 Demonstration of the pulpitil fossa. This is the prom cadaver. This is the left leg. I am demonstrating from the left side the camera person is on the right side. Pulpitil fossa is a diamond-shaped space in the back of the knee. Therefore it's got a supralateral boundary, supramedial boundary, infrolateral boundary, infromedial boundary. So let's take the supralateral boundary. Supralateral boundary is the structure which I have lifted up here. This is the biceps femoris, the long head and the short head. The tendon gets inserted onto the head of the fibula. So this is the supralateral boundary. Supromedial boundary are the combined these two muscles. This tendon structure that you see here, this is the semi-tendinosis and this fleshy portion is the semi-membranosis. So these muscles are actually muscles of the posterior compartment. They are the hamstring muscles. Now let's come to the infrolateral and the infromedial boundary. This is the infrolateral boundary. This is formed by the lateral belly of the gastrocnemius. This is the gastrocnemius muscle. And the infrolateral boundary is also formed by this small muscle here which I have separated. This is the plantaris muscle. So this is the infrolateral boundary. The infromedial boundary is formed by this muscle here. This is the medial belly of the gastrocnemius. So therefore the propitial fossa is damaged shaped. It's got an apex above, it's got an apex below. Two of the propitial fossa is formed by the propitius fascia, which is a continuation of the fascia of the lateral thigh, which continues on to the fascia cruris or the fascia of the leg. Floor of the propitial fossa. Now we have retracted the structures, contents of the propitial fossa to show the floor. As you can see the floor is rather deep and this whole cavity was filled with a lot of fat which has been removed along with it the propitial lymph nodes. The upper part of the floor is composed of the propitial surface of the femur and we can feel the bone here. Then we have the posterior capsule of the knee joint here in the middle and for the lower down we can see just a little bit of the muscle here. This is the propitius muscle. The propitius muscle is covered by the propitius fascia, which is reinforced by the insertion of the semi-membranosis. So these three structures from the floor of the propitial fossa. Now let us take a look at the contents of the propitial fossa. The most important contents apart from fat and lymph nodes are the following three neurovascular structures in this order going from lateral to medial and going from superficial to deep. The same three order follows. We have the nerve this is the shatting nerve. Propitial vein, propitial artery. So going from lateral to medial is nerve vein artery. Going from superficial to deep is the nerve vein artery. Deep means it is more anterior because we are in the posterior aspect. So let's say a few quick words about each of them. Let's start with the nerve. This is the shatting nerve. The shatting nerve is continuing from the gluteal region as we can see here and it is running in the back of the thigh between the superficial group of muscles that is the hamstring group of muscles and the deep which is the hamstring component of the adductor magnus. As it comes down somewhere in the region of the back of the thigh which is a little variable usually at the junction of the upper two-thirds and lower one-third but in this case it is lower down. It divides into its two components the common fibular and the tibial. The common fibular runs laterally under cover of the biceps femoris and then it winds behind the head of the fibular and then it winds around the neck of the fibular and then it goes into the leg. So this is the common fibular. In this location the common fibular nerve is liable to be injured in which case the patient will have foot drop. Now let's come to the tibial nerve. The tibial nerve goes straight across from one apex of the pubic ulfosa to the lower apex and the tibial nerve is the larger component the preaxial division and you can see it is dividing into multiple branches. The tibial nerve supplies the muscles to all the muscles of the leg and the foot. Both the tibial and the common fibular also give a cutaneous branch and one of those cutaneous branches we have retained. This is the lateral sural cutaneous branch of the common fibular and you can see that here. This supplies a little bit of the skin of the back of the leg and this then gives a contribution to a branch from the tibial nerve, the medial sural cutaneous nerve and the two then unite and they form what is known as the sural nerve which runs on the back of the leg. Now let's retract this and come to the next structure, the popliteal artery and the popliteal vein. So let's start from the place where they enter the popliteal fossa. I'm putting my finger in a space here and you can see it is disappearing. This space is the adductor hiatus. It's a space bounded by the tendon of the rectum agnes that is the rectum tendon and the insertion of the rectum agnes to the veneasperal and this opening is the rectum hiatus and from here the femoral artery and the femoral vein they enter the popliteal fossa and then become known as popliteal artery and popliteal vein. So this is the beginning. In this place we have a very important