Knee joint: structure (anatomy)

Structure and diseases of the knee joint

The knee joint is an education that has a rather complex structure. In the formation of this joint involved several bones, so it is called complex. What is the anatomy of the knee joint?

Anatomical features

Bones forming the knee:

• femur;
• tibia;
• knee cap.

Inside the knee joint are cartilaginous plates - menisci. They are located on the border of the femoral and tibia.

Menisci, in fact, divide the knee joint into two equal parts.

The joint has condylar type, which means that the joints of the bones, between which the meniscus is located, are represented by condyles.

The joint movement is carried out in the following directions:

• vertical (sagittal) plane - movements are performed in the flexion and extension directions;
• frontal plane;
• horizontal plane - movements are performed with a bent joint.

The leading and leading movements are carried out within only five degrees

In addition, knee joints perform sliding and rolling.

The following elements are involved in the formation of the human tribe:

• epiphyses of bones that are located on both sides of the meniscus;
• capsule and joint cavity;
• synovial bag;
• cartilaginous plate;
• ligaments of the knee.

Let's talk about these elements in more detail.

Epiphysis of the femur and tibia

Epiphysis of the femur forms the knee from above, and the epiphysis of the tibia is on the underside. The epiphysis is represented in the form of an enlarged end section, which participates in the formation of the knee along with the bone from the adjacent side.

Thickening of the epiphyses of the femur - the condyles - is convex, and the condyles of the tibia are concave. Menisci are located between the surfaces of the joints, since they are not symmetrical. Cartilage plates are able to equalize this discrepancy.

Thickening of the epiphyses of both bones is covered with cartilage. Cartilaginous tissue is represented by a hyaline substance, which consists of a collagen substance.

Collagen provides strength to cartilaginous tissues

The structure of the knee joint of a man includes such elements:

• Chondrocytes are the main cartilage cells;
• tissue fluid;
• organic substances;
• The growth layer, which contributes to the restoration of cartilaginous tissue.

Hyaline cartilage does not exceed five millimeters in thickness. Despite the constant friction of the joint, the cartilage always remains smooth. Cartilage has elastic properties that have a damping effect.

An important role in the formation of the knee is played by the patella - the sesamoid bone. The patella is located inside the tendon, or rather in its thickness of the femoral muscle. The patella is directly involved in the process of extension of the tibia.

If you look at the knee cap on the inside, it is covered with massive cartilage, which facilitates easy movement of the joints of both the femoral and tibia.

The main task of the patella is to limit the lateral displacement of the femur and tibia

The patella improves muscular work and performs a blocking function.

Joint cavity

The articular cavity is represented by a closed space that looks like a gap in appearance. The cavity is limited by the inner layer of the joint capsule, and also by the surfaces of the joints of the femoral and tibia.

Joint Capsule

Also you can read:What does the ultrasound of the knee joint show?

The main function of the joint capsule is the protection function. It protects the knee joint of a person from increased mechanical influence from the outside.

If you look at the capsule from the inside, it is covered with a synovial membrane. The tension of the articular knee bag is weak. Due to this, the motor activity can occur in different planes with different strengths.

If you look at the posterior part of the joint capsule, then at this point it is slightly thicker and differs by the presence of numerous openings, which are original channels. Blood vessels pass through them.

In the capsule, the following shells are distinguished:

synovial. It lays the inner surface of the capsule of the joint. The shell does not cover only the articular surfaces of the epiphyses of the femoral and tibia. The synovial membrane produces a synovial fluid.

The liquid contains small vessels, so it is a good food for cartilage tissue. Also, thanks to the shell, the mobility of the joint increases. The sheath is a good protection against mechanical stress. If there is an inflammatory process of the bone tissue, the synovial membrane does not allow the pathological process to spread further and damage the joint cavity.

Vorsinki are the outgrowths that form the synovial membrane. They contribute to an increase in the surface area of ​​the synovium, and also participate in the production of intra-articular fluid;

fibrotic. The membrane on the outside covers the joint capsule. The main component, which is part of the fibrous membrane, is a collagen substance. The shell reaches the periosteum.

In the structure of the knee joint, an important role is played by the synovial bag

Synovial bags

They are located under the muscles and near the tendons. To ensure that the muscles and tendons are not rubbed while moving, the bags are filled with synovial fluid.

