 Hello, I am Dr. Upasna Gaurav. At the very outset, I would like to thank the organizers for giving me the opportunity and today I will be talking on the normal sonanatomy and scanning protocol of the knee joint. We all know that knee is a bicondylar synovilion joint that is capable of flexion extension movement mainly and also rotation and side to side movement to some extent. Like any other synovil joint, it has articular cartilage covering the articular surface and also a thick fibrous capsule and has important structures like mini-sky and anterior and posterior cruciate ligaments which are intra-capsular but extra synovil and medial and lateral-collateral ligaments and all the structures have their own cruciate roles to play. And also reminding many important bursae and the recesses around the knee joint, we will move into the ultrasound screening of the knee joint. Starting with the anterior knee, the patient is supine knee flexed at 30 to 40 degrees, put it below the knee joint to make the patient comfortable and we are going to see the following structures one by one. So here we are going to see the quadriceps muscle forming the quadriceps tendon, the patella and the pre-patellar area, the patella tendon, retinoculum, suprapatellar recess and the pre-patellar and infra-patellar bursae. So in the thigh, the rectus femur is being the most superficial structure and the bursas laterally and medially are the intermediate layer and the deepest layer is formed by the bursas intermediate. So as we move down, we can see the muscle fibers getting thinner and they are opposed and ultimately refuse to form the quadriceps tendon about one centimeter above the patella. In long-exists, we can demonstrate the trilaminous structure of the quadriceps tendon nicely and the tendon fibers appear hypoequic because of its oblique orientations and anisotropy with the intervening hyperequic loose area rotisserie layers that allows some gliding movement between the tendon fibers. Underline this, we have suprapatellar fatbed and prefumoral fatbed which are well defined and a little bit compressible and in between them, we have the suprapatellar recess which is an important part because we have to shake there for the joint effusion, synable thickening or loose booties, etc. And even in cross-section, we can demonstrate the trilaminal pattern of the quadriceps tendon very nicely. Retinocular are demonstrable as biliminal fibers sit on either side of the patella in postural oblique orientations and they are inseparable from the underlying capsules and ligaments. They act as a stabilizer and hold the patella and prevent its lateral translocation. The most cranial fibers of the medial retinoculum, they are thickened and blend with the medial patella femoral ligament that passes from the patella supermedially to get inserted into the femur between the medial epicondyle and the adacto tibacle. In the pre-patellar region, we used a floating technique that is we put lot of gel over the patella and put the probe very lightly over it to avoid any compression so that we can visualize the superficial fibers from the rectus femoris crossing over the patella and joining the patella tendon below. Also, have a note in this area for the pre-patellar basal which is usually not seen there in ultrasound normally if it is not implanted and distended. Sliding the probe into the infrapatellar region, we can see the patellar tendon arising from the infrapole of the patella, crossing over the hofers pet-pet and the tbl epiphysis and inserting into the tbl diversity. Joining the patellar and the tbl diversity will have the nice privilege pattern of patellar tendon which is about 3-5 mm thick and it overlays the hofers pet-pet here and it has clinical implication associated with patellar tendonopathy. We should look for pre-patellar and superficial infrapatellar basal here and usually in normal cases we don't see any fluid there but we may have deep infrapatellar basal in this area and it may show some fluid in normal ultrasound also. Muts can throw the wide transverse axis of the patellar tendon throughout the length and the width that shows a nice brass and on appearance to roll out any focal pathology. Knee fully flexed, putting the probe in slight posterior oblique orientation, we can see the smooth and equi-homogeneous layer of trochlear articular cartilage that follows the contour of the trochlear. And even we can measure the trochlear focal angle if it is more than 155 degree it suggests trochlear dysplasia and that can result in patellar femoral instability. Keeping the probe over the tbl diversity and rotating the cranial line towards the lateral femoral condyle you can visualize only the superficial part of the anterior cruciate ligament there. Keeping the knee extended we can post a patellar from its superior aspect inframidally and you can scan there to see part of the retro patellar cartilage on medial side but remember the lateral part is not accessible as it is covered by the prominent trochlear. So we can have a good idea about the extensional system of the knee shipping along the anterior aspect of the knee joint. Next we'll move into the medial compartment. On the medial aspect we are going to see the medial meniscus and medial joint client, the deep component of the medial co-lateral ligament which is fused posteriorly with the posterior oblique ligament and is overlaid by the superficial medial co-lateral ligament. We have MPFL there as we've already seen in the anterior compartment and of course we have to see the placensuriness tendons and the placensuriness buds there. And the knee will be flexed at 20 to 30 degree with the leg and hip externally rotated during examination. Putting the probe in long axis over the joint intermedially we can see the medial joint line and with the two articular surfaces of the tibia and femur which is covered by the articular cartilage and the medial meniscus superficial part as a small triangular area there. But remember the visualization of this structure in ultrasound is always inadequate and parcel. On the medial aspect from superficial to deep we have the superficial amp cell, deep amp cell which blends with the medial meniscus which appears as a triangular ecosine structures lying between the articular surfaces of the femur and the tibia which are covered by articular cartilages. So the deep amp cell is actually a thickened capsular ligament and it underlies the superficial amp cell and few straighter meniscus and it has a 15 millimeter long menisco-hemoral component and a 5 millimeter long menisco tibial component that few straighter superficial amp cell distally. Superficial amp cell is about 2 to 3 millimeter thick and 9.5 centimeter long. It arises below the medial epicondyle and at this side it is much thicker and wider and needs the detailed evaluation because most of the pathologies including tears are most common in this region. So as you move