have you ever seen what an arthritic knee looks like well here is a real human knee with multiple degenerative changes the primary one being osteoarthritis so today I'm going to show you what's wrong with this knee while showing you many of the cool ligaments like the ACL the MCL and even what's left of each meniscus we'll also talk about what causes knee degeneration in this type of pain and more importantly what you can do to prevent and treat it it's going to be a neat one so let's do this so let's Orient you to this knee so you know exactly what you're looking at so here we have a right knee and why I know it's a right knee is because I've got the kneecap here or the patella which means this is the front or the anterior aspect of the knee if I reflect that out of the way you can see me tapping the femur with my thumb so that's where the thigh would be and then we've got the bones of the lower leg we've got the tibia in the fibula now there may have been times where I've been a little obnoxious with some of my students because sometimes when they're first learning these bones they might say tibia amphibia and I'm like no no no it's tibia infi la la la la la because the LA in fibula helps to remind you that it's the lateral bone and that's probably how the mom and shits Creek would pronounce lateral okay well this coffee has nothing in it oh it's just a gesture David stop being so literal but either way because we know that the fibula is the lateral bone we can bring it over to Jeffrey and if I put it on the left side you you can see how that wouldn't work because that fibula is on the inside but if I move it over to the right I've got the fibula where it needs to be the kneecap where it needs to be you can see how that would compare to Jeffrey so we've got this right knee but as a fun little FYI did you notice what bone Jeffrey is missing in his knee if you do go ahead and put it in the comments but let's take a look at some of the cool ligaments on this knee the first ligament that we'll take a look at is the medial collateral ligament also known as the MCL if I can get my probe underneath there you can see how Broad and flat this ligament is now this ligament is one of the more commonly injured ligaments in the knee and it also forms an interesting relationship with the medial meniscus well what's left of this particular medial miniscus and I'll get into that in just a second but the upper portion of this MCL will actually attach to that medial meniscus so if you were to tear or damage the medial collateral ligament or that MCL up here that could simultaneously tear or damage the medial miniscus as well but let's move over to the lateral side of the knee we've got another ligament called the LCL or the lateral collateral ligament you can see me tracing that with the probe there now if we go inside we've got some other commonly known ligaments that you've probably heard about the one that you've probably heard the least about actually between the two in here is the PCL let me probe it and then I'll show you up close on the camera there so right at the tip of the probe is the PCL and that's actually jutting backwards like so and PCL stands for posterior Cru ligament cruet referring to crucifix because this is for going to form a cross with the very commonly known ligament known as the ACL now let me show you the ACL here so right at the tip of the probe is the ACL and you can see that going backwards and upwards there and that ACL again is a very commonly torn ligament that you hear about with people um often with sports injuries now in a typical anatomy class you'll often hear ligaments connect bone to bone and that is absolutely abolutely true but I do feel like we could go a little bit further and give ligaments a little bit more credit I will tell my students yes ligaments connect bone to bone but they also Define the range of motion of a joint and what do I mean by that well let me give you an example here and hopefully I don't tear my own ligament by getting on a rotating chair here I'm going to try to be a ninja here okay so what I mean by the ligaments Define the range of motion of a joint we learned four ligaments there and essentially the ligaments of the knee say you can go in flection extension so move this way and this way and a little bit of rotation whoops as I rotate the chair and don't die there so what I mean by this is like let's say the MCL we've got here that would prevent the lower leg from moving outward or going into abduction or what somebody might say is prevents like a valgus strain if something pushed far enough on the outside of your knee and pushed it inward that could potentially tear your MCL the LCL prevents your lower leg from going inward or like adduction or if somebody were to put like a Varys strain which would be pushing outward that could tear the LCL the ACL prevents you your lower leg from sliding forward and hyperextending where the PCL prevents your lower leg from sliding posteriorly or backwards and so essentially that's what we mean by Define the range of motion of a joint those ligaments keep that joint stable Define its movements and again if you push too far one way or the other that could tear some of those ligaments so finally let's take a look at what's wrong with this knee this knee has major degenerative changes mainly on the articular cartilage so if we look inside here we can see this cartilage is rough looking not smooth not uniform and just I guess BL is our technical term for degenerating cartilage but when we have degenerative cartilage in the joint like this we call it osteoarthritis now the nicest piece of cartilage we probably have on this knee is right here you can see it's more glossy smooth and uniform and if we had a healthy knee just imagine this type of cartilage being more uniform up on both Condes of the femur and in between on that Groove now I do have a knee that has a little bit less arthritis and so if we go over here here's another right knee up here you can see the cartilage is a little bit better smooth smoother I should say more uniform but as we move down on the Condes you can also see on this knee it thins out and gets a little bit more arthritic not nearly as bad again as this knee let me see if you can actually hear this so try to listen closely here I'll tap right here so we got some cartilage there but if I tap over here pretty much all the way down on bone right there so severe arthritis in this knee now arthritis may not only just affect the articular cartilage it can also affect those fibro cartilage pads that we call the minisi minisi is just plural