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Join us for this on-demand teaching session led by Bianca, a fifth-year medical student and educational lead for the surgical undergraduate P teaching alliance. In this session, Bianca is joined by Adam, a fellow fifth-year medical student keen on orthopedics and sports science. This session will kick off with a focus on lower limb trauma and orthopedics, starting off from the hip region, moving down to the knee and then in future sessions moving from the knee towards the foot and ankle. The session is full of detailed, yet clearly explained information. Topics covered include the in-depth explanation of the hip bone and its various surfaces and borders, the study of the ischium and pubis, and an in-depth discussion of the hip joint and its structures. This session is perfect for those who want to expands their understanding of lower limb anatomy and trauma.
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Learning objectives

1. By the end of this teaching session, the learners should be able to comprehensively describe the anatomy of the lower limb focusing on the hip region to the knee, including the bones, stability of the joints, muscles and movements of the hip joint. 2. Participants will be able to explain the anatomy of the pelvic girdle, its constituent parts and its function within the locomotor system i.e., weight-bearing and serving as an attachment site for various muscles. 3. Learners should be able to in-depth discuss the structure and importance of the hip joint, elaborating on its synovial articulation, acetabular structure, joint movement possibilities and it's the role in weight-bearing. 4. The learners should be able to describe the details of the ilium, ischium and pubis along with their individual bones parts, surfaces, borders and their role in forming the hip bone. 5. Learners should be able to identify and describe the function of the ligaments in the hip joint and their role in providing dynamic stability during movements.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

Hi, everyone. Um, can everyone hear me just checking for you again? Hopefully it should be ok. Um, hi, my name is Bianca. I am 1/5 year medical student and one of the educational leads for, um, the surgical undergraduate P teaching alliance. And today we have Adam over here who is going to talk to us about, um, the lower limb trauma and orthopedics first session. Um, before I begin, I'd just like to thank our sponsors, especially. Um, this week we've got a new sponsor as well. The Royal College of Surgeons. Um, and yeah, I'm gonna hand over to Adam who'll take you through it. Ok. Hi, everyone. My name's Adam. Um, I'm 1/5 year medical student at UCL. Um, and I quite like orthopedics and sports science and today I'm going to be giving, um, a tutorial on the lower limb. Er, today it's just going to be going from the hip region all the way down to the knee and then on Wednesday and, um, following that there's gonna be more tutorial sort of going on from the knee down with, uh, with the foot and ankle and then also with some clinical cases. Ok. So just to begin, I'm going to, um, talk about what this tutorial is gonna be covering. Um, I'm gonna be talking about the hip, I'm gonna be talking about the bones, the stability of the joints and also the movements on the hip joint. Um, then I'm going to be going onto the muscles in the gluteal region. Um I'll be discussing the lumbosacral plexus which supplies the innervation to the lower limb. Um I'll discuss some neurovascular structures, um some sites for intramuscular injection. Um Then I'll move on to the thigh region and, and talk about the bone, the femur, the long bone in the leg. Um Then I'll go onto the muscles around the femur which allow movement and then I'll just be finishing off with um some more neurovascular supply. Ok. So, to begin with, let's talk about the bony pelvis. Um There's a pelvic girdle. This consists of two hip bones, the sacrum and the coccyx. And um the hip bone is basically um three bones which fuse together around the age of puberty. This is the ilium, the ischium and the pubis. Um The reason it fuses uh puberty is because you want to have some space for the head of the femur to sort of articulate into the socket. Um and it just allows uh space for the bones to grow into um allowing good movement in the future. So, the hip articulates anteriorly at a special joint. This is called the pubic synthesis if we just look over here. Um and also posteriorly, um the pelvis is sort of anchored to the axial skeleton. Um This is at the sacrum um and this is by the sacroiliac joints over here. And sometimes you can have inflammatory conditions which sort of affect certain joints. For example, the si joints and you can see this on sort of x-rays and other scans. So what are the functions of the bony pelvis and the hip? So the main functions are, it allows weight bearing. It allows the body's weight to be transferred from sort of um the upper body, um the abdomen region and then um basically down into the hips. It also allows for low commotion and movement. Um and it also um serves as an attachment site for various muscles, again, allowing efficient movement um and gait. So um here we can just see the acetabulum. It basically forms what we call the socket joint. Um because the hip and the shoulder are both basically essentially hip, um ball and socket joints. Um So the acetabulum basically forms the socket, which the femoral head will basically sit inside so that you can imagine the femur um acting as a ball and the acetabulum is basically the socket. Ok. So um I'm going to be going into some detail about each of the three bones that I mentioned earlier, the ilium, the ischium and the pubis. So like the ilium, it is basically a blade slash fan shaped bone and it consists of two main parts. Um This is the body and then also the wing, the ilium has three surfaces. Um These are the gluteal surfaces, the iliac surface and also the sacral pelvic surface surface. So the gluteal surface basically starts from the outer lip of the iliac crest. It moves inf um mo it moves to the inferior gluteal line. Um and it also contains the anterior and posterior gluteal lines. Ok. And we can just see that over here. So we have the iliac crest here. You move down to the anterior superior iliac spine, the anterior inferior ilex spine, and then it just carries on here. Ok. Then we have the iliac surface. Um This basically starts superiorly by the inner lip. Um it continues inferiorly by the arcuate line er posteriorly by the iliac curiosity and then the auricular surface as well. And then you have finally, the sacral pelvic surface. This is basically forming um from the posterior surface, er posterior iliac fossa to the posterior extent of the ilium. And it contains the a auricular surface which forms the si joint and the iliac tuber. And this basically serves an attachment site for muscles and for ligaments. So these are the main surfaces of the ilium. There's also four borders in the ilium. These are the superior, anterior, inferior and medial borders. Um And over here, we can just understand that the superior is basically from the iliac crest and it contains basically the inner and outer lips of the ilia of the iliac crest on either side here. And then you have the anterior border, which basically consists of the anterior superior iliac spine, the anterior inferior iliac spine, and then all the way down to the acetabulum, um inferior border consists of the psi s so the posterior superior iliac spine over here, um this carries on inferiorly to the posterior inferior iliac spine. Um And then it forms the upper border of the greater sciatic notch, just not to here. And then you finally, we have a medial border which is hard to see on these um on these two images on the side, but it basically