Paediatric Basic Science: Skeletal Dysplasias



This on-demand teaching session is relevant to medical professionals and will cover topics such as classification and treatment principles for skeletal dysplasias. Commonly discussed conditions, such as achondroplasia, osteogenesis imperfecta, spondyloepiphyseal dysplasia, and multiple hereditary exostosis, will be covered as well as the genetics of skeletal dysplasias. In addition, Professor David Littlehead of the Department of Sydney Children's Hospital and his work trialling sclerosedin antagonists with AustraGenesis Perfecter will be discussed. Attendees will leave with a greater understanding of the treatment principles for skeletal dysplasias and the associated genetic components.
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Learning objectives

Learning Objectives: 1. Learn the different components of a long bone from epiphysis to metaphysis to diaphysis. 2. Identify and discuss the different causes of skeletal dysplasias, including chromosomal aberration. 3. Understand the genetics of skeletal dysplasias and their implications. 4. Analyze and identify the treatment principles for skeletal dysplasias, including preventive measures and interventions. 5. Determine how to classify the different types of skeletal dysplasias using the Ruben’s classification framework.
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The following transcript was generated automatically from the content and has not been checked or corrected manually.

My front. Yeah, that all looks good, great stuff. Well, thank you very much for inviting me to give this talk rather unusually. Um I have the privilege this time talking on something which I'm actually genuinely other interested in. I love skeletal dysplasia. I've, I've sort of stumbled into um doing a lot of skeletal dysplasia work slightly serendipitously. Um uh And partly out and one thing I was going to say, um Rajiv's already mentioned it. Who's this guy, everyone? So this is manager Ramachandran. Um And before we start, I hope you all know this already. But this is the book to buy, to prepare for your basic sciences in for the F R C S. Auth Monash happen to do the same fellowship as me out in um Sydney. Um And he wrote this shortly thereafter, Monash is a very savvy guy. Um And one of the things he did after writing this book was he sent a free copy to everyone who has an F R C S examiner and therefore it rather um rapidly became basically the basis of the curriculum. Um So if you don't have it by it, um Anyway, so, um we will quickly, sorry, that should say summary, not conclusion. I'll tell you exactly how I managed to sort of stray into bony in displays is we'll talk a bit about the genetics, talk a bit about classification. We will then concentrate a little on achondroplasia since it's the communist cause of it's the communist bone dysplasia that, um, that we deal with. And then we'll actually move into what I think the more interesting side of the story for orthopedic surgeons, which is to talk a bit about the, the the treatment principles, which basically means preventing subluxations and dislocations, re establishing or maintaining the mechanical access. Um Rajiv's already talked about, oh, I, but I will briefly touch again on fascia divall rods, which I love also. Um we'll mention leg lengthening, but I always also explain to you why I do none at all. And then um just at the very end, we'll talk about multiple hereditary exostosis, which also fit into the sort of the Portman to uh great uh uh random selection of conditions which are regarded as bone dysplasias. Um I haven't do engineering before I did medicine and I think that's one of the reasons why I do actually particularly enjoy the sort of the business of reestablishing the mechanics, which is part of only displays is then I did medicine. Then I went out to Sydney and I worked with this chap here. Does anybody know who that is? That's Professor David little head of department um at Sydney Children's Hospital. Um and he is probably, well, he is one of the world's leading experts on bone displays is both from a, a science perspective and from a clinical perspective. And what we're actually doing here, which relates to Austra Genesis in. Perfect er was that we were we're trialling sclerosed in uh antagonists and Rajiv uh didn't get onto Ramosa mob but actually that the the future possibly of the treatment of osteogenesis infector in Children um is anti sclerosed in antibodies. Um And we won't dwell on that here. Maybe Emma will tell you about it in the next lecture. Um And then I fell in with this family here. Um All of whom are my patient's, these are my Children dysmorphic though they may look. Um and this chap who is an act ical work Davis with his wife Sam set up a charity which is a support network for people with skeletal displays is um and I have actually for a very long time been part of