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Summary

In this second installment of the Lower Limb Trauma Orthopaedic series, fifth year medical student Joey Kim provides a deep-dive into the anatomy of the lower limb. Building on previous learnings, Joey walks through the structures of the knee, leg, ankle, and feet, with a focus on the femur, tibia, and patella. Apart from understanding the physical structures, Joey also discusses the functional aspects such as how the leg can lock in a fully extended position due to its bony structure. Finally, he covers ligaments, vessels, and nerves, highlighting key knowledge areas like meniscus function and potential injury, the role of bursas in lubricating the knee joint, and intriguing features of the leg muscles. This comprehensive session serves as a solid foundation for medical professionals wanting to further their understanding of orthopaedics.
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Learning objectives

1. By the end of this session, learners should be able to understand and explain the anatomical structure of the lower limb, particularly focusing on the knee, leg, ankle and feet. 2. Learners should be able to identify and describe the components of the knee, including bones, soft tissues, menisci, ligaments and bursas. 3. Participants will learn about the knee's primary functions, mechanical properties, and movement degrees, as well as specific factors such as the locking mechanism in the extended position. 4. Medical professionals will gain knowledge about the common injuries of the lower limb and the significance of certain structures, such as the medial and lateral menisci in the knee and the anterior cruciate ligament. 5. By the end of the lecture, the audience will understand the anatomy of the leg and foot, including the various bones, muscles, vessels, nerves and their specific functions, aiding in diagnostics and treatment planning for lower limb trauma cases.
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Computer generated transcript

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

Hi, everyone. Welcome to our second talk in the Lower Limb Trauma Orthopedic Series, um led by Joey Kim today. Um And um before I hand over to him, um I just want to thank our sponsors once again, um for allowing this talk and this educational series to take place, um including our new sponsor, the Royal College of Surgeons as well. Um And yeah, without further ado, I'll hand over. Hi, I'm Joe Kim and um I'm 1/5 year medical student at UCL and welcome to the second lecture in the Lower Limb Trauma and orthopedic Series. So, just carrying on from um where Adam stopped last session two days ago. Um We're continuing with the anatomy of the lower limb, the sec. Um and, and, and I think he covered the, the hip, the thigh and then some parts of the knee. And so we're gonna continue down from the knee through to the leg and the um, ankle and the feet today. So, um firstly with the knee, um basically what's involved the bones and the soft tissues. The there, there are the femurs tibia patella and in the um the important thing to really know about the, the, the bones here is the patella that's formed within the, the tendon, the quadriceps, femoris tendon, and its primary function is to act as a fulcrum to increase the power of knee extension. As for soft tissues, you've got the menisci, the ligaments and I'll touch a bit on the bursas in terms of knee movement. Um So the knee is primarily a hinge joint, but there's, there's quite a lot of degrees of freedom with the, with the knee. Um As I said, you can, you can do extension, um flexion, it also does a little bit of lateral rotation and some medial rotation. An interesting thing here is that when the knee is completely extended, um the entire leg basically has a mechanism of locking where if you can imagine a fixed tibia and um the femur on top, it slightly rotates. Um It's so yeah, so it slightly screws medially upon a fixed tibia. And this isn't from muscles or, or, or soft tissue. It's basically because of the bony structures of the um the femur and how it articulates with the tibia bone. And therefore, as it completely straightens, there's a medial locking of the femur into the tibia and then to flex your knee, then you require a muscle to kind of laterally rotate the femur in relation to a fixed tibia. And that's carried out by the um by the pop muscle. And that's basically the diagram of how it works. So when it's completely extended, it kind of medially rotates and then to flex it, you need to unlock the knee and that's basically done counter directional. And so in terms of the meniscus, um the main function is to deepen the grooves um where the female articulates to the tibia, and it also acts as shock absorbers. Um The medial meniscus is a lot more fixed to the tibia and the lateral meniscus is a lot more, it's, it's less attached. So there's a lot more freedom and thus you get a lot more injuries with the medial side and it's more significant because it's very fixed. And uh so there's a lot more tearing potential and then the bursas, they basically just synovial fluid encapsulated. Um They act basically to lubricate the knee joint and you've got a few bursas. So the suprapatellar one above the patella, um the prepatella, the infrapatellar and the semimembranosus bursa in the diagram on the top, right, you can see a subset bursa. Um I personally don't believe it's very important to remember that, but the other bursas are um more of core knowledge. And then in terms of ligaments, you've got the collateral ligaments and these are just very like fibrous tissues that are very um ta and rigid. So they don't really allow for a lot of movement. They, they are there just to provide support. So you have your medial meniscus and the lateral meniscus and um the medial me, me, the, the medial me, sorry, the the the collateral ligaments. What am I saying? So yeah, the the, the me, the medial collateral ligament is attaching from the femur to the tibia, whereas the lateral collateral ligament goes from the femur bone to the head of the fibula. So it's more of like a sideway. Um You're prohibiting like lateral movement kind of and then the cruciate ligaments with the most popular one being the anterior cruciate ligament. Well, of athletes often have like a career ending moment if you have an ACL tear. Um so the ACL the anterior cruciate ligament is basically also another very like um fibrous tissue that does not allow anterior translation of your tibia relative to your femur. So if you can imagine you're lying down and you have your knees at about 90 degrees flexed and you pull onto your tibia, you don't want to allow the tibia to slide forwards relative to a fixed femur. So that's anterior tran um anterior translation, you want to stop that. So if you can imagine um anatomically, you want to have a very rigid fiber going from your posterior articulating surface of your femur to the anterior articulating surface of your tibia to prevent that translating movement. And then same goes for posterior cruciate ligament where it attaches from the anterior part of your tibia to the posterior part of the articulating femur. So you don't want to allow the posterior translation movement and, and then I'm going to come to the leg and the foot and the ankle. So, in terms of the legs, you've got the bones and the muscles