is from the iliac crest and it moves medially to the iliopubic eminence. And the lower part of this forms the um pectineal line. Ok. So there's quite a lot of detail regarding the bones. Um I'm going to be going on to the last two bones of the hip which is the ISS and the pubis. So the ischium is basically an l shaped bone and it forms the posterior lateral portion of the hip bone. And again, just like the eye, it has two parts, a body and a ramus. So in more detail, the body basically contains three surfaces, a medial surface, a femoral surface and a posterior surface. Um the femoral surface of the body forms part of the superior border of the obturator foramen and then the posterior surface um is basically a conical projection, which is known as the essure spine, which you can see over here. Um And below this lies the lesser sciatic foramen and the essure curiosity again, I know I'm mentioning quite a lot of um long terms, but hopefully along the tutorials, it will sort of make sense um why um these names are important um and why these foramen are important. Um because these basically act as gateways into um for the um nervous supply and the arterial supply um to the lower limb, you also have the inferior ischial ramus. And this basically meets with the inferior pubic ramus to form the ischiopubic ramus. Um And this basically forms the inferior border of the obturator for and you can just see this over here. Ok. Finally, the third bone, this is the pubis, it's the smallest and the most anterior portion. Um and it contains a body and a superior and an inferior ramus. So again, the body will articulate with the opposite pubic body. As um I showed in this slide over here, we can basically see the two bodies of the pub is forming the synthesis over here, which is a cartilaginous joint. And also the pubic symphysis contains a pubic crest superiorly which extends laterally as the pubic tubercle. Um There's two remi the superior and the inferior remi the superior forms part of the acetabulum laterally. So again, this is just part of the socket here. And then we have the inferior ramus which forms the lower border of Chota Foramen, which you can just see over here. So there's three parts of the body, the superior ramus hair forming part of the socket. And then you have the inferior hair which helps to form this obturator foramen over here. Two. So let's go into some more detail about the actual hip joint. The hip joint is basically a synovial articulation between the hemispherical head of the femur and the lunate surface of the acetabulum. And it forms essentially what we call a Multiaxial ball and socket joint, ball and socket joints are really good for mobility. However, this can sometimes come at a cost of stability. So it's very important that joints such as the hip and the shoulders have um good strong ligaments and muscles around them and this allows the joint to stay intact. However, in some cases, we can have um dislocations notably in the shoulders, but it can also happen in the hip joint. So the acetabulum, this is inferiorly marked by an acetabular notch. And this essentially allows passage of neurovascular structures. And we can just see that here with this arrow going here. It essentially allows the neurovascular supply um to the bone and to sort of the ligaments around the hip joint at the acetabulum. You also have um an articular surface on the acetabulum. Um This is smooth and it's crescent shaped and it essentially um does the main role of weight bearing where it transmits most of the body's weight through the pelvis and then down into the lower limb, it's covered by um something known as hyaline cartilage. And this is also covers the femoral head and this is just allows for efficient movements and smoothness in the movements. You also have the non articular surface which you can see over here. And this is basically um rough and it forms a shallow depression known as the acetabular fossa. Um And this is basically continuous with the notch. Ok. So we can see here, it's just basically the um acetabulum doesn't have a complete sort of circle going around. And then the ligament here, the transverse ligament essentially completes the full circle here allowing for good stability. The main movements around the hip joint are basically all the movements that can be um permissible in a joint. So you can have flexion extension, abduction, abduction, medial and lateral rotation and also circumduction where it's a combination of movements. We also have a synovial membrane and a false membrane. These both help to enclose the hip joint allowing for more stability and smoothness of movements just quickly. I'm going to go into some detail regarding the ligaments um that are present in the hip joint. These help to provide some dynamic stability to the hip joint allowing for the ball and the socket to remain intact. During uh movements such as running and sometimes even simple movements such as walking. So the key ligaments are the iliofemoral ligament, the pubofemoral ligament, the ischiofemoral ligament. And then we also have the transverse acetabular ligament over here, which helps to complete this circle and we have the ligament of the head of the femur. So I'll go into some detail about each of those. Now, the iliofemoral ligament basically acts as a triangular or y shaped ligament and it's trans it travels from the anterior inferior iliac spine and it goes down to the acetabulum. And we can see this over here where it essentially forms this sort of triangular shape. Um and the base is attached to a bone along the intertrochanteric line over here. So you can imagine here we have the anterior inferior iliac spine, the ligament starts here, it travels down and here we have this line on the femur and this is where the ligament attaches. We also have the pubofemoral ligament. This is again, another triangular shaped ligament which we can see over here, it's essentially um deep to the iliofemoral ligament. Um This begins at the iliopubic eminence which is over here and it travels medially and it blends with the fibers of the first ligament mentioned the iliofemoral ligament. And it again attaches along the intratrochanteric line. And we can imagine these strong fibrous ligaments help to basically ensure the um the ball and the socket remain intact, especially during fast movements such as running. Finally, we have the third of the main ligaments. This is the ischiofemoral ligament. Um This basically provides posterior reinforcement to the joint. It travels from the ischium and it travels medially to the greater trochanter um laterally. So you can see that over here, it's just traveling along and it inserts into the greater trochanter of the femur. So if you can imagine with these bones, the main reason why there's so many long names. Um and so many different lines, essentially, these bones have grooves in them. These can act as usually um markers which the ligaments and the muscles can attach to. So they basically serve as sites for attachment. We also have the transverse acetabular ligament which I mentioned earlier over here. And it essentially converts this notch into a foramen and this allows for access to neurovascular structures. And finally, we have a very small ligament. This is known as a ligament of the head of the femur. And is this is going to be very important later on clinically. So this essentially um goes from the head, from the fovea on the head of the femur and it goes to the acetabular fossa and it essentially is going to provide protection to the artery which lies within this ligament which supplies the head to the femur. And this is very important later on. Ok. So just some more um detail on the stability of the hip, hip joint, essentially split um stability into two sort of variables. You can have dynamic stability and you can have um static stability. So