Anatomy of the knee joint. Bags of the knee joint

Anatomy of the knee joint (Sinelnikov RD and other authors consider it in sufficient detail) is rather complicated. This articulation in the human body consists of many parts. The connection takes on the most complex loads, distributing the weight, several times higher than its own. The complexity of the joint is due to its constituent parts. These are the largest bones of the lower limbs.

In the formation of the joint involved 3 bones. They are connected by a powerful articular apparatus, which includes a capsule of the joint, ligaments and synovial bags. The entire joint is set in motion with the help of the muscles of the legs.

The structure of the knee joint

The knee consists of three bones, the muscles that support its movement, nerve endings and blood vessels, menisci, cruciate ligaments. Such a complex structure is due to high loads. Anatomy of the knee joint provides maximum comfort when traveling on 2 extremities. In primates, the structure is much easier due to the presence of 4 limbs.

The surface of the femur (condyle) is ellipsoid. The medial condyle has a greater curvature than the lateral one. Between the condyles there is a patellar surface. It is located in the anterior part of the femur and is divided by a vertical groove into a smaller inner and larger outer areas. They are connected to the posterior articular surfaces of the patella.

The surfaces of the condyles are slightly concave and do not correspond to the bends and curvature of the condyles of the femur. Despite this discrepancy, the interarticular cartilage (internal and external menisci) align it.

Functions and movement

The knee joint can perform the following movements: flexion, extension and rotation. The nature of the joint is condylar. When the meniscus is unbent, they are compressed, they are released when folded. Due to the fact that the collateral ligaments are relaxed in this position, and their attachment points are as close as possible to each other, there is the possibility of movement - rotation.

When the shank is rotated inward, the movement is limited by cruciform ligaments, while they move outward, they relax, and the amplitude is limited to the lateral ones.

Menisci

The anatomy of the knee joint has for many years been studying the structure and function of the meniscus, since trauma associated with them is very common.

Menisci are trihedral cartilaginous plates, thickened from the outside (fused with the articular capsule), inside facing towards the joint and pointed. Above they are concave, flattened from below. From the outer edges, the anatomy of the upper margins of the tibial condyles is repeated.

The lateral meniscus is similar in shape to the part of the circumference, and the medial resembles a semilunar form.

The attachment of the cartilaginous plates takes place from the front (using the transverse ligament of the knee) and from behind to the tibia (intercondylar elevation).

The main ligaments

A brief anatomy of the knee joint always describes the cruciate ligaments (anterior and posterior) that are directly in the knee. They are called intracapsular ligaments.

In addition, there are lateral collateral (medial and lateral) in the joint. They are also called extra-capsular ligaments, since they are outside the joint capsule.

Extra-capsular ligaments are represented by tibial and fibular collateral ligaments. They begin with the medial and lateral epicondyle of the femur and are attached to the superior epiphysis of the tibia and the outer surface of the fibula, respectively. Both are connected to the capsule of the joint.

Intracapsular ligaments, anterior and posterior cruciate, begin on the inner surface of the lateral and medial condyle of the thigh, go forward and inward (down and inward), are attached to the anterior and posterior tibial bone, respectively.

Supporting ligaments

Topographic anatomy of the knee joint, in addition to intraarticular and extraarticular, also studies other ligaments.

The patellar ligament is the tendon of the 4-th chapter of the thigh muscle, which comes from the top down, approaches the patella, wraps it around and extends down to the tibia. Lateral tendon bundles run along the sides and are directed from the patella to the medial and lateral condyles of the tibia. They form the outer and inner supporting patellar patches.

There are also horizontal bundles in the supporting patella of the patella, which are attached to the epicondyle of the femur. The function of supporting ligaments is to hold the patella in the desired position.

At the back of the articular capsule is strengthened oblique popliteal ligament. It starts from the condyle of the tibia and is attached to the femoral condyle, giving off a part of the bundles of the joint capsule. The ligament takes a part of the bundles from the tendon of the hip muscles, namely from the semimembranous muscle.

The arched popliteal ligament also participates in the retention of the patella. It starts from the femoral and fibular bones, and is attached to the tibia. The ligament begins and ends on the lateral condyles.

The transverse ligament of the knee connects the menisci along their front surface.

The anterior meniscus ligament originates from the anterior part of the inner meniscus, upward and outward, to the lateral condyle of the thigh.

The posterior meniscus ligament originates from the posterior edge of the outer meniscus, should be up and inward, to the medial condyle of the thigh.

The condylar knee joint works as a block-shaped joint, being in the extended position. The anatomy of the knee joint allows rotation on the vertical axis in a bent position.

Joint Capsule

The joint capsule is attached to all three bones involved in the formation of the joint.

To the femur, the attachment occurs under the epicondyle, to the tibial - along the articular surface, to the patella - along its articular surface.

The synovial membrane covers the connecting surfaces of the bones to the cartilages and lining the cruciate ligaments. In addition to a smooth structure, the membrane forms a multitude of synovial villi and folds.

The most developed folds are the pterygoids. They go up the sides of the patella. And they contain a podadikolennik fat body between their sheets.

The podnikolennikovaya synovial fold lies below the bone itself, is the continuation of the pterygoid folds. It originates above the patella, goes into the joint cavity, is attached to the anterior margin of the fossa, between the condyles of the femur.

Synovial bags of the knee joint: anatomy and structure

The knee joint capsule forms several synovial bags. They can be in different places of muscles and tendons, lying inside and between them. Synovial bags can be found among bones and ligaments.

The tendon of the 4-th chapter of the thigh muscle and the anterior surface of the patella form a subordinate pre-tufted bag.

A patellar patch and tibia form a deep patellar synovial bag between each other. Sometimes it has a connection with the cavity of the knee joint and is separated from it by a layer of fatty tissue.

These are the largest synovial bags of the knee joint.

Goose foot of knee joint: anatomy and location

For normal operation of the knee joint, there are a number of muscles that can be divided by their location:

• The anterior surface of the thigh is the quadriceps muscle.
• The posterior surface of the femur is biceps, semisuscular, semimembranous.
• The inner surface of the thigh is large, thin, long, short, leading muscles, comb muscle.

On the lower leg there is a place where 3 muscles of the thigh are attached - tailor, semi-tendon and thin. In this place a goose-foot is formed, where the synovial bag is located.

Injuries to the knee joint

A knee injury is a very common occurrence. In order to diagnose the cause of pain in the joint, the doctor very often appoints an MRI. The anatomy of the knee joint (bones, ligaments, muscles, arteries, etc.) is visible in the picture, which will allow us to determine the cause of the unpleasant sensations.

Very often knee injuries are received by athletes, as well as those who have work associated with physical labor. In order to reduce the risk of injury to the knee, you need to regularly strengthen the muscles and ligaments. Perform simple exercises from joint gymnastics, regularly drink vitamin and mineral complexes. All these measures contribute to strengthening the knee joint and the muscles that drive it.