At what age do kneecaps appear in children? Anatomical structure and damage to the knee joint Structure of the knee joints in a 7-year-old child

There are many myths associated with the difference between the body structure of a child and an adult. One of them is the opinion that children do not have kneecaps until a certain age. But this information is erroneous, and even an unborn baby already has patellas, but in structure until about 6 years of age they differ from adults, so during an X-ray examination they are not visible in the image.

The formation of kneecaps in children occurs by the age of six years.

Newborn knee joints

A newly born baby has cups, but in infancy they are made of thin cartilage rather than bone. Therefore, in the first months of a baby’s life, it is quite difficult to see them on an x-ray, which gives rise to false information about the structure of the musculoskeletal system in newborns. To avoid damage to the cups, it is not recommended to massage the knees of an infant, because they are fragile and can be damaged.

When do kneecaps appear and what are they like in children?

The patella is the largest sesamoid bone in the human body, surrounded by the tendons of the quadriceps muscle, located above the joint cavity of the knee. The patella can be easily felt under the skin; it moves effortlessly in different directions when the leg relaxes. The main function of the kneecap is considered to protect against strong lateral displacements of the femur and tibia, which make up the knee joint.

The development of kneecaps in children can be negatively affected by an unhealthy pregnancy, illness, or injury to the baby.

The calyces are formed during the development of the child in utero, approximately in the first trimester at the 4th month of pregnancy. During this period, cartilage is formed, which still replaces bone tissue. At this stage of development, babies' knee joints are soft and fragile. During pregnancy, problems with joint formation may occur. But such a violation is rare. There are a number of negative factors, both external and internal, that can adversely affect the health of infants.

Common causes of violations:

• abuse or misuse of medications;
• infectious diseases of the mother during pregnancy;
• influence of radiation and unfavorable environment;
• metabolic disorders.

Exposure to any of these factors in the first 3 months of pregnancy can lead to the fact that the cups may not form at all. If maternal health problems are detected at such a crucial time, this will give rise to various knee joint defects in the child in the future.

09
Jul
2014

In the human body, the knee joint is the largest joint. The structure of the knee joint is so complex and at the same time strong that traumatic dislocations of the lower leg occur extremely rarely. If we compare other dislocations, then damage to the knee joint accounts for only 2-3% of all cases. Such low rates are explained by the anatomical and physiological characteristics of the knee joint.

In the medical literature, the knee joint is classified as biaxial, condylar, complex and compound.

Bones of the knee joint

The knee joint is a combination of the surface of the tibia, the femoral condyle, and the patella.

The entire surface of the articular bone is covered with hyaline cartilage, which performs a protective function. Thanks to it, the friction of the articular surfaces that articulate with each other is reduced. As for the thickness of hyaline cartilage on the condyles of bones, it is characterized by its heterogeneity. In men, this indicator is 4 on the lateral condyle and 4.5 on the medial. The thickness of hyaline cartilage in women is different and has slightly lower values. As for the tibia, it is also covered with cartilage.

Knee joint ligaments

Ligaments perform a strengthening function. The femur and tibia are firmly attached by cruciate ligaments. The anterior and posterior ligaments of the knee joint are located inside the articular capsule, that is, they are intra-articular.

Intra-articular ligaments consist of the following ligaments:

• oblique arcuate;
• fibular and tibial collateral;
• lateral and medial patellar ligaments.

Cartilaginous layers

The fact that the knee joint has a complex structure, as it includes many component parts, has already been mentioned above. The upper part of the tibia is connected to a layer of cartilage called the meniscus.

The knee joint has two such menisci. They are internal and external, and are respectively called medial and lateral. Their main function is to distribute the load on the surface of the tibia. Due to their elasticity, the menisci help absorb movement.

The menisci, just like the ligaments, perform the function of stabilizing the articular surface, limiting mobility, and monitoring the position of the knee, the latter being performed thanks to certain receptors.

The cartilaginous layers are attached to the joint capsule using tibial ligaments. The medial menisci, in turn, are additionally attached to the internal collateral ligament.

Warnings! It must be remembered that the medial menisci, due to their lack of mobility, are often damaged and torn.

In young children, the cartilage layers of the knee joint are filled with blood vessels. With age, they remain only in the outer part of the cartilage, while a slight inward movement remains. Almost the entire part of the meniscus is “nourished” by synovial fluid, and the rest by the bloodstream.