you can imagine um when you're moving and you're running, you're going to need some sort of dynamic stability. And this comes in the form of er ligaments. This comes in the form of muscles basically. Um these are um structures which are stretched during movements and they help to basically contract back in. And again, this just provides that stability keeping the main goal of the hip joint, which is to keep the ball and the socket intact, allowing for efficient movement. So, with the hip joint, we have various stabilizing factors. Um the osseous congruency of the bones, um for example, through the shape of the head of the femur is very important. And you can compare um this with the shoulder joint where there you can see some sort of similarities but also some differences. So you can imagine the hip joint um with the ball and socket, you have the ball which fits completely into the socket of the hip joint. And this is unlike the shoulder joint where you can imagine the entire head of the in the shoulder does not fit into the socket. And you can imagine when you have um more space with the head, not inside, you can have greater movements. Um and this happens in the shoulder in the glenoid cavity. Um On the other hand, with the hip joint, the entire head fits into the socket. And you can imagine this just forms a tighter seal in the hip joint and this is essential for weight bearing as well as mobility. Um And this is why um the shoulders are very prone to dislocation. Whereas in the hips, it usually requires um a greater amount of um trauma and high energy impact for a dislocation to occur. Whereas you always hear about shoulder dislocations quite commonly happening. Ok. There's some other factors which cause stability in the hip joint. This this includes the labrum. Um This is basically a fibro cartilage ring around the head of the femur. And we can see that over here. And what does this do? Essentially this deepens the socket of the hip joint, essentially acting um um as a tighter seal because you can imagine you have more surface area for articulation and it essentially acts as a suction seal allowing um around the head of the femur and it maintains it in the hip joint. Um And if you are lucky enough to experience um sort of um being in theaters, you and getting to see sort of a total hip replacement, you will see just how hard it is for the surgeons to essentially remove the head of the femur from the acetabulum. And this is partly partially because of the labrum which essentially acts as such a tight suction around the head of the femur. Ok. Um Other stabilizing factors include the ligaments which we mentioned earlier. Um Over here, I've just explained sort of the main movements which these ligaments help to restrict. So, um the iliofemoral ligament um acts to limit hyper extension abduction and lateral rotation, which are all very common movements during the um during running. And you can imagine this just helps um again, just to keep everything intact, you have the issue of femoral ligament. This essentially limits forward flexion and also medial rotation. You have the pum puber femoral ligament. And this um has a main role of limiting abduction. You also have some other ligaments such as the zona orbicularis, also known as the annular ligament. Um This wraps around the neck of the femur and this just helps to provide some more stability. Finally, we have two more factors. We have the joint capsule. Um Here we have the articular fibrous capsule which extends from the acetabular rim surrounding um all the way down to the intra to counter crest. And unfortunately, there's no image for this. But you can imagine this essentially covers the entire hip joint just as like a final layer to the onion. And this basically provides some more stability. And finally, we have about 21 muscles which cross the hip joint. Um These is notably the iliopsoas muscle and the rectus femoris muscle and these act as dynamic stabilizers. OK. So, as I was mentioning earlier, we have some gateways to the lower limb, these is basically um openings which are made um through gaps in the bones and the muscles. And they allow for um important neurovascular structures. Um important nerves, arteries and veins to basically enter into the lower limb and supply the muscles of the lower limb. So we have the great ascitic foramen. And with all these foramen, it's important to know the boundaries um as well as the actual content of w what passes through these gateways. So those are the two factors that are important to remember about these gateways. So we essentially have four them in the lower limb. We have the great ascitic foramen, the less ascitic foramen, we have the obturator canal and we also have the um gap where the inguinal ligament and the pelvic bone merge and there's a gap there. And this is very important later on with the femoral triangle. So let's go into some detail. With each of these, we have the greater sciatic foramen and this essentially has the boundaries which are the greater sciatic notch. Um It has the upper borders of the sacral spinous and sacral tuberous ligaments. And it also has er is bound by the la laterally by the sacrum. Um This um the Great Sat Foramen contains two different parts. Um And this is divided by the piriformis muscle which we can see over here and here we can see the two different arrows. So the contents above the piriformis muscle are basically the superior gluteal nerve artery and vein. And I've just wrote here N A and V for that. And then we have the vascular structures below the piriformis muscle, still within the greater sciatic foramen. And this is the sciatic nerve. You have the inferior gluteal nerve artery and vein. And then you also have some more nerves which I've listed over here. Soendral nerve, posterior, femoral cutaneous nerve nerve to the obturator internus, and the superior and inferior chlamys nerves and also the nerve to the quadratus femoris. So you can imagine um to simplify things, these are gateways which allow nerves and arteries and veins to enter into the lower limb and essentially supply the muscles allowing for these good movements. Secondly, we have the less ascitic phenomenon which has the boundaries superiorly of the issue of spine and sacral tuberous ligament over here. Um anteriorly, it's bound by the issue of body and posteriorly, it's bound by the sacral tuberous ligament. And there's um some neurovascular structures which pass through here. These include the pretend nerve and the internal pretend vessels. And these pass into the perineum from this gluteal region. You also have an important muscle tendon which passes through the lesser sciatic foramen. This is the n the tendon to the obturator internus muscle, which I'll mention later on. Ok. You also have the um gateway, which is basically between the inguinal ligament and the pelvic bone. And this will be mentioned later on. And this acts as a very important um pathway. You can imagine here's the inguinal ligament. Um This acts as essentially a very important pathway for the nerve arteries, veins and also lymph tissue which passes um into the, into the legs. Finally, we have the obturator canal and this is over here, this is basically um a bony canal. Um and it essentially contains the obturator nerve, the obturator artery and the obturator vein. The boundaries are superiorly, um the obturator groove on the superior pubic ramus inferiorly by the obturator membrane, which is essentially a membrane which forms part of the foramen. And you also have the obturator internus muscle and the obturator externus muscle acting as an inferior border. Ok. Now, I'm going to go into some detail regarding the actual muscles which are present in the hip region. So, as I mentioned earlier, there's 21 muscles which um enclose the hip joints. So you can imagine just how important it is for these