mainly. Um and then I'll cover the um vessels and nerves after this. So the bones tibia fibula, and then in the feet, you've got your tonsils, metatarsals, phalanges, very similar to um bones in your hands. And the muscles in the legs can divide them into anterior lateral and the posterior compartments. And interestingly, they actually form the extrinsic muscles that go all the way into the feet. And at the feet, you've got your intrinsic muscles which originate and attach within the, the feet themselves. So you can divide them into two groups, the dorsal and the plantar group. So the tibia or the shin bone, um you can easily quite feel it if you palpate your, your leg on, on the anterior aspect, um you can divide them into three parts. So the tibia is, is, is a long bone and um not quite as long as your femur, but it's still um wells right below your femur, it forms part of your leg. So it's still quite a long and strong bone. Um proximately, it forms the tibial plateau, which is where it articulates with the femur. And you can see in the diagram on the right, there are intercondyle eminences for attachments of the soft tissue mentioned earlier. But um anteriorly, you can see the tuberosity where the patellar tendon attaches to and then moving downwards, you have the shaft and the shaft has an anterior border. As I mentioned, it's, it's palpable as the shin is that it has a posterior surface and lateral border. Ok. And then laterally to the tibia, you get the fibular bone. Um And yeah, as I said, the patellar tendon attaches into the tuberosity in the picture. And posteriorly that is the sodium line, which is where the sodium muscle attaches. Um the soleal muscle forms, the soleus forms part of your calf muscles. And um the lateral border gives rise to inter ulcerous membranes. And that's a fibrous sheath of tissue um that binds the tibia and fibula together and then distally there's a widened area of the tibia to basically increase surface area of contact and to increase stability mainly. Um and then immediately you get a medial malleus projection and this is the part that articulates with the tarsal bone of the, the foot to form an angle complex. And then literally, there's a notch that, that, that basically signifies where the fibula attaches to and then the fibula um almost as long as as the tubular bone. I think it's just slightly slightly shorter. Um But you can also split into three parts, similarly proximal shaft and distal part. Um the proximal part articulates with the lateral condyle of the tibia and the distal part articulates with the fibular notch. And there's also a projection called the lateral mellas, which you can also feel on your foot uh at your ankle. And um the shaft here has three surfaces, the anterior lateral and posterior surface and each of them correspond to different compartments of the leg. So it's quite easy to remember. And um and then in terms of articulation, as I mentioned, you've got the proximal articulation and your distal articulation all superior and um inferior based on how you look at the, the bone. Um But yeah, on the, on the image on the left, that's the proximal articulation. And then on the right shows you the distal articulation. The image in the center is just the the ankle complex from posterior view. Um As you can see on, on the left, especially there's a lot of ligaments holding the entire knee together. Um So it's really quite a strong complex and, and it requires a lot of impact to damage the the bones. Yeah. And that's basically what I said. Um Yeah. And, and, and a good thing to remember is that the lateral collateral ligament actually attaches to the head of the fibular, not so much the tibial bone and the bicep soma runs all the way um from the eal tuberosity down to the fibular head. And, and it's interesting because it spans two separate joints. So the hip joint and also the knee joint. So it kind of does extension of the hip and also flexes the knee at the same time and distally, um you've got ligaments. So your anterior inferior tibial fibular ligament and posteriorly, you have your posterior inferior tibial fibular ligament and extension called a transverse ligament. Basically, these are just tissues to hold the um tibia and fibula together. And then the inter membrane, as I said, it's a fibrous sheath. Um It spans the entire length of the tibial fibula. There are two openings. Um The main one being the opening superiorly for anterior tibial vessels, um mainly the anterior tibial uh artery and um and then at the bottom one inferiorly, it's just for the perforating bunch of like the fib fibrillar arteries. And um and then I'm going to cover the muscles which are ii have made them quite specific here. But the important thing to note are the color codings. So blue would be the origin point, orange, the attachments and red, the function and um green as innovation. So looking at the leg, your interior compartment has four main muscles, um your tibialis, anterior. Um and and that basically attaches all the way into your foot on the medial side. I if you want to, you can memorize medial cuneiform based metatarsal one. But I think it's, it's easier for me at least to remember that it attaches to the medial side. So it goes from the lateral surface of the tibia, it goes to the medial side of the foot. So if you imagine a AAA string and you pull on the string, what it does, it, it Dorsey flexes the foot brings the foot up and inverts it. So it kind of moves the foot slightly medially. Ok. And then you have your extensive digital arm Longus also in the interior compartment. It functions to extend the digits as as the name suggests. And um the digits are the second to fifth digits, excluding basically excluding the great toe. And um it also funct functions to a dorsiflexor foot slightly. And the third muscle is the extensor, hallucis, longus hallucis being the big toe. Um So that's what, what, what the name is just extends the big toe and um slight dorsiflexion contribution. And then the fourth muscle is the fibrillar tertius, which originates from the medial surface of the fibula. And then it goes all the way down to the foot and it attaches on the lateral side. So the fifth metatarsal on the lateral side. So if you pull on it, it actually dorsiflex the foot. But this time events it so it brings the foot laterally away from your body instead of the t um tibialis anterior, that actually does it towards your body. So this time, it goes away because it's attached to the lateral side of the foot. And all four of these muscles are innervated by the deep fibrillar nerve. Um So here's just a summary um picture of, of what we've covered. Um So the first one, the first muscle that you can see if it goes from the tibia, it goes all the way down and then it attaches to the medial side of the foot. That would tell you that um that's the tibialis anterior cos, then it does what it does is it inverts the foot brings it immediately closer to your body. And the Ortho dorsiflexor, if you think about how it pulls and then the second um blank is you, you, you follow the tendon all the way down to its insertions. It goes down to the second to 4th, 2nd to fourth phalanges of the feet. So that's the extensor, digi digital and Longus and then the last one, the third one. So the third one is going to be um the, yeah, it touches to all the way down to the big. So that's how I lose it longest