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Bone Composition, Physiology, Metabolism and Bone Graft for Orthopaedic Exams
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Bone Composition, Physiology, Metabolism and Bone Graft for Orthopaedic Exams
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Segment:0 .
hello, everybody, again, welcome to the FRCS mentor group, some housekeeping rules first. If anybody who isn't speaking, please to put on your mics at the very if you have questions, please use the chat function.
We use the hand up function for visor practice at the end of the session, which is not recorded. Today's session is going to be by agit. Sorry, Ami, who's a consultant, orthopedic trauma and orthopedic surgeon with the health ministry in Sri Lanka. He's we're very lucky to have him presenting about bone today, specifically bone grafting, bone physiology and bone banking.
Quite an important topic, and it's a topic, which is, though covered in a lot of textbooks, is not covered in a kind of concise way, which I look forward to hearing adults talk today. Without further delay. We'll start. Got a head at you! Thank you, Sean. Hi, guys, good evening.
So today, as Sean said, I am from Sri lanka, so I will talk about very important topic for is exempt from orthopedic exam bone. Those I selected this topic because it's a very common question comes to schools and even survivor table and not important is born is a very easy cash topic. If the fact, if you present it very methodically, very structured pattern and there are many definitions you need to know at the tip of your tongue if you present it in your exam and the bone pathology borne virus so you can easily score high marks and not the important thing I want to emphasize in my lecture because there are few diagrams they commonly asked in vivo exam.
So I have made all diagrams in dyslexia, all handmade diagrams you do understand. Uh, how to draw is a quick, structured diagram in during your exam to explain your examiner so. So I hope that will help you to get a good idea about this diagrams and the bond properly concentrating on q and is Viva. OK, now we'll move.
Usually in exam, they will enter in an in vivo table, they will show you this kind of picture. This is a true experience I am sharing with you. In my view, a table in basic sense, they showed this picture and asked, what is this? Now, imagine, as everybody knows, this is a film, but I don't think. You should talk about FEMA here because it's not tenotomy IRA. This is a far more basic science table, so as a common sense, you need to understand, OK, this, the examiner asked about both.
So if they ask what is, then you need to talk about bonds or it's very important rather than wasting your time. This is how sometimes it's time to start your discussion. So or what is born born is a composite and dynamic form of specialized connective tissue. Which is a nice. So this definition, definitely you need to know.
And I sort of it mean that is there are mechanical property will change your car in the direction, directions of the law that. So then you talk about the composition when you talk about the compassion, always divide and talk because try to emphasize the examiner that you are very methodical candidate because that will give you more marks for composition can be cellular components and across so substance about 10% and rest of the All majority comes as nearly 90% Tell substances on your site.
Osteoclast osteoblasts and borderline insane. Axilo substances, again, we divide into organic and inorganic. Organic substance type 1 traject like mainly inorganic substances, calcium phosphate, calcium sulphate, calcium, oxalate hydroxyapatite. If you start with this kind of answer with the definition and dividing composition, then the examiner will be really impressed and he will.
He will continue the vyver table without any problem and you will easily achieve a good mark. Next important thing you need to know what are the functions of the board? You don't have to know in detail and very minor minor structures. There are four main function. These are the four main functions you need to remember to talk in your view of a table structural support, protect the internal organs, human policies and is a calcium and phosphate done only for this mentioned, that is more than enough.
Then you need to know about the structural types of. This is a very common area, they ask, because they ask, what are the type of bone structures then you'd need you make your bones and make your bones, you match your bones one board. Metro bonds is a bond is the bond is a very common area, they will question and they will ask you to draw a bond structure. That's why I at the beginning of this lecture, you need to some kind of diagram under these bond topics and the one bonds we will talk.
This collagen fibers are arranged very randomly, haphazardly. But in lamina, born there, has a stretch oriented collagen fiber. And lamellar bones example cortical and Kessler suture, but all bone examples are embryonic and neonatal skeletal metathesis of growing bone, practicals and pathological bones like tumors. This one wants out there is no level of arrangement, but in lamela, born there is a particular arrangement.
I will discuss that later. But the important point is human bones are isotropic. At the beginning of definition, I told that bones. We under definition, we basically use the LaMelo born definition. At that under that definition we discussed is a knowledgeable but who bones are isotropic. That is the point you need to remember if the says is one wants mechanical property is the isotropic, that is correct.