Bursa

The structure of the knee joint also consists of an articular cavity, which is hermetically surrounded by an articular capsule attached to the bones. The outside of the bag is tightly covered with fibrous tissue, which allows it to protect the knee from external damage. The reduced pressure inside the bursa helps maintain the bone in a closed position.

Muscles of the knee joint

To properly restore the knee joint, you need to know its structure. The knee joint is made up of the following muscles::

• Tailoring. It is this muscle that allows the lower leg and thigh to flex, as well as externally rotate the thigh.
• Four-headed. From the very name it becomes clear that this muscle has four heads - the rectus femoris, vastus medialis, vastus lateralis and vastus intermedius. It is one of the largest muscles in the human body. Extension of the lower leg, that is, straightening of the leg, is performed due to the contraction of all four heads. Flexion of the knee occurs when the rectus muscle contracts.
• Thin. Thanks to it, the leg rotates inward during ankle flexion.
• Double-headed. Allows you to straighten your hip and also bend your leg at the knee. The outward rotation of the tibia is facilitated by the bent position of this muscle.
• Semitendinosus. Takes part in hip extension and shin flexion. It also plays an important role in the process of torso extension.
• Semi-membranous. Performs the function of flexing the ankle and rotating it inward. It is indispensable when pulling back the knee joint capsule as it bends.
• Calf. Takes part in the process of bending the knee and ankle joint of the foot.
• Plantar. Its functions resemble those of the gastrocnemius muscle.

The mobility of the knee joint is very high. If these indicators are measured, they will be as follows:

• 130° — flexion in the active phase;
• 160° — flexion in the passive phase;
• 10-12° - maximum extension.

In children and adolescents, the bones, cartilage, ligaments and muscles of the knee joint are actively developing. The mechanics of movements in the knee joint of a child are the same as in adults, and the main functional difference is the presence of growth cartilages in the bones. The distal germ cartilage of the femur is shaped like two inverted parachutes, spanning both condyles and connecting at the center of the bone. The junction of the lateral and medial parts of the cartilage falls on the most concave part of the intercondylar fossa, and in the anteroposterior direction it penetrates the entire thickness of the distal femur. The thickness of the growth cartilage is 2-3 mm. At the medial edge of the lateral condyle, next to the cartilage, the anterior cruciate ligament is attached.

The growth cartilage of the tibia resembles a completely flat disc: its center is located at the same level as the edges. In children, the anterior part of the cartilage merges with the growth cartilage, which lies in the area of ​​the tibial tuberosity. As the skeleton forms, the apophysis in the area of ​​the tuberosity separates, as a result of which the germinal cartilage takes the described shape.

The structure of the ligamentous apparatus, menisci, articular surfaces of the condyles of the femur and tibia, and patella is the same as in adults. In children and adolescents, the anterior cruciate ligament is attached entirely within the articular part of the epiphyses, on the tibia - to the upper epiphysis and its growth cartilage.

History and physical examination

When collecting an anamnesis, it is necessary to clarify the circumstances of the injury, the direction and strength of the traumatic impact, the position of the leg at the time of injury, and factors that increase discomfort. The non-contact nature of the injury most often indicates, especially if the patient notes a click that is heard or felt at the time of injury. The click can also accompany . A click with a contact injury is more likely to indicate a collateral ligament or fracture. When the anterior cruciate ligament or meniscus ruptures, as well as swelling rapidly increases. Blockage of the joint or difficulty moving in it, as a rule, indicates a meniscus tear. For rupture of ligaments, including the anterior cruciate, and dislocation of the patella, a feeling of “failure” in the joint is more typical; for pathology of the femoral-patellar joint or articular mouse, a feeling of friction of the articular surfaces (crepitus) is more typical.