the um the medical panel who who, who, who advise and give, give, well, hopefully um supportive talks on dysplasias. Um This incident is Dominic Thompson who's also a great friend, John Crawford, who's a spinal surgeon with a particular interest in Great Ormond Street in, in skeletal dysplasia is now um we have to briefly touch on the genetics of skeletal dysplasia is partly because unfortunately, these things come up fairly commonly in the M C Q S. Um And I, I will briefly talk you through the slide for those of you who prunes print maybe a little small. Um the commonest one and the one you must unequivocally know is that achondroplasia. Um and indeed, hypochondriac plasia are both caused by defects in the five blast growth factor receptor three um pseudo achondroplasia, which actually has a very similar phenotype is caused by defect in the cartilage, oligomenorrheic matrix protein. As indeed. So is any d although also sometimes um college in nine, which I think we've touched on too. Um What my, my, my greatest love actually in skeletal dysplasia management is spagnolo Epivir seal dysplasia. And Raju has already told you that too. So, um sed is caused by defect in um in type two collagen synthesis. Um And you've already heard that type two collagen is the primary collagen of joints. Also the primary collagen of nucleus parp osis of discs. The primary collagen of fice is and the primary collagen actually of the vitreous humor um in the eye. And that is relevant to because in fact, I work very closely with the Chapel Martin Snead who runs um a National Type two Collagen Opathy service out of Addenbrooke's because of the risk of retinal detachment that's associated with coal, do cold to disorders. Um We mentioned the Mitzel condo dysplasias, Schmidt and the Janssen type. Again, they, they are probably slightly overrepresented in orthopedic clinics in, in comparison to, um, their, their frequency there incidents or their prevalence in the, in the population because they almost always end up requiring some sort of, um, leg alignment Corona plane realignment. Um, and it's very satisfying because it's, you do a sim simple day case, a plate type surgery. Um, and you take Children who are so bowlegged that they can barely walk. Um, and over the space of a year or 18 months, um actually completely correct their alignment, which is very satisfying. Takes away the pain increases. The function. Schmidt type is um is a defect in type 10 collagen you Hansen in parathyroid hormone receptor. Um We've already heard from Raju beautiful talk on osteogenesis infector and of course, um osteogenesis imperfecta equally as um brad, you said type one collagen defect therefore, does not only affect bone. Um of which type one collagen is the primary collagen, but actually all other soft tissues to it affects ligaments and tendons. Um And the skin and indeed rather frighteningly when I was working Peterborough. At the end of the case, we'd, we'd very carefully done a sort of logroll transfers with child with type three osteogenesis infector at the end of the case. Um The ODP tore off the that the, the diathermy plate and with it tore half of the thigh of this child, half half of the skin. So you have to be very cautious, not only of bony fragility, but actually of, of soft tissue fragility to um bone is analogous to reinforce concrete. Um Collagen provides the tensile strength like steel rods in reinforced concrete hydroxy appetite. Um apposition in uh provides the the compressive force. And if you take away the collagen, you get what everyone who works behind the test, go check out will tell you very confidently is brittle. Bone disease. Osteogenesis causes a brittleness because you've lost the, the tents, I'll uh there is a resistance to tensile forces uh in the bone. Whereas Ricketts of course, which is a failure to um to Aasif i the immature skeleton um causes this this duct ill itty and bend Innis and plasticity of bone, multiple hereditary exostosis. There's many, many genes um being discovered all the time, but they're, they're, they're E X T genes. Um The evelina in London is running a very interesting program looking to compare phenotype two genotype um in, in M H E. And also uh seeking to address the quite difficult question about how you screen M H E patient's in adulthood. Um in order to ideally pick up any evidence of malignant transformations when um osteochondromas transformed to chondrosarcoma enchondroma tosis, including, of course, oh Liaise and Nephew Cheese disease are, are a very, very diverse set of genetic defects, but they all essentially affect the hedgehog pathway. And osteopetrosis iss leash in, in the chloride channel, which enables osteoclasts to create a highly acidic environment in which the resort bone, sorry about the genetics. But unfortunately, I think all of those conditions, um and particularly since they actually come up in Menashe's book, all