which is down is less degree, that's good for joint reaction force.
That's one answer to the examiner. Do you agree now coming to distances? Remember, we said that C. Remember c, which is a distance from the head to your abduct, of course. Imagine that is small, right? Which has got so belga. Everyone agrees. You read that is small and that's bad. So you get a worse for your joint reaction force.
And the last thing is, B is good. The closer the center of gravity is to the B a center of rotation. It's better. So therefore this is the basic principle and I want you to verbalize it examiner of the trends test. Or when you put your body across the same side, you're getting this line closer, which is B is becoming smaller. So happy with that, everyone.
So that is what in a simple way, rather than trying to read many books, is what we get from joint reaction force. Why is this important as a surgeon, because this is a surgeon's perspective, so so far, maybe I think I was about 12 or 13 minutes. Is that right? One how many Mason have passed? Just about that?
Yeah so 12 or 13 minutes was unfortunate. I used the word, unfortunately, because this is not something we trained as surgeons to do it, and I didn't open up just I wanted to hammer in hips and knees, but we needed to know this. It's important. And now why? So when we talk about the question is, what happens to joint reaction force in gait running, stumbling bedrest?
I mean, who asked this question or Sean asked this question? Everyone will give an answer that is 5 times body weight, seven times body weight. But what we want to seek in the vibha is your higher order thinking. And what do you truly understand by 1848? What what is it worse than 2 times body weight? So that answer is that these are the figures. Yeah, we all know these figures.
Slow walking is three times Bodyweight class walking, even seven times body weight. If you are stumbling, get eight times body weight. What does it mean? This means that if you're kilos, man. And this is why the first statement I made was important. If you're talking about eight times body weight, it is 100, which is your axilo remember into your mass, which is your body weight and 8 times of that.
But we have to add in your 9.8 meters to get your answer in newtons, and that's 8,000 newtons, which is a huge amount of magnitude of force applied. And just so, you know, femoral neck fractures happen at about 9 thousand, so stumbling can truly cause the magnitude of your newtons to be so high. So I hope once again, I made it very clear and simple that what it means by body weight, rather than just saying three times, five times, seven times.
So this really gives you as to what it means. Now, let's go into something interesting, which we are surgeons and we want to bang in our hips and knees. So what is offset? So offset is the distance between the long axis of the FEMA and the center of rotation of your hip. And this could be a virgin hip or it could be your joint replacement.
Yes, but that's what I want to recreate is my obsession and tell the examiner that I do know of that is important and it changes with what the changes at neck length. So you can change the neck length and how you influence that length. That's very simple. Use of +5 head. Use a zero head or a minus 5. OK, so that's neck legs.
But it's also important that your offset changes with neck angle. So if you change your neck shaft angle, you have a change in offset. So keep that in mind. Now, the average object in the world is could be editing. Would be 40, et cetera and the range is from 27 to 757. So please accept there is a wide range. And the statement, which is very important to remember, is a various neck shaft angle varies.
So if you're in various. You have an increase offset, so keep that as gold standard of what I'm saying. So where is an. And do you have an increase of. And if you have a valid is next year and you have a decrease offset? OK, so next question to the examiners or the examiners or when you're talking, if you're given an implant and you're holding your hand.
Start talking about offset and then say, I do know offset is important because and everybody gets confused as to why you need correct offset. The best answer is, I feel say that I want to recreate correct offset of that patient or I want to increase or slightly increase. Offset is optimal because I want the best lever on ratio. So I hope you'll have to make this first statement. NYICD want that is that it's there to optimize my attention of the adductors.
So if I have my correct offset, I get the correct optimum attention of my abductors. And that indirectly increases my stability of my soft tissues, and it directly causes less imprisonment. So once again, every year I ask everyone, why do you want correct offset? And the answer is, is there. But clearly I want to correct or injuries. Offset is optimal is the best lever arm ratio.
It gives me my best attention of my abductors. It increases my stability of my soft tissues and I get less impingement for points. You know the words that it come out and then what can I do to get my offset better? Remember, we said the correct nickel and correct injection of angle or various will give you my better offset, and that's optimal and better offset. Is you can get this offset.
So you can increase offset without increasing net length, which indirectly for me as a hip surgeon means what? That I can get better at Dr. tensioning, I can get better stability, but I don't change the length of that limb. Right I don't want to make the patient long. So you get that by. Influencing your offset by changing into various. So that leads us to what is your normal neck and.
So Olvera is a neck angle, which is 1 to five, and as you go up more into valleys, you're into higher 125 and the neck shaft. If you look at measurements of the world population, the average I'm telling you is 1.88. But do you agree that DHS is a 5 at the hip Charnley hips all 1.30 five? You agree with that answer. I mean, it is you have other options, but the general answer wanted be back.
So whenever I ask is, why did this happen? Why is it one when truly, we know in the world that all our hips are probably at 128? And the answer to that is this that remember we said that best offset or various inkling of that is good because we get it's good for abductor function because you have a good offset. But and these are the three words which those giving the exam next week or any time are going to say.
That increased offset, however, unfortunately will increase. Three words bending moments in the proximal femur. So please remember that. OK, so that's what happens, and that bending moments in the proximal femur is worse when you're getting up on the chair or from the state line. Now, in the past when because of this increased bending moments, the proximal femur and metallurgy was not good when we had various stems, which are angled at, say, 125 120 eight.
You got what is called a stem breakage. So that is to happen. Metal break that you serve stem failure. We don't get that now with our new experts and you see the keys, but that was the reason why we opted for a little more about this. But for you at the basic science level, that's the fundamental reason. And therefore the opposite of that is a values in position is not really very good for best adaptive function.
But it does decrease the bending movements that FEMA. So the paradox is increased movement, growing weight bearing you get and where do you get it? Now this is once again, I know Sean and honey ask these questions that if you're doing a segment hip, where is the maximum strength? So this indirectly is telling you that the strain is within the stem and the death. That's one and the increased in on the medial cement pattern.
So that's the reason why now you know that I want the best cementing there and I want the best cementing here. Yeah so indirectly, we're covering another topic as to where we want our best cement, and therefore this could potentially lead to increased loosening and fracture, which I said doesn't happen now. So that was one concept, so what have we covered so far?
We've covered joint reaction force for stumbling falling fractures. We've covered the importance of true offset. We covered how offset is influenced by Netlink and changing your angle. We also covered why or where the bending movements are the most and where you should try to avoid having the best cement or where it fail failed right to be. Got that?
Now we're going to do a little next topic. Imagine you're giving an implant to hold as how do I want as a surgeon, my best implant? So where do you want to use is? I want my implant to be not dramatically stiff because the increase is detrimental. Yes, because you'll have more. What is the word I wanted to use, which all of you will say that increased stiffness of that implant or the metal will cause stress shielding, which I don't particularly want, they'll examine all modern implants will not have shock notches and shop owners because that's detrimental and will have increased stresses that.
Next thing and say that most of the modern hips, like the Exeter or the CBDS, will be in the vicinity of about 150. When you open your box and you're doing your time out in your checked list, all of them will say 150. Why is it 150? Why is it not five mm? Why is it not 550 millimeters? So for that, introduced the concept to your examiner that I do know that every implant is divided into three parts is the proximal and the distal.
The proximal and the distal are called the load transfer regions, and the middle is called a load sharing region and hence it, it's important for me. To have that and therefore high the percentage of the load carried by the stem in the middle region, more loaded, transfer distributed and detrimental. So therefore, you don't want to stiff import. So what is exactly stress feeling? I find this the simplest definition.
Higher the percentage of load carried by the stem in the middle region. More load to transfer distally, which is detrimental because that's where we are. And a lot of people ask, why don't you use a longer stem? That's not better. All you're doing is separating the proximal and distal regions. And theoretically, and I use what theoretically because once again, I'm a hip surgeon.
The collars are meant to transfer load. Approximately whether it truly happens or is not there, but that is the basis of your color. All right. So for transfer, remember three parts of the stem. You don't want to increase stiffness and you don't want sharp corners, and in the end, therefore we go to a fully coated implant. Why is it good?
It's good because you get initial rigid fixation, which is advantages of the examiner. This is imagine you're given an unlimited stem in your hand to talk about. You'll say yes, it is completely, fully coated. The advantage would be initial rigid fixation. However, I do know that this may have increased spot well and increased stress shielding, which is detrimental.
And then imagine you're given the next implant, which is your unselected stem, which is approximately peel-back in that you'll say this is approximately coated and unlimited stem. It has more of a physiological load transfer and theoretically less stress shielding. But there may be an initial, less rigid fixation. All right. So that's I'm just giving brief.
This is where we are with ultimate standards. So, so just to recap, now we are coming to the. Difficult question where everyone asks that, you know, what is your ideal here or which you could use? And everyone gets a little scared and say, although they failed me because I know he's a cement user and I use it for Allen. I said this and I said that it doesn't matter. We use whatever help you want, but you need to justify it by a particular manner.
So this is the way I think you can talk it. The first thing you say is and because you're joining me as a consultant said, I will use a generic. You use the name, I'll use a brand name, which is an Exeter cemented or cemented Trident doc. See that? And don't stop that. You have to immediately say that the reason I say this system is the system I want to use is because I want a system which reproduces the normal anatomy of patients to make that statement as your first statement and then say, I do know I will be tackling patients with different anatomic variants.
Therefore, I want a complete system, which is adequate inventory for all my anatomy deliveries. That's your basis of which system you use. Then say I need a robust planning or template input, which I can reproduce that patient's anatomy. That's important. And then say I want to reproduce the three most important things of hip replacement, which is recreating my hip center.
So I want that statement to be made, and I get that hip system like the Exeter or whichever you want to use it. It makes no difference, which reproduces offset. It reduces net length and it reduces neck angle. And then say, I want a hip system which has all the variability of optimal head neck ratio, I could use that word. I'm introducing that.