I mean, it has a universal mechanical property in all directions of law that. Yeah, I have mentioned two questions. What are the differences between cortical and Kessler suture? That is a common view of fish. Another thing is, though, the a system. If you go to the Harbison system, this is the hand, you need to know, this kind of a very simple diagram here.
You can see this collagen fiber arrangement and we can see the oblique arrangement in adjacent layers. And there are 5 to seven layers arrangement and theory of sodium and endosperm and in-between. At the middle of we can see they have a thin canal which contain blood vessels, and those are connecting with this volkmann canals. Everything you need to know how to do the diagram and this you can see the posterior side and which are connected, which can accumulate.
And if you draw this kind of a very simple diagram, that is more than enough. Next at the same time, I have taken a textbook diagram as well to you to explain, because this kind of a diagram, it's not possible to draw in your exam by the table because whatever the diagram, you have to draw within two or three seconds. So that's why I always advise you to practice this kind of your own method of diagram, then it's easy to carry on your restaurant quickly.
Keep your floor. These are the differences between the cortical and cancellous bone cancer, cortical bones are always dense and very strong. It has a particular system and it has a arrangement compared to this cancellous bone. Their metabolic turnover is quite less, but in mid Kessler stone, it has eight times metabolic turnover compared cortical bone.
And it has more cells in the cancer bone compared cord and cortical bones we commonly see in the devices and keyboard bone. While this cancer has gone, we can see the metal prices, prices and the center of for if you quickly list out these differences that enough in your vivoactive. Then you need to know about cell types. This this is a very important and the frequent location in your paper.
That's why you have highlighted different passwords here because they frequently ask these words and these areas in your paper. I mentioned previously, there are four types of cells in the bone osteoblasts of your site, osteoclast and bone line instead. You can go to osteoblasts that is derived from undifferentiated mesenchymal stem cells. That is M65.
In the bone marrow, they produce oxygen, which contain collagen type one, it has a greater synthetic capacity. What happened this main type of osteoblasts differentiate, some of these osteoblasts is mediated by bond proteins and cytokines. What is the ultimate fate of this osteoblasts? Because majority, they control your side, they're trapped inside the cancellous bone matrix that has calcified bone matrix, and they cannot ask your side.
And rest of the amount they can into dormant state, they become inactive online and to die. They go into apoptosis. Then ask your side, as I said before, it's trapped in the calcified bond metric that is the major main type of cells in the bone, about 90% It has intracellular connections it can feel like, and this osteoarthritis is the main function.
This is important for calcium and phosphate metabolism, which is responsible for parathyroid hormone and calcitonin. I will discuss that later when I discuss the calcium metabolism. Bottom line, it's a kind of dormant cells lining down on the surface of the pond patio of an stadium. It is an inactive form will never need. They are happy to reactivate, and one newborn formations mainly contribute for position of.
And osteoclast, that is a very important one you need to know about this in and out because it's common location in Mexico and your Sam, osteoclast function and diagram and everything they are of are your favorite osteoclast arise from imo politics. The metal quality, macrophages and monocytes, stem cell lines. It's a large multi density.
Yeah the functions of osteoblasts and osteoclasts. This is the key word you need to use. That's the coupling mechanism. Because bone resorption and bone formation, it's a coupling cancer. It's a coupling of osteoblasts and osteoclasts. There are quite a kinds interleukin one, mainly that sensitive point, interleukin six, human necrotic factor alpha and platelet growth factor, those are cytokines, which accumulate and which upregulate the red light receptors.
Frank, like endorsed industrial blog. What happened that after upregulate in this increase, the number of Frank lichen on the surface of osteoblasts, they go and combined with the rank receptors on the osteoclast and the copper they buy and they stimulate osteoclasts and make sure that is also I come from osteoblasts and ryong receptors from the osteoclast. Yeah, Yeah.
And they bind and they form them. They stimulate the maturation of osteoclast. Then they scream, they get the osteoclast function. This is osteoclast song, so you need to know how to draw this track. Because they commonly asked how osteoclast function, because osteoclast main function is the bone resorption and that involving four.
That in for remodeling process. So you need to know it, it has it's a large cell, multiple nuclear cell, and it has a brush board that is called roughly border, and it's combined with the hulking slap. It's bit of the bone surface and it's combined by integrating bonds. What happens? They have to aggravate this.