of those conditions are fair game for MCQ S. Um How do we then start to think about classifying the different uh little displays is, well, I think the nicest or a nice framework on into which onto which to, to, to, to put uh skeletal displays is there's Rubens classification. Um And Reuben basically goes through um the different components of the Fyssas or the different big different components of a long bone from epiphany Asus through Fyssas to metaphase iss and then two diabetes iss. Um And then it's worthwhile remembering just one or two conditions to fill each of those, to fill up that grid. Who knows what Trevor's diseases? Hello, anybody there. Um Can, can somebody let me know if there uh were here? I think it's probably just a lack of knowledge. I mean, beyond, beyond hyperplasia of the pegasys, I'm not, I'm not entirely very good, very good. So hyper and what, what, so what happens when you have a structure of bone and cartilage which undergoes uncontrolled hyperplasia? Um Well, when it happens in the uh in the metaphor Asus, um it's called an osteochondroma and that's exactly what Trevor's diseases to Trevor's diseases, osteochondromas of the fight of the epiphany Asus. Okay. Um And they most commonly occur around the ankle. Interestingly, I'm not 100% sure why. But I've also seen them um, pretty much everywhere else as well, including, um, certainly in the knee, fairly frequently. So, hyperplasia of the epiphysis is Trevor's disease. High pa plasia is bundle epithelial dysplasia, multiple epithelial dysplasia, um, and pseudo achondroplasia. Um, hyperplasia of the Fyssas is enchondroma tosis. Um So it's, again, it's aaliyah's disease and the Fuji's where little bits of the Fyssas um break off and undergo um autonomous um uh proliferation and, and hyperplasia. Um Whereas at the other end of the spectrum, there is the Matarasso condo dysplasias and achondroplasia, which essentially represents a, a significant undergrowth of, of, of the Fyssas. Now, each of these conditions, actually, you can start to think about predicting the um that, that the phenotype um once you start to get a grip of on, on which bit of the bone they affect. Um And so um it, for instances, achondroplasia only really affects the Fyssas of long bones. So it very specifically causes a long bone shortening. Whereas actually the intramembranous formation of the, of the, of the virtual column, the ribs, the the other as you as you know, intramembranous rather than enchondral bones tend to be less significantly affected. And so you get, you get a normal ish trunk and you get short limbs and we'll talk about, as I say, another way of thinking about, of describing um uh the, the, the the skeletal displays is in a minute um overgrowth of the metaphor assis is um is hereditary, multiple exhaust Asus. So just as Trevor's diseases, osteochondromas of the Fyssas, uh H M E is or, or, or standard extra articular osteochondroma is exhaust osi's a hyperplasia of the metaphysis. And in fact, actually, what they really represent is the same as enchondroma tosis um within the medulla. These represent little bits of Fyssas which break away from the normal faisal plate and get carried away with the advancing tide of bone as the Fyssas moves away. So they stay of course where they are. But then they do exactly what vices is, which is that it grows bone. Where is the active part of an osteochondroma? Luke? Uh Is it um I don't know, they kind of get left behind, isn't it? I think the pathology of how they're formed as in the Fyssas grows away from it. So I'm not active tumor, the near plastic, I'm going to say near the Fyssas, but then the cartilage cap is the cartilage. It's neoplastic lutely. So, so there are textbooks which tell you how important it is when you remove exostosis to sorcerer rise the base. That's absolute nonsense. There's no active growing tissue in the base of a exhaust osis. It's all in the cartilage cap and it's actually much more likely that you'll get a recurrence if you leave the perichondrium of the cartilage gap, if you, if you too assiduously peel off all the soft tissue until you're actually down on cartilage, then you're leaving actually perichondrium, which does have the potential to cause a recurrence. Um osteoporosis um is basically, as I say, is a, is a defect in the function of osteoclasts. It's an inability to, to form um an acid rich environment in which to resolve bone, which is part of the um is possibly part of the, the, the function of osteoclasts. And if you don't have this bone resorptive process, um then you get hyper dense, although not actually um terribly strong bones. The 22 completely separate conditions, osteosclerosis, tosis. And um and von Bucaram's disease are actually um conditions in which you get stronger, bone won't dwell on them here. But that's it. Those two conditions were actually where the root into understanding the whole wind Dickov