During the examination, attention is paid to the color of the skin, the presence of external injuries, the severity and localization of edema, the position of the knee (flexion contracture), swelling along the joint space, effusion into the joint cavity, the condition of the tibial tuberosity, atrophy of the quadriceps femoris muscle, the position of the patella (high, low), the symptom of “camel hump” (a protruding mound of fatty tissue due to subluxation of the patella), as well as the shape of the leg as a whole. During palpation, it is important to note an increase in skin temperature, crepitus, especially in the femoral-patellar joint, the point of greatest pain and features of hemarthrosis. A functional examination includes determining the range of motion, the correct position of the joint parts during movements, as well as assessing the strength of the quadriceps and posterior thigh muscles. Movements should not be limited or accompanied by a feeling of obstruction. Assess the trajectory of the kneecap; angle Q should not exceed 10°. The J test is considered positive when, with the knee fully extended, the patella is dislocated laterally (the trajectory of its movement during leg extension resembles the letter J). A positive test for premonition of dislocation indicates instability of the patella or a previous dislocation. When the doctor stabilizes the patella relative to the articular surface of the femur, on the contrary, neither pain nor signs of concern arise - this is considered a positive test for the reduction of the patella. Patellar dislocation is usually accompanied by pain in the medial femorotibial joint and medial suspensory ligament, as well as crepitus. Other causes of knee pain include a displaced meniscal tear. Pinching of the peripatellar synovial fold is characterized by dry clicks, most often at the internal condyle. The fold can be felt above the internal condyle in the form of a dense cord; when inflamed, palpation can be painful. However, in most cases, pinching of the peripatellar synovial fold is not accompanied by pain.

Radiation diagnostics

The X-ray examination includes four images: in direct, lateral, axial (for the patella) and tunnel projections. With their help, one can detect pathognomonic symptoms that facilitate the diagnosis of certain diseases (fractures, patellar dislocations, tumors, osteochondromas). Additional methods are bone scintigraphy, CT and MRI.

Special methods

To diagnose cartilage injuries, palpation of the patella and femoral condyles and the Wilson test are performed. The latter is performed to exclude dissecting osteochondrosis of the medial part of the lateral condyle. The shin is turned inward, then the leg is bent and extended at the knee joint. At the moment of rotation, the intermuscular eminence of the tibia comes into contact with the zone of cartilage separation and causes pain, which is relieved when the tibia is turned outward. Pain when extending the leg to 30° allows us to speak with great confidence about osteochondrosis dissecans. When palpating the condyles of the femur, a cartilage defect can be detected, since most of the condyles are not covered by the patella. With careful palpation, the area of ​​the defect or osteochondral fracture can be very accurately indicated. Pain on palpation can also be a sign of bruise of cartilage or bone. Pain in the anterior part of the joint with its active hyperextension and pressure on the patella indicates deforming osteoarthritis of the femoral-patellar joint, and pain at the apex of the patella is characteristic of. Pain in the area of ​​the patellar ligament occurs with its tendinitis (jumper's knee), pain and an increase in the tibial tuberosity - with.

McMurry and Epley tests are usually used to diagnose meniscal injuries. The McMurry test consists of the following: the leg is completely bent at the knee joint, and then extended, turning the shin outward or inward. The Epley test is performed in the prone position, with the knee bent at an angle of 90° and the tibia pressed against the femur, then the tibia is rotated outward and inward. Pain during both tests and during palpation in the projection of the joint space indicates damage to the meniscus.

The condition of the collateral ligaments is checked using abduction and adduction tests when the child bends the leg 30° at the knee joint (displacement of the tibia to the sides). If it is possible to displace the tibia, a rupture of one of the collateral ligaments or a Salter-Harris fracture is likely. The same test that is positive with the leg fully extended can also be a sign of a torn cruciate ligament or Salter-Harris fracture.

Stability of the knee joint in the sagittal plane is determined by the symptoms of the anterior and posterior drawer and the Lachman test. The anterior drawer symptom and the Lachman test are scored from 0 to 3, also taking into account how the movement ends - a sudden stop or a smooth “braking”. The accuracy of the study can be increased by comparing the result with the study of the other leg. A lateral change of the fulcrum is also tested: starting position - the patient’s leg is bent at the knee joint, the foot is turned inward; when the leg is extended, an anterior subluxation of the tibia occurs, which, when flexed, spontaneously reduces with a noticeable dull sound.