and then going on to the posterior compartment. Now, um here, there are two subdivisions. So the superficial and the deep compartment, you have three muscles and four muscles respectively. There, there are some bursa. Um Again, it's, it's not very important to remember, but it's just good to know you have Calcaneal like you have, you have bursas around there like the Calcaneal tendon basically. Um And, and they're quite important because all these muscles in the posterior compartment, most of them all attach onto the Calcaneus, which is the heel bone. And so you need a lot of kind of lubrication to make sure everything's working well. Ok. Again, just remember the color coating, superficially, you have your gastrinemia. There are two heads on, on the gastros. There's, it, it comes from the lateral femoral condyle and the medial femoral condyle. Um and, and it's, it's unique in the sense that this is one of the, the few bipennate muscles that we have in, in the human body bipennate. Meaning you get muscle fibers that run in two directions instead of one direction, usually where all the fibers run in a straight line or a slightly curved. But they all move unique directionally. This one, you have two origin insertion points that come from separate directions and they meet in the center and they go, they converge downwards into the heel. And if you think about it, starting from the femur bone attaching to the calcaneus, you pull on it because it spans again, two joints that is primarily plantar flexing of the an uh ankle joint and also some flexion at the knee joint because it spans both joints. And then the soleus, it originates from the soleal line showed earlier and goes down against calcaneus and it enables plantar flexion and you have another third muscle, the plantaris, it starts from the lateral supracondylar line of the femur. So just remember, it starts from the femur and it inserts into the calcaneus. Again, it spans two joints. So again, it does primarily plantar flexion and a little bit of knee flexion and within the deep compartment itself, um you have the Popliteus muscle, which is the unlocking of the knee. Um It's responsible for the unlocking of the knee starts from the lateral condyle of the femur and also the lateral meniscus. And it inserts into the proximal tibia right above the soar line. OK. And its function as, as I um mentioned earlier, laterally rotates the femur and, and then you have your flexor digitorum longus. So if you have your extensors in front of your leg, you have your flexus behind. So it goes again now from the medial tibia and it goes all the way down to the plantar surfaces of the lateral four digits. And that works to basically flex the um the, the f digits, 2 to 5, your third muscle in the deep compartment would be flexor hallucis longus. Similarly, it flexes the big toe this time. And then your last muscle is the tibialis posterior, which starts from, there's quite a large origin point here for the tibialis posterior. So it starts from the posterior surface of the inter membrane um of the between the tibia and fibula and it goes all the way down to the medial tarsal bones. So if it's on the medial side of the foot, if you think about pulling it, it, it contributes to inversion of the foot and also plantar flexion and all these muscles are innervated by the vertebral nerve. Um the image on the right over here. This time is the um superficial compartments. Um they've just dissected it. And then the first one, the gastro followed by um the thin muscle that goes also spans two joints, plantaris, and then the larger one soleus muscle. Um Also an interesting thing here to note is the gastrone is largely very fast twitch fibers compared to the um the soleus, which is slightly slower, it's also quite fast but not as like anaerobically um expensive compared to the gastro muscle. So in, in a sprint, you would use predominantly a lot of gastrone activity. Whereas in a um longer distance activity like a marathon, um it would be largely Sodi activity. And similarly, this is now going into the um deeper compartment after dissecting it superficially top, that's the popliteus. Um And then the other three here, you can't really tell because you can't really see the origin and attachment points. But basically, you get the hallucis longus which actually originates slightly laterally. Ok. And then it goes down. And then after that, you have your um flexo digital arm longus slightly more medial origin and it goes into the um the the the the toes to allow for flexion. And then the last one should be the tibialis posterior. Um Yeah, we similarly, it does the opposite compared to the, the tibialis anterior except that it also does some foot inversion. So it does plantar flexion but also does some foot inversion and in the lateral compartment is quite straightforward, two muscles, the fibularis, longus and fibularis brevis, longus, the longer muscle, brevis, the shorter muscle. And if you still remember there was the fibularis tertius in the anterior compartment. Um Yeah, that's a tertiary. Um One thing to note is that the terms peroneal and Friis are quite um interchangeable. It's just these days, it's fibular because they, they're based on the bone, but people still do refer to them as Peroneus or Peroneal. Um and the fibrillar longus basically starts on the lateral surface of the fibula and then it goes down into the medial cuneiform. So, but it, but ii, although it's medial cuneiform, it doesn't straight away, go immediately to the feet. It goes on the lateral side of the foot and at the bottom it traverses and attaches to the medial cuneiform. So if you pull on it, if you imagine pulling on it on the lateral side of your leg, what it does is it inverts your foot and also slightly plantar flex mainly to e butt and, and then the fibrillar brevis, um it attaches straight away to the fifth metatarsal tubercle. And if you pull on it, that, that causes eer so bringing your foot away from your body, they are innervated by the um superficial Peroneal or fibrillar neria. Yeah. So, yeah, that's the diagram just shows where they originate from. And then the, the, the pictures of the, the feet at the bottom show how they attach. Yeah. So in the first picture, that's basically how the um fibularis longus attaches to it traverses across the bottom of your feet and inserts into the, the base of your first metatarsal. So in terms of vessels and nerves, if you were here during Adam session, he would have covered it in a lot more detail. Um So basically continuing from around the knee, it's your popliteal artery that moves down the posterior thigh and then at the lower border of your popliteal, it then divides into the anterior tl artery and a a very short um tibial perineal trunk. OK. And um the anterior tibial artery will then go through the inter membrane on the superior gap that I mentioned earlier. Um And then, whereas the tibial peroneal trunk will then continue downwards inferiorly and divide into the um posterior tibial and the other fibular arteries. And, and following on from there, the posterior tibial artery follows the tibialis, posterior muscles and then it enters the soles of the f the feet through a tarsal tunnel, which I will come to later on tarsal tunnel. And as for the fibrillar arteries, um it descends posteriorly uh in the post um to posteriorly to the fibula in the posterior compartment. And then