 Hello, good day everybody. Welcome to our next sort of dissection some surgical dissection My name is dr. Sanjay Sanyal. I'm a professor and I'm a surgeon by profession. I'm also a neuroscientist This time we have chosen the public deal for some and we'll mention a few surgical aspects about the public force also So let's first give a quick overview of the anatomy of the public deal for some as all of you know This is a quadrangular space the back of the knee Therefore it has got a super lateral at a supermedial boundary Infra lateral inframedial boundary This is a prone cadaver and the left leg of the cadaver is being seen here This is the upper end of the cadaver. This is the lower of the foot end. This is the lateral aspect There's the middle side the cadaver is prone and there's the left side The super lateral boundary is formed by the biceps femoris tendon The supermedial boundary is formed by the semi membrane osis muscle and it is overlapped by the semi tendon osis tendon By the way, you can see the semi tendon osis tendon is getting inserted onto the medial aspect of the tibia Along with other gracilis and the sartorius which forms what is known as the best ad serenis. Okay, let's come back This is the infralateral boundary and that is formed by the medial head of the gastrocnemius And this is the Infra medial boundary which is formed by the medial head of the gastrocnemius and therefore this small quadrangular space is the public deal for some These are the boundaries What about the floor of the public deal for some for ease of understanding and divided into three parts? The upper part is the femoral part the middle portion is the capsule of the knee joint and the lower part is the tibial part So the posterior aspect of the femur is the upper part of the floor The posterior aspect of the capsule of the knee joint is the middle part of the floor and a little bit of the Populitis fascia and the populitis muscle forms the lower part of the floor now Please note that point because I'm going to come back to it again a little later What about the roof of the public deal for some the roof of the public deal for size formed by a tough fascia called the public deal fascia The public deal fascia is actually an extension of the fascia the thigh above and it continues down into the fascia crurus of the leg below This is a tough fascia and that has got a clinical significance, which I shall mention in the next slide Coming to the contents of the public deal for some apart from the usual contents fat and lymph nodes the three most content important contents are visible here Here we can see the public deal artery the public deal artery is the deepest structure in other words If you see from the public deal side, it is the deepest that means it is the most interior Then you have the political vein and we ideally we're supposed to see the tibial nerve which goes from one apex and Exits through the other apex of the public deal Quadrangle however in this particular specimen the shatic nerve is dividing low And normally the shatic nerve divides at the junction between upper two thirds in the lower one third of the thigh up above But here it is dividing low So therefore the shatic nerve is entering into the public deal for some and here in the public deal for site is dividing into the common Fibular nerve and the tibial nerve so the tibial nerve is ideally the content of the public deal for some and that also I mentioned in my clinical correlations So we have seen the important contents and finally The short syphilis vein which runs on the back of the leg It pierces through the public deal fascia between the two heads of the gastrochemias and therefore that at terminates on the Public deal vein. So the termination of the short syphilis vein is also a content of the public deal for some Now, let's see a few important clinical correlations the most basic being Palpitation of the public electric We'll mention three three aspects of it first the position of the patient the location of the palpation and what should be the position of the leg I've seen it mentions the literature where the patient is being palpated with the patient in the supine position or the Well, that is not exactly advised I would prefer that you put the patient if the patient is in a position to be moved the patient should be in a prone position Because that is the only way we can dip our fingers deeply inside Where exactly do we palpate now? I told you the public authorities rather deeply located therefore the finger has to be dipped in very deep and It cannot be possibly be palpated as such also the public authorities very difficult to palpate and on top of that It is not possible to palpate it on the posterior surface of the knee on the posterior surface of the femur So ideally it should be palpated when it is in relation to the tibia Or in relation to the property is muscle, which means it is should be palpated at the lower end of the property till fossa And then comes the important part what should be the position of the leg the legs should be flexed Because I told you there's a tough fascia here called a public facial and as long as the public facial is stretched It is impossible to dip our fingers deep inside as it's required Another important reason is when the leg is extended the semi-membranosus tendon It comes more laterally and it covers part of the public facial fossa And therefore it becomes even more difficult to palpate the populated artery for these two very good reasons The legs should be flexed and then we should give our finger deep inside We'd be the two heads the gastrocnemius in relation to the tibia and we should try to feel the public artery in On the posterior aspect of the tibia When do we feel for the public ear pulse usually it's quite difficult to feel it as I told you earlier and We try to do it not to diagnose a peripheral this thing peripheral circulatory failure or shock syndrome Because for that we have the carotid artery Here we do it when we are suspecting peripheral vascular disease of the lower limb and that is the time and even if you Don't feel it we can still try to feel the distal The dorsalis pedias or the posterior tibial artery, which will also be an indirect evidence that the public is Circulation is intact. So that's about the public palpation of the public artery Now let's take another aspect of this property lottery and that is known as a public artery entrapment syndrome Now the public artery as I told you is rather deeply located in the political fossa And there have been numerous mentions in the literature though. It's quite rare condition as the term implies It is the public lottery getting entrapped by certain structures inside the political fossa Now there are several classifications The simplest classification is that of the Heidelberg classification which states that the type one two and three Type one of the Heidelberg classification states that there's an abnormal course of the popular artery Type two an abnormal attachment of the muscle in the political fossa and type three when there is a combination of both But to go a little deeper the love and valiant classification is the one which is more detailed and