Anatomy of the knee joint | Symptoms of meniscus rupture

Anatomy of the knee joint

The knee joint (Articulatio genus) is the largest joint in the human body. However, there are actually two different joints in the knee. One is the connection between the thigh bone (femur) and the bone of the lower leg (tibia), which is therefore called Articulatio femorotibialis.

The second joint of the knee is formed between the femur and the patella and is therefore called Articulatio femoropatellaris. As is characteristic of a true joint, the bones involved in this joint are covered by a layer of cartilage on the surface where they touch (joint surface). This layer has the task of ensuring that the bones can move against each other without pain or friction.

The synovial fluid surrounding the joint (synovia) performs the same function and provides additional nutrition for the cartilage. The knee joint is enclosed by a joint capsule and thus separated from the adjacent muscle tissue. The knee joint has a ligamentous apparatus to secure it.

This means that there are ligaments on the knee that stabilize the joint and thus limit the extent of movement. This serves to protect the attaching muscles from overstretching or even tearing, which could otherwise occur if the joint is moved excessively. The ligaments (ligaments) that secure the knee joint are, on the one hand, the collateral ligaments (inner and outer collateral ligament), which are also called collateral ligaments (ligamentum collaterale mediale and lateral).

On the other hand, other important ligament structures play a role in the knee with the cruciate ligaments (Ligamentum cruciatum). In the knee there are so-called menisci, namely an inner and an outer one. These are crescent-shaped cartilages that play an important role in the transmission of force within the knee joint.

Due to their shape and their position between the upper and lower leg bones, they increase their bearing surface and thus also the joint surface. On the one hand, this results in greater stability of the joint, since the menisci improve the contact between both bones. On the other hand, it also plays a major role in the even distribution of the pressure that acts on the joint and which, without the menisci, would be transmitted between the bones at points and, thanks to them, is now transmitted evenly and over a large area.Without intact menisci, cartilage wear at the rubbing contact point of the bones would occur very quickly, leading to arthrosis (joint wear). Finally, the back of the knee joint, the popliteal fossa (popliteal fossa), is also important in the knee, since large blood vessels and nerves run deep into it.