muscles to basically um carry out certain movements um mentioned later on. Um and you can imagine that these muscles basically have to have the same insertions and the same origins sometimes. So they can sometimes form er common tendons. So you can imagine that certain muscles can be divided um into different er regions. So I'm going to be first talking about the superficial muscles of the gluteal region and later on about the deeper muscles of the gluteal region. And then we can have some comparisons between the roles of the superficial and the deep muscles. After this, we can discuss the muscles which continue down the leg and provide different types of movements again at the hip joint. So let's begin with the superficial muscles. There's essentially four muscles over here. The overall function is to cause a B duction and also extension of the thigh. So extension of the thigh basically means moving the hip um at the hip joint, you're moving the leg backwards. So as if you are moving your leg behind yourself, and this is very important during running. Um s also it causes abduction or a B duction which essentially um allows the leg to move away from the midline of the body. And this is very essential again, for lateral movements. So we have four muscles here. These are the three gluteal muscles. You have the gluteus minimus, the smallest one which is over here. And then you have the Gluteus Medius, which is over here. And then we have the gluteus maximus which forms the main muscle. Um and it's basically the most powerful and largest muscle in the body. Finally, we have a muscle which goes along the side. This is known as the tensor fascia lata, and it essentially acts as a very um tough structure on the side of the leg. However, this can cause problems during running such as iliotibial band syndromes. So let's start with the gluteus maximus it's basically um what can be described as quadrangular shaped. Um and it's the largest muscle in the body. It basically um causes extension of the hip and also external rotation. So you can imagine um external or lateral rotation allowing for important movements. And for any of those who play sports, you can imagine this is key for um for example, football where you want to um have lateral rotation allowing you to pass the ball. Ok. The gluteus maximus is the only muscle out of these four, which is supplied by the inferior gluteal nerve. Whereas the other three muscles are supplied by the superior gluteal nerve. And essentially the gluteus maximus travels from the fascia which covers the gluteus medius, the external surface of the ilium behind the posterior gluteal line, the fascia of the ecto spinae, the dorsal surface of the lower sacrum, the lateral margin of the coccyx and the external surface of the sacral tuberous ligament. And it basically travels to the posterior aspect of the iliotibial tract of the fascia lata and also to the gluteal tuberosity of the proximal femur. OK. Now, let's mention the other three muscles. We have the gluteus, medius and the gluteus minimus. You can describe both of them as sort of fan shaped muscles. And we can see that here and basically, um they lie deep to the gluteus maximus and the main movements they allow are abduction and internal rotation. So we can have a comparison between the meus medius and maximus where the maximus is supplied by the inferior nerve. Whereas the medius and minimus are supplied by the superior nerve. Also the minimus and medius cause internal rotation. Whereas the maximus causes external rotation. So this is an easy way to just remember the opposites. Then you have the TFL. The TFL is the most anterior muscle of the group. Um and it causes internal rotation and also some weak abduction at the hip joint. It also causes external rotation and some weak flexion extension movements at the knee joint because it covers both the hip joint and also the knee joint because it's quite a long muscle. And this allows it to cause movements both at either joint. Um It's made, it also has um something known as the iliotibial band, which is essentially a thick band of fibrous tissue. Um and this has three layers and it basically again acts to stabilize the knee joint. However, some uh condition which is very common is known as iliotibial band syndrome. This happens where the it band becomes quite inflamed and tight. Um sometimes due to running is very common in runners. Um And as a result, you have um a lot of inflammation which can require some physiotherapy and sometimes injections to treat. Ok. So let's go on to the deeper muscles of the gluteal region. These lie deep to the aforementioned earlier and they provide very important movements to the leg. A quick way, um A quick pneumonic to basically remember this is patched goods, often go on quilts. And if you just imagine the first letter from each of these words, and you associate it with one of the deeper muscles. So for P, we have the piriformis for G, we have the Gemellus superior, then we have the O for obturator internus, we have the next G for Gemellus inferior, we have the next O for obturator externus. And finally, we have Q for quadratus femoris. So these are the main muscles, the main muscles of the gluteal region line deep to the gluteal muscles. The main functions are very important to remember. This is external rotation of the thigh, also abduction of the thigh and this happens from a flexed hip and they essentially provide some stability again as I was mentioning earlier to the hip joint. So let's go through some detail with each of these muscles. Now, we have the piriformis which can be described as basically a pear shaped muscle. Um and it forms the most superior muscle of the group, the most superior muscle. Um and the superior gluteal nerve artery and vein as mentioned earlier, pass above it. And then we have the inferior gluteal nerve artery vein passing below um part of the greater sciatic foramen. So we also have the obturator internus muscle. This is a flat muscle and we can see this over here and it essentially forms this right angle as it inserts into the insertion point, which is on the greater trochanter. Um Also, there's two muscles, the superior and inferior game Gemellus. We can see those over here and the obturator Internus essentially lies in between these two muscles. It curves up and around the ischium at a 90 degree angle and then it passes all the way onto the greater trochanter. And it also inserts onto the greater trochanter with the Gemellus muscles. It forms a common tendon. OK? And over here, there's just some more detail regarding the innervation to these muscles which lie deep to the gluteal muscles. And over here, there's also some functions. However, the main functions to remember are external rotation of the thigh, abduction of the thigh and also stability. OK. And it's very good to remember pneumonics because in medicine, there's loads of muscles to learn, there's loads of ligaments, there's loads of bones to learn, there's loads of different landmarks and sometimes pneumonics can help for it to just stick in your mind and forming these associations is very good for exams. So a good example would be remembering um with the superficial muscles that the minimus and medius are provided by the superior nerve. Whereas the maximus is by the inferior nerve, that's good to remember. Also with regards to movements. If you sort of associate certain movements with certain muscles, this can again help you. OK. So let's move on to the femur now, which is basically the longest bone in the body. And here we have some images essentially showing all the anatomical sites present on the femur. Ok. The femur basically forms a very important role in transmitting this body weight from the hip ball and socket joint down into the lower legs. And it also affects our ability to stand and also our ability to move. The