Synovial bags are of different types:

• an overstrained look of the bag. The bag is located between the femur and tendon. Next to her is the cavity of the knee joint;
• podadikolennikovy type of bag. It is located between the patella and the patella;
• prednadolkovnikovy type of bag. It is located between the skin and the patella. During motion, the bag slides over the patella;
• semimembrane kind of bag. It is located between the semimembranous and gastrocnemius muscle;
• popliteal view of the bag. A bulging capsule of the knee is the bag of the popliteal muscle.

Synovial bags often communicate with the cavity of the knee joint

Orthopedics

Pathological processes of the musculoskeletal system can be the result of congenital pathology or disorders in prenatal development, as well as injuries. In addition, orthopedics provides information on diagnostic methods and treatment measures for diseases of the musculoskeletal system.

Let's talk about the sections of orthopedic medicine:

• outpatient department. Outpatient medicine is a rather significant section, as in most cases patients undergo out-patient treatment;
• children and teenage industry. The main task of this section is prevention and timely elimination of congenital pathologies;
• operative orthopedics. In this case, the main method of dealing with the problem is surgery;
• implant orthopedics (replacement or prosthetics);
• sports section;
• traumatology.

Orthopedics is a section of clinical medicine that studies not only the causes, but also the development of various pathological processes from the musculoskeletal system

Pathology of the knee joint

Knee diseases can be of such a nature:

• inflammatory character;
• dystrophic nature;
• traumatic origin.

Most pathological processes are divided into two groups:

• Arthritis, which is an inflammatory process with a different nature;
• Arthrosis, which causes dystrophic changes in the joint.

Common causes and manifestations of diseases of the knee joint

The most common lesions include the following:

• pathological processes in the meniscus;
• trauma associated with a ligamentous apparatus disorder;
• intraarticular fractures of bones;
• hemorrhage.

Pathologies are associated with mechanical damage or trauma that occur as a result of severe overloads

The main sign that indicates the presence of disorders in the knee is the appearance of painful sensations and inflammatory process. The degree of damage, as well as the cause of the problem, affects the intensity of pain and their localization.

Pain can appear periodically, can be of a permanent nature, and it happens that their appearance is associated with physical stress.

Effusion

The disease manifests itself in the form of the appearance of such clinical symptoms:

• severe swelling;
• increase in volume;
• limited mobility;
• painful sensations in any physical exertion on the leg.

The exudation is a pathological intraarticular accumulation of synovial fluid

If any of the above symptoms are found, you should immediately contact a specialist. Self-treatment can only exacerbate the problem.

The key to successful therapeutic measures is to carry out a comparative analysis with other pathologies, as well as an accurate definition of the causes that caused the accumulation of fluid.

Such a diagnostic study can only be carried out by a qualified specialist.

The most dangerous pathologies are those in which the pathogenic microflora penetrates into the joint.

The fact is that the synovial fluid is a favorable environment in which these pathogenic microorganisms multiply.

This condition is a threat to the life of the body, so you should immediately consult with a specialist.

Bursitis

Microtrauma, having a permanent character, as well as increased loads are the main reasons for the development of the inflammatory process. If, in the presence of damage, ignore the recommendations of specialists and continue to engage in physical exercises, the problem can only worsen.

Bursitis is an inflammatory process in the synovial knee pouch

At risk, strangely enough, there are housewives who often stay standing or lean on their knees when washing floors.

Bursitis is quickly detected by a specialist on examination:

• soreness with palpation;
• swelling;
• redness;
• local and general temperature increase.

Acute injury

Fall, kick, excessive bending or twisting of the foot - all this refers to a sudden injury. The first signs, which indicate that the damage is serious, are such symptoms:

• strong pain;
• swelling;
• bruising.

The patient will not be able to proceed to physical exertions soon, since the rehabilitation period includes ensuring complete rest

Emergency assistance in case of sudden trauma includes the application of a tire that can provide complete rest to the damaged joint.

Therapeutic measures also include taking analgesic and anti-inflammatory medications. The most serious pathologies are treated with the help of surgical intervention.

Methods of struggle directly depend on the degree of severity, and the doctor takes into account and such features:

• age of the patient;
• its individual characteristics;
• general state.

So, the structure of the knees is quite complex, playing an important role in the life of the organism. It is impossible to imagine a full and active life without the work of the knee, so take care of them.