Then say, I need a system which has an initial stable fixation with ongoing lifelong fixation and then say, therefore, I use whichever of your traject 10 readings which got this paper, which shows a 15 year survival. So this is where your survival comes in. You're justifying that with nice and with all that and then say, I do know the stiffness is such that it is optimal and the stresses are reduced, then say, I want a system which has the best flexible bearing surfaces.
Therefore, don't get bogged down by OU ceramic for everyone or everyone. Tells you an exam. Say ceramic because otherwise, trouble. Everyone says ceramic and poly. You'll forget about it. You are all consulting colleagues in real life. I want a system which has a flexibility of all bearing surfaces.
And in true life in the UK, I will make that decision on cost. And therefore, it's a long term track record, it's non-experimental. Then you can add educational support and excellent support. OK, so this is but the basics is I use an implant because of these fundamental reasons, which are your biomechanical reasons. So that was my first boss, not too confusing one.
The first part of the talk was, unfortunately the biomechanics, and I hope I made it a little more interesting as to why we do it as a surgeon. So this is the first part. The second part is how to talk regarding a difficult hip management in the exam. So the first thing is. Imagine this is shown to you, and you all agree that on this X ray, the first thing will strike you is that it's not a straightforward hit.
It's not a straightforward hip you take on and in your mind, you all agree that this would probably be common in the realms of a complex hip. Right? I'll keep the true description of how we describe the hip just towards the end. But I want to point out first as to what we will say when we come across and why it is complex. And how we will manage this, so what I would like you to say in the exam, once you've described the extra in the manner which I do in the case discussion, OK, once you know it is complex, you're going to finish by saying, yes, this.
I see this, this, this, this and then the exam is going to ask you, how will you tackle this now in your mind? Do you agree? And I go back again. You agree. There's a degree of complexity to it. You talk about why, but it's not straightforward. And one of the things that I wanted to tell you, everyone is don't ask the examiner that does the patient have pain, has the patient has infection, has the patient had a stick, has the patient?
Don't ask that and don't even say that I will examine the patient and do a neurovascular deficit and run through points which are not truly relevant. As a consultant talking to you, but you can't. You can't go over the fact that you have to history and examine the patients. The best way of tackling these difficult situations is start by making a statement, which is assuming that I've taken a history, a complete history and I've completely examined the patient and conservative measures have been exhausted, and there's no true contraindication to joint replacement surgery, which is a recent stroke and there's no issue of fulminating infection.
This patient is a candidate for staged complex bilateral hip replacement, so you have to use those words. There's no doubt rubbing around the bush and saying, I'll give him a stick, I'll give him physio. Please don't do all that. OK, say that assuming the oldies have been exhausted, this is what I do. And then say it is complex surgery. So now my realm of my talk before I come on to X-ray interpretation is why did I feel it's complex or why should anyone feel it's complex?
So for me, as a hip surgeon, the complexity is divided into four points. So one is, am I going to struggle with my exposure? Is that exposure? And that would include the true pathology of the hip, which would make me struggle, but also where there's previous scarring if she's had four surgeries, five surgeries previously. Also, if the patient is obese, the patient's obese, in my opinion, it comes under a complex primary and when I booked my patients is very clear it could be obese patients.
My bookers know that I've written on very clearly. It's complex primary with a 1.5 hour slot, so keep that in mind. So exposure is one. Second is will I struggle or will I have difficulty in getting my hips center restoration? So this is the second word which I wanted to use when you're talking about any extra in the exam, either on Monday or for the people giving it next time.
So will I get my hip center restoration heard is to say I want to know whether there's any complexity on my femoral side. For example, is there a screw in place which I can't get my parole down? Is there or to me in places I can't do, right? So that's your femoral side. And then on your acetabular side, for example, is any destructive lesion, et cetera.
So just let go each of them in more detail. The exposure is I want to get exposure and discrete safety. So like I said, obesity and previous scarring is your soft tissue dissection to get into. And on the true hip side, I feel that free hips, which I challenge me, you agree, is pretty easy to tell examiners is the producer. Therefore, it's a challenge of exposure. There's an analysis, therefore, you know, it's stiff and you cannot destroy it.
Third is a box of magna, which is a large head. You don't know where to end, you know where to begin your distribution. So these are the only three entities where you struggle with exposure. So that's your one big heading where it is complex. The second big heading, which is complex, is how will I get my hips into restoration? So this is in your DDA shoes or any hip which got a destructive superior lip?
So tell examiner my aim is to get my hip center correct. And with that, I want to ask myself the Libya nerve problem, so am I really crystallizing everything? And will I get it with just a soft tissue and getting my cup where it is? Or is it so high that I will need resection of both? That's your question on your hips into restoration. Then I ask myself on my femur, right? What are our problems?
So one is, is an outpatient if it's not patent? Well, it's going to be difficult. Second, is there any metalwork there, which I'm going to remove at the same sitting? Or is it a metal work put in when the patient was three years old and now the patient 75? OK, it's going to be a struggle to remove that one screw, which is going to come in the way of your hip. Third, is there deformity?
Depression have a previous osteotomy and if that's all I'm worried about. And can I get my stem down? And therefore, that gives me the answer in your management that will have to do the same sitting material removal later date material removal. Do I have to do osteotomy same sitting or later? And do I use a short stem? That's all will be on the principles of management.
And moving on onto the acetabular side, what is my worry? My first worry is, can I get my cup down? As you know, when you're doing your MD, it's or hip all of us hip hop, two plastic surgeons. The question is, have I got my hip inferior, my cup in? So in other words, what is the word which I want you to use is can I localize the floor? Second is one side infuriated my cup and localize it to 4 and put my cup where I wanted to put.
Is there going to be unkind effects, really? And is that large enough to need? What will it need? Impaction bone grafting will need to augment the structural bone grafts. These three words I've used, which are all which you need to know that once I get my cup in the true floor, then is the uncontained effect superior?
How am I going to tackle that? And the three ways of tackling it would be impaction, bone grafting, structural bone grafting or augment? And then I divide my mind. So this is what I think in my mind. On the inside side is superior problem. And then I this the more difficult ones are what is happening in the true, as you know, the floor area.
So that is producer. And how far has it gone? And last question, I look at the extras. You don't need. Keep out of plastic surgeons. We get a lot of information from x-rays. But every time I ask the question, the first thing they say is I want to see you don't need a seat, you need to integrate plain x-rays.
And for that, the last thing is the column. And the walls intact. So the anterior column posterior wall intact. And therefore, I finish with this extra that if this X-ray is put to you, how are we going to talk about it that thank you again? I hope I've been as clear as I can at about 35 minutes on a very big topic, but I think it's such a topic that globalization and words coming out are important.
And this is a book, which is why the emphasis meant a good book. And as well we have the audio books, books so keep. And again, this is a donation to our UK and which is a charitable organization. And like I said, it's fantastic for teaching the UK. So thank you very much for that. OK I have a question, if that's OK. Yes and why is it so important to have your offset correct?
What what is the advantage mechanical advantage? I think the mechanical advantage one would be that, like I said, if your offset is key to getting your center of rotation has to be right. And if your center of rotation is right, your offset will follow depending on your implant, right when you do a hip replacement. And that's the difference between a virgin hip, and we're doing a hip replacement that we may put up perfectly.
But then if we put up perfectly with a perfect center of rotation where it's meant to be, we need the head and the neck to be in that center rotation. And we get that by only getting that offset right now. If we didn't get that offset right, let's say we got the offset wrong by either a combination of the neck length not being right, which is a common one people try to influence. Or we get it by truly not using the implant choice to us because all systems will have a varied level of implant choice.
You have a law set, you have a box of errors, then you have a high offset, you know, a very high offset. So these options are given to you. And if we get that right, then the abductor would, I would say therefore, if by getting the correct offset, which truly means the interpretation is correct, I recreate and get the best abductor tension. And the abductor tension is key to the hip stability, impingement, limp and outcome.
Right and the fourth is that what I try to push on is that when I do a gorilla, when I do on it, I do sometimes change my offset by actually using the cost of error stem. So I practically do it in real life, right? Because I don't want to link it. The mistake people make is they want to get the attention and the length and limb, and especially on cement it.
I see so many tips which are kept long. Right that's not right. So this is where Thanks for the question, because that's where offset is so important. Absolutely The when you talk about in terms of absolutely everything there is correct. But even more basic than that is inefficient. Abductor means that the joint reaction force across your prosthesis is minimal because the abductor doesn't need to work.
So hard. And so therefore you're also as well as all the other things which are extremely important and far more important than this. But that means your is less than or is less as well because of decreased joint reaction force. Long term survival? Thank you for that. In fact, that's a point, which is without a doubt that your long term survival will depend on joint reaction force being optimal, which happens only with correct about retention.
Thanks for that, Shawn. OK, so another question. So in order for total hip replacement to you, prefer to the small or large cup? Honey, if you don't mind when someone asked this, I think they were asking a very valid question is that there's a word called jumbo cops, which, you know, people, I guess this question is, will you put in a jumbo cop?
In other words, would you put in a cop? Which is more? The answer is in modern hip replacement surgery. I believe that you need to get your center of rotation perfect, which means the answer direct answer. This question is no. You need to get your cup perfectly positioned with the correct size cup, and that effect filled up with opening, so it's easier to put a larger cup.
It's easier to do a jungle cup, but the answer is no. And if you don't mind honey, when I go through some slides, that will become clear. For example, this one which is on the screen, it's not true at all this basis, but we need to tackle that. So we'll talk about that. But the direct answer is no. I don't think we should use large cups of jumbo cups. We need to get that hip center correct.
OK, so in case of long standing, Cox are vulgar, it is easy to increase the offset without any releases, any soft tissue release, is that one of the questions? Yes yeah, I would say even for that, I would say, I think and shivani will agree that these questions are more pertinent to fellowship level discussions, and I don't think because Sean and Annie, we are very particular that we want this to be true.
As far as guess based questions and answers, I can give the answer and the answer is no. The issue really is what I really don't do. So you get everything right and see where you are. But this will not be a pass or fail, and it won't be particularly asked. Do you agree with that? Yes this is beyond passes, and it's more highly specialized fellowship level.