it, it has perforating BS um which if you still remember there was an inter membrane with the inferior gap. So it goes through those um that gap and then it it basically supplies the um tissues around that. And um the anterior tibial artery will then follow down anteriorly through the gap in the inter oss membrane. And then it goes down to the foot forming the dorsalis pedis um artery. Um As for the nerves, it's quite straightforward. It's largely all by the sciatic nerve comes down. It gives off the common lar nerve and the tibial nerve. And um yeah, basically, you can see the, the, the pictures already tell you how it basically goes into your foot. Um But the image in the center just show you the dermatomes, which um which is how they, how you get sensation on the skin. So, different parts of your skin are innervated in terms of sensation by different nerves and, and that's just a distribution. Yeah, similarly over here, that's just a, a close up picture of the deep fibrillar nerve in the feet and um how they innervate if you can see the, the green, the green, um the green nerve that, that gives rise to the sensations that you feel betw on the webbing in between your 1st and 2nd metatarsal. So that's by the deep fibular nerve and then the rest of it's innervated by the superficial fibula, at least in the skin now moving on to bones of the feet. Um We've got the tarsals, the metatarsals and the phalanges. And um in the diagram on the right, they basically correspond to the dots between the words correspond to where the, the cut offs are for, uh they correspond to the, the image above and below in terms of the bones and, and, and where the cut offs are. So the tarsals would be the seven bones um on the left approximately and then the metatarsals and followed by the phalanges. And some people like to differentiate them into hindfoot, midfoot and forefoot, where hindfoot is basically comprised of your calcaneus and your tais, your midfoot consists of your navicular cuboid and the cuneiforms. And then the fore feet would be the metatarsals and the phalanges. Ok. But for um purposes of the anatomy side of this session, I will be referring to the large metatarsals and phalanges. And then in terms of tarsals, as I said, are seven bones. Um the more superior one is the tais which articulates mainly with the um tibia and fibula. So it transmits the, the weight, the entire body. And then if you reach down now to feel your heel, what you're feeling that bony prominence is the calcaneous and that's the largest tarsal bone and and then um anterior to the tela bone, that's the navicular and then further slater you get the cuboid, which, which is blue in the picture and then to me medially to the navicular but anterior to the, to the sorry, medial to the cuboid. But anterior to the navicular, you get three bones and they are cuna forms. So from uh medial to lateral, they are medial cuneiforms and the intermediate and then the lateral cuneiforms. And after that going interiorly, they are the metatarsals. So they're labeled 1 to 5 for me to lateral. So your big toe would be along the um first metatarsal and then the phalanges are what comes after metatarsals very similar to your hands. So they're great to only has two phalanges, your proximal and distal Phung and your second to fifth of three. So you have proximal middle and distal Phung. And as I mentioned before, extrinsic muscles were covered earlier. They're largely responsible for inversion, inversion, p flexion, dorsiflexion and um and then your intrinsic muscles are within the feet. So intrinsic muscles on the dorsal aspect, they are a lot more straightforward to remember. It's just the extensor digitorum brevis. So the shorter extensors of your digits, your lateral four digits and your uh shorter extensors of your big toe. And they all originate from the calcaneous and um part of the retinaculum which is a sheath um on the lateral side of your foot. OK. And then they, they, they each insert into the extensor tendons of the, the medial photos and the um base of the proximal phalanx of the great. So respectively, and yeah, they basically do the function as as the name suggests to extend and then looking at the foot from the bottom, the plantar aspect, if you take away the skin subcutaneous layers and the, the the fat, the fat tissue and, and the sheath, you will get the first layer. Um the three muscles, abductor, hallucis, flexor digitorum, brevis, and abductor, digiti minimi um muscles in the feet are quite complicated. So it would be II II, I don't think it's really um necessary to memorize everything down to, to, to the details. But um it would be just good to know the names and uh what kind of functions that, that, that they each serve. But of course, you um if you have access to the slides, you can just take a look and, and revise. Um so the abducts, so it abducts the big toe abduct, meaning take away from the central or, or the me uh uh a medial area, sorry, not medial area. Uh a central line, if you can imagine a central line running through the feet, um If you abduct, you're taking it away. So if it's a big toe, you're pulling it immediately. So abductal hallucis pulls uh the, the, the great toe media and it also contributes to some um flexion cause it's on the plantar aspect. Um And then you have your flexor digitorum brevis, the shorter flexors of the digits of the foot. Um Again, it also starts from the calcaneus and then it goes into your digits and then you have your abductor digiti minimi um digiti minimi, meaning the small, the small toe. So your fifth toe and um that that's abduction again, So that basically pulls your um your little toe laterally. OK. And if you peel off that first layer, again, going slightly deeper with your second layer, two muscles here, the quadrata planta and um lumbrical. So the quadris sponte, they start from the calcaneus and then it inserts onto the tendons this time. So not onto bony surfaces but into the tendons of the extrinsic muscle. So flexor digitorum longus, which originates from the posterior compartment of the leg. So it goes all the way down into your digits and it connects um the it's connected by the quadratic. So it basically assists the um the flexor digitorum longus in flexing the lateral photos. And you also feel lumbrical which start. Now they start from the tendons of the flexor dial longus and they insert into the extensor hoods of the lateral four digits. So, since the extensor hoods, um the function would be primarily to flex the metatarsophalangeal joints, but extend at the interphalangeal joints. Ok. And the nervous um the innervation here is it a bit different cause the medial lumbrical. The the one closest to the biggest toe is innervated by the medial plantar nerve. Whereas the other three lumbrical are innervated by the lateral plantar nerve. And if you take that layer off again, um you've come to the third layer. Firstly, you have your flexor hallucis brevis. So that's the shorter um great toe, flexor and then you also have your abductor hallucis. So opposite to abductor this time. And then you have your flexor digiti minimi brevis. Um So, yeah, in terms of your flexor Leis brevis, um basically does flexion of the great toe and um it attaches from the, from the um plantar surfaces of the cuboid and the natural cuneiforms and, and um another tendon again this time, the posterior tibialis tendon and it