pathway, which is the basis of of Wolf's law where the final para crime mediator is sclerosed in. Um Don't worry at all about diet, fear seal dysplasia. It's only here just to fill a gap in the grid. Um It is, I've never come across it before in my life, not, not aware of its clinical significance. Um And then hyperplasia, the diagnosis we've mentioned already, osteogenesis, imperfecta type one collagen deficiency. So that's a nice grid. I think it's a nice way. It's always easier to remember things. Um in medicine, if there is, if there's some sort of way of structuring um your thoughts. Um And this is the picture from the Bible from Menashe's book, which basically shows exactly the same thing that the, the epiphany sis the Fyssas, the Metaphysics and the diagnosis and conditions which, which affect each of those parts of a long bone. Um are saying that that actually knowing a little bit about um the mechanism, the site of Axion of the genetic defects, which leads bony dysplasias, then actually gives you some windows some insight into into why the phenotype is different. Um And so the, as well as rubens classification um into which bit of the bone is affected, we actually also think of another way to classify skeletal dysplasia is um is into their sort of phenotypic characteristics. All bony dysplasias, all of the sorry, all of this little dysplasias. Um Well, not all, so not multiple heritage, your exostosis, but the your butt, all the standard um skeletal displays is due cause diminished height, low, reduced um stature, and then they can be um sub classified into proportionate or disproportionate. And when you're talking, when, when, when we're talking about proportionality, we're talking about the ratio of size between the trunk and the limbs. Um and actually most little dysplasias cause a disproportionate dwarfism. Um And uh there are some which cause a short trunk. My classic in that category is sed Spahn Spahn low pitch seal dysplasia and there are some where the trunk is relatively normal and the limbs are short. Um And that and again, the classic in that category is achondroplasia. Um The the part of the limb that's affected can then be described in terms of rhizomelic meso Milic or acromegalic. When where rhizomelic means the proximal segment of the upper or lower limb, right? Miso Milic, the distal segment of the upper or lower limb and Akram Ilich just means hands and feet like the acropolis, Penelope, um and rhizomes like roots. Um This is a classic example of a comparison of proportionality. Um This is a chap called Warwick Davis who is an actor. Um and he has spondylopathy seal dysplasia. I use these photos with their express permission and this is his wife um Sam who has achondroplasia. And if you look at um that Warwick's arms, he can literally touch his knee caps um without actually bending down. Um Whereas by contrast, and so he has so he has SED which is classically a short limb disproportionate dwarfism, a beg pardon, sorry. He has sed which is classically a short trunk disproportionate dwarfism. Whereas, whereas same has a con which is classically a short limb uh disproportionate dwarfism. And indeed, she has rhizomelic disproportionate short limb dwarfism. The humerus is disproportionately shorter than um the forearm or the hands. Um Can somebody make a guess? This is this these salmon uh Warwick's Children. This is uh this is Harrison and this is Annabelle have a guest somebody. Um uh Ben Davis does Harrison have um has he inherited his mother's condition or his father's condition, his father's condition, correct? Short, short trunk. So he has a very short trunk. He actually has very long arms. Um and Annabelle, um, somebody else outlet who's, who, who else is close to the exam? Luke, uh who should I be quizzing and challenging in it? Honestly, that's where I am. So, who else are that? So, who, sorry, who's that institution? Uh Yeah. Yeah. Perfect. So you tell me, oh, goodness me, I don't know. I'm going to guess. I think she inherited her mother's um uh mutation. Absolutely wrong. Uh Thank you for volunteering. Um Well, or at least being pressured into uh to answer is no. So, so, um, so Anabelle and Harrison both have sed. Um uh so they have, they both have short limb, sorry, I've said it twice wrong now, they both have short trunk, um, disproportionate dwarfism. Um Does anybody actually know practically what is one of the really, really significant problems with the rhizomelic, short limbed dwarfism of achondroplasia? Think about personal activities of daily living, just like cleanliness of going to the toilet or something of your arms, not long enough to clean behind or something like that. Exactly. Right. Thank you. So, I'm sorry to be so, so, uh vulgar, but actually one of the really serious problems, um, the adults with achondroplasia, um, have to deal is, is that often they cannot wipe their own bottoms when they go to the