A source: http://MoyaSpina.ru/info/stroenie-kolennogo-sustava

Anatomy of the knee and ligaments: structure in the photo

The human skeleton has a complex structure. Each element performs a certain function, answering for normal life activity. So, the area of ​​the knees, including bone tissue, ligaments, nerves, joints, is responsible for the mobility of the limbs.

Damage of at least one component can cause limitation of motion, or complete immobility.

Therefore, it is so important to know the anatomy of the knee and ligaments in order to be able to recognize the signs of an impending disease and start treatment in time.

Elements of the knee

The main components of the knee:

1. large bones with muscles that form the entire structure of the knee area;
2. menisci, thanks to which the joint moves;
3. nerves and blood vessels are responsible for the sensitivity and response to various stimuli;
4. ligaments with cartilage connect bones and muscles. These elements account for the main burden of the knee area.

Anatomy of the knee joint is very complicated, and makes it difficult to treat this site in case of various diseases.

In order to better understand the anatomy of this important part of the skeleton, we suggest to consider the structure of the knee joint in pictures, and to get acquainted with each constituent element of the knee separately.

Bone patch

We'll figure out what bones are part of the knee:

The name of the bone. Description

Femoral	The convex part (from below) is the surface of the joint (upper bone). Bottom of the bone there are two spherical heights, covered with cartilage tissues. This is the articular plane
Big tibia	Tubular structure, located at the very foot (lower bone)
Patella	Rounded bone, located in front of the knee.
Femoral condyles	Located below the femoral plane. They differ in spherical shape, touch the tibia

Anatomy of the structure of the knee joint is such that the bones that make up it are covered with cartilage. The cartilage tissue is designed to reduce the load on the bone tissue during movement (the bones are not erased from each other).

For the patella, the barrier from erasure is served according to the anatomy of the knee joint, bags filled with synovial fluid. The purpose of bags, as well as helping the muscles while walking.

Muscle

The knee area is provided with two groups of muscles responsible for flexion and extension of the limbs.

Extensors are in front of the femur. These muscles are responsible for motor activity, when they work, the knee joint is able to straighten.

Flexors are located behind the hip and in the knee area. When this type of muscle contraction, the limb can bend at the knee.

Menisci

Let's turn again to the anatomy of the knee joint in the pictures, where you can see the location of the elements in detail.

Menisci are between the condyles and the plane of the tibia. Their purpose is to distribute the load from the femur to the tibia.

If any damage occurs with the meniscus, or if they have to be removed during surgery, irreversible changes in cartilage tissue can develop.

In the central part of the meniscus is much thinner than in the peripheral. Due to this, on the surface of the tibia, a shallow depression is formed, evenly distributing the load.

Nerves of the knee

The back surface of the knee is provided with popliteal nerve endings, which simultaneously provide the sensitivity of the shin and foot.

Rising slightly above the knee joint, the popliteal nerve is divided into two types: tibial, peroneal.

With injuries of the knee area (this is the anatomy of the structure), both nerves are in the risk zone (they may get damaged).

Blood vessels

Large vessels include the popliteal artery and popliteal vein. Both blood vessels are located on the back of the knee.

The task of these vessels is the supply of blood from the lower leg and the foot. The artery carries the flow of nutrients peripherally, the popliteal vein - to the direction of the heart.

The artery is also divided into the following blood vessels:

• upper lateral, which is divided into even more accurate vessels;
• upper medial (above the medial condyle);
• the middle knee feeding the capsule of the joint;
• lower, knee, literal;
• lower, knee, medial.

Vienna is divided into:

• large subcutaneous, which empties into a large femoral vein;
• small subcutaneous, starting from the back of the foot. Further, the vein goes up to the popliteal fossa, where it merges, forming a popliteal.

Ligaments and cartilage

Consider the anatomy of the ligaments of the knee joint - connective tissue of the knee region.

The function of the ligaments is to connect and strengthen the bones that form the joint. Bundles are divided into two types - extra-capsular and intracapsular.

Both species are divided into varieties that perform certain functions:

Extra-capsular. Intracapsular

Tibial tibial is fused with meniscus and joint capsule	Frontal cross-shaped
The collateral tubercle is also connected to the capsular part	Rear cross-shaped
The oblique popliteal passes between the condyles	Meniscus ligaments: - transverse; - front - rear
An arch is attached to the popliteal

Look at what the anatomy of the knee is in the photo attached below.

Cartilages in the knee serve as shock absorbers for any movement. The joint is constantly experiencing friction during walking. But, the cartilage tissue remains elastic, smooth, despite heavy loads.