Please try and keep it towards the FRC and I'll encourage these questions. But if they are like this, don't worry. If you ask this question, it means you've already come to the level of your 7 because you've answered the remaining adult reconstruction. Viva and all, you're sitting with me, as you know, as a fellowship or you're going through the states or any center for fellowship, and this actually is put in front of you.
Just tell me about this X. How will you start to move? I would start by saying that this is a AP radiograph of the pelvis centered on the symphysis pubis showing significant degenerative changes with significant bone loss in both of the femoral heads. The acetabulum is this plastic or both sides?
I cannot appreciate any deformities in the femur or the hemi pelvises are more or less equal and the there's not much rotation in this field, so very good. Um, I want to know whether there is a past history of be useful to know whether there is a past history of parentage disease or ADHD, or infection in this case.
And I would like to evaluate this patient clinically and take a detailed history and examine a lovely. Very good. So that's excellent. So if I just can stay on the screen, but because this is still part of the talk of teaching many, so everyone or everyone who comes the first thing to say, Emily, I'm very impressed. The first thing I want everyone to know is that if it's a building axilo, it's a knee or shoulder or ankle.
If you look at our policy has meant to book. There are a number of views, which are truly described, which are the correct views for that particular pathology. So for example, as a arthroplasty surgeon, I want you to start by saying this is the pelvis with both hips. X-rays centered over the simple pubis is what you want right now, Mattie and others. If imagine you saw an X-ray of the pelvis, which was adult reconstruction, but with your entire if your leg crests were also see, you agree that was not a arthroplasty extremity.
Yes that's what trauma, that's a trauma, so I want that clearly put to you that this is a girl, correct? So example, if you have a knee, talk about the correct knee. If you have a shoulder, say it's a preview of elbow view or whatever view you want to say. And if it's not correct, use the word attempted view. Is that the first statement I want you to make? Yeah so it's an attempted pelvis with both hips.
However, I'm not happy. It's not center views. So the first statement next may be while you're there, what else do you want it to be a perfect X ray? You can see the object performing a spherical. Yeah, I know you came to it later on, but in your talk, let it be first. Yeah, I know you came to it later, but let it be first. So and you want to say the symphysis pubis and the caucuses are in the same lines.
There's no relation there. So three points 4x ray is a pelvis to both hips centered over subscapularis. I'm happy with that obturator. Fundamental central on both sides and the simplest view is in the coccyx on a straight line. Now, in my next statement, I'm very glad with what you said. So maybe you said, what is the word you use bilateral? Just repeat the word destruct.
What do you say? Destructive I can't remember what exactly I said, but I think I said bilateral severe, destructive in the joints. Exactly so for everyone in the hip or any other technology, the first thing I want all of you to say is say, what did you see bond straightaway? So if you're seeing significant arthritis, use the word. I see bilateral significant destructive rapidity.
So now the word is that happy with the word destructive means automatically. You're joining my club of orthopedic surgeons and consultants to speak correctly, right? So the our property, if something is bombed or as a diagnosis. Now do you agree there is no bond in this? You know, it's not this. It's not.
It's not this. Not that. So then don't say anything. But imagine if it was a bond door this. Then you agree. Maybe at this stage as a consultant level talking, you'll say it is, but don't. We're down the line. Yeah, but the first thing you'll see is striking to you is destructive of both hips.
Next, I would say medical every hip. Why don't you just straight away say that I notice there's definite superior migration of both hips? Are you happy to make that statement? Yeah Yeah. So, you know, so in other words, you're saying directly that is a superior migration and my interpretation is changed.
Happy with that statement because that's the first thing which strikes me, right? So there's to be a migration of both FEMA and the center stage. So this is a statement I want. We want to use for all interpretation of X-rays. And next, I want you to divide your mind into the FEMA and the acetabular, right? So for the fema, if you don't mind, how many do we have for this session?
Honey, there's pre three volunteers problem. We have another volunteer. OK, but in that case, let me just carry on it, maybe for a few more and I'll explain this. So and for everyone when I start talking on the female side, right start, you jump straight away into destructive activity and then you went and said straight away, there's no issue in the canal, right? And you said the FEMA appears satisfactory.
Right? there's no sir, but there's a lot more we want. I want you all to talk about in the head. So the first thing you'll say in the head is describe the head and put this. I will say that is near the word I would use is near complete rehabilitation of the head. Are you happy with that? Maybe there's no head, right? Yeah near complete obliteration of the head.
Then you're going to say there are definite cysts in the head. Right, so you're talking with the head now in the head after you finished your destruction. The word you're using is complete on your destruction of the femoral head. What are the other options may if you didn't have this head, you could have a head, which has maintained its veracity. That's the most common hip. You get my point.
Yep yeah, so imagine you showing a bond or hip arthritis, which we do day in and day out, you agree in that if you ask to describe it, you're going to say the specificity of the head is one thing you agree. Correct Yes. But in this one, you are going to say there is near destruction of the family. So what is the third option, the head, which potentially you can see you will see a head, which is misshapen.
You agree. It's got a misshapen head. I could use that word. That's the third word which everyone should use, that you have a misshapen head. The fourth you agree, you have a large head, which you get in both these or Magna. You happy with that many? Yeah, so you'll get a coxswain magnet, that's your fourth type of head, and that's all you'll get.
Yeah and the last one, if you really want to be stick it. Sometimes we see a portion of the head, which is collapsed. And we call that sectoral collapse. You know, sometimes you see your head, which is nice and round, but just the corner. Your superior like corner is defect. You agree. And that because the. So this is so now, honey, I'm happy, and then we go on to the next.
So in the neck, I want you to say that I would expect that you will say that the neck is short and you agree it's or shorten. It's a shorter neck than normal, right? So you see it as a four foreshock neck. However, the values in various is one gained, so it's not particularly in value. So I want you to talk about that and then say in the intro to Kendrick.
And the soft Kendrick area, I do not see any evidence of a osteotomy. I do not see any evidence of a previous metalwork or tract of metalwork removal. So that's all you can see in that area. What are the three things many repeat again in the traject? Repeat for me in the. So you still in the software category, peripheral country and region, there is no sign of a previous operation or osteotomy or any metal work or metal or deformed or deformity or a tract of metal.
You know, when you think like that. So deformed in your words, the words you can verbalize is posturing. Previous ostomy, previous metalwork and a cracked of metal rock removal. Right? and last say, the canal is patent, yeah, and the canal appears to be happy with that. And then finished by saying maybe on this particular radiograph, I cannot see, and I expect that we should not have any trauma, but if there is any evidence of egawa trauma, I want a full length femur.
You're going to make that statement right. So this gives me higher order thinking. OK, that's fine, Mary, very well done. So can we move to the next one? Sorry imagine you finished your camera side. And thank you for once again, I'm not. It's not a testing of your exam knowledge to initiate a discussion, literally.
So now imagine you've finished the funeral side and now say on the acceptable side, what will you talk on the acetabular side? Tell me what? You talk there. So on that side? I see are the most acetabulum displaced migration of the femoral head.
This superior erosion of the upper part of the acetabulum, I can say it is hard to describe one. The head is still inside the stadium with super migration. Good very nice. Broken, broken, broken. Shenton line on both sides. Mm-hmm What does that give you? Said that?
What does that mean to you? This means the center is migrated separately in relation to the teardrop. OK very good weather. Yes, fine. Love you. The acetabular solar cell is more than 10 degrees or I can say it, but so what angle you inclined? Yeah, you're talking very well.
So I'm using the saucer cell, the adjustable solar cell or the roof have a roof angle. Yeah OK. Very good. Excellent So very impressed. So for everyone, I've tried to cover the favorite part to give you all the options. And now I'm trying to tell you what I'll talk about in the axilo 2012.
You're very correct. First thing you can tell people or say that there is definite, you know, you said superior and then you weren't sure what word to use. So I would particularly say there's definite superior lip destruction. You have to use that statement. Superior lip of the stability structure. Yes Yes.
And then you can say this means there's definite superior migration of femoral head right to make that statement, then say that the acetabular angle has definitely increased, right? Forget about dropping weight, and just all you want to see is the angle. If I ask you how to draw it, it's the angle at the lower end of the teardrop and another line going to where the acetabular finishes.
Yes and what are the values? Do the value of that? The normal value is 35, but as you were more inclined, you agree as you go more upwards. More and more destruction here. You agree your angle is going more and more upwards. So that's above 45 is considered as an issue right now. Once again, do you agree that this is not a barn door person who was born with dysplasia?
Do you agree with that? Yes Yeah. So this is not a true deed in a young girl who's. Do I say that at most the DHS would have the femoral head nice and round, but it'll be lying somewhere here and there. So all these crew classifications of DH try not to use when there's actually a spiral of destruction.
You get my point very well. Yeah yes, that this is dysplastic. I agree. You can use the word dysplastic, but is dysplastic because there's to be a destruction. It's not dysplastic, but the patient was born with it, right? Correct Yeah. So there's a subtle difference, so that's the first thing to tell you just talk with Astrid angle.
So once you finish the angle, so what are you going to start by construction? You're going to talk about the angle, then you're going to say, can you visualize your jaw drop or not? Just say, yes, I can, right? You can see I can. I can see both sides. Yes, but Yes.
So what does that mean? That means you're indirectly telling me that the flow of the as satisfactory? Is that right? That gives me good information that I'm happy. Is that right? Yes Yeah. So that's your next statement you make. And then you'll say, I like to draw which lines will you like?
Like what line is this? And then what line is, is this? What line is this first line and the line, right? So what does the yellow line? Give me information on the center column of the terminal, and the line represents the Western column exactly where you want to remember the way I remember it or your pubic? Yeah, will be the opposite of B. So it is the anterior wall, right?
The opposite of B is enter your wall and there is still. It still gives me information about the book and wall is the columns. Yeah so do you agree at least looking at this? Do you agree that a column is intact between? Now, both musical and looks intact, but you see how much information you're getting and you can say this.