femur has three distinct parts. It has a proximal region, it has the shaft and then it also has the distal region of the femur. So let's go into some detail with the proximal femur. First, we begin here with the head of the femur. This artic cases with the acetabulum to form the hip joint is covered by hyaline cartilage um everywhere except for like the fovea. Um And this is where the ligament teres attaches the ligament to the head of the femur. Then we have the neck. This is cylindrical in shape and it projects superomedially from the shaft. You can imagine up and inwards basically. And the usual angle which we can imagine over here is 135 degrees. And sometimes we have conditions which can cause this angle to be reduced or this angle to be um increased and this can come with its own problems with biomechanics. Some other important landmarks are the greater trochanter over here. As I've mentioned earlier, it forms an attachment site for many muscles both um in the superficial and deep region of the gluteus region, then we have the lesser trochanter, which we can see over here it on, it's a smaller projection and it's located posterior medially. So basically uh at the back and more towards the inside, we have an intra trochanteric line. This travels from the GT, the greater trochanter down to the LT, the lesser trochanter. And again, it forms an attachment site for muscles and also for important ligaments. And we also have the in intertrochanteric crest. This is basically um a bony ridge between the trochanters and this is actually on the back. So on the front, we have the intertrochanteric line between the trochanters and on the back, we have the intertrochanteric crest which you can see over here. Ok. So this is all the proximal region of the femur. So now let's talk about those two angles. You have Coxa Valga, which is essentially an increased angle um between the shaft and the neck of the femur. And then you have Coxa Vara which is where the angle is reduced and it's under 120 degrees. And we can just see that here in this image. So we have roughly 100 and 20 degrees um and below causing Coxa Vara normal over here with around 100 and 30 degrees. And then we have Coxa Valga, which is about 140 degrees onwards. And you can imagine the problems this can cause with uh biomechanics in a clinical aspect So a quick question now, what has happened here and why is this important? Hopefully, the image is clear. OK. So I can't actually see the chat, but I'll give you guys a minute just to see what's been going on over here. OK. Very good. So yes, this is basically a neck or femur fracture and we can see this over here with the um line pointing towards it. So let's talk about the neck or femur fracture. It's very important clinically. So what is this image showing this is an ap an anterior posterior view of a neck or femur fracture. Um It can happen in both the elderly and also in the young. However, it is very common in the elderly and you'll see this during your clinical placements. So in the elderly, um is the most common cause is as a result of a fall. And you can imagine in the elderly where they are um more susceptible to um sort of having thinner bones, osteoporosis, uh very um low impact, low energy um trauma such as a fall can induce a fracture. However, the neck of femur fractures can also happen in young people. Um this happens um usually as a result of high energy trauma, for example, um car accidents um will also falls from a great height, for example, from a tree. So let's talk about the clinical importance of a neck or femur fracture. And before we do this, we have to talk about the blood supply to the femoral neck. So the blood supply to the femoral neck comes from the medial and lateral circumflex arteries which are branches of the deep artery of the femur. Why is this important? So it forms a ring at the base of the neck. And from here, it penetrates the branches, entering the joint capsule and it supplies the head of the femur. This is also reinforced by another artery which is the artery of the ligamentum teres. So this blood supply you can imagine is very fragile and it's basically branches of branches. And it, the reason it's important is because during neck or femur fractures, what can happen is this blood supply can be interrupted. Um and this can result in something known as avascular necrosis, which is basically if we break it down, death of the bone tissue necrosis, this happens as a result of a lack of blood supply. So it's avascular. Why is this um why is this important? Um having dead bone tissue can lead to um significant problems, significant levels of pain. You can have very limited range of motion and you also on presentation, sometimes hear a sort of cracking sound or crackling sound. And the management will involve a core decompression which will help to reduce the pressure around the neck. Um This will promote some blood flow. However, in severe cases, the bone is essentially too far gone and this will require a total hip replacement. So you can imagine the psychosocial impact of having a total hip replacement uh notably in a young patient. OK. OK. And here, we can just see an image of the blood supply. So we have the medial and the lateral circumflex arteries which come from this deep branch, they travel around the neck of the femur upwards supplying the head. And you also have this reinforced by the artery of the ligamentum teres here, which is protected by that ligament mentioned earlier. And necrosis here will cause um very significant um problems with pain and may require um emergency surgery. So, let's continue with the femur. Now, we're onto the shaft of the femur now. So um this is the femur, the longest bone in the body. The femur descends in a medial direction um allowing the knees to sort of come together towards the body's center, um um center of gravity and this allows for stability. There's some important landmarks and ridges on the um shaft of the femur. These include the li the linear aspera and we can see this over here. Um We also uh this essentially forms a ridge on the posterior surface and it splits approximately to form the pectineal line here and also to form the gluteal tuberosity. So you can imagine it comes down in this sort of y shape forms a linear aspira and then it splits again into er two lines, the medial supracondylar line and the lateral supracondylar line. So this image here is off the right leg from the back. And these i these names here are very important because the actors again, landmarks for muscles, the gluteal tuberosity acts as an attachment site for the gluteus maximus. The Pectin line is also mentioned here and it acts as an attachment site for some more um muscles in the gluteal region. We also have the distally, the linear asper separating into those two lines. The MSL, the medial supracondylar line ends as this adductor tubercle, which is an attachment site for the abductor muscles, which I'll mention later. And we also have um the lateral supracondylar line over here. Now, let's mention the last part of the femur, the distal femur. Um this is essentially split into two condyles which are basically um bony ends. And we can see this over here with a medial projection and a lateral projection. So um this is um they basically articulate um anteriorly with the surface of the patella whilst the posterior articulates with the tibia. So you can imagine um the sort of articulations being formed um at this joint which is essentially the knee joint, the medial and lateral epicondyles are bony elevations um on the non articular regions. So um this is essentially just not joining to any other joints and they form as um origin points for the M CL and the LCL which are important ligaments around the knee. We also have this gap over here, this is known as the intercondylar fossa and this is essentially a deep