In patients with Down syndrome, Marfan syndrome, Morquio syndrome, osteogenesis imperfecta type I and pseudochondrodysplasia, instability of the knee joint in the sagittal and horizontal planes and weakness of the posteroexternal ligamentous apparatus of the knee joint are possible. Many disorders in patients with hereditary syndromes may be only part of the syndrome, and not an independent orthopedic disease. For example, pain in the anterior knee joint is very characteristic of congenital luxation of the patella and osteoonychodysplasia (a syndrome involving hypoplastic and split nails, hypoplastic or absent patella, underdevelopment of the lateral femoral condyle and head of the fibula, bone spurs on the ilium, flexion contracture of the elbow joints with a decrease in the heads of the humerus and radius). Patients with Marfan syndrome often have ligamentous weakness. Down syndrome is characterized by hyperextension of the knee joint and habitual dislocations of the patella and femur. Decreased joint mobility, skin retraction and striae are pathognomonic symptoms of arthrogryposis. Sometimes constant hyperextension of the knee joint is found in patients with spina bifida or congenital dislocation of the knee. X-shaped curvature of the legs is characteristic of Morquio syndrome (mucopolysaccharidosis type IV) and chondroectodermal dysplasia (Ellis-van Creveld syndrome. With rickets, the curvature of the legs is often O-shaped, although X-shaped is also possible.

The knee is one of the largest and most complex joints in the body. The knee connects the femur to the tibia. The smaller bone that runs next to the fibula and the kneecap are the other bones that form the knee joint.

Tendons connect the knee bones to the leg muscles, which move the knee joint. Ligaments connect to the knee bones and provide stability to the knee.

Two C-shaped pieces of cartilage, called the medial and lateral menisci, act as shock absorbers between the femur and tibia. Numerous bursae, or fluid-filled sacs, help the knee move smoothly.

The joint surfaces of each bone are covered with a thin layer of hyaline cartilage, which gives them an extremely smooth surface and protects the underlying bone from damage.

In this article you will learn: what is the structure of the knee joint, what injuries and pathologies can affect its performance and how to avoid them.

The structure of the knee joint - characteristics

The knee is the largest and most complex joint in the human body. It provides a connection for the hip or thigh, lower leg or lower leg. Composed of bones, muscles, tendons, ligaments, cartilage and synovial fluid, the knee has the ability to bend, straighten and rotate laterally.

The knee consists of four bones, namely the femur, tibia, patella and fibula. Ligaments connect different bones. Five major ligaments contribute to the stability of the knee structure, which are the medial ligament, posterior cruciate, anterior cruciate, lateral ligament and patellar ligament.

Since the knee is one of the most stressed joints in the body, you need to take good care of it to ensure it serves you well as you age. You can do this by exercising regularly and living a healthy lifestyle.

The knee joint is the largest, most complex and vulnerable in the human musculoskeletal system. Three bones take part in its formation: the distal end of the femur, the proximal end of the tibia and the patella.

It consists of two joints - the femoral-tibial and the femoral-patellar, among which the first is the main one. This is a typical complex joint of the condylar type.

The external landmarks of the knee joint are presented in the figures, the anatomy of the knee joint is presented in the figures. Movements in it are carried out in three planes.

The main plane is sagittal, having an amplitude of flexion-extension movements within 140-145 degrees. Physiological movements in frontal (adduction-abduction) and horizontal (internal external rotation) are possible only in the flexion position.

The first are possible within 5, the second - 15-20 degrees from the neutral position. There are two more types of movement - sliding and rolling of the condyles of the tibia relative to the femur in the anteroposterior direction.

The biomechanics of the joint as a whole is complex and consists of simultaneous mutual movement in several planes. Thus, extension within 90-180 degrees is accompanied by external rotation and anterior displacement of the tibia.

The articulating condyles of the femur and tibia are incongruent, which allows for significant freedom of movement in the joint. In this case, a large stabilizing role belongs to soft tissue structures, which include menisci, capsular-ligamentous apparatus and muscle-tendon complexes.

Menisci

Menisci, which are connective tissue cartilages, play the role of spacers between the articular surfaces of the femur and tibia covered with hyaline cartilage.

To some extent, they compensate for this incongruity by participating in shock absorption and redistribution of the supporting load on the articular surfaces of the bones, stabilizing the joint and facilitating the movement of synovial fluid.

Along the periphery, the menisci are connected to the joint capsule by the menisco-femoral and menisco-tibial (coronary) ligaments. The latter are stronger and more rigid, due to which movements in the joint occur between the articular surfaces of the femoral condyles and the upper surface of the menisci.

The menisci move along with the tibial condyles. They also have a close connection with each other, with the collateral and cruciate ligaments, which allows a number of authors to classify them as its capsular ligamentous apparatus.