So now coming down to the management is how will I manage this? So how will you manage this? You manage this. So how will you manage this patient? I didn't drive it very well. I'm very impressed. I will take the laboratory and then examine the patient. My aim in this case is to restore the center of rotation through due diligence.
Describe the collar is a little understood the femoral offset. Yeah very nice. How do I need to also to augment the starboard effect on both sides with American graft? So what? You're going to get the hip centered down. So now do you agree with that? If anyone before that, you know, when the person asking you a jumbo cup, I know they didn't mean it in this, but using a large jumbo copier is not right.
You need to get your hip center back here, right? So mentally, you're going to hit your hips into Down. And then this defect here, you're going to cover with what? What is your choice? What are your three choices and what will you do? The best option is to was bone graft. I reconstructed with bone graft. What bone dry now because you've talked well and.
Yeah, my spoon graph from the small heads. If it's not enough, I have to prepare allogeneic bone graft. Do you think this head will give you anything or is it in your head at all? Nothing, right. So you'll have to get what you will, but we'll use impaction, bone grafting or you're going to just structural bone structure, structural bone graft, and they will fix it by screws or mesh. Fantastic OK, so that's excellent.
So just to, you know, you said you said you use screws and then you said mesh, you're just to make everyone clear that once you recreate and get your hips, enter right, everyone. So whether you put your cup there, you'll have a defect here and this defect. First of all, agree to uncontained effect everyone. So four principles point of view. This is the uncontained effect.
The first thing to get a 7 or eight, you say, I'd like to convert this into a contained defect. And one way of doing that is to use a mesh and I will use impaction bone grafting. So mesh and impaction grown grafting go together as one statement, right? Yeah so that's one. The other way of doing it is no right or wrong, the different ways surgeons do, but you need to know the principles is that this defect I will use a structural bone graft and fix of it screws right like you want it.
And the third, I will use caboclo metal augment. And just so you finish, I think I'll finish with what I did. So just to know is, you agree now. I got my. You agree the cup is meant to be and whatever I used might suppose I show you this X-ray as a partial. What did you say? You see, I this is it was mesh on the induction bone graft. It was cemented on back graft.
Yes, exactly. But before you started metal, you would have a nice to say that on the femoral side, I don't see any problem. I will use my dippold stem. You agree that also makes the examiners feel that you're not worried about the female, then say the complexities of the vascular side and you say what you said and this is what I did.
Yeah so if you show it to them, you say I noticed this mesh is impaction bone grafting behind the mesh. So just to finish for everyone, just to give you an example, schwa Nanite and give you just 1 minute. You agree. If you're showing this X ray, everyone will say that the word I would use is this is a classical osteoarthritis of the left hip.
Start by saying this is the femur. Do you agree now that is completely wrong? You're going to say that by women are not equal. It's not centered correctly. Then you're going to say the classical. The what I see is a hip arthritis with a severity of the head being maintained, the neck of your satisfactory, the neck shaft, angle of your satisfactory and the shaft and the protected area was satisfactory.
Imagine if you're showing this degree in this one, you'll say there is destruction of the criminal head with superior migration with superior limb destruction. Yeah imagine what you'll say for this one. You grieve for this one, you'll say that I notice there's a. Head, which is, what do you want to call it? You can see a misshapen head, everyone. You agree that you cannot see the difference between the cup and the acetabulum, so you'll agree this is an enclosed metallic.
Yeah and so what is my complexity here is and you agree now that is there's no pattern see of the canal, everyone. Right? for example, you agree that is a deformity in the rock area. So once you know what you're talking about, this is not going to be easy. So you say all these things, these are misshapen head there is enclose the joint.
There is a slap traject gastric deformity. There's no patency of the canal and on the top side. Well, I don't think the cup was an issue. Imagine on this one. Very easy to say, what are you going to say? Yes, folks are happy with everyone. Yeah, Yeah. But you also talk with acetabulum beer, but you say my FEMA off your satisfaction, you know, so you're talking with sense.
And this one, you agree. Australia big changes, very short neck. Previous Australian. And this one, you're going to say producer, Yeah. How are you going to say it? You agree that the humor is beyond your line, right? So that's how we finish. Yeah OK. So thank you.
This is what I did for one of them. This is this is a difficult one. Remember the one which you can get right? The cop is straightforward, but you can all see the canal. That's where you have to struggle. So my complexity why I took about three hours to do it would be the complexity in the criminal side. Yeah OK. And thank you.
So I'll end there. Sorry over Shanahan know very much talking to, as always, under your structured way of answering the questions is, I think, quite important for our candidates to learn. So I do recommend reviewing this video when we put it up on our YouTube channel. Because I end up, I sometimes go over these videos, especially from my view, on the basis that essentially he has the perfect structure for the answers.
Thank you so much.
Segment:0 .
The evening, everybody. Welcome to another Wednesday session or joint between ORUK and the FRCS mentor site. Today, we are very pleased to present Mr Mahaluxmivala.
He's a consultant orthopedic surgeon who has both affiliation with the UK and a relation with the FRC mentor group since its inception. He was a consultant. He's a consultant in Prince Alexandra Hospital in Harlow Ramsey River Hospital. He is special interest in lower limb and joint arthroplasty in revision surgery.
He's completed his original orthopedic training with the prestigious Royal National Orthopedic Hospital in Stanmore rotation, and is also spent a lot of time as a visiting fellow and world renowned, which centers all across North America. He's co-director of the park's ortho revision course at the Royal College of Surgeons England, which I strongly recommend to anybody that can attend this course as I attended it as well, and I thought it was really useful with both himself and Mr Sherman.
He's also been invited as a national speaker at international conferences, and he's on the faculty of numerous teaching courses, including in Harlow, total knee replacement course and Cambridge based science course, and as a former faculty member at the combined best instructional course with us in the FRC mentored group since inception. I have always enjoyed listening to his talks, even when I was preparing for my exams.
I look forward to when I knew he was out. Of course, I always look forward to hearing from him on a personal level. He is an amazing teacher and I'm really proud to present him today in this matter. It's a pleasure to meet you. Thank you. Thank you very much, Sean. That's very good of you.
Can you hear me? One in honey. Yes yeah, Yeah. Thanks that an excellent introduction. Thank you so much and Thanks for being there, and also to our UK to Hannah and Imogene. So just to thank everyone. Like I said, I've been involved in a war for many years and we're there for us.
Since inception, the FARC has meant a group really way beyond the pandemic that we're beyond Zoom being popular. They were in the forefront of international meetings, and I'm really glad to be part of them with which one and all the mentors who started it. In addition, like swan said, I am passionate about teaching both the Duke and Duchess of Cambridge's cause and their.
Royal college course, which is me and Mr. Sherman co-host. Now this talk is important, and I shouldn't already has done an excellent talk on free body diagram, which is on the YouTube channel. But I thought talking about biomechanics from the surgeons point of view is always easy to repeat because however much time you repeat it, it's one of the talks where you agree and you want. People don't talk about it in the coffee room, et cetera.
You agree with that. So globalization of these, this topic, I think, is important to repeat. Is that correct for both of you? Would you agree with that? Yes, absolutely. It's the basis of understanding what we're putting in and. Yes, thank you. So we all do.
The talk is let's talk about start with free body diagram. Talk about offset. Talk a bit about the loosening. And one of the questions, which always is an issue every candidate, every six months or one year as to which hip to put in. What should I say? What should I not say? So I thought, I'll just expand on that.
And I put it in the talk that because there's is an excellent format. You know, you have a lecture, then you have a case discussion. And because I was leading onto the case discussion on hips because I'm a hip surgeon as well, that I thought that the end part of this talk, I will include how to interpret complex hip X-rays. And it's not complex because it's fellowship level.
It is. You're going to be shown a complex picture in the exam, there's no doubt about it. You don't expect to know how you'll truly tackle it, but the principles of talking about it are important once again. Sean and honey, do you agree that point is there, that it's not fellowship level to tackle it, but the interpretation of the X-rays would be expected?
Would that be correct? Both of you? Absolutely, Yeah. Kurita interpretation of the X rays, especially in the yeah, exactly. So however complex it is, we have to talk about. So that's what I'll end the talk with. And then we go on to questions the tiny will ask and then we'll have the discussion in the same team.
Yes, that's the plan for everyone today. So let's talk now. Going back to basic biomechanics. What is false? This is still the examiner. There are many definitions that you can go through all the textbooks, but we're not object is pushed or pull of forces apply. Just remember that statement.
And remember to tell the examiner that force could be tangential, shear compressive, et cetera. That's what the next thing is. What is weight? So weight is the gravitational force by the Earth on object. And remember that statement? So what is weight? Weight is the gravitation force by the Earth on object. So when an object is pushed, a couple of forces applied.
Yeah, and the force could be tangential, shear or compressed. OK and what is wait, so wait, is the gravitational force by the Earth on object, so tell the examiner that I'm going to commence by knowing what is weight. So weight is the gravitational force by the Earth. On object and the magnitude of that would be a nuisance. And the way I get that would be the mass of that human being is 100 kilograms into 9.8 meters, and that gives you the nucleus.
If you just remember that part. So moving on. What is moment? So just a simple definition of moment is the bending action about a point. It's the bending action of what a point is a moment. And remember that is different from a true leader. So what I'd like to tell you is start by saying examiner, I do know what a moment is and a moment is the bending action about the point.
Now, that is a bit different from talk, which is a rude reaction about the point for the point. The important issue is start telling the examiner when you're drawing a free body diagram that I'm selecting my point. So the point I select is sent to the femoral head center off of the ankle, et cetera, and then say the movement, which I want to talk about, is the bending action about that point, which is a center of my femoral head.
So moving on, what is the movement arm? So movement arm? And this is again a repetitive, but I just repeating again, it's the perpendicular distance from the line of action of the force. This is a line of action, of course. This is the perpendicular distance, and that's your moment of that's next statement, which I which all of you all know.