goes into your great toe, whereas the AUC losis is a bit more complicated because there's two heads. So it starts from the base of the 2nd, 3rd and 4th metatarsals. And that constitutes the oblique head. Whereas transverse head is from the plantar ligaments of the metatarsophalangeal joints. Basically, what they do is they insert onto the lateral aspect of the, the great toe. So you can imagine if you pull on it, it basically brings the great toe back onto um to towards the center of your foot. OK. And um yeah. So basically pulls the, the great to laterally. And then the last muscle, the flexibility mean me brevis flexes little toe at the metatarsal langer joint. Um basically, it goes from the um base of the metatarsal, the fifth metatarsal to the base of the proximal pharynx of the fifth digit. And the innervation here are slightly different. So the medial plantar nerve and then you've got the the lateral plantar nerve for the other two muscles here. Doctor hallucis and flexibility, meaning the perfect. And then if you take that layer again, it's the last layer, the fourth um layer of the plantar aspect. So this is still on the plantar side of the foot. OK? But although it sounds a bit confusing, you have two layers of inter assays, this is still on the plantar side, but you have your plantar inter assay and also a dorsal inter assay at the bottom of your feet. OK? Um And that's why they all contribute to flexion at the metatarsophalangeal joint. Um You can take your time to, to read this and try to understand it. But I mean, the main thing to, to really note here is the banet and un um pen nature of these muscles. So dorsal inter assay is Bienne and the planta inter o is, is a unipennate um muscle which the, the, the p also serves to adopt the lateral three digits, whereas the dorsal one serves to abduct the lateral four digits. So it moves the four digits laterally, takes it away and um and then it also contributes to infection, I guess. And they're both innovated by the lateral Ponta nerve and coming to nerves and vessels in the feet. You've got two main arterial supply, dorsalis pedis from the um anterior tibial artery that's still causing down into your foot. And then you've got um arterial supply from the posterior tl artery and, and um and in terms of venous drainage, um Adams already covered it. But the, the main thing here to remember is, um, you've got the great suen veins and the small suen veins and their branches actually follow a very similar naming scheme to the arteries. Um, depending on the location. Ok. So you've got a small saphenous vein which then drains into your poppit vein, your great saphenous vein, um, drains into your femoral vein that's just below your inguinal ligament. Um Interestingly, the great softness vein can be harvested and used as a vessel in a um coronary artery bypass. So that's why clinically sometimes you can check patients. And if they've had uh a similar sur uh a surgery like that, you can see a scar around um around the, the, the leg area where the great staph in this vein was, was harvested and then coming to the architecture of the foot. Um Yeah. So mainly the ankle. It's a, it's a like a hinge joint which is, is primarily a hinge joint, but it produces a lot of other movements. And um it's contributed by all the other different joints around within the foot. Ok. And it's supported by ligaments. The ankle complex is spotted by two main groups of ligaments. The um the deltoid ligament which connects the medial me to the calcaneus talus and navicular bones. And you've got the other group, the um lateral collateral ligaments which can be separated into three ligaments. So, the anterior talar febrile ligament, posterior talofibular ligament and the calcaneal fibrial ligament. And here are the other joints. Um Again, there's a lot of different places where the bones of the feet articulate with one another. And movements around there contribute to different um different overall movements of the feet. Um A syndesmosis is a, is a joint where it's a fibrous joint doesn't really permit a lot of movement. And that's the same type of joint in between the um distal tibiofibular joint. So that's a fibrous kind of uh syndesmosis. So there's not a lot of movement between the fibula and um tibia. But yeah, so overall, they, they contribute to like gliding rotation, which then permit the feet to, to perform aversion, inversion and um other kinds of rotational movements. So again, four main movements, plantar flexion. So bringing the foot up, sorry plantar flexion, bring the foot down dorsi flexion, bringing the foot up, you've got your usual abduction, abduction of the foot. And then you've got um eer and inversion um which is on the image on the right. You can, you can kind of see an inversion is um rotating your foot. And I mean, so, so is eer so it's basically rotating along a different axis and then other other parts of, of, of the foot, you've got arches, um three main arches, your medial longitudinal arch, lateral, longitudinal arch, and transverse arch. The importance of, of these arches are just to make sure your feet, your, your your, your feet are stable and able to support your weight and um the arches because they're, they, they're kind of like convex shape and um they're maintained by mainly the structure of the bones. So when it's compressed, so when there's load being transmitted through the bones, it all sits together nicely in an arch shape. And it's, of course, also helped by the um plantar aponeurosis, which is a, a sheath, uh another fibrous tissue layer sheath um at the bottom of your feet. and, and then there are other ligaments around the bones. And um so I'm gonna talk about the win loss mechanism. So it's, it's not really a mechanism, but it just describes the way. Um the plantar fascia acts. So it's a, it's a sheath connecting from um the calcaneus and then it goes into your digits. It's, it's rigid, not very flexible, but the moment that you start to dorsiflex your toes. So if you dorsiflex your phalanges, it then tightens the entire plantar fascia. So when that is tightened, it, it increases the visibility of your arch. So it brings your entire arch up. And um it's a good test to check for whether or not um a patient is plantar fascitis, co it'll be very painful, especially around the heel if there was inflammation in the plantar fascia and you're performing this wind loss test. And also you can check obviously for a rupture in the plantar fascitis because you won't see an arch. Um that's more accentuated, it will remain the same or the patient will basically be in pain. And um, basically the fia is important because when it's in this position, when it's very top as, as your toe dorsiflexor, it allows for shock absorption. So you're landing on your ground after you jump, it helps to absorb shock. And it's also useful for a push off face when you're walking or when you're running cos it, it's like a spring, there's a lot of potential energy stored within, within the pot fost. And um so now I'm gonna talk about the tarsal tunnel. Um It's basically on the middle side of your ankle, infer uh not inferior posterior to your medial malleus. OK. Um So it's a tunnel kind of similar to a carpal uh carpal tunnel tunnel, but this is a toss tunnel. So it goes that it's bound by the um bony surfaces. And um and the roof is formed by a flexi by a retinaculum. So, and that goes