that describes it into six types Type one is in the political artery is a little more Medial than its normal location. Therefore, it gets entrapped by the medial head of the gastrocnemius. That is type one in type two The medial head of the gastrocnemius is migrated more laterally and therefore it traps the political artery in Type three. There's an additional slip of the muscle of the gastrocnemius which entraps the political artery In type four when the political artery is entrapped by either a fibrous band or by the popliteus muscle Though it's a little difficult to understand how the popliteus muscle may be involved because normally the political artery runs on the surface of the popliteus muscle Then we have type five where apart from any one of those above previous features if the poplitean vein is also included in the entrapment then it is called type five and Finally, we have a type six which has been added rather Recently that is when what is known as the functional entrapment syndrome Where both the popliteal artery and the muscles are normal? However, the patient has functional symptoms suggestive of entrapment due to hypertrophied muscles And that has been described as the functional type or type six of PAES That means we do the demographics in which type of population does it seem as I told you it's rather rare and Most of the reports in the literature are case reports Obviously these abnormalities anatomical abnormalities are congenital However, they manifest themselves only in certain groups of people and they're usually seen in young muscular males or athletic males Those who play those have sports and young soldiers. It is being increasingly recognized by the military surgeons So there the abnormality underlying abnormality does exist and on top of that The muscles get hypertrophied and they compress the popliteal artery and therefore they present with all the features of Prodication and it has been recognized as one of the causes of prodigation in a young muscular male without any features of a therosclerosis and As like any other compression it can also produce a post-enotic dilatation It can produce post-enotic aneurysm thrombosis embolism and all of the complications And when it is symptomatic the only treatment is surgical if the fibrous man's or the muscle can be repositioned The artery can be repositioned then should be done. Otherwise by prose grafting is the only answer So that is about the popliteal artery entrapment syndrome in brief Now let's take a look at another aspect Because the property arteries located in relation to the femur and in relation to the tibia Any major fracture of the femur or the tibia can injure the popliteal artery and then can be severe hemorrhage Even if it's a minor injury They can be because of the close proximity between the popliteal artery and the popliteal vein There can be an artery venous fistula and as I told you it can also be the subject of aneurysm Like one of them being the popliteal artery entrapment syndrome or it can also be an aneurysm due to any other causes If there's a hemorrhage of the popliteal artery and we have to ligate it We need to ligate the femoral artery after it is given off the profunda femoris Well, we can ligate it because there's a very rich in osmosis Which is known as the genicular an osmosis given up by the popliteal artery branches five of them and a few Contributions from the femoral artery and the tibial arteries. So therefore in such cases we can ligate the femoral artery what about The aneurysm if it's a very severe aneurysm, then again bypass grafting is the only answer Or if it's an artery venous fistula, then also we have to bypass and graft it We must also remember another thing the popliteal artery also gives plenty of muscular branches The popliteal artery gives plenty of muscular branches, which has got a very rich and very clinically important an osmosis with the branches of the profunda femoris artery and Also with branches the gluteal artery. So therefore they do provide collateral circulation So that is about a few words about aneurysm archivitis fistula and hemorrhage and what does thing to be done and finally Let's take a look at this condition Which is referred to as the popliteal cyst also called the baker cyst or the modern baker cyst named after the person who described it first Here the underlying condition is something totally different compared to what we have discussed earlier Here the person is suffering from chronic Sinovitis and chronic knee joint effusion and there is always an underlying component of osteoarthritis of the knee joint As we know the gastrocnemius muscle has got a bursa in relation to it just under its attachment Similarly the semi-membrinosis muscle also has got a bursa between its insertion and the attachment of the gastrocnemius The this bursa the gastrocnemius bursa communicates with the knee joint capsic and the cavity The sign of a cavity to the knee joint. Similarly the popliteal muscle also has got a bursa under it Which also communicates with the knee joint and apart from that we know the knee joint has got many bursa all around it The most common cause of popliteal cyst is when The bursa from this burst through the capsule of the knee joint from the gastrocnemius And it presents as a swelling on the back of the knee that forms a popliteal cyst The same thing can happen when the semi-membrinosis bursa also burst through the capsule of the knee joint And it presents as a swelling or the other possibility is When any of the periarticular bursa are on the knee They release the sanomial fluid and they all collect in the knee joint and form a separate swelling and that forms a popliteal cyst Now no matter what the swelling is whether it's a popliteal cyst or whether it's an aneurysm or anything We must remember one very important aspect and that is the popliteal space is a very limited space and Whenever there is a need the need space occupying lesion as we call it The structure which is most liable to compression is the tibial nerve And the tibial nerve can get directly compressed whether it's by an aneurysm or whether it's by an enlarged lymph node or whether it is by bursa or and It can either be directly compressed or The vasin or most of the tibial nerve can be compromised and then the patient will present with all the features of tibial neuropathy and Paralysis and weakness of the muscles supplied to the tibial nerve on the back of the leg and the foot How do we differentiate an aneurysm from a lymph node swelling An aneurysm will present with an expansile pulsation on the back of the knee and a lymph node swelling Which is situated on top of the popliteal will have a transmitted pulsation Additionally, if there's a person has got an arterial venous fistula Then we will be able to feel a palpable Thrill when we palpate and we will be able to hear a continuous machinery murmur so-called bruit in the case of arterial venous fistula So these are a few words quick words about the clinical correlation surgical aspects about the popliteal region Thank you ladies and gentlemen for watching. If you have any questions or comments, please put them in the comment section below Have a nice day