But I would like to say that again. Moving on, what is the movement, therefore? Is the force into the perpendicular distance, the force we need to know and the perpendicular distance from the point? And that gives you the movement. Now, direction of movement is something which every one of you will argue with your colleagues as to what is the direction of movement.
One would say this one or the other. The best way to remember this is it's the right hand thumbs up rule. So you put your hand. Yeah, everyone can use. Can anyone? See me now, can you see my hand, right hand and you put it a thumbs up your direction of finger as your brain is anti-clockwise?
So anti-clockwise is positive. That's one physical way of annoying. And I got this from a physics book, so. So the anti-clockwise is positive. Just remember that. So moving on, verbalize to the examiner that I do know and I want to know when I'm drawing you my free body diagram that I need to know the magnitude of my force. And that is the length.
So tell the examiner, the magnitude of my force is the length of the arrow, which I'm drawing, then say I need to know the line of action. I remember one word either use the word line of action or use the word line of orientation, so that could be either vertical. It could be. It could be horizontal, it could be vertical, it could be oblique.
So that's your line of action. And the third thing that the examiner, I will draw the arrow, which gives me my sense of the direction. So the three statements when you start drawing the first arrow is a magnitude is the length. The orientation is the angle. And the third is the direction, which is a set. And then say that we can now calculate forces by drawing to scale, which is the typical method.
That's your next statement. And then say, I do know that, I want to introduce a topic called couple. And what is a couple? Couple is a pair of horses, but in opposite direction. And I do know the resultant force of a couple is zero. So just going back again, this is the statement which I want you to give for drawing any free diagram. Whether it's the hip, the ankle, the spine is using these words, which is magnitude, orientation and sense.
Saying that I will calculate it by the tail method, then saying I need to know what is a couple that a pair of forces with opposite sense and the result of that force is zero? So moving on, we have the attachment of muscles, so can everyone see this? Yeah, so this is your attachment of your abductors, you agree at this. So we agree this is the magnitude, which is the length.
You agree that this is the body weight. Correct and this is the resultant force of the hit. Now one of the statements, which always confuses him and I ask or Sean or Henry when we are wavering, everyone puts the arrow or the sense down to the weight because that's no confusion. You agree. But when we draw the abductors, the abductor arrow is downwards and some people put it up where they can't understand why we are putting it downwards.
And the best way of explaining this is that imagine and once again try and just see where they can see my hands above me. So imagine that as a person, I am in the middle of the femoral head and I am trying to get my head out from the head. So and the right hand pulling down is your wit. OK now, imagine if there was no force pulling this way. You agree that if this pull down, I would just stumble across and go spinning, spinning, spinning.
So the way the body is up is going to neutralize that is. That's the reason why this is downwards and the abductor has to be in the same direction. And you as the head inside is coming out trying to get out through the head, and that's your result with force. So that's the best way I can explain it, rather than trying to argue with people as to why the arrows down rather than up.
OK, so this is just one simple way. But remember, the Arrowhead of both is going to be downwards. And the resultant force, of course, is here. And so once again, when you're telling the examiner, tell him, I'm going to draw your free body diagram, this is my type. I picked the center of the femoral head. This is the way downwards. This is the abductor force. And then moving on.
You have to ask the question, what are the common questions, what is the joint reaction force on the hit in single stance and opposite hand? Other question is tell me what happens when you swing your body over the affected hip? And tell me what happened? Do you agree? Five questions are the common ones asked. I don't have time to do all, but I just tell you how I want you to verbalize straightforward and simply as to what we do.
Tell me the joint reaction force in the hip in single stance, which is the common one asked. So for that, tell the examiner and verbalize that I do know that this is my magnitude and the arrow of pointing downwards. Yeah, that's. And that's five six. What do you eat? And that's when someone is standing on the left lower limb.
Right so that's downwards. Then say when in equilibrium, the known clockwise movement, you agree that this is clockwise and you agree by my convention of the off the thumbs up rule. You agree it's minus everyone. That's what we had said. This clockwise movement, which is downwards, has to be balanced by the unknown black-white anti-clockwise movement, which is here around the center of the femoral head.
Therefore, the first thing I want to know is what is the adductor muscle force? So the way I get that is I do know that it is 5 centimeters before that. We know B is 15 centimeters. So that's how we know the distances. We know until examiners, the forces or the couple is zero. And therefore, this force, which at the moment is unknown to me, this is unknown to me at the moment force into a which is this that's 5 plus.
Remember, we agree that coming down is minus for the body weight and to b, which I know this level 0. And by that calculation, I get 2.5. Body weight is my adductor force, and that's the direction of my arrow. Do you agree everyone? Now I want to know what is my joint reaction force? Now I know that this arrow downwards is 5 six body weight.
I know this arrow in this angle. And with the arrow down is 2.5 body weight. So therefore, when I do my. Dipped to Dale method. We agree this is 2.5 in this direction down. 5.6 there. And therefore the joint reaction force is 3.3. I believe that everyone gets confused because without knowing the abductors, they try to get this diagram.
But I'm trying to say is that you need to get to the force abductor first, which is on this slide right? You have to get my abductor force first and then you get the joint reaction force. So that's the simpler way of explaining it in the exam. So let's move on. Now we can just talk as to what is good, right, so we agree that if your body weight, which is down is less degree, that's good for joint reaction force.
That's one answer to the examiner. Do you agree now coming to distances? Remember, we said that C. Remember c, which is a distance from the head to your abduct, of course. Imagine that is small, right? Which has got so belga. Everyone agrees. You read that is small and that's bad. So you get a worse for your joint reaction force.
And the last thing is, B is good. The closer the center of gravity is to the B a center of rotation. It's better. So therefore this is the basic principle and I want you to verbalize it examiner of the trends test. Or when you put your body across the same side, you're getting this line closer, which is B is becoming smaller. So happy with that, everyone.
So that is what in a simple way, rather than trying to read many books, is what we get from joint reaction force. Why is this important as a surgeon, because this is a surgeon's perspective, so so far, maybe I think I was about 12 or 13 minutes. Is that right? One how many Mason have passed? Just about that?
Yeah so 12 or 13 minutes was unfortunate. I used the word, unfortunately, because this is not something we trained as surgeons to do it, and I didn't open up just I wanted to hammer in hips and knees, but we needed to know this. It's important. And now why? So when we talk about the question is, what happens to joint reaction force in gait running, stumbling bedrest?
I mean, who asked this question or Sean asked this question? Everyone will give an answer that is 5 times body weight, seven times body weight. But what we want to seek in the vibha is your higher order thinking. And what do you truly understand by 1848? What what is it worse than 2 times body weight? So that answer is that these are the figures. Yeah, we all know these figures.
Slow walking is three times Bodyweight class walking, even seven times body weight. If you are stumbling, get eight times body weight. What does it mean? This means that if you're kilos, man. And this is why the first statement I made was important. If you're talking about eight times body weight, it is 100, which is your axilo remember into your mass, which is your body weight and 8 times of that.
But we have to add in your 9.8 meters to get your answer in newtons, and that's 8,000 newtons, which is a huge amount of magnitude of force applied. And just so, you know, femoral neck fractures happen at about 9 thousand, so stumbling can truly cause the magnitude of your newtons to be so high. So I hope once again, I made it very clear and simple that what it means by body weight, rather than just saying three times, five times, seven times.
So this really gives you as to what it means. Now, let's go into something interesting, which we are surgeons and we want to bang in our hips and knees. So what is offset? So offset is the distance between the long axis of the FEMA and the center of rotation of your hip. And this could be a virgin hip or it could be your joint replacement.
Yes, but that's what I want to recreate is my obsession and tell the examiner that I do know of that is important and it changes with what the changes at neck length. So you can change the neck length and how you influence that length. That's very simple. Use of +5 head. Use a zero head or a minus 5. OK, so that's neck legs.
But it's also important that your offset changes with neck angle. So if you change your neck shaft angle, you have a change in offset. So keep that in mind. Now, the average object in the world is could be editing. Would be 40, et cetera and the range is from 27 to 757. So please accept there is a wide range. And the statement, which is very important to remember, is a various neck shaft angle varies.
So if you're in various. You have an increase offset, so keep that as gold standard of what I'm saying. So where is an. And do you have an increase of. And if you have a valid is next year and you have a decrease offset? OK, so next question to the examiners or the examiners or when you're talking, if you're given an implant and you're holding your hand.
Start talking about offset and then say, I do know offset is important because and everybody gets confused as to why you need correct offset. The best answer is, I feel say that I want to recreate correct offset of that patient or I want to increase or slightly increase. Offset is optimal because I want the best lever on ratio. So I hope you'll have to make this first statement. NYICD want that is that it's there to optimize my attention of the adductors.
So if I have my correct offset, I get the correct optimum attention of my abductors. And that indirectly increases my stability of my soft tissues, and it directly causes less imprisonment. So once again, every year I ask everyone, why do you want correct offset? And the answer is, is there. But clearly I want to correct or injuries. Offset is optimal is the best lever arm ratio.
It gives me my best attention of my abductors. It increases my stability of my soft tissues and I get less impingement for points. You know the words that it come out and then what can I do to get my offset better? Remember, we said the correct nickel and correct injection of angle or various will give you my better offset, and that's optimal and better offset. Is you can get this offset.
So you can increase offset without increasing net length, which indirectly for me as a hip surgeon means what? That I can get better at Dr. tensioning, I can get better stability, but I don't change the length of that limb. Right I don't want to make the patient long. So you get that by. Influencing your offset by changing into various. So that leads us to what is your normal neck and.
So Olvera is a neck angle, which is 1 to five, and as you go up more into valleys, you're into higher 125 and the neck shaft. If you look at measurements of the world population, the average I'm telling you is 1.88. But do you agree that DHS is a 5 at the hip Charnley hips all 1.30 five? You agree with that answer. I mean, it is you have other options, but the general answer wanted be back.