notch between the two condyles. And it essentially acts as an attachment site for two of the other important ligaments in the knee. This is the ACL and the PCL and an ACL tear is very common and is something which is um always heard about in the sports world because it's a very common injury that happens in athletes and also in the general population. So as I was mentioning earlier, one final very important gateway into the lower limb is known as the femoral triangle. And what is the femoral triangle? It's essentially a web shaped depression which forms as a junction between the abdomen and also the lower limb. It allows for very important nerves, arteries and veins to enter into the lower limb. And also um it allows for lymphatic drainage from the lower limb back into the venous circulation. So let's discuss the boundaries of the femoral triangle. We have the base here in the form of the inguinal ligament which travels over here. Then we have the medial border which is formed off the medial margin of the abductor longus muscle, which we can see over here, we have the lateral border which is formed by the medial margin of the sartorius, which you can see here. So if you can see the boundaries of the triangle and just to finish it off, we have the apex which is basically continuous with the a fascial canal, also known as the abductor canal which descends immediately so inwards and posteriorly, so backwards um through the abductor mus magnus muscle, the floor of the femoral triangle is formed by two more muscles. The pectineus muscle and the abductor longus muscle, as well as the iliopsoas muscle laterally. And the in the main ingredients you could say of the femoral triangle are over here and this is the femoral nerve, the femoral artery, the femoral vein, then we have some extra space and then we have the lymphatic drainage and another pneumonic to remember this is a naval NAV el. So we have the nerve artery vein, extra space and then lymphatic drainage. Also the femoral sheath covers the artery, the vein and the lymphoid tissue. However, the nerve is not protected by the femoral sheath. And we can see this over here. Now let's move further down and let's discuss the compartments within the um femur basically the muscular compartments. This is can essentially be cut into three. And we can see this in this image over here where we have a cross section of the femur. So we have an anterior compartment over here. We have the femur over here, we have a medial compartment. And then finally, we have the posterior compartment. And these compartments are basically divided naturally by intermuscular septum, which basically allows each muscle to have its specific compartment. The reason these compartments are important are because the anterior compartment provides specific movements. The medial compartments provides more medial movements. And the posterior compartment essentially provides specific movements and is supplied by a specific um innovation. And this can help for us to categorize into these three compartments. So let's discuss the anterior compartment. First, it involves um the sartorius muscle as well as the four large quadricep muscles. These are all supplied by the femoral nerve. Then we have the medial compartment which may seem small over here, but it contains six main muscles. So you have the gracilis, we have the Pectineus, we have the abductor, longus magnus and Brevis. And then we have the obturator externus. These are all innervated by the femoral nerve. Again. However, the abduct of Magnus has a sciatic um region which is innervates it. And we have the obturator externus which is supplied by the obturator nerve. But the general rule is the anterior and medial compartments are mainly and generally supplied by the femoral nerve. Finally, we have the posterior compartment essentially known as the hamstrings. Um These are three main muscles, they are all innervated by the sciatic nerve. So again, just as a recap, the anterior and medial compartments are generally supplied by the femoral nerve. Whereas the posterior compartment is supplied essentially by the sciatic nerve. There are a few exceptions as I'm going to mention now. So these are the muscles of the anterior thigh. There's quite a lot and the best way to categorize them is into the quadriceps, which essentially form the four large muscles which insert as a tendon and then we have some other muscles as well. So let's discuss the iliopsoas muscle. First, this originates as two separate muscles, the Iliacus and the psoas muscle and they basically insert as a common tendon. So the tendons uh merge um and this inserts into the lesser trochanter as mentioned earlier on the hip. Um This forms an very important muscle called idios soas which is a very strong flexor of the hip joint. Um And it also provides some internal rotation. Then we have the quadriceps muscle, which is essentially the bulk of the muscle on the anterior thigh. It consists of four muscles, the vastus medialis, the vastus intermedius, we have the vastus lateralis and then we have the rectus femoris and we can see all of these muscles over here. Essentially, these are all supplied by the femoral nerve. They mainly act um to cause extension at the knee joint. So um you can imagine the knee extending out like this, locking it out again, this is very important for sports and also for just normal walking. Um And the tendon inserts into the margins of the patella um and this helps to provide stability to the patella during movements. Finally, we have the sartorius which we can see over here. However, it's been cut, it's quite a superficial muscle. Um and it basically is quite powerful and it's a strap like muscle cos you can imagine it's just going across immediately like a like a strap. Um And this muscle is again supplied by the femoral nerve and it again causes some flexion at the hip joint and also causes flexion at the knee joint as well. So it covers both joints. Ok. Let's move on to the medial muscles of the thigh. So these include the abductors and also the gracilis and the Pectineus and the obturator externus. So the gracilis is the most superficial muscle and it's been cut away in this image over here. However, we can see the tendon here inserting with the sartorius. We have the Pectineus which is quite a um quadrangular muscle again in shape. Um And this basically forms the floor of the femoral triangle, again supplied by the femoral nerve. Then we have the abductors. So they of course, of course abduction of the leg, bring it back towards the midline. So we can split these into the adductor Longus brevis and then the main one, adductor Magnus abductor, Longus is a fan shaped muscle. And it basically again forms um part of the floor of the femoral triangle. We have the adductor Brevis which is over here and it basically lies posterior to the pectinous muscle here. So it's behind it. And it is triangular shape again being supplied by the obturator nerve. Then we have the adduct of magnus which is the largest muscle. And it's the deepest muscle of the group. Um This splits into a medial and also into a lateral region. That's how big the muscle is. It has two different parts. So the medial part which is closer to the midline of the body, um this acts as um a part of the hamstrings. So it will help to cause flexion of the knee joint. Um and it also is supplied by the er different division which is known as the tibial division of the sciatic nerve. Then we have the um abductor region of the abductor magnus and this is supplied by the obturator nerve and it causes abduction and also some medial rotation. Finally, we have the obturator externus muscle, which we can see just over here behind the other muscles and is supplied of course by the obturator nerve. It causes lateral rotation of the thigh at the hip joint. Ok. So now, finally, let's discuss