Cartilage ends all the joint bones involved in moving, and touching each other.

Synovial fluid is a nutrient medium for cartilage tissues and maintains its damping properties.

Capsule with liquid

The appointment of the joint capsule is protection. From the inside, the area is filled with synovial fluid, so that the joint can move without damaging cartilage tissue.

Synovial fluid not only protects the cartilage, but also serves as a nutrient medium.

The liquid also serves as an obstacle to the path of various inflammatory processes, not allowing them to penetrate into the joint cavity.

You can see the full structure of the knee joint on the video attached below.

Diseases in the knee area

Looking at the structure of the knee joint of a person and his illness, you can divide them into two groups:

• Arthritis, accompanied by various inflammatory processes;
• Arthrosis, when there is deformation of the joint tissues.

Diseases of the knee area occur for the following reasons:

1. injuries of varying severity with damage to ligaments;
2. inflammatory processes in the meniscus or its removal;
3. fractures of the knee joint;
4. hemorrhage in the region of the knees.

If you feel pain when you feel your knees, there is swelling - be sure to contact specialists for advice, diagnosis and treatment.

It is important, as soon as possible, to diagnose the disease of the knee joint, so as not to lead to surgery and a long, recovery period.

One of the obvious signs of the disease of the knee joint is the limitation of walking, the feeling of stiffness of the knee area. This happens when the articular cavity begins to accumulate a large amount of synovial fluid. Manifestations of the disease are as follows:

• increases the volume of the knee;
• there is swelling;
• difficult to bend, unbend knee;
• at any, even insignificant load on the limb, there is a lot of pain.

Only a doctor can carry out diagnostic measures. Do not try to get rid of the accumulated fluid of the joint yourself. The main thing is not to let the synovial fluid get to the joint cavity.

The anatomy of the ligaments of the knee is such that, when injured, they can tear. When ruptured ligament appears tumescence in the popliteal (pit), instability and pain in the limb.

In addition to visual signs, the break signals a crunch, a sharp pain.

The first thing to do in this situation is to stop the movement (there is a loss of stability), ask for help.

You can not move on your own, because with a trauma to the ligaments, a heavy load on the limb will even have its own weight.

After various knee injuries, bursitis can develop - an inflammatory process of sacs filled with fluid.

The liquid is designed to improve the slip between the tendons and ligaments. Bursitis manifests itself with constant pain, swelling, swelling, swelling of the knee joint.

In rare cases, bursitis leads to a febrile state.

Getting acquainted with the anatomy of the knee joint of a person it is clear that the patella is one of the most vulnerable areas.

When a trauma occurs, severe pain, and then swelling of the knee.

After recovery, you should know that the displacement of the kneecap can be repeated more than once.

With each subsequent injury, the pain becomes stronger.

It is important during the recovery period to perform medical appointments and preventive measures to avoid re-injury.

Diseases of knee joints affect not only adults, but also children.

Adolescents engaged in professional sports often injure knee joints during training associated with heavy loads.

As a result, Schlätter's disease is manifested - an inflammation of the tuberosity of the tibia. Symptoms of the disease:

• pain under the knee cap;
• formation of a tumor in the region of the tibia;
• unceasing painful sensations even in a calm position.

The feeling of discomfort in Schlätter's disease, in some situations, passes only when the adolescent is growing up.

In addition to diseases of the knee area, resulting from injuries, there are chronic diseases:

• arthritis. It has many varieties, one of which is rheumatic arthritis, accompanied by constant stiffness during movement;
• osteoporosis(wear of cartilage tissue);
• gout(swelling of the knee region);
• chondromalaciaPatella when the pain affects the front of the knee.

To the listed diseases results the big weight, constant or old traumas, the big loadings, age changes, professional sports, insufficient elasticity and flexibility of muscles.

Diagnostic measures

Various methods are used to diagnose the disease in the knee area. The anatomy of the knee joint on the MRI is clearly visible. The method allows you to see the exact images of the joint tissues.

The use of MRI makes it possible to follow all changes in the physiological plan that take place in the joints, to see the deformation that has occurred in the tissues.

To determine the changes in the anatomy of the knee, ultrasound is used as often. Diagnostic procedure is prescribed in situations:

• presence of neoplasms on the joint bones (to determine their nature);
• inflammatory processes;
• ruptures of ligaments;
• if the meniscus or knee cap is damaged.