from the um medial metus to your calcaneus, that green highlighted band that's ba basically signifying retinaculum. And what goes through our um six vessels, not really vessels but six 66 components. So, namely from anterior to posterior, you have the tibialis, posterior flexor digitorum longus, followed by the tibial vein and then the artery tibial nerve. And then the last one is your flexor hallucis longus. And um a pneumonic is Tom dick and a very nervous Harry. Um But keep in mind that the A and V. So, and they very, so that's basically one A and one V, it's kind of swapped around. So, from anterior to posterior, it's vein first before tibial artery. And it's clinically important because if you get any form of like inflammation or, or, or swelling around the um that location, it may compress into the nerves which may affect your sensation. And if it's really severe, it um may also affect some motor function of the muscles uh involved in the um tunnel itself. So I'm gonna go through all three clinical conditions. Um And then the rest will be covered in the third session. Firstly, we have um tibial shaft fractures. Ok. So just a quick revision, the, the tibia is a long bone and so it's prone to fractures and um it's also prone to trauma as you can feel on your shin, your e especially on your anterior medial side of your shin. It's, it's there's not much soft tissue. So it's quite easy to be um hit and, and very prone to trauma. And thus, yeah, it's easy to form like open fractures because there's not much soft tissue for it to protrude out of the skin. Um trauma here could be direct. So a fall or a direct blow or it could be indirect as well. So, twisting, bending motions and and yeah, all that can, can also cause tibial fractures. So what are the clinical features? Um firstly, there will, there will be pain, so severe pain, then you need to start querying maybe compartment syndrome, um whereby there's a lot of like inflammation going on impacting your vessels within the leg itself, um which can be very critical and this is not a clinical condition that will be covered in the third session. Um Another one would be inability to wait there cos it's really painful. Um There may be clear deformity and if you see blood, then you must start thinking about open fractures, check if there's any protruding bones and um and then usual fracture signs, symptoms. Yeah. Yeah. So you really need to start inspecting surrounding skin. Ok. For all, all the other, the area of the floor for any blood. So what are the usual fracture signs and symptoms? Um This is for closed fractures, co open fractures, you would be able to identify it. Um So you get bruising discolored skin, you may get swelling, pain that worsens with movement pressure. So the patient can't move, refuses to move. Um numbness or tingling. That's when you really start to worry if it's, if it may, may have had potentially lacerated, a nerve, um deformity doesn't look normal and um loss of function. So with the tibia, if it's meant to support weight, well, you can't do that anymore. And so what are the risk factors for a fracture or a tibial fracture? But more so a fracture mainly, it's a reduction in overall bone density. Um anything. So, so on this list, you have advanced age, advanced age y cause patient could be instable, uh unstable, sorry. Um From, from, from maybe a, a neurological problem. So you may need to refer. So, so if, if, if a patient keeps on falling down and, and that's, that's a risk factor. Um chronic corticosteroid use, you know, um reduces bone density. Um and you have the alcohol consumption, chronic smoking, menopause and um personal history or family history of osteoporosis. And um you also have low calcium and all Vitamin D and around 20% of the um UK population is Vitamin D deficiency. Um So yeah, that's also a risk factor and um sedentary lifestyle because we know that in order for bones to keep growing and maintaining its structural integrity, um it needs longitudinal or axial pressure in order to grow to grow stronger and um lastly low BM because it's correlated with lower intake of um nutrition. And so then that also relates to bone health and uh bone density measurements. So what could it be? It could also be a soft tissue injury. Um It could also be an ankle fracture depending on the location of the fracture. If it's very distal in your tibia, it could also be a tibial plateau fracture if it's a lot more proximal. And because of where the fibular is relative to the tibia, it could also be a fibular fracture, but it's very rare for it to be an isolated friar fracture where the tibia isn't affected. Um, it's usually together or just the tibia. So what kind of investigations should be carried out? You need to carry out, as I said, a neurovascular examination because you're worried about lacerations of the nerves and also blood vessels around that. Ok. And um, importantly, you have to do an, a two assessment to quickly assess to make sure the patient is stable. And especially if it's in major trauma. If there's a lot of blood loss, you need to do group and safe um get a coagulation screen to um yeah, to, to basically see the patient's blood type. You need to know that and, and get the, the, the blood ready. And then of course, you need imaging to visualize the actual fracture and the imaging could be um plain radiographs. So x-rays ap um anterior posterior, so that you know the patient doesn't have to move so much, you can be lying down comfortable and you can take it um from anterior to posterior. And um if, if it's permissible, then you could also take it in another film. So laterally, you could take it. Um and then you can also carry out a CT scan to exclude or include intraarticular fractures. Um I'll be covering tibial plastic fracture later, which is close to the knee joint. But yeah, you, you basically want to be aware of any fractures um around joints as well. And in a nonacute setting, urinalysis can be carried out to also check if there's a problem with intestinal absorption of calcium. Or maybe there could, could have been a leakage of calcium to the kidneys leading to well lower bone density and thus um a risk factor for fracture. And in terms of management, you want to realign it as soon as possible um to prevent malunion whereby um the bone starts recovering by itself in an awkward position or an abnormal position. And um and how you could also maintain this, um This realignment is by immobilizing it. So you immobilize above the back slab, uh above the knee using a back slab to to limit rotation of the, of the um the leg itself. So you cos as as I said earlier, the knee also permits rotation. So you want to immobilize that to make sure the leg can really be, be, be rotated, elevate it quickly. And um so in terms of immobilizing the leg, you can do it with the knee slightly flexed. Um because if it's slightly flexed, it lasts for preservation of the extension function. So in as opposed to keeping the leg like completely flexed or at maybe 90 degrees, you have it only slightly flexed so that there's still some form of extension because one of the first motions to go away after a long period of im immobilization is extension. That's the first thing to go. And, but also, you don't want it to be fully extended. Um because if it's fully extended, then all the muscles are tight and all the ligaments are also taut and you would then be