So whenever I ask is, why did this happen? Why is it one when truly, we know in the world that all our hips are probably at 128? And the answer to that is this that remember we said that best offset or various inkling of that is good because we get it's good for abductor function because you have a good offset. But and these are the three words which those giving the exam next week or any time are going to say.
That increased offset, however, unfortunately will increase. Three words bending moments in the proximal femur. So please remember that. OK, so that's what happens, and that bending moments in the proximal femur is worse when you're getting up on the chair or from the state line. Now, in the past when because of this increased bending moments, the proximal femur and metallurgy was not good when we had various stems, which are angled at, say, 125 120 eight.
You got what is called a stem breakage. So that is to happen. Metal break that you serve stem failure. We don't get that now with our new experts and you see the keys, but that was the reason why we opted for a little more about this. But for you at the basic science level, that's the fundamental reason. And therefore the opposite of that is a values in position is not really very good for best adaptive function.
But it does decrease the bending movements that FEMA. So the paradox is increased movement, growing weight bearing you get and where do you get it? Now this is once again, I know Sean and honey ask these questions that if you're doing a segment hip, where is the maximum strength? So this indirectly is telling you that the strain is within the stem and the death. That's one and the increased in on the medial cement pattern.
So that's the reason why now you know that I want the best cementing there and I want the best cementing here. Yeah so indirectly, we're covering another topic as to where we want our best cement, and therefore this could potentially lead to increased loosening and fracture, which I said doesn't happen now. So that was one concept, so what have we covered so far?
We've covered joint reaction force for stumbling falling fractures. We've covered the importance of true offset. We covered how offset is influenced by Netlink and changing your angle. We also covered why or where the bending movements are the most and where you should try to avoid having the best cement or where it fail failed right to be. Got that?
Now we're going to do a little next topic. Imagine you're giving an implant to hold as how do I want as a surgeon, my best implant? So where do you want to use is? I want my implant to be not dramatically stiff because the increase is detrimental. Yes, because you'll have more. What is the word I wanted to use, which all of you will say that increased stiffness of that implant or the metal will cause stress shielding, which I don't particularly want, they'll examine all modern implants will not have shock notches and shop owners because that's detrimental and will have increased stresses that.
Next thing and say that most of the modern hips, like the Exeter or the CBDS, will be in the vicinity of about 150. When you open your box and you're doing your time out in your checked list, all of them will say 150. Why is it 150? Why is it not five mm? Why is it not 550 millimeters? So for that, introduced the concept to your examiner that I do know that every implant is divided into three parts is the proximal and the distal.
The proximal and the distal are called the load transfer regions, and the middle is called a load sharing region and hence it, it's important for me. To have that and therefore high the percentage of the load carried by the stem in the middle region, more loaded, transfer distributed and detrimental. So therefore, you don't want to stiff import. So what is exactly stress feeling? I find this the simplest definition.
Higher the percentage of load carried by the stem in the middle region. More load to transfer distally, which is detrimental because that's where we are. And a lot of people ask, why don't you use a longer stem? That's not better. All you're doing is separating the proximal and distal regions. And theoretically, and I use what theoretically because once again, I'm a hip surgeon.
The collars are meant to transfer load. Approximately whether it truly happens or is not there, but that is the basis of your color. All right. So for transfer, remember three parts of the stem. You don't want to increase stiffness and you don't want sharp corners, and in the end, therefore we go to a fully coated implant. Why is it good?
It's good because you get initial rigid fixation, which is advantages of the examiner. This is imagine you're given an unlimited stem in your hand to talk about. You'll say yes, it is completely, fully coated. The advantage would be initial rigid fixation. However, I do know that this may have increased spot well and increased stress shielding, which is detrimental.
And then imagine you're given the next implant, which is your unselected stem, which is approximately peel-back in that you'll say this is approximately coated and unlimited stem. It has more of a physiological load transfer and theoretically less stress shielding. But there may be an initial, less rigid fixation. All right. So that's I'm just giving brief.
This is where we are with ultimate standards. So, so just to recap, now we are coming to the. Difficult question where everyone asks that, you know, what is your ideal here or which you could use? And everyone gets a little scared and say, although they failed me because I know he's a cement user and I use it for Allen. I said this and I said that it doesn't matter. We use whatever help you want, but you need to justify it by a particular manner.
So this is the way I think you can talk it. The first thing you say is and because you're joining me as a consultant said, I will use a generic. You use the name, I'll use a brand name, which is an Exeter cemented or cemented Trident doc. See that? And don't stop that. You have to immediately say that the reason I say this system is the system I want to use is because I want a system which reproduces the normal anatomy of patients to make that statement as your first statement and then say, I do know I will be tackling patients with different anatomic variants.
Therefore, I want a complete system, which is adequate inventory for all my anatomy deliveries. That's your basis of which system you use. Then say I need a robust planning or template input, which I can reproduce that patient's anatomy. That's important. And then say I want to reproduce the three most important things of hip replacement, which is recreating my hip center.
So I want that statement to be made, and I get that hip system like the Exeter or whichever you want to use it. It makes no difference, which reproduces offset. It reduces net length and it reduces neck angle. And then say, I want a hip system which has all the variability of optimal head neck ratio, I could use that word. I'm introducing that.
Then say, I need a system which has an initial stable fixation with ongoing lifelong fixation and then say, therefore, I use whichever of your traject 10 readings which got this paper, which shows a 15 year survival. So this is where your survival comes in. You're justifying that with nice and with all that and then say, I do know the stiffness is such that it is optimal and the stresses are reduced, then say, I want a system which has the best flexible bearing surfaces.
Therefore, don't get bogged down by OU ceramic for everyone or everyone. Tells you an exam. Say ceramic because otherwise, trouble. Everyone says ceramic and poly. You'll forget about it. You are all consulting colleagues in real life. I want a system which has a flexibility of all bearing surfaces.
And in true life in the UK, I will make that decision on cost. And therefore, it's a long term track record, it's non-experimental. Then you can add educational support and excellent support. OK, so this is but the basics is I use an implant because of these fundamental reasons, which are your biomechanical reasons. So that was my first boss, not too confusing one.
The first part of the talk was, unfortunately the biomechanics, and I hope I made it a little more interesting as to why we do it as a surgeon. So this is the first part. The second part is how to talk regarding a difficult hip management in the exam. So the first thing is. Imagine this is shown to you, and you all agree that on this X ray, the first thing will strike you is that it's not a straightforward hit.
It's not a straightforward hip you take on and in your mind, you all agree that this would probably be common in the realms of a complex hip. Right? I'll keep the true description of how we describe the hip just towards the end. But I want to point out first as to what we will say when we come across and why it is complex. And how we will manage this, so what I would like you to say in the exam, once you've described the extra in the manner which I do in the case discussion, OK, once you know it is complex, you're going to finish by saying, yes, this.
I see this, this, this, this and then the exam is going to ask you, how will you tackle this now in your mind? Do you agree? And I go back again. You agree. There's a degree of complexity to it. You talk about why, but it's not straightforward. And one of the things that I wanted to tell you, everyone is don't ask the examiner that does the patient have pain, has the patient has infection, has the patient had a stick, has the patient?
Don't ask that and don't even say that I will examine the patient and do a neurovascular deficit and run through points which are not truly relevant. As a consultant talking to you, but you can't. You can't go over the fact that you have to history and examine the patients. The best way of tackling these difficult situations is start by making a statement, which is assuming that I've taken a history, a complete history and I've completely examined the patient and conservative measures have been exhausted, and there's no true contraindication to joint replacement surgery, which is a recent stroke and there's no issue of fulminating infection.
This patient is a candidate for staged complex bilateral hip replacement, so you have to use those words. There's no doubt rubbing around the bush and saying, I'll give him a stick, I'll give him physio. Please don't do all that. OK, say that assuming the oldies have been exhausted, this is what I do. And then say it is complex surgery. So now my realm of my talk before I come on to X-ray interpretation is why did I feel it's complex or why should anyone feel it's complex?
So for me, as a hip surgeon, the complexity is divided into four points. So one is, am I going to struggle with my exposure? Is that exposure? And that would include the true pathology of the hip, which would make me struggle, but also where there's previous scarring if she's had four surgeries, five surgeries previously. Also, if the patient is obese, the patient's obese, in my opinion, it comes under a complex primary and when I booked my patients is very clear it could be obese patients.
My bookers know that I've written on very clearly. It's complex primary with a 1.5 hour slot, so keep that in mind. So exposure is one. Second is will I struggle or will I have difficulty in getting my hips center restoration? So this is the second word which I wanted to use when you're talking about any extra in the exam, either on Monday or for the people giving it next time.
So will I get my hip center restoration heard is to say I want to know whether there's any complexity on my femoral side. For example, is there a screw in place which I can't get my parole down? Is there or to me in places I can't do, right? So that's your femoral side. And then on your acetabular side, for example, is any destructive lesion, et cetera.
So just let go each of them in more detail. The exposure is I want to get exposure and discrete safety. So like I said, obesity and previous scarring is your soft tissue dissection to get into. And on the true hip side, I feel that free hips, which I challenge me, you agree, is pretty easy to tell examiners is the producer. Therefore, it's a challenge of exposure. There's an analysis, therefore, you know, it's stiff and you cannot destroy it.
Third is a box of magna, which is a large head. You don't know where to end, you know where to begin your distribution. So these are the only three entities where you struggle with exposure. So that's your one big heading where it is complex. The second big heading, which is complex, is how will I get my hips into restoration? So this is in your DDA shoes or any hip which got a destructive superior lip?
So tell examiner my aim is to get my hip center correct. And with that, I want to ask myself the Libya nerve problem, so am I really crystallizing everything? And will I get it with just a soft tissue and getting my cup where it is? Or is it so high that I will need resection of both? That's your question on your hips into restoration. Then I ask myself on my femur, right? What are our problems?
So one is, is an outpatient if it's not patent? Well, it's going to be difficult. Second, is there any metalwork there, which I'm going to remove at the same sitting? Or is it a metal work put in when the patient was three years old and now the patient 75? OK, it's going to be a struggle to remove that one screw, which is going to come in the way of your hip. Third, is there deformity?