The knee area in the diagnosis is scanned in different projections, which makes it possible to examine the lesions of the joint.

The procedure does not require any preliminary preparation, painless and takes a little time (about 20 minutes).

Based on the results of a knee joint examination with the help of ultrasound, a doctor diagnoses the disease.

A source: http://sustavec.ru/bolezni/anatomiya-kolennogo-sustava-i-svyazok-stroenie-na-foto/

Knee joint: anatomy and structure

I like the class

Knee joint - the largest and most complex in its structure in the human body, its anatomy is extremely complicated, because it should not only to withstand the weight of the body of the owner, but also allow him to perform a variety of movements: from dance pas to lotus pose in yoga.

It consists of the following formations:

1. bones - femur, tibia and patella,
2. muscles,
3. nerve endings and blood vessels,
4. menisci,
5. cruciate ligaments.

Functions

The knee joint is close in structure to the articular joints. This allows not only to bend and unbend shin, but also to perform pronation (rotation inward) and supination (movement outwards), turning the bones shanks.

Also, when bending the ligaments relax, and this makes it possible not only to turn the shin, but also to make rotational and circular motions.

Bone components

The knee joint consists of the femur and tibia, these tubular bones are connected together system of ligaments and muscles, in addition, in the upper part of the knee is a round bone - a patella or knee cup.

The femur ends with two spherical formations - the femoral condyles and together with the flat surface of the tibia form a junction - the tibial plateau.

bone components of the knee

Connecting components

The main ligaments, together with the bones that make up the knee joint device, are cruciform. In addition to these, lateral collateral ligaments, medial and lateral, are located on each side.

Inside are the most powerful connective tissue formations - cruciform ligaments. The anterior cruciate ligament connects the femur and the anterior surface of the tibia.

It prevents the tibial bone from moving forward when moving.

The same is done by the posterior cruciate ligament, not giving the tibia, to move posteriorly from the hips.

Bundles provide the connection of bones during movement and help to keep it, the rupture of ligaments leads to the inability to perform arbitrary movements and rely on the damaged leg.

ligaments of the knee

In addition to ligaments, there are also two connective tissue formations in the knee joint that separate the cartilaginous surfaces femoral and tibia - menisci, which are very important for its normal functioning.

Their importance for the normal functioning of the joint is easy to understand, considering the structure of the human knee - the photo provides an opportunity see the meniscus located between the spherical epiphysis of the femur (lower part) and the flat surface of the tibia bones.

photo of a meniscus

Muscles of the knee

Muscles located around the joint and providing its work can be divided into three main groups:

• anterior muscle group - hip flexors - quadriceps and sartorius muscles,
• posterior group - extensors - biceps, semimembranous and semitendinous muscles,
• medial (internal) group - the hip-producing muscles are a thin and large adductor muscle.

muscles of knee joint

• One of the most powerful muscles in the human body is the quadriceps.It is divided into 4 independent muscles, located on the front surface of the femur and attached to the knee. There, the tendon of the muscle becomes a ligament and connects with the tuberosity of the tibia. The intermediate muscle, one of the branches of the quadriceps muscle, furthermore joins the knee capsule and forms the knee muscle. The contraction of this muscle helps to unbend the shin and flex the hip.
• Tailor muscle is also part of the muscles of the knee joint. It starts from the anterior iliac axis, crosses the surface of the femur and on the inner surface it goes to the knee. There she bends it from the inside and attaches to the tuberosity of the tibia. This muscle is two-parted and due to this it participates in the bending of both the thigh and the shin, and also in the movement of the shins inside and out.
• Thin muscle - starts from the pubic articulation, descends down and attaches to the knee joint. It helps to bring the hip and bend the lower leg.

In addition to these muscles, the tendons of the biceps femoris, the chrysalis, the half-membranous and popliteal muscles pass through the knee joint. They provide the leading and outgoing movements of the shin. The popliteal muscle is located directly behind the knee and helps with flexion and rotation inwards.

Innervation and blood supply of the knee

The knee joint is innervated by the branches of the sciatic nerve, which is divided into several parts and innervates the shin, foot and knee.

The knee is directly innervated by the popliteal nerve, it is located behind it, and is divided into the tibial and peroneal branches.

The tibial nerve is located on the posterior surface of the tibia, and the peroneal nerve is located in the front. They provide sensory and motor innervation of the shin.

Blood supply to the knee joint is performed with the help of popliteal arteries and veins, whose course repeats the course of nerve endings.

knee blood supply

What is the risk of injury?

