 So we have sliced here the quadriceps tendon, the patellar ligament, we have sliced the iliotibial tract and we have sliced the capsule and we have reflected the patella along with the quadriceps tendon and the ligament and the patellar. First let's take a look at the reflection of the fibrous capsule. When we are cutting the fibrous capsule, we can see the remnant of the fibrous capsule attached to the margin of the femoral condyle here. We can see it here and I'm picking it up the remnant of the fibrous capsule here. So the fibrous capsule was attached here and from there the fibrous capsule got attached to the margins of the patella here on the lateral side and on the medial side. The fibrous capsule got reinforcement from these structures here. This is the lateral and the medial patellar retina column respectively which got attached to the sides of the patella and to the tibial condyle and we can see the remnant of the fibrous capsule here also to the tibial condyle. So this is about the fibrous capsule and inside the fibrous capsule of course is the reflection of the sinusoidal membrane. Having reflected the patella, we can see the surface of the femur which was articulating with the patella. So these are the femoral condyles. This is the lateral femoral condyle, this is the intercondylar groove and this is the medial femoral condyle covered by highland cartilage and we can see because this is an elderly kid ever, the highland cartilage is partially degenerated. So just to bring up to speed, this is the base of the patella, this is the apex of the patella, these are the sides of the patella. This is the outer surface, this is the articular surface which is covered by the highland cartilage which also shows signs of degeneration. Now let's take a look at the articular surface of the patella. We can see that there's a ridge here. This ridge fits into the groove here between the two condyles of the femur. This is the lateral articular surface, this is the medial articular surface. The lateral articular surface is larger because it articulates with the larger condylar surface of the femur. The textbooks describe it as having two ridges which divided into an upper middle and a lower portion. This is the medial portion of the articular surface of the patella which articulates with the medial femoral condyle here and there's a small vertical ridge on the most part of the medial portion which is the non-articular part of the medial surface. This is what constitutes the femoro-patellar articulation. At this point, let me mention a few words of clinical correlation. There's something called a q-angle. The q-angle is the angle between the long axis of the femur and the mid-patellar line. When we have a condition known as gyru-valga or knock knee, the line of weight-bearing goes through the lateral femoral condyle to the lateral tibial condyle. The knees are bent inside. In such situation, q-angle, which normally is 9 degrees, q-angle becomes more than 17 degrees in which situation there's a tendency for the patella to dislocate laterally. There's an opposite condition known as boleg or gyru-varum when the line of weight-bearing goes through the two medial condyle, the medial femoral condyle and the medial tibial condyle and in such situation, q-angle, it becomes less than 9 degrees and that is known as boleg or gyru-varum. There's a theoretical tendency for the patella to dislocate medially, however, lateral dislocation of the patella is more frequent. This is an x-ray of the knee to show transverse fracture of the patella. We notice that the proximal fragment has been widely pulled apart from the distal fragment by the proximal pull of the quadriceps tendon. It typically occurs in sudden violent contraction of the quadriceps muscle. So that is about the femoral-patellar articulation. Now let's take a look at the interior of the femoral tibial articulation or the knee joint proper. We are going to flex the open-out knee and we can see the interior of the knee much more clearly. So we have cut open the capsule as you can see here to see the structures in the front. Let's start off from the lateral aspect. We can see this muscle here. This is the bicep femoris and the bicep femoris gets inserted onto the head of the febola, which is here. And we can see that the bicep femoris tendon is split by this strong stout ligament which I have lifted up here, this ligament. This is the febola or collateral ligament which extends from the lateral femoral epicondyle. It splits the bicep femoris tendon and gets attached to the head of the febola. First of all, it's a short stout cord-like structure. Number two, we can see, since I can put my instrument here, it is free from the lateral side of the capsule of the knee and it is also free from the lateral meniscus of the knee. And the reason why it is free is because from behind one of the tendons of the popliteus muscle passes through here and it separates the febola collateral ligament from the knee joint. This is the febola collateral ligament. Now let's take a look at the corresponding ligament on the medius. Now the camera person has moved to the opposite side, to the right side of the cadaver, to show the medial side of the left knee. This is the febola collateral ligament which I have picked up here. We notice that in contrast to the febola collateral ligament, the febola collateral ligament is a flat band. It extends from the medial epicondyle of the femoral to the upper medial surface of the tibia. Between the febola collateral ligament and the upper medial surface of the tibia, there may be a person. The next thing we notice is that febola collateral ligament is situated just under the insertion of the pest ancerinus. This is the sartorius. This is the gracilis. Further posteriorly, we have the semitendinosis. So sartorius, gracilis semitendinosis, these three triple insertions which constitute the pest ancerinus are located just superficial to the tibia collateral ligament. Between these three tendons and the tibia collateral ligament, there may be a person which is referred to as the ancerine person. We can see that we can pick up the tibia collateral ligament only in the lower portion. We notice that in the upper part, the tibia collateral ligament is densely adherent to the medial part of the capsule of the knee joint and is also adherent to the medial meniscus. This is the coronal MRI of the knee to show the internal structure of the knee including the ligaments. Please take special note of the fact that the febola collateral ligament is free from the lateral meniscus while the tibia collateral ligament is adherent to the medial meniscus. So this brings me to a very important clinical coordination. Tibia collateral ligament is much more frequently ruptured compared to the febola collateral ligament and when this is ruptured, it can also produce a bucket handle tear of the medial meniscus because it is fused here. That's about the two collateral ligaments.