The free edge of the meniscus faces the center of the joint and does not contain blood vessels; in general, in an adult, only the peripheral parts contain blood vessels, constituting no more than 1/4 of the width of the meniscus.

The cruciate ligaments are a unique feature of the knee joint. Located inside the joint, they are separated from the cavity of the latter by the synovial membrane.

The thickness of the ligament is on average 10 mm, and the length is about 35 mm. It begins with a wide base in the posterior sections of the inner surface of the external condyle of the femur, moving in a downward, inward and forward direction, and is also attached widely anterior to the intercondylar eminence of the tibia. Ligaments consist of many fibers united into two main bundles.

This division is more theoretical in nature, and is intended to explain the functioning of the ligaments in different positions of the joint. It is believed that during full extension, the main load in the anterior cruciate ligament (ACL) is experienced by the posterolateral ligament, and during flexion, the anteromedial ligament experiences the main load.

As a result, the ligament retains its working tension in any position of the joint. The main function of the ACL is to prevent anterior subluxation of the lateral condyle of the tibia in the most vulnerable position of the joint.

The posterior cruciate ligament (PCL) is approximately 15 mm thick and 30 mm long. It begins in the anterior sections of the inner surface of the inner condyle of the femur and, following posteriorly downwards and outwards, is attached in the region of the posterior intercondylar fossa of the tibia, weaving some of the fibers into the posterior sections of the joint capsule.

The main function of the PCL is to prevent posterior dislocation and hyperextension of the tibia. The ligament also consists of two bundles, the main anterolateral and less significant posteromedial. To a certain extent, the PCL duplicates the two meniscofemoral ligaments. The Humphry bundle is in front, and the Wrisberg bundle is behind.

The medial collateral ligament (MCL) is the main stabilizer of the joint along its inner surface, preventing valgus deviation of the tibia and anterior subluxation of its medial condyle. The ligament consists of two portions: superficial and deep. The first, which plays a mainly stabilizing function, contains long fibers that spread fan-shaped from the internal epicondyle of the femur to the medial metaepiphyseal parts of the tibia.

The second consists of short fibers associated with the medial meniscus and forming the meniscofemoral and meniscotibial ligaments. Posterior to the ISS is the posteromedial portion of the capsule, which plays a significant role in stabilizing the joint.

It consists of long fibers oriented in the postero-caudal direction, which is why it is called the posterior oblique ligament; its function is similar to the MCL.

Isolating it into an independent structure is of practical importance in terms of ensuring the stability of the medial and posteromedial sections of the capsular ligament apparatus (CLA), also called the posteromedial angle of the knee joint.

The lateral and posterolateral sections of the CSA are a conglomerate of ligamentous-tendon structures called the posterolateral ligamentous-tendon complex.

It consists of the posterolateral structures, the lateral collateral ligament and the biceps femoris tendon. The posterolateral structures include the arcuate ligament complex, the hamstring, and the popliteus-peroneal ligament.

The function of the complex is to stabilize the posterolateral parts of the joint, prevent varus deviation of the tibia and posterior subluxation of the lateral condyle of the tibia. Functionally, the structures of the posterolateral angle are closely related to the PCL.

Bursa

The joint capsule, consisting of fibrous and synovial membranes, is attached along the edge of the articular cartilage and articular menisci. In front it is strengthened by three wide cords formed by tendon bundles of the quadriceps femoris muscle. The patella, covering the knee, seems to be woven into the middle cord. front.

On the sides, the bag is strengthened by the internal (medial) ligament of the tibia and the external (lateral) ligament of the fibula. These ligaments, when the limb is straightened, exclude lateral mobility and rotation of the lower leg. The back surface of the bag is strengthened by the tendons of the lower leg and thigh muscles intertwined with it.

The synovial membrane, covering the joint capsule from the inside, lines the articulated surfaces and cruciate ligaments; forms several pockets (volvulus and bursa K. s.) of which the largest is located behind the tendon of the quadriceps femoris muscle. Cavity K. s. communicates with the synovial bursae located at the attachment points of the muscles surrounding the joint.

Nerves

The structure of the knee means that the largest nerve there is the popliteal. It is located behind the joint. It is part of the greater sciatic nerve, which runs through the foot and leg. Its main task is to provide sensitivity and motor ability to all these areas of the leg.