toilet. Um, whereas by contrast, sed has that doesn't have that problem at all. Um Anyway, so having talked a bit about how we classify things, um, and not gone into terribly much detail about the majority of those conditions. I'm going to spend a little more time talking about achondroplasia if you get a case um in your, in your visors or indeed, if you get quizzed in your M C Q s um on any particular condition, then way, way, way most likely it's going to be achondroplasia because achondroplasia is massively the most common condition. Oh, sorry. Just again on the, on this one. Ok. So classically sed gives you Jenny Vulg um and a con gives you Jenny very um just again a sort of comparison view. Um and um the so um so achondroplasia is inherited in an autosomal dominant fashion. It is a deletion or uh an abnormality of the F G F R three, the fiberglass growth, the fact that growth, the fact that um type three receptor. But although it is inherited in an autosomal dominant way, actually, 80% of achondroplasia, life birds represent day novo mutations. That is to say again, practically that 80% of all Children wrong with achondroplasia are born to average height, parents. Okay. So um I was quite surprised when I was first invited to go to a word to skeletal dysplasia, uh support groups that actually most of the people they're uh average height. And so it was, it was, it was a little bit of a culture shock to realize that, that, that most of the parents were, were actually, even though these are all genetically determined, genetically inherited cases that there's such a high day novo uh mutation rate that in fact, most um Children with only displays is have average height parents. Um We've said it already, it's a disproportionate. Uh Dorff is um with short limbs and rhizomelic, it's the, it's a proximal segment thighs and so femurs and humorous is human, right? Which are most affected. Um There is also a classic faces with, with a large head with relatively prominent forehead and with a relatively um uh whatever the opposite of prominent is with relatively un prominent midface. Um Sure far away if or as because 800 places usually also dominant to the kids, not have both conditions. Oh, good question. So, um same and Warwick have had four Children. Uh same has had, has given birth to four Children. Um And the first two were co dominant, but unfortunately sed and a con um codominance is not compatible with life. So, um they both died very early on and that's, of course, you know, it's a very difficult situation. It's not uncommon for um for, for skeletal dysplasia. Um adults actually to, to choose to, to, to uh to marry each other. And therefore, but it, but it comes with this um with this implication that the codominance is is often, um, uh, is often not compatible with life. Um Does that answer your question? Uh sort of, but, but therefore these two just a bit luckier and they was the matter with life for them or no. So, uh, so are you at all familiar with how genetic inheritance works? So, so, so Sam, Sam in the FGFR three region has one normal gene and one abnormal gene as it happens, her dad Peterborough's has um a con and her mum doesn't. Um And so she's inherited her mom's um normal FGFR three gene and her dad's abnormal FGFR three gene. Warwick both were, his parents are average height. He's uh inherited the coal um to um abnormality. Um It always is developed a day, no vocal to abnormality. Um And, but also has a normal gene. So there are four options for their Children. Okay. They can either have an S E D gene and a normal gene and have S E D. They can have an A con gene and a normal gene and have a con. They can have an S E D and an A con gene but not survive or they can have a normal gene and a normal gene. Um And be average height zounds your question. Yeah. Very good. Thank you. What's the plot called? That's my brain is going but that, you know, way draw that grid anyway. Um It's the, the upper limb features we've already said short, humorous really difficult because it had it face personal activities they live in, made even worse by the fact that they often that Children with Children, adults with achondroplasia often actually are unable to fully extend their, um, their elbows, which functionally again causes a shortening of the limb and then they have this trident thumb. So, in fact, actually, um the, the, the, uh, the little and um, ring fingers tend to bunch together, the index, the index and the middle fingers bunch together and then the thumb sits out on its own. Um And incidentally, all the fingers are relatively short. So there is, there's actually bracket actually together with this, this accentuated, whatever that is third webspace and first webspace leading to the appearance of a trident think Neptune or somebody else decided. Um And then in the lower limb as demonstrated on the, on the clinical photos, there is almost always June Ferrum