the muscles of the posterior thigh. The three main ones mentioned are the biceps femoris. We also have the semitendinosis and we have the semimembranosus. So let's discuss each of these. Um individually, we have the biceps femoris. This basically lies lateral in the posterior compartment and it has a long head and a short head. So the long head crosses the posterior thigh obliquely and then this travels basically from medial to lateral and it joins with the short head distally or you can see the short head of the biceps over here. Also, we have expansions from the biceps for tendon, this blends with the ligaments um of the knee. And it helps again to provide some stability of the knee joint. Then we have the semitendinosis and the semimembranosus semi me sorry, the semitendinosis is medial to the biceps from morus. And we can see this over here and then we have the semimembranosus which actually lies deep to the semitendinosis and expansions from the semimembranosus tendon reinforce the ligaments and the fascia around the knee joint. So you can imagine these structures on individual um as per se, they actually help to um contribute to um stability and other factors within their respective joints. Again, this helps to imagine the the lower limb as a continuum as opposed to sort of just individual compartments. But for the sake of um structure and anatomy, we can imagine the thigh having three regions, the anterior, medial and posterior. So now let's discuss the innervation to the lower limb. This essentially consists of the lumbar plexus and the sacrum plexus. And together they form the lumbo sacral plexus, similar to the brachial plexus in the shoulder. So the lumbar plexus is formed from anterior rami of L1 to L4. These form cords which will then come together to form six major peripheral nerves. These descend the posterior abdomen wall and they travel to the lower limb. These are mentioned over here and there's a good pneumonic to remember this as well. So we have the iliohypogastric nerve. We have the ilio inguinal nerve, the genito femoral nerve, the lateral cutaneous nerve. And then we have the main two, which we have mentioned it before. The femoral nerve supplying the anterior compartment or no, the obturator nerve supplying the ad ad doctoral region. So let's start with the iliohypogastric nerve. This is basically um traveling from L1 and it has both a motor and sensory supply. The motor supply is to the internal oblique and also the transversus abdominis muscles. We also have a sensory supply which is the posterior lateral gluteal skin. So imagine just on the outside of the gluteal region. The next nerve is the ilioinguinal nerve. This essentially also comes from L1 but has contributions from T 12 and it basically has AAA motor supply to the internal oblique. There's also a sensory supply which is to the anteromedial thigh. Um the skin on the root of the penis and anterior scrotum. And this is in males and in females, this nerve supplies sensory innervation to the skin over the mons pubis and the labia majora. Then we have the genito femoral nerve, which is um has contributions from both L1 and L2. So you can imagine we're working our way sort of down the lumbar region. This has a motor region supply to the cremasteric muscle. And this essentially induces a reflex. We also have sensory innervation to um anterior scrotal skin on in males and again in females to the mons pubis and the labia majora. Finally, we have the last three nerves. The lateral femoral cutaneous nerve is a very important nerve. In regards to sensory innervation, it comes from L2 and also L3. And it essentially supplies sensation to the anterior and also to the lateral thigh all the way down to the knee. Then we have the two important nerves which supply the bulk of the muscles of the thigh region. We have the obturator nerve which comes from L2, 3 and four. This has a motor supply to the medial compartment and it has um skin sensory supply to the skin over the medial thigh just over those muscles. Then we have the femoral nerve. This has um innervation from L2, 3 and four as well. And it has um innervation motor to the anterior compartment to the um fem to the um muscles which cause extension of the femur, the quadriceps. And then we have a sensory supply to the anterior and medial thigh. So these are the main six nerves from the lumbar plexus. Then we have the sacral plexus. This essentially forms the last part of the spinal column. And it also consists of quite a few very important nerves. We have um contributions from S one all the way to S four. Again, it forms some cords, these come together to form five major nerves. Um and these again, descend from the posterior pelvic wall, they travel to either the greater sciatic foramen or they remain in the pelvis. So again, let's start from the top. We have the superior gluteal nerve. We mentioned this earlier. It has contributions from L4 L5 and S one and it leaves via the Great ASAT foramen above the piriformis muscle. It supplies motor innovation to the gluteus minimus, the gluteus medius and the TFL. Then we have the inferior gluteal nerve. This has contributions from L5 S one and S two and the motor supply is solely to the gluteus maximus. These two nerves do not have any innervation, um sensory innervation only motor. Then we have the sciatic nerve. This is the major nerve of the sacral plexus and it has contributions all the way from L4, all the way down to S3 or you can see this massive nerve over here. And it's very, again important clinically when it comes to um inserting injections um with lumbar punctures and also um with regards to um important injuries to the back and to the spinal cord. So the sciatic nerve comes from L4 to L3. It has two divisions, it has a tibial portion and also it has a common fibular portion and this is with respect to the innervation lower down below the knee. So the motor innovation of the tibial region supplies the posterior compartment. So it supplies the hamstrings and also the hamstring region of the adductor magnus. Then we have the common fibular region. This supplies um the shorter biceps, femoris and all the muscles in the anterior and lateral compartments of the leg. But below the knee, we have some sensory innervation. This um is tibial on the skin of the posterior lateral leg, the lateral foot and also the sole of the foot. And then we have the common fibular region of the sciatic nerve, supplying skin on the lateral leg and also the dorsum of the foot. We have another nerve. This is known as the posterior femoral cutaneous nerve. And this has a role of solely sensory supply and this is of course to the posterior surface of the thigh and the leg and also to the skin on the perineum. Finally, we have the pretend nerve. This has innervation from S two down to S four. It has a motor and sensory innervation muscles to the perineum, external urethral sphincter, external anal sphincter and the levator ani. It also has a sensory innervation to the penis, the clitoris and also to most of the skin of the perineum. A good pneumonic to remember these nerves here would be some Irish salar pesters, poly. So if we just imagine the letters again, so some s superior gluteal nerve, Irish, inferior gluteal nerve, um salar sciatic nerve pesters, posterior femoral cutaneous nerve and predental for point. And this is the order for the sacral plexus. And this is what I was mentioning earlier with respect to the sciatic nerve. Um sometimes patients require intramuscular injections. However, these come at a risk if the mus if the injection needle goes into an important vessel or into an important nerve, and we need to avoid these neurovascular structures. And the main one to avoid is the sciatic nerve here. In this diagram, we can see the sciatic nerve just traveling down here and a good way to avoid that sciatic nerve during