Born organic and inorganic substance for bone resorption. How did this resumption happen with inorganic substances? They create a low pitch area, low atmosphere within this pit. It's a hulking slap. There are three ways this time secure and this. There are three ways they produce low pitch. One thing is the carbonic anhydrase second one is ATP dependent proton pump.
The third one is the sodium hydrogen exchange system. Through these three ways they produce lopate and that dissolved hydroxy epatite. That's how they dissolve this inorganic substance when it comes to the organic substance that they secrete lysosomal degradation inside. The persistent acid phosphatase and cathepsin B hydrolyzed organic substances, you need to know how to draw this diagram and explain this to me can sum up to explain the resorption functions of your class.
So there are two receptors here, rank receptors and calcitonin receptors, I will discuss that. So osteoclast activation, as I said before, by mainly ranked Leiden and interleukin one, osteoclast inhibition by calcitonin and interleukin 10. These are the two point. Now we get into the bone matrix, we discuss about bone health.
Now we discuss about bone matrix. Bear bought bone matrix, mainly inorganic and organic and inorganic hydroxyl calcium hydroxide, but you need to know how to write this equation in your bio. Sometimes they will. Sometimes even for. And out of that, 99% of body calcium. We can see in the board.
And 85% of body phosphate in the bone and 40% to 60% of total body sodium and potassium we can see and this inorganic substance, mainly this hydroxy epatite calcium hydroxide hydroapatite responsible for compression, strength of the bone that is important. The compression strength of support when you go into inorganic substance magnetite form collagen 90% of organic substance.
It contains type I collagen that is responsible for tensile strength of support. Now we're going to block supply of the ball. This blood supply of the bone, you need to know. There are three. Main supply, one thing is high pressure system. Low pressure system that is through the blood supply. Third one is metal prices Allen epimysium.
You remember that, too. That's for a high pressure system, it is mainly from the nutrient artery, from the nutrient formula that supply through it enters the medial epicondyle at the diet region, then it supply from industrial tuberosity from inside to outside. That is a main supply that is called centrifugal circulation. The normally bone has centrifugal.
Because it's supply enough to that. So starting from inside, then it's applied towards outside. What happens when you are doing framing from the interim? That is a common viral Kessler. They are started the blood supply of the board. Then they will question about, OK, tell me what is the alterations of the circulation? Then you need to know that reverse is said to be centrifugal circulation to tend to be there for centripetal circulation.
What happened you dreaming of the endosperm? The circulation get stopped. Then it stopped circulation from outside to inside. That is called centripetal. That is the important point you need to know about circulation of the blood type. This diagram also clearly shows this is from inside out. That is centrifugal. This is outside.
That is sensory details. OK, a little bit about Battiste film. This is a. Ultra quality of the ball, it's composed of two layers out of fibrous layers and in a cellular layer, it has four main function that is important for a growth of the bone. It gives the blood supply out of one third, and it provides the attachment to tendons, muscles, ligaments, and it prevents the spillage of politicians in that adjacent soft tissue.
Now we are getting to the very important area now. Now we talk finish about basic area of the bone blood that bone composition cells, then matrix. And circulation. Now we are getting to very important topic, important area and a frequent question about this in your table and even.
That is calcium metabolism. You need to know. You need to know the diagram of this also. But looking at the diagram, it will, you might feel it's very complicated. But once you understand the real concept of that, it's a very easy to draw the diagram in. So Kessler metabolism, usually the 2.5mm, the normally calcium calcium is important for know stimulation conduction, muscle contraction, hormone function and activation of protein cascade.
What are the important hormones involved in this calcium metabolism parathyroid hormone, which is secrete from. T cells from parathyroid gland and one point five, I had to call a cholesterol calcitonin that is T cells from thyroid gland and corticosteroid and estrogen. OK this is the diagram, but I understand it, by looking at this, you might feel it's really confusing, but I will tell you one by step by step, then you will see it because you need to know how to draw this diagram in your table.
So this, you realize, comes. Our bodies, the skin has seven high cholesterol. It's transport, and even through the diet, we get this call. Seven, I had to call it Because it came to the liver. From here, it is catalyzed by 25 hydroxylase it could not into quantified, I had to call it for all.
Then it goes to. Kidney proximal, convoluted tubule. It contains 1 alpha hydroxylase. In the proximal candidate, the. By catalyzing. This this one, alpha hydroxylase and some death converting this tie dye hydrochloric acid all convert into one tie dye hydrochloric acid.