down you can see the ligament passing across the joint line moving down into the proximal tibia to get its insertion about 6 to 7 centimeter below the joint line. Lying between the distal amp cell and the anterior tibial concavity we have the medial genicular artery and nerve and that actually serves as an important landmark to identify the base sensor in the tendon that lies anterior to the mcl and they are actually intermingling fiber of the surgery. In this case, gracilis and semitendinosus getting insertion just anterior to the mcl into the proximal tibia and we have base sensor in this bursar there between the bone and the tendons and it's usually not seen in ultrasound unless it get inflamed with some infection or inflammation. We can perform vulgar stress test to see the intactness of amp cell, the knee should be banned at 30 degree and the vulgar stress is applied and if there is opening more than 5 millimeter compared to the other knee then it's significant. After medial knee we will move to the lateral knee and we will examine the knee at 20 to 30 degree flexion, leg is internally rotated. On the lateral side we are going to see the lateral joint line, the luteal tract, lateral co-lateral ligament, bicep humerus tendon and the popliteus tendon. Placing the probe on the anterior lateral aspect of the knee in long axis we can see the articulate surface of femur and tibia which is covered by the articulate cartilage. In this case the superficial triangular portion of the lateral meniscus and above test this is the popliteal fossa which is occupied by the popliteus tendon that you can see in cross-section. Inserting into the gut is cervical where it fans out, luteal tract can be seen as a thin fibros band and it slides between the anterior and middle third of the lateral leg and is oriented along the major axis of the thigh. Next we will scan it in short axis, in fact we should make it a habit to scan all the structures in short axis along the anterior leg. Now to examine the posterior lateral structure of the knee joint inserting into the fibular head we have to identify the fibular head either by palpation or we have to move across the tibia into the posterior lateral aspect to find out the ponic cortical margin of the fibular head. Now keeping the cordial edge of the probe over the fibular head, rotate the cranial and anteriorly with probe orientation along the leg we can visualize the lateral cortical ligament as a thin cylindrical cord leg structure joining the lateral femoral epicondyle to the fibular head. And here we can see the con joint tendon at the distal and of the LCL and it is wrapped around by the bicep femoris tendon very nicely in this picture. Keeping the cordial end of the probe fixed over the fibular head, now we rotate the cranial and posteriorly along the axis of the thigh and we are able to see the bicep tendon inserting into the fibular head. As we move up we can see the cordially extended muscle fibres from the short head of the muscle inserting into the tendon and this muscle fibres also help us to identify the tendon. For the posterior knee patients will lie prone knee extended and we start the examination from the lower thigh level. Finally moving to the posterior knee the important structures we are going to see are the popliteus muscle, planteris muscle, psorias, bicep femoris, semi-membranosus, semi-tendinosis, lateral and medial head of gastrocnemius, the popliteal fossa with the neuropascular bundle there and of course the semi-membranosus gastrocnemius spasa or the molynebic assist. Screening down on the medial aspect of the thigh we can see the muscle fibres of the semi-tendinosis and semi-membranosus progressing towards the maternal junction and ultimately forming their own respective tendons there. And on the lateral aspect we can see the medial head of gastrocnemius arising with its typical eccentric location of its tendon. And between the semi-membranosus and gastrocnemius tendon we have the semi-membranosus gastrocnemius spasa or the molynebic assist and it is important to show the pedicle joining into the cavity. And on the medial aspect we have semi-tendinosis, sartreus and gracilis muscle that forms the best answering complex and passes into the anterior medial aspect of the knee to get insertion there. Now the semi-membranosus spasa is to get inserted into a fossa on the posterior tbl epipasis with the medial head of gastrocnemius crossing it by its side to get its proximal insertion into the medial condylofema. Tentris muscle can be identified in the short axis view that appears between the two head of gastrocnemius as a triangular muscle belly and it becomes more prominent as it moves upwards to its insertion site into the supra condylo reach of fema. Pupilates muscle form the base of the pupilates fossa and it can be identified underlying the pupilates vessels in long axis and also we can demonstrate its insertion into the pupilates fossa. The pupilates neurovascular bundle can be better demonstrated in short axis view on the posterior lateral aspect of the knee and we can demonstrate the posterior tbl now with the pupilates belly and the pupilates artery from the supra fissile to the diparous spine. Short axis view in the mid-public television shows the intercondylofosa and in case of a cell tear there may be some bleeding or hematoma that we have to look for. Keeping the caudal aspect of the probe over the tbl epiphysis will rotate the cranial end of the probe towards the medial epicondyne in a societal oblique position. Then we can see the distilled two-thirds of the posterior cruciate ligament that appears as a tic hypochloric cord-like structure with a bucket-handled appearance. Another common structure that we ask to see is the common peritoneal nerve under posterior lateral aspect of the knee joint and we can demonstrate it nicely with little bit of practice. So after origin from the sciatagnum cpn process distilly along the posterior medial aspect of the bicep humerus muscle then throw a restricted space between the bone and the fossa at the fibular head level. Then it wins around the fibular neck deep to the attachment of the peroneous longest muscle and here it divides into the supra fissile and deep peroneal nerve. And lastly we should have a look into the proximal tbl fibular joint and of course the insertion of the lateral head of gastrocnemius into the lateral condylofema that may contain acesamide bone which is called favela and it acts as a stabilizer to the soft tissue structures under posterior lateral aspect of the knee. So that concludes our knee examination and in conclusion I would like to say that every diagnostic tool has some advantages and some limitations and we should know our limitations because limitation inspire innovation and there is always a key to success and in MS culture sound good anatomical knowledge a proper protocol and practice give us that key to success. Thank you so much.