intramuscular injections is by dividing the gluteal region into four quadrants. This can be done using two lines, a vertical line here which starts from the highest point on the iliac crest and it travels down all the way to the issue of tuberosity. Then we have a horizontal line which essentially travels halfway between this line, essentially forming four quadrants. And we can imagine the sciatic nerve um as a general principle runs in the inferior medial quadrant. Um So the safest site would be the complete opposite, which would be this one here. This is the best way to avoid injury to the sciatic nerve, which can be essentially um very damaging to patients. So finally, we're going to be discussing the arterial and the venous supply to the leg all the way down to the knee. So we have the common iliac artery, this travels from the abdominal aorta and it forms two branches. These are the internal and the external iliac arteries. This happens over here at the pelvic brim in front of the sacral iliac joint. So we have these two arteries here, an internal and an external. So let's talk about the internal, first, the internal iliac artery will give off several important branches. These include the obturator artery, the inferior and superior gluteal arteries. And these all combine to sort of supply um blood to the gluteal region. Then we have the main artery of the lower leg. So we have the common iliac artery forming the external iliac artery. This will continue. And once it passes the inguinal ligament, it is renamed as the femoral artery over here. And the reason this is important is because this is a very thick artery and it supplies essentially the whole lower leg. So the external iliac artery gives off a very, very important branch. This is known as the deep branch, also known as the deep femoral artery. And you can see a branch coming off over here. This branch here um basically travels laterally and it gives off two major arteries which supply again the head and the neck of the femur. These are the two mentioned earlier, the lateral and medial circumflex, the femoral artery then continues down on its own. So not the branch, but the actual femoral artery, it continues down and it leaves by the abductor canal essentially on the posterior aspect and then it will become a different artery. And this will be mentioned in the uh next anatomical lecture. So just as a quick recap, we have the common iliac artery, it forms the external iliac artery. This continues down becoming the femoral artery which will continue down to the knee. And the femoral artery gives off important branches known as the profunda femoris, the deep femoral artery. This will give off two very important branches to the neck of the femur, the medial and lateral circumflex. And this is important to avoid um avascular necrosis in neck of femur fractures. So here we have just a diagram um essentially um simplifying um what I've stated earlier. So we have the common part, external femoral, deep femoral lateral medial circumflex and then from here onwards will be discussed in the next lecture. Ok. Finally, let's discuss the venous drainage. A good principle to remember with an er anatomy in general is venous drainage. Um of the deep veins usually just follows the same names of as the arteries. However, the superficial veins will drain into the deep veins. So those are two important principles to remember. So we have the deep veins following the same name and landmarks as the arteries. So, of course, the deep vein of the thigh will be um essentially following the deep femoral artery. We have the femoral vein which is basically the opposite to the femoral artery. And then we have the external iliac vein which is essentially the opposite to the external iliac artery. The second principle is that the superficial veins will drain into the deep veins and this happens via perforating veins and this happens at specific junctions along the lower limb. Finally, um I've mentioned just some more detail with regards to the actual um venous supply to the lower limb. So let's start with the deep veins. So the foot and the leg, let's begin with the foot and the leg, we have the dorsal venous arch which we can see over here. This drains into the superficial veins mostly. However, some of the veins penetrate deep into the leg forming the anterior tibial vein which we can see over here. So the dorsal venous arch forms the Antero vein, medial and lateral plantar veins are also present and they travel of course, um taking blood from the plantar region of the foot. And these combine the medial and the lateral veins combine and this forms the posterior tibial and the fibular veins. So, these are the three main veins in the lower limb. And these will then combine in the popliteal region to form the popliteal vein. And we can see this over here. Once the popliteal vein enters the thigh, it will empty into the distal femoral vein. And this will essentially form the main vein which is the external iliac vein. So again, it's just following the arteries. Finally, we have the gluteal region. Um and the deep veins in the gluteal region are the inferior and superior gluteal veins these empty into the internal iliac vein. So, of course, you can just see the um contrast between the arteries and the veins. Then we have the superficial veins. The main two to remember are the great saphenous vein and the small saphenous vein. So let's discuss the great saphenous vein. First. The great saphenous vein travels from the medial aspect of the dorsal venous arch. So over here, it ascends upwards and it travels anterior to the medial mallotus. And this will travel um anterior to the medial malleolus and posterior to the medial condyle at the knee. So you can imagine it traveling upwards and then round the back of the knee. And it basically ends by draining into the femoral vein inferior to the inguinal ligament. Then we have the final superficial vein, the small esophagus vein. This isn't um a contrast to the great saphenous vein because it drains from the lateral side. So essentially, it also drains from the dorsal venous arch and the dorsal vein of the little toe. And it basically ascends on the posterior side of the leg along the lateral border of the Calcaneal tendon on the back. And this again, just like the great saphenous vein drains into the popliteal vein and this happens between the two heads of the gastrocnemius muscle. So again, just a general principle to remember the deep veins follow the same names as the arteries. Um and the superficial veins would drain into the deep veins. Ok. And I think that is it. So I'm sorry, guys, there was a lot of content there, but it's very important to remember the general principles with the lower limb. And it always helps to divide the sort of the lower limb into the gluteal region and then the thigh region and then compartments within. So with the gluteal, you have a superficial and a deep region. And with the thigh, you have an anterior medial and a posterior region and then making these um connections um with the nervous supply will help um form associations which can help with the revision and always consider the clinical implications of anatomy, for example, with the intramuscular injections and also with damage to the sciatic nerve. Ok. And thank you so much for coming as well guys. So if you could fill that out and you should be able to access slides when you fill that out and it should be also on the medal event page for this talk as well. Um Thank you so much. Um I'm not sure if you want to answer any questions or if there are any questions in the chat. If there are no questions, then thank you so much, Adam. Um That was an incredible talk and I hope to see all of you guys at the next two talks which will be running on Wednesday and Thursday at 7 p.m. as well. Thank you. Thank you for coming guys. OK.