This one testified I had to call a counsel for all day function in three places. One thing it acts on the act to the kidney. It helps to calcium reabsorption and increase phosphate excretion. Then it occurred to. Got increased calcium absorption by increasing calcium binding lips, of course, in the vagina.
Then it's act on the board. How do they act on the bond? They do not act. They stimulate bone resorption to increase the calcium level in the blood. How do they will not directly affect the osteoclast for born this option, what they are doing? They act on those osteoblasts first they upregulate rent liken.
Then they bind to rank receptors of the osteoclast through that they stimulate osteoclasts and increase bone. So that is a very important area and the integral point they will ask sometimes is 1 to I had to call it cultural directly from the osteoclast. No, it's to osteoblasts. So you need to know that three function of this one, two and then parathyroid hormone, this is secreted from T cells of the thyroid parathyroid gland.
That also act in. To three areas, mainly to the kidney by increasing 1 alpha hydroxylase that. STEAM let productions of one testified I had called parole. Now the thing is, they act on born again, it act to osteoblasts, to osteoclast and that stimulates bone resorption.
In addition to that, that indirectly act to the guard parathyroid hormone by increasing production of one two and I hate to call it calcium and increase the calcium absorption. That is how increased the calcium level when the calcium level is low. But when the calcium level is high. Then calcitonin come into the action.
What happened that? A health from thyroid gland dissected calcitonin that directly act on osteoclast. That is a good point. You need to know that calcitonin, because there is a calcitonin receptor on the osteoclast I showed in the previous diagram. I show you that diagram of the osteoclast here. You can see the receptor calcitonin receptor on the osteoclast, so it directly acts on osteoclast.
And they reduce the compromise, the osteoclast function. There are three ways they compromise. They flatten the Russian border. And the. Stimulate apoptosis, and they reduced osteoclast mortality. And they reduced the cytoplasmic extension.
Through that, they reduce osteoclast function and they come from this top bone resorption. That is the calcium metabolism now in the liver table, if they are OK, tell me the calcium. And if you draw this diagram, if you practice yourself and draw this diagram and explain why are trying, then I believe you can score very good marks.
Now we understand the different data protection here. Again, very important area, the fracture healing. It is. There are two discrete process we talk about here intra membrane certification and induction classification. This in the membrane of ossification. This is kind of a. Bone formation, because there are.
Undifferentiated there are multiple stem cells. On the petrous team, this. Multipotent stem cells convert into progenitor cells, and they directly lay down newborn that is membrane. But this new information is not sufficient to bridge the fracture. What happened, they argue it just becomes more vital, and second.
That is what we can see in the X-ray at the initial part of the healing process that is in remembrance of Kessler, but it doesn't bridge the fracture. But when you are talking about the bridging of the fact through hearing it's in the control, ossification plays a big role. That is the important area we discuss and the fracture healing that is in the loss.
Proctor hinted there are two types primary healing and secondary healing. In your exam. Tenodesis, if at seminars in your basic pilot table, explain the practical steps. I believe you need to explain about second healing step. So there are four steps we talk here.
Start with blood clot formation. It's a platelet aggregation. And clot formation. This secret platelet derived growth factors that activate the clotting cascade and complement cascade that happen as step by step. Those are the key words you need to use. The second step is inflammation. We'll talk about the inflammation, there are three buzzwords you need to matter to tell.
Hemostatic, angiogenic and Oscar induction. Humidity comes with phagocytosis, this phagocytosis they killed, they engulf all dead cells and debris that happens initially first with neutrophils, which is followed by macrophages. Then angiogenesis is a new vessel, formations at the fracture site they produce, they transport undifferentiated mesenchymal cells to the fracture site to differentiate later.
And in addition to that, they transport to substances like bone mineral protein that stimulate healing process. Third step is a phrase that is the phrase deformed, callous from you, talk about the risk of a repair place. This pattern here is very important. You need to mention in your access.
That is in theory that the repair process happened depending on the mechanical and chemical environment. Chemical environment, those are the substances, cytokines born in the body, mechanical in the spray, at the fracture level. Instead, the strain is less than 2% It's healed by primary bone here, so it needs absolute anatomical reduction into fragments of decompression.
I will tell that later. Is a Cardinal strain, according to parents, in theory, depending on the strain level type of healing process changes, if the strain is less than two, it will hit by a primary bone healing. The strain is 2 to 10% That's where that secondary healing happens. It is more than 17, it happened five blocks union, up to 100% congratulations.