um that you need to briefly be able to describe some of the characteristics characteristics of the Pelvis. Um And it has this classic so called um uh it's champagne glass appearance um to the to the, the Pelvic Inlet, okay. Um And for those of you don't think that's what a champagne glass looks like. Um It is the classic old Champlain Glass. We seem to have gone to flutes now, which is completely impractical because they overflow when you fill them. But in fact, traditionally, champagne was always served in a glass of, of, of this appearance and it's supposed to represent that sort of, that's that broad, um, and curved in that view. Um Does anybody, um So long as this is too vulgar for this forum, um, know exactly how the shape of the champagne glass is supposed to have been. I think this is apocryphal but is supposed to have been modeled. Maybe I'll leave that if nobody knows. So it was supposed to have been modeled on the breasts of Mary Antoinette um moving on. Um And then you have this flat acetabular roof um with in fact, increased acetabular coverage. Often you actually start to get impingement because the, the roof is so high is so broad and then a short neck, so Coxib forever um um which again tends to cause a limited abduction and, and uh and impingement. Um I need to know a little bit about the spine as well. Um Most importantly, um uh frame Magnin stenosis, which is responsible for uh for uh sudden infant death syndrome. And ours involved with Dominic Thompson from gosh, in writing up some guidelines and with women from Wira Chung from the Evelina to say that actually, basically all achondroplasia, Children should have a feed and wrap um MRI scan within the first few weeks of life to check whether or not they are at risk. Unfortunately, it's one of those conditions which is a symptomatic right up until you die. Um And so it needs screening, you can't watch Children and look for symptoms be too late. Um Then thor ical lumber, kyphosis, um lumber, stenosis and lumber hyper lord osis. And it's, and actually it's a combination of, it's been partly the hyper lordosis which leads to the stenosis. And at least when, in fact, actually every single achondroplasia adults I know gets clinical spinal claudications and 25% of them go on to do surgery and it's tricky surgery. And the guys here, Doug and John, um and actually Rodney Lang who does does the surgery says it's, it's tricky. Um, we've talked about one of the goals being concentric contained of joints. Um These are all sed Children. Um and the risk in sed is of progressive Coxa Volga. But we all also, but there is also a bony dysplasia. Um, guess everyone. Where is the femoral head in this on this in this spell? This number one, number two or number three, anyone three, correct. Very, very good well done spot on. So, in fact, the cops a vulgar is, this is the same child, by the way, the cops, a vulgar is so severe that in fact, you get this this acute rather than obtuse femoral neck shaft angle. And in this child, it was about 45 degrees instead of 100 and 35 degrees. Now, the problem with cops, uh like cops severa and dysplasia is what can somebody tell me? Well, the answer is that the correction for the, the osteotomy for correction of, uh, they're a, is to do a proximal femoral valgus osteotomy. But what is that likely to do in the context of a dysplastic acetabulum? Well, the risk is that it will cause a dislocation. Um, and indeed done the other way around. This is this isn't a bony dysplasia. This is Perth days, but the classic treatment for subluxation and dysplasia in Perth days is you do exactly the opposite. You do a various osteotomy to vary eyes, the femoral neck increase the next shaft angle or to reduce, make more variously net shaft angle and actually to redirect the head back into the socket. So when I first started operating on these Children and having actually asked around including David Little in um in Sydney, but actually also Andreas row posh and various others um in um around, around the country. Uh They said to me, no, don't do um uh valgus osteotomy because you'll dislocate the hips and you make things worse anyway. But I was allowed by my colleagues to take children's theater and do a um an arthrogram. If I play the arthrogram, now get your eye in for a second. So I'm adducted in the hit their okay. What adducted does is that it basically mimics a vulgar. This osteotomy. Think about that far. It back at me if that doesn't make sense. But adducted in the hip is like doing a vulgar. It's osteotomy what happens here? Which was remarkable and astonishing to me is that far from subluxation, the hip in um uh in uh in adduction, in fact, the Concentra city, the, the, the, the coverage and the, the, the reduction if you like of the subluxation of the hip improved, does everybody get that? So can you see that the there's this large medial um die pool representing subluxation in