straining the soft tissue around the knee. Ok. And, and then also you prescribed the usual painkillers, you would also want to um monitor for any signs of um compartment syndrome because um that's usually when the patient still feels a lot of pain, despite um a lot of an uh analgesics and then um late uh and then later on, the mainstay of, of, of management is largely surgical, depending on where the um fracture location is on the tibia. You may want to carry out intra meu nailing. So that's basically through the shaft of the tibia. And then if it's proximal or distal, um you may need to carry out orif or open reduction internal fixation. So that's a surgical procedure. You uh basically open up the, the, you open up the, the, the, the skin and then you, you would try to um place back the, the, the bones using screws and plates. Um But if the patient is unstable and there's a lot of evidence of soft tissue injury, external fixation will be um done first just to allow the soft tissues to heal, to allow patients to recover slightly. And um conservative management, you have a cost. But yeah, I mean, ii don't think I've come across this cast before, but you can have, you have this option of conservative treatment as well. But it's only if the fracture is stable and in the distal half of the tibia, again, it will then follow um uh application of long leg cast, what kind of complications could arise? So, as I've mentioned quite a few times already, compartment syndrome, ischemic limb, if it's well, um prolonged compartment syndrome, when the um the swelling within the, the leg itself is compressed on into the arteries for too long or potentially, the bones may have lacerated a uh an an important artery in the limb itself. Um You could get open fractures where the bone manages to cut through the surface of the skin and then if not realigned early or realigned well enough, you may get more union. OK. And, and then now coming on to tibial pla fracture. So this is kind of similar to a tibial um shaft fracture, but just more proximately towards the the knee joint. And this is a significant injury um in which very high forces impact the femoral condyle onto the tibial plateau itself. So onto the sort of the knee joint. So fractures here, they occur after high energy trauma. I highlight high energy trauma here because it's not, not really to do with a fall. Um as seen in elderly patients, you, you kind of need forces coming from the side laterally to cause um later or immediately to, to cause a ti tibial passive fracture. Um and it's more common to have it on the lateral side because your lateral side of the leg is a lot more exposed than the uh the medial side. And, and then if it's untreated, um yeah, it may lead to like degenerative changes within the knee or, or early onset arthritis because the force distribution is is changed from the nerve. So I'm going to go through um yeah, the the clinical features now or the mechanism of action of how the the injury occur. So a classic scenario is is kind of a bumper, bumper fracture, whereby a car is striking um a pedestrian's fixed knee, fixed knee um could be well, could be the patient. Uh the the the the patient could be standing. So there is axial force loading. So going through longitudinally through the bones and all of a sudden there is a lateral impact. So there's still force going through the knee itself. But at the same time, there's impact all of a sudden high impact, striking the side of the knee and thus leading the um the fracture of the tibial bladder. Um and the the other feature is usually pain, a lot of fracture kind of um symptoms. And then you may also get tenderness along the uh medial or lateral aspects of the knee joint. So maybe your uh medial or lateral collateral ligaments were torn um when you were being hit from, from, from the side. So it could also be because of the nature of where the injury is, it could be a knee dislocation. It could also be soft tissue injury. Again, be meniscus or ligaments. It could be a patellar dislocation or a knee fracture. So the patella actually um fractured or maybe even the femur and um of course, it could also get tendon uh rupture. Just keep in mind that these are not exclusive um uh injuries where they they occur by, by themselves. They could all occur together with Aib fo fracture as well because it's very high impact high energy. So in terms of investigations, again, neurovascular examination, because you're worried about the jagged edges of the bone lacerating vessels around it. Um Yeah, vascular injuries are common in, in, in type four tibial part fractures. So the medial side, slightly more rare. Um you may also get neuropraxia, um loss of sensation and some, some form of um altered sensation. So, nervous injury, you would want to carry out an x- ap views again, um laterally, if you can and then intercondylar notch, just to visualize the the knee specifically, you could also carry out CT scans um such as the image on the right, that's act scan image and a a hypo hemo arthrosis is an indication of an intraarticular fracture. Um That's when you see a so on the image on the right. Um you, you see three layers. So and on right, right above the um the central um hyperdense bone that you can see the, the white halo ring above that you see three separate colors. Um So from the very top, it's completely dark. So that's the least dense, that's fat and then followed by s effusion and then the bottom that's blood pool. Um Yeah, that's just an indication that, that um there's an intraarticular fracture and then you also want to carry out MRI scans um just to visualize the soft tissue um if the ligaments are OK, and the menisci as well. And in terms of classification, um this is very niche again, but as I said, the type 41 is the one where vascular injuries are quite um common and you can tell it's a medial site because of where the fibula is. So if the fibula in from, from our perspective, yeah, is on the left side, it tells us that the left side is lateral and then on the right side's medial. And in terms of management, um non operative management, there's um it's usually only indicated in minimally displaced fractures whereby um the articular step. So in the image of type two, there is a step like um shape there. So if the step was less than uh was more than two millimeters, that would be a uh a more of a complicated fracture. So if it's minimally displaced less than two millimeters, and there's an angular deformity of less than um 10 degrees or and, and if there's any shaft involvement that would not qualify as a mini, mini, um, displaced fractures such as in type six where you can clearly see the shaft um involvement. Ok. So if you don't have those, then that's more like a minimally displaced fracture. It allows for a non operative type of management. Um Yeah. And then you would carry out um, passive range of motion exercises in a hinge brace and then slowly work your way up until you can wait as tolerated. And you need physiotherapy just to make sure the muscles are working well again and are healthy. And um, in terms of operative management, if they're complicated, um, the management options would be or if and um, yeah, and then postoperatively again, a hinge, uh a hinged knee brace and physiotherapy after that, but similar to a tibial shaft injury. If that's an extensive um soft tissue injury, then you would do external