You need to know about parents and the mentioned that is a buzzword. The last step is a remodeling phase that is a long process that happens over years. Here you need to talk about wolf law because it obeys the rules. That's a balance between the anabolic and catabolic base of support. That's the balance between osteoblasts and steel resorption.
For remodeling processes, you need to know and you need to know the diagram even to draw how remodeling happened. Before that, I will see what I will tell, what is Wolf law? Sometimes they will last. But if also that's enough, but better to know what, if, if in case they ask what is will or if the for, then it sounds really good. So Balkan consumes that configuration and bone shape based on the stressed economic.
This osteoclast activity being predominant on tension sites in the proposed detention site, osteoblasts blast activities be more dominant on electronic compression sites. So that's all will flow is depend on the stress applied on this for. Then remarkable. When you talk about remodeling, you better know you need to know how to draw this remodeling McMansion with.
Like this, as I said, that it involved in osteoblasts and osteoclasts, both in Myanmar. What happened is parathyroid hormone that recruit osteoclast formation, and they bind with the bone surface with their shuffleboard. They go to the Hawkins lacunae and combine they start with option. Like, as I said before, inorganic and organic substances, they dissolve, they start resorption.
While this option, what happened insulin like growth factor 1 liberated from born. This insulin like growth factor. They act again at the same site, osteoblasts. What happened is osteoblasts activation happened. In addition to that osteoblasts differentiation, this differentiation of precursor cells to osteoblasts happen by in the presence of bone, mineral protein and other hormones like estrogen.
So mainly intellectual that is aimed to pinpoint what happens is they start bone formation, bone resorption happen at the same time it bone formation, wild bone formation. What happened is activated osteoblasts dissected interleukin 6. This interleukin six, at the same time, they stimulate again, recruitment osteoclast and again stimulate bone resorption through stimulating osteoclast.
This happened concurrently at the same time they embedded more while they are forming, like they are laid down newborn. They embedded again that interleukin insulin like growth factor 1. So this osteoclast resorption and osteoblasts deportation that happens concurrently at the same time. So it it is remodeling process. It happens according to the wool.
If you know how to draw this diagram, if you know how to explain that remodeling and the floor, that's enough, for example. Now we'll get into primary healing. That is primary healing mean we have to talk about cutting costs. Here is cutting corners. It's mainly formed by osteoclast, but by this austere class, they form a tunnel through the fracture and they create the pathway and subsequently what happened?
These new vessels angiogenesis and followed by osteoblasts come in behind that. And this osteoblasts did directly lay down newborns, that is Osteria. This cutting call, this is also I drew my handmade diagram you to understand because very easy diagram in your exact. Only a few seconds.
Draw Start with this sharp edge that is a cutting zone, then reversal zone, you need to do the diagram and this inverted, this reverse shape. This osteoblastic cell arrangement then closing. So on the austerity position done. So primarily, we talk about this cutting. If you this is a diagram, this is complicated. You can't draw this diagram in your primary bone healing this cutting cone.
It is starting. This is the osteoclasts that formed the tunnel to the fracture to make the tunnel. Then followed by these new blood vessels come and osteoblasts come. Then osteoblasts lay down newborn formation. So you need to know this simple diagram to draw in your accent because I'll show you a textbook. Diagrams are very complicated.
These are very complicated. But if you practice before your exam, this can be very simple. Your own diagram that would be very easy to remember, and because it's very two or three seconds you can spend for your right. So so that's all about cutting consent and the primary healing. OK when you talk about the primary healing, so we need to have absolute stability.
Those are requirements. Absolute stability achieved by reduction and into fragmented compression. So whether this compression plate get the primary healing and the lack through those are the main areas, we can see the primary here. OK this is a very important. Christian in Viva cable. What are the differences between the primary and secondary?
Primarily, it needs absolute stability with an atypical reduction. So can the ruling happens with relative stability? The fracture train for primary healing should be less than 2 percent, but train should be more than two to between two 10% for second. And you can see cutting cones, but no cancer, no Kessler suture Mason, no remodeling. X-ray, we can see Kessler formation in primary, but second reading we can see callus formation, industrial certification and we can see remodeling and X-ray.
We can see if you mentioned these two differences, that's enough in. What are the factors I will ask this is are local factors, systemic factors, you know, all these things, so do are textbook theories. I'm not spend more time for this. OK, inspect some of the abnormal healing. Delayed union, fibrous union, non-union, non-union, we need to know it's a different separate topic.