the neutral position which then actually disappears. And this is exactly the same thing going the other way where in fact, a medial die pool appears as we abduct. So this then gave me the confidence to actually start doing this, which was doing massive vulgar. So osteotomy is 90 degree valgus, osteotomy. Um And this is a child who now looked after when this was something we did five years ago. Um And he went from basically having a totally scissoring gay, struggling to walk, actually largely wheelchair bound. So now he actually he goes on two and three mile walks with his family and he loves it and his hips as well as actually um uh sorry, way too far back. Well, his, his femoral heads have actually started to Aasif I um as well, which I suspect, I don't know, watch this space. We were, we've got a little case series of these which will write up, but hopefully, actually the ball in the socket, certainly he's very happy with the result. And indeed, because a lot of these Children are online because they're largely not the 1st 15 rugby players. Um they chat to all their mates. And so I've had, you know, a lot of referrals from elsewhere including um Cornwall and Manchester. Um That's the end of me talking about um hip containment. We're now going to talk just a little bit about reestablishing the mechanical access. Um And this is, this is why I particularly mentioned uh Chondroma taf seal dysplasias, um Schmidt and um Jantzen type and this is, this is actually Schmidt type. Um This is the original paper, um, 2012, only a little over 10 years ago written by the inventor of eight plates. Um Professor Peter Stephens, um from Salt Lake City in Utah. And he demonstrated that actually if you do um, single event multilevel eight plate surgery, you can basically take Children in who again are struggling to walk because of their massive cooks of error. Um And they're massive genevieve air. Um and you can send them home the same day and then 18 months later, they have normal looking legs and this is a lovely little chat with Bennis who I look after. Um, and um, we took him as a safe and again, a little bit like the previous chap, somebody who really was struggling to walk very simple surgery, you know, anyone can do this. Um And actually 18 months down the line, um, he had very normal looking legs and massively improved function. Um And the goal of course, is not only just um to, to provide better function in the short term, but actually, to avoid all the problems which all of, you know, come with significant malalignment, which is um young adult osteoarthritis. Um in, in chondroma to have seal dysplasia, you get Jenny very. Um, and we do the lateral eight plates, multilevel, lateral eight plates, um in achondroplasia, you get Jenny very. Um And so we do lateral eight plates. This girl incidentally was only five, her parents um came to see me and actually they incredibly well informed, a lot of self help groups who were advising Children to have this done. Um And so they came and said, weird, like natural distal femoral temporary Picazio DCIS, very, very educated and informed people. Um And you know, she's done, she's done very dramatically well through what? Again, it's simple, you know, entry level surgical difficulty, um just eight plates uh in, in and out of the day case. Um uh and this is sed sed, they get Jenny Vulg. Um This is actually a girl who um from Manchester and unfortunately, um I operated um in 2019 and then I didn't see her again until 2022 because of COVID and would actually overcooked. So there is an unintended consequence of the mischief of basically shutting up shop through COVID. Um This is, this is a, this is slightly controversial. This is um this is, again, that's the same Condron that have sealed displays your child, but actually, um using eight plates on the proximal um femur, um some of my colleagues believe that's nonsense. But in fact, actually, if you, if you look at the angle between the screws, they are diverging. Um And if you look at the neck shaft angle, it is becoming less various um facet Duval rods. I, well as one of the group who published the, the first um non inventor um series on Facet Duval Rods, they're brilliant and just again to, to make the point there a passive device. Okay. There is a male solid rod which you tap in and put screw threads into the distal Fyssas. And then there is a female hollow tube which you, which which you tap into the proximal Fyssas. And then over time the growth plates grow and the, and the, the the tube basically um comes off the rod until eventually, if you do it very early, then the rod and the tube actually disengaged and then you have to start off all over again. And as rad, you said, it only works if the rod and the um tube are straight. And therefore, if you've got a curved leg, you have to do this kebab technique of cutting the leg into several segments so that you can actually get your