Depression have a previous osteotomy and if that's all I'm worried about. And can I get my stem down? And therefore, that gives me the answer in your management that will have to do the same sitting material removal later date material removal. Do I have to do osteotomy same sitting or later? And do I use a short stem? That's all will be on the principles of management.
And moving on onto the acetabular side, what is my worry? My first worry is, can I get my cup down? As you know, when you're doing your MD, it's or hip all of us hip hop, two plastic surgeons. The question is, have I got my hip inferior, my cup in? So in other words, what is the word which I want you to use is can I localize the floor? Second is one side infuriated my cup and localize it to 4 and put my cup where I wanted to put.
Is there going to be unkind effects, really? And is that large enough to need? What will it need? Impaction bone grafting will need to augment the structural bone grafts. These three words I've used, which are all which you need to know that once I get my cup in the true floor, then is the uncontained effect superior?
How am I going to tackle that? And the three ways of tackling it would be impaction, bone grafting, structural bone grafting or augment? And then I divide my mind. So this is what I think in my mind. On the inside side is superior problem. And then I this the more difficult ones are what is happening in the true, as you know, the floor area.
So that is producer. And how far has it gone? And last question, I look at the extras. You don't need. Keep out of plastic surgeons. We get a lot of information from x-rays. But every time I ask the question, the first thing they say is I want to see you don't need a seat, you need to integrate plain x-rays.
And for that, the last thing is the column. And the walls intact. So the anterior column posterior wall intact. And therefore, I finish with this extra that if this X-ray is put to you, how are we going to talk about it that thank you again? I hope I've been as clear as I can at about 35 minutes on a very big topic, but I think it's such a topic that globalization and words coming out are important.
And this is a book, which is why the emphasis meant a good book. And as well we have the audio books, books so keep. And again, this is a donation to our UK and which is a charitable organization. And like I said, it's fantastic for teaching the UK. So thank you very much for that. OK I have a question, if that's OK. Yes and why is it so important to have your offset correct?
What what is the advantage mechanical advantage? I think the mechanical advantage one would be that, like I said, if your offset is key to getting your center of rotation has to be right. And if your center of rotation is right, your offset will follow depending on your implant, right when you do a hip replacement. And that's the difference between a virgin hip, and we're doing a hip replacement that we may put up perfectly.
But then if we put up perfectly with a perfect center of rotation where it's meant to be, we need the head and the neck to be in that center rotation. And we get that by only getting that offset right now. If we didn't get that offset right, let's say we got the offset wrong by either a combination of the neck length not being right, which is a common one people try to influence. Or we get it by truly not using the implant choice to us because all systems will have a varied level of implant choice.
You have a law set, you have a box of errors, then you have a high offset, you know, a very high offset. So these options are given to you. And if we get that right, then the abductor would, I would say therefore, if by getting the correct offset, which truly means the interpretation is correct, I recreate and get the best abductor tension. And the abductor tension is key to the hip stability, impingement, limp and outcome.
Right and the fourth is that what I try to push on is that when I do a gorilla, when I do on it, I do sometimes change my offset by actually using the cost of error stem. So I practically do it in real life, right? Because I don't want to link it. The mistake people make is they want to get the attention and the length and limb, and especially on cement it.
I see so many tips which are kept long. Right that's not right. So this is where Thanks for the question, because that's where offset is so important. Absolutely The when you talk about in terms of absolutely everything there is correct. But even more basic than that is inefficient. Abductor means that the joint reaction force across your prosthesis is minimal because the abductor doesn't need to work.
So hard. And so therefore you're also as well as all the other things which are extremely important and far more important than this. But that means your is less than or is less as well because of decreased joint reaction force. Long term survival? Thank you for that. In fact, that's a point, which is without a doubt that your long term survival will depend on joint reaction force being optimal, which happens only with correct about retention.
Thanks for that, Shawn. OK, so another question. So in order for total hip replacement to you, prefer to the small or large cup? Honey, if you don't mind when someone asked this, I think they were asking a very valid question is that there's a word called jumbo cops, which, you know, people, I guess this question is, will you put in a jumbo cop?
In other words, would you put in a cop? Which is more? The answer is in modern hip replacement surgery. I believe that you need to get your center of rotation perfect, which means the answer direct answer. This question is no. You need to get your cup perfectly positioned with the correct size cup, and that effect filled up with opening, so it's easier to put a larger cup.
It's easier to do a jungle cup, but the answer is no. And if you don't mind honey, when I go through some slides, that will become clear. For example, this one which is on the screen, it's not true at all this basis, but we need to tackle that. So we'll talk about that. But the direct answer is no. I don't think we should use large cups of jumbo cups. We need to get that hip center correct.
OK, so in case of long standing, Cox are vulgar, it is easy to increase the offset without any releases, any soft tissue release, is that one of the questions? Yes yeah, I would say even for that, I would say, I think and shivani will agree that these questions are more pertinent to fellowship level discussions, and I don't think because Sean and Annie, we are very particular that we want this to be true.
As far as guess based questions and answers, I can give the answer and the answer is no. The issue really is what I really don't do. So you get everything right and see where you are. But this will not be a pass or fail, and it won't be particularly asked. Do you agree with that? Yes this is beyond passes, and it's more highly specialized fellowship level.
Please try and keep it towards the FRC and I'll encourage these questions. But if they are like this, don't worry. If you ask this question, it means you've already come to the level of your 7 because you've answered the remaining adult reconstruction. Viva and all, you're sitting with me, as you know, as a fellowship or you're going through the states or any center for fellowship, and this actually is put in front of you.
Just tell me about this X. How will you start to move? I would start by saying that this is a AP radiograph of the pelvis centered on the symphysis pubis showing significant degenerative changes with significant bone loss in both of the femoral heads. The acetabulum is this plastic or both sides?
I cannot appreciate any deformities in the femur or the hemi pelvises are more or less equal and the there's not much rotation in this field, so very good. Um, I want to know whether there is a past history of be useful to know whether there is a past history of parentage disease or ADHD, or infection in this case.
And I would like to evaluate this patient clinically and take a detailed history and examine a lovely. Very good. So that's excellent. So if I just can stay on the screen, but because this is still part of the talk of teaching many, so everyone or everyone who comes the first thing to say, Emily, I'm very impressed. The first thing I want everyone to know is that if it's a building axilo, it's a knee or shoulder or ankle.
If you look at our policy has meant to book. There are a number of views, which are truly described, which are the correct views for that particular pathology. So for example, as a arthroplasty surgeon, I want you to start by saying this is the pelvis with both hips. X-rays centered over the simple pubis is what you want right now, Mattie and others. If imagine you saw an X-ray of the pelvis, which was adult reconstruction, but with your entire if your leg crests were also see, you agree that was not a arthroplasty extremity.
Yes that's what trauma, that's a trauma, so I want that clearly put to you that this is a girl, correct? So example, if you have a knee, talk about the correct knee. If you have a shoulder, say it's a preview of elbow view or whatever view you want to say. And if it's not correct, use the word attempted view. Is that the first statement I want you to make? Yeah so it's an attempted pelvis with both hips.
However, I'm not happy. It's not center views. So the first statement next may be while you're there, what else do you want it to be a perfect X ray? You can see the object performing a spherical. Yeah, I know you came to it later on, but in your talk, let it be first. Yeah, I know you came to it later, but let it be first. So and you want to say the symphysis pubis and the caucuses are in the same lines.
There's no relation there. So three points 4x ray is a pelvis to both hips centered over subscapularis. I'm happy with that obturator. Fundamental central on both sides and the simplest view is in the coccyx on a straight line. Now, in my next statement, I'm very glad with what you said. So maybe you said, what is the word you use bilateral? Just repeat the word destruct.
What do you say? Destructive I can't remember what exactly I said, but I think I said bilateral severe, destructive in the joints. Exactly so for everyone in the hip or any other technology, the first thing I want all of you to say is say, what did you see bond straightaway? So if you're seeing significant arthritis, use the word. I see bilateral significant destructive rapidity.
So now the word is that happy with the word destructive means automatically. You're joining my club of orthopedic surgeons and consultants to speak correctly, right? So the our property, if something is bombed or as a diagnosis. Now do you agree there is no bond in this? You know, it's not this. It's not.
It's not this. Not that. So then don't say anything. But imagine if it was a bond door this. Then you agree. Maybe at this stage as a consultant level talking, you'll say it is, but don't. We're down the line. Yeah, but the first thing you'll see is striking to you is destructive of both hips.
Next, I would say medical every hip. Why don't you just straight away say that I notice there's definite superior migration of both hips? Are you happy to make that statement? Yeah Yeah. So, you know, so in other words, you're saying directly that is a superior migration and my interpretation is changed.
Happy with that statement because that's the first thing which strikes me, right? So there's to be a migration of both FEMA and the center stage. So this is a statement I want. We want to use for all interpretation of X-rays. And next, I want you to divide your mind into the FEMA and the acetabular, right? So for the fema, if you don't mind, how many do we have for this session?
Honey, there's pre three volunteers problem. We have another volunteer. OK, but in that case, let me just carry on it, maybe for a few more and I'll explain this. So and for everyone when I start talking on the female side, right start, you jump straight away into destructive activity and then you went and said straight away, there's no issue in the canal, right? And you said the FEMA appears satisfactory.
Right? there's no sir, but there's a lot more we want. I want you all to talk about in the head. So the first thing you'll say in the head is describe the head and put this. I will say that is near the word I would use is near complete rehabilitation of the head. Are you happy with that? Maybe there's no head, right? Yeah near complete obliteration of the head.
Then you're going to say there are definite cysts in the head. Right, so you're talking with the head now in the head after you finished your destruction. The word you're using is complete on your destruction of the femoral head. What are the other options may if you didn't have this head, you could have a head, which has maintained its veracity. That's the most common hip. You get my point.