I will not talk about non-union in this topic. The non-union there are three types air traffic, oligo traffic and hypertrophy. That's all I discussed here, but it's a separate, vast area. It's a separate topic. I will, if you want, I can discuss it later. OK, now I go into a different area that is bone grafting very important. They frequently question about this, especially in the table and even in.
You wanted to know what is bone grafting because. If you mention definition, a very healthy definition that shows how you are confident. That helped you to make a good impression about you in your examiner's mind. So definition of bone grafting is a use of implanted material alone or combined with other material which promote bone healing by providing hospital induction or steel conduction and osteogenic to the local side.
Very important, you need to mention about that three Botsford induction, conduction and osteogenic. What are the bone grafting allograft? Autographed cinemagraph and synthetic graft, but other functions we talk about graft, mechanical function and biological function. What is your induction or still induction is a biological stimulus of the crop, stimulate mitosis and differentiation of undifferentiated cells into progenitor cells or ultimately bone formation.
What other substances that induce induction, bone, mineral protein, insulin like growth factor 1 and two, fibroblastic growth factor and colonic stimulating factor, those are insecure. What is still construction or steel construction, it's provides a tri dimensional scaffolding structure for the bone formation, which supports the growth of capillaries, very vascular tissues and osteogenic because.
The base is still the scaffolding support. Osteogenesis means ability of graft to lay down bone, that graft got even precursor cells. It has lifestyle so it can produce itself new born from graft. So that is osteogenesis. You need to know these three functions to explain. What are the graphs substitute?
There are cell based substitutes factors will substitute and calcium phosphate, calcium carbonate hydroxyapatite and calcium sulfate and so many. What are the other practices practicing method for systemic enhancement that means giving substances sometimes injury to disturb skeletal or sometimes they do cock cortex osteotomy to stimulate healing electromagnetic fields, low intensity pulsed ultrasound therapy.
Oxygen therapy dosing. I include this slide to sake of completion of the fact so little bit know about it, that's. OK this is a great new area graph in cooperation. You need to know about it, because they can ask if they start to of a table with bone grafting. Eventually, they will ask about graft in corporate. Graft in cooperation, it's a process which with invasion of the graph by the host for.
You need to tell that. Well, there are three four stages here also targeting tenotomy, tuberosity, then revascularisation and induction, then conduction then remotely out of this format that this cortical graft and counselors craft. These first two methods are common. This is a common Viva topic is what are the differences between the cortical graph in cooperation and the council is drafting cooperation?
If you know that fact, that's more than enough on the graph in common. That's all you need to on that graph in cooperation. Counsellors in cooperation, this is very quick process compared to photographs, because revascularization, inflammatory process that all happens very rapidly. Phase one is very rapid. Then phase two is a creep substitution that is a buzzword that is insecure.
Crude substitution means that means osteoblasts lay down over dead trapping that can hold a scaffold of the graph while osteoclast resorption simultaneously, that happens concurrently. Because of all initial osteoblasts lay down that early access that officials the early day increased the density of the extra.
Surgeries, these are remodeling. What of remodeling along the trabecular along the lines of force with associated decree with that will decrease the bone density? Remember 3 and remember crib substitution under counsellor's graft incorporation. Going to go to court cortical drafting cooperation again, that first two steps happens here also, but it's slowly compared to court drafting cooperation.
Going to go to. Chris tool, it has osteoclast resorption, why are cutting corners? This is the buzzword you need to talk in court drafting and cutting concept. Initially, osteoclast born this option, then bond formation happened. That is my first initial stage, this once the photograph we applied that mechanical senses reduces 40% to 60% reduced, but it's come to normal level over one year.
So as a summary, if these two differences under this draft incorporation cortical and cancerous drafting cooperation, initially it's a rapid process, information and request. This is a slow process, and we can see the creep substitution on the Kessler, but cortical we can see cutting on an entire graph incorporated in Kessler one, but graph not incorporated in cortical bone and there is no remodeling.
There is a remodeling in Kessler draft, but no remodeling facing cortical grafts that happens only cutting all. That's all about crafting cooperation. Then born banking. This is a very hot area topic they will ask. And if You know these steps and if they are to tell me something about bone bang, if you can tell quickly step by step and keep on talking.