Depending on which of the components of the knee is damaged, the classification of injuries, diseases and pathologies also occurs.It can be:

• dislocations,
• fractures of bones surrounding the joint,
• inflammatory and dystrophic diseases,
• damage to tissues located inside and near the joint, that is, cartilage, capsules, ligaments, and also adipose tissue.

A source: http://sustavu.ru/sustavy/kolennyj/anatomiya-kolennogo-sustava.html

Anatomical structure of muscles and ligaments of the knee joint of a man (video lesson)

Knee joint (Articulatio genus, Articulatio genus)Is a complex bone-cartilaginous formation, consisting of many different elements, due to which the joint becomes mobile, functional and, at the same time, susceptible to multiple injuries. Let's see, what is the structure of the knee joint.

As the anatomical atlas shows with a photo, the knee joint is shaped like a ball-shaped ball in shape. In its unfolded state it works as a block-shaped one.

The knee joint is formed by three bones: the distal (lower) epiphysis of the femur, the proximal (upper) epiphysis of the tibia and the patella (ca.

epiphysis - rounded end portion of the tubular bone forming the joint).

The joint surface of condyles (protrusions on the bone epiphysis) of the femur has an ellipsoidal shape, with the medial condyle larger than the lateral one.

This discrepancy is equalized by the medial and lateral meniscus, which is located between the condyles of the femoral and tibia.

Meniscus of the knee joint and articular capsule

Meniscus is a trihedral cartilaginous plate, different in shape and size. They are arranged in such a way that the lateral (outer) edge is thickened and fused with the joint capsule, which is shown in the figure.

The medial (internal) free edge is pointed and inverted into the joint cavity. Meniscus attached to the front and back to the intercondylar elevation of the tibia.

The transverse ligament of the knee joint connects the front edges of both menisci.

Great importance in the knee joint has an articular capsule. Most often, it is the cause of pain in the knee, limiting the movement of a person (approx.

the joint itself can not be sick in principle, since there are no nerve endings there). As the picture shows us, the joint capsule is attached to the edge of the femur under the epicondyle, to the edge of the tibia and the patella.

To the patella it is attached in such a way that its anterior surface is outside the joint cavity.

Structure of the joint capsule: inside it there is a synovial membrane, which is lined on the surface of the jointed bones to the line of articular cartilage.

The articular capsule of the knee joint forms a series of synovial bags that lie along the muscles and tendons, and they do not communicate with the joint cavity itself. The largest bag is the nadnadkolennikovaya bag, and it is located between the tendon of the quadriceps muscle and femur.

Knee joint ligaments

The knee joint is supported by ligaments, which are usually divided into two groups:

• extra-capsular (ligaments located outside the joint cavity);
• intracapsular (ligaments inside the joint).

External links include:

• The tibial collateral ligament, which starts from the medial condyle of the femur and is guided down, fused with the joint capsule and the medial meniscus, reaching the proximal epiphysis of the tibia bones;
• The fibrocar collateral ligament, somewhat narrower than the previous one, comes from the lateral epicondyle of the thigh and is attached to the lateral surface of the head of the fibula.
• Bundle of patella. In fact, the patellar ligament is a continuation of the tendon of the quadriceps femoris muscle. The tendon of this muscle approaches the patella, covers it from all sides, and continues downward, reaching the tibia. Some of the beams of this tendon, which reaches the tuberosity of the tibia, is called the patella ligament.
• Lateral and medial supporting ligament. This is also a continuation of the tendon of the quadriceps muscle, but these bundles are guided from the patella to the outer and inner condyles of the tibia.
• Supporting patellar ligaments. Attached to the epicondyle of the femur. Based on the name, these ligaments perform an important role, keeping the patella in the right position.
• Slanting and arched popliteal ligament. The oblique ligament strengthens the posterior parts of the joint capsule and is part of the bundles of the tendon of the semimembranous muscle. The ligament originates from the medial condyle of the tibia to the lateral condyle of the femur. The arch starts from the external condyle of the hip and the head of the fibula, is attached to the oblique popliteal ligament and extends further to the lateral condyle of the tibia.