for meniscus we have a medial meniscus and a lateral meniscus in the knee but on this particular knee with severe arthritis the meniscus is pretty much completely gone with the exception of the outer rim of it so let me see if I can touch that for you so you can see it closely right there just that outer little Rim is what's left of the meniscus here and even a little bit on the front and if I put a picture up you can see what a normal meniscus should actually look like but we just have that edge or that Rim left now the meniscus on this knee or the minisi aren't much better here you can actually see here's the medial miniscus on this particular knee and I actually can slide it off the medial cond of the tibia here watch this sliding off right there so some wear and tear on this meniscus as well and the manisi are extremely important for shock absorption for the knee and actually proper tracking of the knee so what actually causes these degenerative changes in the knee what causes the articular cartilage to start degenerating and even the meniscus creating this osteoarthritis there are several factors that can put someone at risk for developing osteoarthritis this incl includes age joint injuries obesity genetics anatomical factors and sex age related changes in joint tissues make them more susceptible to osteoarthritis one of the many benefits of Aging I guess you could say and Joint injuries can initiate inflammatory processes that lead to degeneration of the cartilage obesity can add mechanical stress and can contribute to pro-inflammatory states that exacerbate arthritis plus anatomical misalignments can also predispose certain individuals to abnormal wear and tear for example if someone is a little bit more bowlegged that could put more stress and wear on the cartilage that's on the inside or medial aspect of the knee now as far as the pathology of osteoarthritis or the process of how it starts it is thought to involved a failed repair process that leads to these characteristic changes in the joint tissues and structures that we've seen in this knee today and one of the main reasons why cartilage does not repair or heal well is that it is avascular it doesn't have a direct blood supply so it has to get its nutrients from surrounding tissues and the fluid inside the joint called sovial fluid which is a slower process than say like some other tissue like muscle tissue that has a direct blood supply the initial changes in osteoarthritis often start with the articular cartilage this could be an injury to the articular cartilage or an injury to surrounding structures like the meniscus or an ACL tear and if you were to zoom into cartilage and look at it from the microscopic level you you would see these cells scattered throughout this extracellular Matrix and these cells are called condr sites condro just means cartilage site just means cell and in between these condr sites you'd see collagen fibers scattered about as well as these glycoproteins known as proteoglycans and these proteoglycans attract water to the cartilage and give cartilage some of its unique features and again let's say you did get some damage to this articular cartilage or to a surrounding structure like the meniscus or the ACL this can cause a disruption in the collagen of this articular cartilage causing the collagen to loosen which will then allow those proteoglycans to attract even more water and Swell this actually ends up leading to further degradation or inflammation of the cartilage and eventual death of the cartilage cells and to make matters worse due to the cartilage breaking down the bone beneath the cartilage that we saw earlier here the subchondral bone starts to thicken because the cartilage is no longer doing its job which then just puts more pressure on the cartilage and even excess stress and pressure on the ligaments as well as the minisi leading to a potential degeneration of those structures and so we kind of get this cyclic or snowballing effect some people will even develop osteophytes which is just a fancy pants name for bone spurs and all of this can lead to sovial inflammation which is the membrane on the inside of the joint which then can lead to joint swelling and instability so I know that all sounded kind of terrible but it's not all gloom and doom because there are things that we can do to reduce our risk of developing osteoarthritis and slow its progression through various treatment strategies now these first set of strategies for reducing one's risk of developing knee osteoarthritis are actually the same initial strategies for those that already have arthritis there may just be some more specific patient tweaks or nuances on how these strategies are applied depending on the severity and the current ability of that person with the osteoarthritis and one of the first things you can do is engage in regular exercise there are studies that have shown that quadricep muscle weakness is highly correlated with osteoarthritis of the knee so an exercise program would include strengthening these quad muscles but you wouldn't want to neglect the hamstrings either as these muscles cross the posterior aspect of the knee and can also provide support you can think of this increased strength as taking pressure off the joint like a stronger muscle being a more efficient shock absorber you would also want to maintain Mobility at the joints so including some full range of motion exercises and stretching could also assist with maintaining joint function which we do have some videos on those topics that I'll link at the end now there are a few myths that we need to dispel and the first one is osteoarthritis is sometimes referred to as the wear and tear arthritis and this has sometimes LED people to think that high volume high impact exercise activities such as running could lead to the development of Nee osteoarthritis however there has been no definitive evidence to actually support that claim and people that already have knee osteoarthritis may still actually be able to include running in their exercise routine depending on their situation and again I think this is important to note because there is also this misconception that once you get osteoarthritis exercise is going to make it worse which is just not the case as research has shown that exercise is safe and that low to intensity exercise is not harmful for articular cartilage in people that already have knee osteoarthritis there's much more evidence to support that your risk of arthritis goes up with what we already mentioned age obesity specific types of knee injuries that we also talked about earlier