I think that's more than enough in your exam. You can start with it's a complex process with multiple step with. Donor selection. Then once you select your donor, you have to get the consent from the donor. Is the line drawn? We have to get the consent for screening process. HIV screening, syphilis, hepatitis and we need to assess personal medical reports.
We need to get all this on consent. If there's a category. Craft, so we had to get the consent from his next kin. Then third step is a donor screening, you have to screen his medical records, plus his behavioral history because it is a drug abuse drug, IV drug user. So is it it's an exclusion criteria. We can't use bone graft from a drug user, so it's important to know about his behavioral history as.
When you are screaming the door, so we have to get the detailed history, if he's alive, don't we have to get your relations and if you want, you can contact, keep track and trace the medical records everything and you need to look for any exclusion criteria are there. If not only you can think we can proceed for graft. Harvesting the crop. Taking the graph.
The exclusion criteria for HIV, hepatitis b, C malignancies, rheumatoid arthritis, autoimmune diseases like systemic disease, long term steroid use, Alzheimer, multiple sclerosis, dark. And there are lists. So if you mentioned two of these things in your exam, so that's enough. Want to scream once you select that donor is suitable? Then you had a retrieval of the graft, then graft processing, that is a very important area you need to know.
Graph processing, the target of this graph processing to remove all debridement and. Reduce infection. What are the static physical displacement? Removal of superficial protein and cells and tissues. Then all personification. Plus or minus pulsatile about that removes the cells and blood.
Then alcohol stop that will decrease the viral load and bacterial load, in addition that will be maturation of the protein happen. That happens. And then we subsequently used antibiotics. So that will further decrease the bacterial load and then sterilization for. This standardization is to use gamma radiation and chemicals, but this gamma radiation we commonly use, the problem is that will reduce their mechanical strength.
That is the point you need to know. Then as a last step, we do the demonization by. What happened once you use as they dissolve all hydroxide, but they remain only this type of structural arrangement to use this all of. That is the graph process after that graph storage and graph transport graph storage is different temperature, different time periods. If it's a minus 2.
And we can keep one year, if it is minus 70, we can use for indefinite. Graph preservation technique, allograft preservation technique. Fresh, fresh, frozen and freeze dried. Yes, it is, we use immediately it's more immunogenic first person we keep in that 70 minus 70 least impact on mechanical strength and immunogenicity.
And that preserves bone mineral proteins in the car. Onto the feed, right, that is least immunogenic, lower risk of disease transmission, but bone mineral protein is depleted and structure is the main duties rehydrate. If you know this fact that, for example, cancer cells and cortical fresh frozen femoral head, those are the example for allograft restoration ulnar claw.
Thank you very much. That's all about bone. Bone grafting and bone bank. Thank you very much. That's a very difficult topic of multiple areas you've covered quite well. As always, to be an orthopedics, this is something that we must know inside out and it's different ways in different applications and so on.
Just a small point within the UK, HTLV virus is also legally required to be tested HTL the UMMT cell trophic virus, as well as the hep C syphilis and HIV. That's for the guys who are sitting the UK exam. The before we move on to questions, I just want to say the Perine on string theorem is absolutely correct in the way you've described it.
But the easier way to remember it is nature heals bones anyway. We just like to think we can do that. And for a bone to heal, it eventually needs to get to lesson than 2% strain to remodel. So if you think about if an animal or our ancestors broke a bone in the wild, we would. The pain itself would prevent us from moving. That decreases the strain, the hematoma that forms will decrease forever, the strain, the formation of fibrous type cartilage and/or soft callus will decrease the strain further and therefore harder bone callus forms, which decreases strain forever and then with activity and stress on this callus.
You'll get enough strain that you'll get remodeling. Brendan has asked that can we say primary healing is same as membrane calcification with Andrew control because ossification? Oh and the primary here, I doubt whether we can use that to work because in the membrane certification, it's a kind of primary heating, but it's not bridging the fracture.
It's two discrete process, but I really doubt whether we can use that two words under Prime primer here, isn't it, john? What is your I wouldn't use those words can be, but I wouldn't. Yeah, I wouldn't. For me, this confusion. But to be fair, in the exam, they have said, ask that question.
So I just I just prefer to stick to discussion of primary healing and secondary. And I don't know if the other mentors have. Different thoughts. Yeah, I also feel that primary healing and intramembranous ossification can be kept as two separate processes rather than getting them into one. Yeah Brendan, do you?