Yep yeah, so imagine you showing a bond or hip arthritis, which we do day in and day out, you agree in that if you ask to describe it, you're going to say the specificity of the head is one thing you agree. Correct Yes. But in this one, you are going to say there is near destruction of the family. So what is the third option, the head, which potentially you can see you will see a head, which is misshapen.
You agree. It's got a misshapen head. I could use that word. That's the third word which everyone should use, that you have a misshapen head. The fourth you agree, you have a large head, which you get in both these or Magna. You happy with that many? Yeah, so you'll get a coxswain magnet, that's your fourth type of head, and that's all you'll get.
Yeah and the last one, if you really want to be stick it. Sometimes we see a portion of the head, which is collapsed. And we call that sectoral collapse. You know, sometimes you see your head, which is nice and round, but just the corner. Your superior like corner is defect. You agree. And that because the. So this is so now, honey, I'm happy, and then we go on to the next.
So in the neck, I want you to say that I would expect that you will say that the neck is short and you agree it's or shorten. It's a shorter neck than normal, right? So you see it as a four foreshock neck. However, the values in various is one gained, so it's not particularly in value. So I want you to talk about that and then say in the intro to Kendrick.
And the soft Kendrick area, I do not see any evidence of a osteotomy. I do not see any evidence of a previous metalwork or tract of metalwork removal. So that's all you can see in that area. What are the three things many repeat again in the traject? Repeat for me in the. So you still in the software category, peripheral country and region, there is no sign of a previous operation or osteotomy or any metal work or metal or deformed or deformity or a tract of metal.
You know, when you think like that. So deformed in your words, the words you can verbalize is posturing. Previous ostomy, previous metalwork and a cracked of metal rock removal. Right? and last say, the canal is patent, yeah, and the canal appears to be happy with that. And then finished by saying maybe on this particular radiograph, I cannot see, and I expect that we should not have any trauma, but if there is any evidence of egawa trauma, I want a full length femur.
You're going to make that statement right. So this gives me higher order thinking. OK, that's fine, Mary, very well done. So can we move to the next one? Sorry imagine you finished your camera side. And thank you for once again, I'm not. It's not a testing of your exam knowledge to initiate a discussion, literally.
So now imagine you've finished the funeral side and now say on the acceptable side, what will you talk on the acetabular side? Tell me what? You talk there. So on that side? I see are the most acetabulum displaced migration of the femoral head.
This superior erosion of the upper part of the acetabulum, I can say it is hard to describe one. The head is still inside the stadium with super migration. Good very nice. Broken, broken, broken. Shenton line on both sides. Mm-hmm What does that give you? Said that?
What does that mean to you? This means the center is migrated separately in relation to the teardrop. OK very good weather. Yes, fine. Love you. The acetabular solar cell is more than 10 degrees or I can say it, but so what angle you inclined? Yeah, you're talking very well.
So I'm using the saucer cell, the adjustable solar cell or the roof have a roof angle. Yeah OK. Very good. Excellent So very impressed. So for everyone, I've tried to cover the favorite part to give you all the options. And now I'm trying to tell you what I'll talk about in the axilo 2012.
You're very correct. First thing you can tell people or say that there is definite, you know, you said superior and then you weren't sure what word to use. So I would particularly say there's definite superior lip destruction. You have to use that statement. Superior lip of the stability structure. Yes Yes.
And then you can say this means there's definite superior migration of femoral head right to make that statement, then say that the acetabular angle has definitely increased, right? Forget about dropping weight, and just all you want to see is the angle. If I ask you how to draw it, it's the angle at the lower end of the teardrop and another line going to where the acetabular finishes.
Yes and what are the values? Do the value of that? The normal value is 35, but as you were more inclined, you agree as you go more upwards. More and more destruction here. You agree your angle is going more and more upwards. So that's above 45 is considered as an issue right now. Once again, do you agree that this is not a barn door person who was born with dysplasia?
Do you agree with that? Yes Yeah. So this is not a true deed in a young girl who's. Do I say that at most the DHS would have the femoral head nice and round, but it'll be lying somewhere here and there. So all these crew classifications of DH try not to use when there's actually a spiral of destruction.
You get my point very well. Yeah yes, that this is dysplastic. I agree. You can use the word dysplastic, but is dysplastic because there's to be a destruction. It's not dysplastic, but the patient was born with it, right? Correct Yeah. So there's a subtle difference, so that's the first thing to tell you just talk with Astrid angle.
So once you finish the angle, so what are you going to start by construction? You're going to talk about the angle, then you're going to say, can you visualize your jaw drop or not? Just say, yes, I can, right? You can see I can. I can see both sides. Yes, but Yes.
So what does that mean? That means you're indirectly telling me that the flow of the as satisfactory? Is that right? That gives me good information that I'm happy. Is that right? Yes Yeah. So that's your next statement you make. And then you'll say, I like to draw which lines will you like?
Like what line is this? And then what line is, is this? What line is this first line and the line, right? So what does the yellow line? Give me information on the center column of the terminal, and the line represents the Western column exactly where you want to remember the way I remember it or your pubic? Yeah, will be the opposite of B. So it is the anterior wall, right?
The opposite of B is enter your wall and there is still. It still gives me information about the book and wall is the columns. Yeah so do you agree at least looking at this? Do you agree that a column is intact between? Now, both musical and looks intact, but you see how much information you're getting and you can say this.
So now coming down to the management is how will I manage this? So how will you manage this? You manage this. So how will you manage this patient? I didn't drive it very well. I'm very impressed. I will take the laboratory and then examine the patient. My aim in this case is to restore the center of rotation through due diligence.
Describe the collar is a little understood the femoral offset. Yeah very nice. How do I need to also to augment the starboard effect on both sides with American graft? So what? You're going to get the hip centered down. So now do you agree with that? If anyone before that, you know, when the person asking you a jumbo cup, I know they didn't mean it in this, but using a large jumbo copier is not right.
You need to get your hip center back here, right? So mentally, you're going to hit your hips into Down. And then this defect here, you're going to cover with what? What is your choice? What are your three choices and what will you do? The best option is to was bone graft. I reconstructed with bone graft. What bone dry now because you've talked well and.
Yeah, my spoon graph from the small heads. If it's not enough, I have to prepare allogeneic bone graft. Do you think this head will give you anything or is it in your head at all? Nothing, right. So you'll have to get what you will, but we'll use impaction, bone grafting or you're going to just structural bone structure, structural bone graft, and they will fix it by screws or mesh. Fantastic OK, so that's excellent.
So just to, you know, you said you said you use screws and then you said mesh, you're just to make everyone clear that once you recreate and get your hips, enter right, everyone. So whether you put your cup there, you'll have a defect here and this defect. First of all, agree to uncontained effect everyone. So four principles point of view. This is the uncontained effect.
The first thing to get a 7 or eight, you say, I'd like to convert this into a contained defect. And one way of doing that is to use a mesh and I will use impaction bone grafting. So mesh and impaction grown grafting go together as one statement, right? Yeah so that's one. The other way of doing it is no right or wrong, the different ways surgeons do, but you need to know the principles is that this defect I will use a structural bone graft and fix of it screws right like you want it.
And the third, I will use caboclo metal augment. And just so you finish, I think I'll finish with what I did. So just to know is, you agree now. I got my. You agree the cup is meant to be and whatever I used might suppose I show you this X-ray as a partial. What did you say? You see, I this is it was mesh on the induction bone graft. It was cemented on back graft.
Yes, exactly. But before you started metal, you would have a nice to say that on the femoral side, I don't see any problem. I will use my dippold stem. You agree that also makes the examiners feel that you're not worried about the female, then say the complexities of the vascular side and you say what you said and this is what I did.
Yeah so if you show it to them, you say I noticed this mesh is impaction bone grafting behind the mesh. So just to finish for everyone, just to give you an example, schwa Nanite and give you just 1 minute. You agree. If you're showing this X ray, everyone will say that the word I would use is this is a classical osteoarthritis of the left hip.
Start by saying this is the femur. Do you agree now that is completely wrong? You're going to say that by women are not equal. It's not centered correctly. Then you're going to say the classical. The what I see is a hip arthritis with a severity of the head being maintained, the neck of your satisfactory, the neck shaft, angle of your satisfactory and the shaft and the protected area was satisfactory.
Imagine if you're showing this degree in this one, you'll say there is destruction of the criminal head with superior migration with superior limb destruction. Yeah imagine what you'll say for this one. You grieve for this one, you'll say that I notice there's a. Head, which is, what do you want to call it? You can see a misshapen head, everyone. You agree that you cannot see the difference between the cup and the acetabulum, so you'll agree this is an enclosed metallic.
Yeah and so what is my complexity here is and you agree now that is there's no pattern see of the canal, everyone. Right? for example, you agree that is a deformity in the rock area. So once you know what you're talking about, this is not going to be easy. So you say all these things, these are misshapen head there is enclose the joint.
There is a slap traject gastric deformity. There's no patency of the canal and on the top side. Well, I don't think the cup was an issue. Imagine on this one. Very easy to say, what are you going to say? Yes, folks are happy with everyone. Yeah, Yeah. But you also talk with acetabulum beer, but you say my FEMA off your satisfaction, you know, so you're talking with sense.
And this one, you agree. Australia big changes, very short neck. Previous Australian. And this one, you're going to say producer, Yeah. How are you going to say it? You agree that the humor is beyond your line, right? So that's how we finish. Yeah OK. So thank you.
This is what I did for one of them. This is this is a difficult one. Remember the one which you can get right? The cop is straightforward, but you can all see the canal. That's where you have to struggle. So my complexity why I took about three hours to do it would be the complexity in the criminal side. Yeah OK. And thank you.
So I'll end there. Sorry over Shanahan know very much talking to, as always, under your structured way of answering the questions is, I think, quite important for our candidates to learn. So I do recommend reviewing this video when we put it up on our YouTube channel. Because I end up, I sometimes go over these videos, especially from my view, on the basis that essentially he has the perfect structure for the answers.
Thank you so much.
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