rods down um incidentally just for the record. So uh FD rods will allow a doubling of the length of the rod at first insertion. At what age is your femur and your tibia? Half the length that they will be as an adult. Ben Loot. Uh I just keep thinking it was 1.5 centimeters a year from the knee. Uh, but then that's not helpful for the whole leg. Three years old. Your femur is half of its adults length. So we try to never put in FD rods until you're three so that you've got at least a fighting chance that they'll still be working when you hit skeletal maturity. If you can wait till five. That's brilliant because they never then need replacing um leg length. Um leg lengthening, I do know leg lengthening at all. Um It can be done with the frame. I know they do Rogie if it's ready, it's still there. I know they do do leg lengthening a little bit of leg lengthening um in Northern Orange and they do lots in Sheffield. But one of the reasons why uh and you can do it either with a frame or you can do it over a nail. There's various nails available. Very, very clever. It's very nice way of doing things because it's very minimally invasive and you don't have the horror of spending half your childhood with a great big frame on both legs. Um But the reason I don't is largely because of this, rather inspiring, an impressive chat. Does anybody know who that is, he has achondroplasia and he is local to this region who said that. Uh, sorry, I can't, I can't, I can only hear voices. I haven't got Joe. He was one of our lecturers at UVA. Yes. Absolutely. Yeah, exactly. So, he's a, he's a, he's a Cambridge graduate but he's now a lecturer in knowledge. Um, and he is, um, and he's a very inspiring chat. Um, Professor Sir Thomas Tom Shakespeare and his father actually um slightly unimaginatively doctor Sir William Shakespeare was a GP but Tom takes the, I think, completely legitimate um uh opinion that um uh that there's nothing really wrong with being short. It's just that actually, um the wretched average height, people make very, very little provision for people to function in there rather, um you know, unflexed herbal world. And so, um Tom is very strongly an opinion that you should not change people, but you should change the environment. And I have to say I tend to agree with them. Um That's the end of uh skeletal dysplasia is proper. Um We've talked, we've already mentioned the XT one is to, to um causes multiple hereditary exhaust, osi's. These are little chunks of the ISIS which break away and carried away from with the advancing tide of bone. Um We take them off only really when they're symptomatic. Um The other thing that they do is they cause vascular asymmetry around the Fyssas and they potentially therefore cause uh distortion of the Corona plane alignment, particularly around the knees. So often end up putting eight plates in these Children as well. Just to make the point that they really can occur everywhere. This is advised year old lad under my care actually came in and said, um, he, his father organized an urgent orthopedic appointment, it was already under my care. Um, and the little lad said, um, every time I run, it feels like somebody's stabbing me in the chest and every time I cough, it feels like somebody's stabbing me in the chest. And I thought, well, that pleuritic chest pain, I think really is not necessarily an orthopedic problem. But we actually, we got to, we got a chest X ray which showed um uh slight, well showed evidence of rib osteochondromas. And then we got a CT which showed that he actually had this osteochondroma here, which was, which was essentially hitting the pericardium and the heart with every heartbeat. Um So ended up with the uh cardiothoracic team in Leicester, um taking that out. Um So what we've talked about is how I managed to drift into this nonsense. And incidentally, I've recently taken on the role of on the board of the UK Skeletal Displays Group. So it is, it's, it's not, it is something I do have a genuine enthusiasm and interest for, talked about the genetics, have some of the ways where we, how we can sort of structure and classify what is otherwise a very mixed bag of actually phenotypic lee very different conditions. We've concentrated on a con FGFR three um deletion um talked about treatment principles. Um stopping dislocations, maintaining mechanical axis, largely with eight place. Very, very rare that I do osteotomy because I try to get these uh these Children early and actually get the message out there through the sort of help, self help groups which actually a lot of parents and Children, um, you know, do rely on, talked about fracture management in, oh, I, we haven't talked about Ramos. Um, a but everybody should look that up. It's an exciting new drug on the horizon. Talked about leg lengthening and the fact that I don't do it briefly touched on multiple hereditary, your cysto cys. Thank you. Any questions.