Because it's what I understood this, this to this process, this mainly that Industrial Classification is what we divide as primary and secondary, isn't it? Yeah, Yeah. It's also it's possible because it's happened underneath the period at the factory side. But it doesn't help much further. But when it comes to the fact that this Industrial Classification that we divide as primary and second, that is the concept I understood, isn't it, sean?
What do you think? Yeah so to be honest, I have difficulty with I know, I know it sounds pretty basic, but for me, primary has been tremendous and into control has been secondary. But I don't like to mix those two concepts, mainly because these are the concepts that are designed for bone formation in terms of which type of bone, for example, clavicle versus long bone. So long bone growth is a flat bone and things like that, how they form the embryology.
But they are the same processes for healing. So technicality, you can say it, and I suspect a lot of people do use it that way. OK, another question that came up was, I hope we've answered the question, if anyone feels they have a better explanation for this. We would appreciate you coming forward the debate. So the question is in reference to other four sources, according to ramachandran, dBm is Austria inductive or conductive?
Because apparently also bullet says it's only Austria conducted. Anyone any thoughts on the dbm? To be honest with you, I would have I've always said it's just inductive inductive. If you think about it, it has a.
It's even those stimulus, it does have some of the it has factories that allow growth in encourages growth in growth. OK and other questions. Yeah, there are a couple more, please. One of them was. What is the difference between ossification and calcification? Mohammad Carmella's this.
OK also in ossification, there is formation of bone matrix, as well as the calcification of the matrix, which is a matrix with the calcium, which is inorganic materials like what is calcification, just inorganic? So you can say, for example, tendons can become calcified and the process of classification, it's just the mineral deposits of calcium, calcium and phosphate, while ossification is the actual organic bone formation with calcification as part of normal bone formation.
The last question was what is primary gap healing? Yeah, it is a gap healing mean that are explaining in the primary healing, even though we talk about into fragmentary compression, we cannot achieve the exact contact, even though we achieve the anatomical reduction compressed with the compression plate.
You can see this. There's a tiny gap. Opposite side. There is some callus formation there, because even though it is compressed, we can't achieve the exact 100% conversion compression. Because of that, that this is a tension site, there is a tiny bit of get that call gap. Even under primer here.
That's why even on the primary hearing this and close to the plate, we explain it as a contact feeling. Opposite side of the plate, we explain it as a gap because even though we achieved absolute reduction with into fragmentary compression, the achieving the congruent reduction is impossible. That is really where this gap came, and that's where they explain about gap, period.
That's what I understood in. Anybody has any different idea for this. That's correct. So if you ever look at a long bomb that's been fixed with compression plating, if the compression plate is not present, what you'll see is a small bit of callus formation on the opposite side to the plate.
So when we say prevent, we mean a slight bend on your plate to with concave to the bone. This usually forces the outside the opposite side to the plate to compress as you tighten the screws. But if it's not done adequately, watch watch those fractures and you'll see that there is a small little bit of callus formation on the opposite on the opposite side of the plate.
And not the point, not the point. I want to emphasize what they are telling this contact feeling. But they are telling the primary reason that bone union and the cutting cone that means remodeling in the primary heating. The remodeling part is cutting on this bone union and cutting or remodeling happens concurrently simultaneously.
When it comes to the gap healing that happens subsequently, that first bone healing, then remodeling, that is the one difference between the contact healing and the gap. That's an interesting exercise to do with your fracture fixations or with your colleagues fracture fixation to actually watch those ones that are plated and see what happens. And then you can see how good your technique for plate reduction technique.
So plate compression technique is because I always find it quite interesting if you watch the side closest to the plate and if there is osteoporosis, significant osteoporosis and dieback of the bone, that means it's been compressed. While if there is no osteoporosis but there's no healing on the side next to the plate, that means if your fracture hasn't got contact across the bone, enough enough of a small gap or compression that allows primary healing to occur.
So therefore you're getting an absence of healing in that area. And often, if you watch that, you'll actually see a small gap. You might even see gap feeling on the other side in those patients. But yes, everything. But this is just things to do when you're studying your x-rays to establish how well your operation went with your primary intention of what you were doing.
Yeah, and I appreciate the person who asked that question, because that could be questioning your Vivek slap. OK OK, we'll move on. Thank you, everybody. The traject terrific rahami. My apologies. Terrific talk. The it's a difficult topic with lots of different concepts that to put together and apply to clinical scenarios, which you have done quite well.
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