fixation first and do an or later on. Because again, you want to allow the, um, the inflammation of the soft tissue to calm down first before um, operating on it and, and making sure everything is stable. And that also shows um advantages of decreased infection rate and um fewer wound healing complications if you do external fixation first and then other complications of this particular type of injury, posttraumatic, um, posttraumatic osteoarthritis. Um because if it, if, if it's not aligned properly at the knee where a lot of weight is transmitted in between two bones. Um, again, it really affects the force distribution of how, um, someone stands, someone walks. Um, so that may lead to an earlier onset of osteoarthritis. And, and that can also lead to an abnormal gait if it wasn't healed properly or M Malign and chronic pain, of course, um, with a lot of musculoskeletal conditions. And the last condition here is a, this f injury or sometimes called a a fracture. Although it's not a real fracture, cos it's not a fracture of the bone, there wasn't a any bone that was damaged. Um So it really refers to the dysfunct ligament which joins the medial cuneiform to the base of the second metatarsal. In the image on the right, it's shown very clearly here that ligament that lyft ligament has been torn and um because it's such a small joint or, or a small ligament, it's often missed on imaging. And um so you really requires a high degree of clinical suspicion and you need to be very wary and so on imaging. This is what you will see. So on the image, the first image here is where you can see a gap um a gap between the first um the, the, the, the medial uniform and the um the base of the, the second metatarsal, there's a drift and then the, the, the image on in the middle again shows a similar drift. But then the image on the right shows what a healthy foot should actually look like. So there's no gap at all. So how does it usually occur, occurs after rotational portional translation force on a Plantarflex foot? Ok. It's commonly seen in road traffic accidents and athletic injuries because there's a lot of plantar flexion. So I've personally seen AAA male dancer um without any warming up after a whole day of working in the lab standing on, on his feet. Um did a pirouette came down and then that's how he realized he couldn't weight, bear anymore on that foot and it was all swollen. And um and then he came in and they found out it was a ther injury bye in size. Symptoms would be all swelling as I've hinted. Um tenderness over the midfoot, you would see bruising. I saw bruising in my patient. It was um it was quite obvious in the base of the foot. Um There, there might also be pain, there will be pain in the mid foot and you can't really um bear weight and there'll be pain on the um push off face. So when you kind of like doss flex your, your toes, so what else could they be? They could be ankle fractures because of where it is tarsal fractures. Um could be a snowball's fracture, a snowball fracture. It, it got the name snowball's fracture because snowboarders are 15 times more likely to get this type of fracture. So that's a fracture of the lateral process of the tus. So they're 15 times more likely to get this kind of fracture than any other ankle injuries. Um It could also be a proximal metatarsal fracture because of where it uh where, where the this ligament attaches to. It's also metatarsal. It could be a cuboid fracture or it could just be a midfoot sprain. So in order to rule out or to rule in, um it's based on a high degree of, of suspicion, imaging, anterior, posteriorly lateral, um 30 degree oblique projections, taking, taking a AAA radiograph at an angle, basically. And if you're still uncertain, you would carry out weight bearing films, although they will be very painful. But it's important because if you do weight bearing films and you transmit weight through a foot on the ground flat, um it accentuates the drift between um the um the base of the second metatarsal and the medial cuneiform so that the, the drift becomes a lot more obvious if there's weight transmitted through. And then obviously you palpate the foot and um you would also look out for a, a piano key sign. So that's a permanence of the metatarsal bones which um when you press down, it should reduce back, ok. When, when, when you press down on the toe, it should come back to normal. But if it's negative, so if you press down and it doesn't really spring back to normal, that's when you start suspecting something's wrong with the ligament over there. Um And yeah, and if it's very severe, you may get disruptive blood flow because of malalignment of the bones. The ligaments aren't really holding each other very well. It may be compressing on into an artery. So you want to palpate the, the, the sp artery and check the cil and then in terms of management, non operatively, you would immobilize it for 6 to 12 weeks, place the patient in a cast boot or, or a cast if it's a lot more severe, um And then if it's operate, uh if it's even more severe, then you would operate on it, carry out all again through um screw fixation. To allow the tissues to heal, you would go into the bones not to allow the bones to heal, but to allow the soft tissue, mainly the ligaments, um particularly this front ligament, allow it to heal properly because it will heal. But you, what you don't want is you don't want it to heal in an awkward position and then if it's really bad. So if the gap is too big, you may carry out an um arthrodesis. So that's permanently fixing the two bones together and not allowing it to um to move because there's always going to be some motion between bones. So if you carry this procedure out, you're basically immobilizing and fixing it permanently. Um And that's carried out if it's a, if there, if, if, if there's a comminuted fracture or um that displaced fracture dislocations. So it has to be really severe in order to carry that out. Um And then, yeah, you would immobilize the, um, the, the, the foot and again, you always need physiotherapy because the patient won't be weight bearing for quite some time. And the muscles will slowly degrade if they're not used in pain, man, pain management and other types of complications. Um, that may arise to posttrauma, uh posttraumatic arthritis if it's not healed properly. Ok. Um Yeah, the foot is, is, is prone to, to the the foot's prone to posttraumatic arthritis because severe injury um kind of accelerates the process of wearing out of the bones and then you get chronic pain again and you may also get compartment syndrome in your mid foot. Ok? Um That's all, that's all that I have. Ok. Thank you. Thank you so much. That was such an interesting talk and there was so much I learned and really following on from the last talk that we had. Um just to update everyone in terms of feedback, I have put a feedback form in the chat. So if you provide the feedback, you'll be able to get a certificate for attending this talk. Um, slides as well will be attached to the medical event link, so you can also check out the slides. Um And yeah, once again, thank you so much. Um Does anyone have any questions? If so please put them in the chat if not, um we can probably end it there. Um If people keep putting them um, questions in the chat, you can obviously answer afterwards as well. Awesome. Thank you so much. Thank you. Thank you for coming.