Internal links include:

• Cross-shaped ligaments. Here it is worthwhile to distinguish anterior cruciate and posterior cruciate ligament. The anterior cruciate ligament of the knee joint originates from the inner surface of the outer condyle of the thigh, directed forward and medially attached to the anterior intercondylar tibial field bones. On the contrary, the posterior cruciate ligament originates on the inner surface of the inner the condyle of the hip, is directed back medially and is attached to the posterior intercondylar field tibia. Regular out-of-bound movements with the feet in the knees can lead to ruptures of the cruciate ligaments in them.
• There are three more ligaments related to menisci: the transverse ligament of the knee, the anterior and posterior meniscus ligaments.

Muscles of the knee joint

Muscles of the knee joint provide various movements in it, thanks to which a person has the ability to move.

With a fixed thigh, the knee muscles provide flexion, extension, supination and pronation (rotation) shin, and with a fixed shin provide supination, pronation, as well as forward and backward movement hips.

Flexion is provided by the following muscle group:

• biceps femoris;
• semitendinous and semimembranous hamstrings;
• sartorius and thin muscle;
• popliteal muscle;
• calf muscle;
• plantar muscle.

Extension is provided by the following muscle group;

• straight muscle of the thigh;
• lateral and medial broad thigh muscle;
• intermediate wide thigh muscle.

Pronation of the knee joint is provided by the following muscles:

• semitendinous and semimembranous;
• tailoring and thin;
• medial gastrocnemius;
• popliteal.

Supination of the knee joint is provided by the biceps femoris and the lateral head of the calf.

Here we are in general terms and got acquainted with what anatomy of the knee joint and what he is like. And the scheme of his work and its detailed description are offered in the following video story.

A source: http://www.ladygym.ru/kolennyj-sustav-anatomicheskoe-stroenie-svyazki-i-myshcy/

The structure and anatomy of the knee

The knee joint is a large and uneasy structure in its structure, which is part of the human musculoskeletal system.

It is formed by bones, muscle and nerve fibers, menisci, ligamentous apparatus, vascular network.

Anatomy of the knee joint has its own characteristics in comparison with other large joints.

Bones

The scheme of formation of the knee joint is such that it involves two long tubular bones - the femoral (distal part) and tibial (proximal). Above it covers the bone formation, which has a rounded shape. This is the patella (patella), or patella.

Femur

On the convex surface of the femur in the joint area there are two protuberances, they are in the form of small balls and bear the name of condyles.

The inner condyle, or medial, is slightly larger than the outer, or lateral. Their front part serves as a connection between the patella and the femur.

The back and bottom are connected to the corresponding tibia by involving the cartilaginous formation - the semilunar meniscus.

Tibia

The tibia also includes two condyles, through which it is connected by the proximal part to the femur to form a tibio-femoral joint. There is a certain elevation between the condyles.

Small tibia

This bone has no direct abutment to the knee, but its role is to strengthen the muscular extensor fibers, which ensure the movement of the knee joint.

This bone itself is much smaller than the tibia, and is attached to it by means of a ligamentous apparatus. Its distal part is involved in shaping the ankle.

Knee cap

This spongy bone formation, which has a one-sided bulge, turned outward from the knee joint. The device is such that the shape resembles a triangle, in which the corners of the base are slightly smoothed, and the upper part is somewhat sharpened.

The main task of the patella is to protect the joint from damage and increase the angle of deflection during movement.

This formation has a front and back parts, as well as three boundaries.

The anatomy of this structural formation is such that on its front surface there are holes for the passage of vessels through them.

Muscles

All muscles that are located near the knee joint are divided into flexion and extensor.

The muscles that bend the hip include a powerful quadriceps muscle and tailor's. They pass along the front surface.

On the back of the muscle extensors - two-headed, semitendinous and semimembranous.

The straight muscle originates from the ilium, runs along the front surface down the thigh, and at the bottom it joins the rest. This is a very strong pelvic flexor in relation to the thigh.

Broad muscles start from the anterior and lateral surfaces of the hip bone. All the heads of the quadriceps muscle are attached to the calyx. The intermediate muscle joins the capsule of the knee joint.

Saddlery

The anatomy of this muscle has its own characteristics. This is one of the longest formations of muscle fibers in the human body.

It originates from the anterior part of the ilium, bends around the front of the hip joint, goes down the front, and then on the back of the thigh, bypassing the knee joint from the inside.

The sartorius muscle flexes the thigh and the lower leg. At the same time, she finishes her thigh, and shins her leg.

Thin muscle

It originates from the lower part of the pubic bone, goes down, and is attached to the tuberosity of the tibia. She bends the knee from behind, is responsible for bringing the hip, and bending the knee joint.