clinical correlation. This adductor hiatus is a potential site of entrapment of the artery. I've lifted up the popliteal artery now and the veins will also be accompanying the arteries. We will remember superior inferior medial lateral. So we have superior lateral genicular. We have superior lateral genicular. Superior medial genicular. Let's come to inferior we have inferior medial genicular this one and we have inferior lateral genicular and we have a middle genicular and we can see the middle genicular here. So these five supply the knee joint and the superior medial lateral and the inferior medial lateral they also participate in the genicular and astromosis by contributions from the top two and one from below. So these are the branches of the popliteal artery. The popliteal artery then as it runs down through the popliteal fossa it can get entrapped apart from the adductor hiatus it can get entrapped in two other places. Let's see them. One site of entrapment is under the medial head of the gastrocnemius and this is a well documented location and you can see the popliteal artery runs very close to the medial head of the gastrocnemius and it can get entrapped here and this is a big classification which is collectively called P-A-E-S popliteal artery entrapment syndrome. In one of the stages of that syndrome even the popliteal vein can get entrapped. And the third place where the popliteal artery can get entrapped is I'm going to put my finger at the lower apex and this is the place where the popliteal artery in the vein they disappear from the popliteal fossa and they come into the leg and they go under tendinous arch of the soleus muscle like this. So that is the third place where the popliteal artery can get entrapped. So to summarize popliteal artery can get entrapped with the adductor hiatus it can get entrapped under the medial head of the gastrocnemius and can get entrapped under the tendinous arch of soleus. Three sites of popliteal artery entrapment. Now let's take a look at this structure here. This is a very important superficial cutaneous vein on the back of the leg. This is the short syphilis vein. This starts from the lateral aspect of the foot and then it climbs up and this is accompanied by the sural nerve which I mentioned earlier. As it comes up it pierces the popliteal spacia and it opens into the popliteal vein and we can see that opening into the popliteal vein. This is used as a landmark to identify the sural nerve on the back of the leg because the sural nerve is a cutaneous nerve which can be used for nerve grafting. So these are the contents that we can see here. Let's mention a few important clinical correlations at this stage. The posterior dislocation of the knee joint can injure one or more of these structures especially the tibial nerve, the popliteal vein of the popliteal artery. Popliteal artery aneurysm in the popliteal fossa is also well documented. Aneurysm is a localized dilatation of the popliteal artery and can produce a pulsatile swelling in the back of the knee. Then we can have a cyst filled with sandwell fluid in the cavity of the popliteal fossa and that is known as a popliteal cyst or a pecker cyst which usually comes from the knee joint or from one of the bursae around the knee joint and it fills up and collects here. This is an axial MRI through the popliteal fossa and the knee to show the popliteal moronbeger cyst. The popliteal boundary as I mentioned is the semi-memory noses and the semi-tendry noses. The semi-tendry noses insertion is rather unique and it is a muscle foot of a goose and we have lifted it up here. It is composed of three tendons. One muscle from the anterior compartment, the sartorius, muscle from the posterior compartment, the gracilis and the muscle from the posterior compartment, the semi-tendry noses and all these three get inserted out of the upper aspect of the tibia in the shape of a foot of a goose and that is called pesansrinus. There can be a persa between this and the bone and that is known as an ansterine bursae. The semi-memory noses which also forms a supra-medial boundary of the popliteal fossa. As it gets inserted it gives expansion to the posterior capsule of the knee joint and it strengthens the popliteal spacial. There may be a persa between the semi-memory noses and the medial head of the gastrocnemius and we can see a little bit of the remnant of the bursae here. This is the semi-memory noses bursae. The popliteal muscle which I showed you forms a floor of the popliteal fossa. This also has a bursae. Here it is penetration to the capsule of the knee joint and that is known as the popliteal bursae and that communicates with the knee joint. The medial head of the gastrocnemius which forms the infromedial boundary also has a bursae which communicates with the knee joint and that is known as the gastrocnemius bursae. So these are all the medial bursae which are in relation to the knee joint and these bursae can also leak fluid into the popliteal region and they can contribute to the popliteal cyst which I mentioned. So these are all the structures and the clinical correlations that I wanted to mention about the popliteal fossa. Thank you very much for watching. Dr. Sanyas signing out. If you have any questions or comments please put them in the comment section below. Have a nice day.