such as a miniscus tear or an ACL tear or if that person has some anatomical misalignment issues or imbalance between the muscles yes there are situations where someone can overdo it with their training like if they continued to run on a joint injury or maybe they never addressed a strength in balance or an alignment and gate issue so for all the high volume Runners it would just be wise to one have some strength training days mixed in two utilize proper Footwear and three if you think you may have an alignment or gate issue there are Specialists out there that can do a gate analysis in order to help you correct your stride and some of those anatomical misalignments and the last thing that I want to mention with exercise for those that already have knee osteoarthritis there are some studies that have shown that exercise can have a similar magnitude of pain reduction when compared with ineds which stands for non-steroidal anti-inflammatory drugs such as ibuprofen so might as well give the exercise a shot another way to help reduce the risk of developing osteoarthritis as well as to help treat it is to maintain a healthy weight yes excess weight does add mechanical stress and load to the knee joint but there's also growing evidence from metab olic contribution to osteoarthritis because excess adapost tissue can be a source of pro-inflammatory cyto kindes cyto kindes being small protein molecules that get involved in various types of cell signaling some of which are involved in inflammation and the cyto associated with obesity can circulate and may promote a low-grade systemic pro-inflammatory state that could contribute to the development of osteoarthritis and this can explain why body weight is a risk factor for osteoarthritis not only in the weightbearing joints such as the knee and hip but also within the hand loss of at least 10% of body weight through a combination of diet and exercise has been associated with as much as a 50% reduction in pain scores in some patients who are overweight or have obesity supplements are another thing that people may try and supplements are a tricky category for preventing and managing knee osteoarthritis because some studies do show some efficacy While others do not some of the the more common supplements you hear about with arthritis are curcumin as well as glucosamine and condroitin none of these seem to be some amazing magic bullet kirkum is said to have potentially anti-inflammatory and analgesic properties and there are some studies out there that showed patients experienced greater pain relief at 12 weeks using circumin compared with Placebo but this was minimal an issue with circumin is that it is poorly absorbed by the gut but there are some curcumin supplements formulated to enhance absorption and bioavailability so if someone is going to choose to use this they would want to choose one of those formulations similar results with glucosamine and krtin minimal improvements if any and the use of these aren't technically endorsed by many professional organizations that develop these ostearthritis treatment guidelines but if I have a patient that really wants to try it and they are not neglecting more effective treatment strategies glucosamine sulfate rather than glucosamine hydrochloride tends to be more effective in those studies that showed a possible Improvement now at this point if someone still can't manage their knee osteoarthritis we're going to move up to medications and usually this starts with topical medications before tablets because for example a topical inid such as diclofenac gel has a lower risk of gastrointestinal kidney and cardiovascular side effects than a pillar or tablet but in moderate to severe cases of knee osteoarthritis a patient may need to step up to a stronger oral insid and someone would obviously want to discuss the specific Civic ID and dosing with their healthc care provider especially if there's going to be long-term use of this medication for more severe cases patient may try intraarticular injections which is just an injection in the joint this could include hyaluronic acid which is a component of the synovial fluid in joints that lubricates and reduces friction within the joint so the idea is that injecting more of this could potentially help however this also has conflicting evidence on its Effectiveness it also tends to be expensive and there can be a risk of infection with any type of joint injection corticosteroids can also be injected into the knee these can relieve pain in the short term so there are cases where it may make sense to use a steroid injection to get someone out of acute pain as these steroids can reduce swelling and inflammation but frequent and long-term use of corticosteroids May accelerate joint deterioration so probably not a good long-term solution Beyond this we move to surgical options such as arthoscopic surgery to Poss try to clean up the cartilage all the way up to something like a knee replacement and as much as I would love to naturally prevent arthritis with lifestyle modifications and avoid surgery I have had patients that have tried everything else and were therefore candidates for certain surgical options and luckily many of them did have positive outcomes with these surgical treatments such as arthroscopy even all the way up to knee Replacements now obviously this is an individualized situation but these are treatment options that people have benefited from from so hopefully being able to see the inside of a real human knee joint helped you with your understanding of arthritis and this is one of the reasons I love the anatomy lab so much that you do a lot of your learning by doing it's interactive and Hands-On it's active learning and that's why I want to introduce you to another way to learn by doing and that's through saying thank you to the sponsor of today's video brilliant brilliant is an amazing interactive online learning platform with thousands of lessons in math science data analysis programing and even Ai and since I've been teaching Anatomy for the past 18 years I would often tell my students to try to minimize the blind memorization ask yourself and think about why was this anatomical structure given this name there was a logical reason for it and this is also what I love about brilliant brilliant helps you to build critical thinking skills through problem solving and again not through just blind memorization so while you're building real knowledge on specific topics you're also becoming a better thinker and currently one of my my favorite brilliant lessons that's 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