Large adductor muscle

One of the most powerful leading muscles. It extends from the anterior part of the ischium and its tubercle, and the second part is attached to the rough line of the femur and its internal epicondyle.

Its functional duties include the reduction and extension of the thigh or pelvis to the femur.

Biceps

Passes on the back of the knee joint of a man. She unbends the thigh, flexes the shin, and helps in her supination. The biceps can be palpated in a hole under the knee.

The semitendinous muscle passes along the posterior surface of the thigh. It begins in the region of the ischial hillock, in the region of the knee joint is located behind and from the inside, ends in the region of tuberosity of the tibia. This muscle extends the thigh, bends the shin and penetrates it.

Semi-membranous with its fibers originates from the buttock of the ischium, and ends at the inner condyle area. Partially this muscle joins the popliteal ligament and muscle, more precisely to its fascia. Flexion of the knee and extension of the thigh passes with her participation.

Triceps

It goes along the back of the shin, and forms its gastrocnemius with two of its surface parts, the third part is located more deeply. It is a soleus muscle. All parts pass into the Achilles tendon, and end on the calcaneus.

The function of the calf muscles is the flexion of the knee and ankle joint of a man.

The inner and outer head of the triceps muscle form a rhomboid popliteal cavity in its upper parts. And on top and on the outside it forms the biceps femoris muscle.

The bottom forms the capsule of the knee joint. Through this fossa there is a neurovascular bundle, innervating and nourishing the shin and foot.

Popliteal muscle

This is a small formation of muscle fibers, which lies directly to the knee joint. It promotes the bending and pronation of the human shin, while pulling back the capsule entering the knee joint.

Bundles

The scheme of structural features of the knee joint and its ligamentous apparatus has some differences from other articular formations.

For a strong connection of bones in the joint, there are ligaments that have a connective tissue structure.

On each side is a ligamentous apparatus that helps to strengthen and stabilize the knee joint, and somewhat restricts its movement in this direction.

Inside the knee, there are cruciate ligaments. They perform the function of limiting movement in the front to back direction.

The anterior cruciate ligament does not allow the tibia to slip forward with respect to the thigh.

Rear - prevents excess movement of the same bone formations posteriorly. Thanks to this, the joint remains stable.

Menisci

Menisci perform an amortization function, distribute the body weight to the entire knee joint, increase knee stability, carry out static and dynamic load distribution.

The anatomy of the meniscus in the knee has certain characteristics.

They have the appearance of gaskets with elastic properties, and occupy up to 2/3 of the entire surface forming the knee joint between the condyles of the femur and the tibial plateau.

Violation of the structure of the meniscus leads to pronounced destabilization with the development of destructive and degenerative changes to which the knee joint is exposed.

Joint Capsule

A sheath that is formed from connective tissue fibers, or an articular bag, is of great importance. It hermetically covers the knee joint and protects it from various damages, mechanical stress and possible rupture.

Its internal surface has a synovial membrane, while the outer surface has a fibrous membrane, and this guarantees high strength to this formation. The cells of the inner shell produce a special fluid (synovial), serving as a lubricant.

Thanks to the synovial bag, the knee joint has a sealed cavity inside which the structures are reliably protected from erasure and wear.

Innervation

The largest nerve passes through the posterior surface of the popliteal fossa, which refers to this joint. It is a branch of the sciatic nerve, provides innervation of the lower leg and foot, subdivided into the nerves of the large and small tibia.

The knee joint under the patella has a multiple small branching of nerve fibers, which is called the infra-patellar bundle.

Vessels

The largest vascular bundle passes along the back of the knee. It is formed by the popliteal vein and artery. They feed and supply the knee joint with oxygen, its tissues and structures located from the knee and below.

The outline of the branching of the artery passing under the knee is as follows: it is divided into the upper arteries - internal, lateral and median. The latter feeds the synovial bag. There are also two lower branches of this artery - the outer and the medial.

Movement of the joint

The knee joint has a high degree of mobility, which determines its structure.

If you measure it in numbers, then active bending in it will be up to 130 degrees, passive - an additional 30 degrees. The maximum extension is up to 12 degrees.

It turns out that the total mobility is up to 170 degrees.

When bending the knee, the collateral ligament apparatus relaxes, and this allows free rotation and circular motion.

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A source: http://Sustaolena.ru/anatomy/stroenie.html