Somewhat above the knee, the popliteal nerve is divided into 2:

1. The peroneal nerve first covers the head of the large fibula, and then passes to the lower leg (outside and side);
2. Tibial nerve. Located behind the lower leg.

If a knee injury occurs, it is often these nerves that are damaged.

Muscular system

The dynamic stabilizers of the knee joint include three groups of muscles located on its anterior and lateral surfaces. Being synergists of certain capsular-ligamentous structures, they acquire particular importance in case of temporary or permanent failure of the latter after injuries or reconstructive operations.

The quadriceps muscle is the most powerful and important, which is why it is figuratively called the “lock of the knee joint.” On the one hand, obvious muscle weakness and atrophy are an important objective symptom of joint disease, and on the other, restoration and stimulation of its function constitute one of the most important elements in the rehabilitation of patients with its pathology.

Particular attention is paid to strengthening this muscle in cases of posterior type of instability associated with damage to the PCL, of which it is a synergist. The posterior group of muscles, consisting of the semitendinosus, semimembranosus and gracilis, located medially, and the biceps muscle, passing laterally, is a synergist of the ACL, at the same time partially duplicating the collateral structures.

Biomechanics of the knee joint

The biomechanics of the knee joint is very complex and knowledge of anatomy is not enough to understand. The basis for diagnosing injuries is knowledge of the functional anatomy and interaction of the structures of the knee joint. For ease of understanding, the knee joint is conventionally divided into anterior, posterior, medial and lateral complexes, which have their own specific functions.

A complex course of movements in the knee joint is possible only with complete functional stability, which is the result of the combined action of the static and dynamic structures of the knee joint.

Static are the bone structures and articular ligaments, dynamic are the muscles and tendons of the knee joint. The static and dynamic structures of the anterior complex work together to hold the patella in its correct position.

The quadriceps femoris acts as a dynamic sagittal stabilizer. As an antagonist of the flexor muscles, it promotes extension against gravity. It interferes with the posterior drawer while actively supporting the cruciate ligament.

The static and dynamic structures of the medial complex work together to protect the knee joint from external rotational forces and valgus stress.

The posterior structures of the functional complex of the knee joint, consisting of the semitendinosus and semimembranous muscles, protect against the action of external rotational forces and the occurrence of the anterior drawer symptom.

The popliteus muscle protects against internal rotational forces and prevents the occurrence of posterior drawer symptoms, and together they prevent pinching of the menisci or parts of the posterior capsule during movement of the knee joint.

The lateral articular ligament is tightly fused with the meniscus, which strengthens the articular capsule in the middle third of the complex and, together with the biceps femoris muscle, protects against the action of internal rotational forces and the occurrence of varus deviation, prevents the occurrence of the anterior drawer symptom and at the same time actively supports the cruciate ligament.

The anterior and posterior cruciate ligaments occupy a special position in the knee joint and are the central main link.

The cruciate ligaments together provide sliding and rocking movements. They prevent inward rotation and provide lateral stability as well as ultimate rotation. The anterior cruciate ligament prevents the occurrence of the anterior drawer symptom, and the posterior cruciate ligament prevents the occurrence of the posterior drawer symptom.

All bony parts of the joint that come into contact during movement are covered with highly differentiated hyaline articular cartilage, consisting of chondrocytes, collagen fibers, the ground substance and the growth layer. The loads acting on the cartilage are balanced between the chondrocytes, collagen fibers and the growth layer.

The intrinsic elasticity of the fibers and their connection with the base substance allows them to withstand shearing forces and pressure loads.

The chondrocyte is the main metabolic center of articular cartilage, all of which are protected by a three-dimensional network of arcaded collagen fibers.

Proteoglycans secreted by chondrocytes and the water they attract form the main substance of cartilage. Since the chondrocyte has little ability to regenerate and loses it with age, the quality of the base layer deteriorates, as well as its ability to withstand stress.

Dying chondrocytes no longer produce the main substance and, moreover, cause damage to still healthy tissue structures secreted by lysosomal enzymes. This physiological aging process is significantly different from traumatic injury. Accelerating or braking forces can cause direct injury. The extent of cartilage damage depends on the amount of kinetic energy acting on it.

Another exogenous factor is indirect trauma. Sudden braking during outward rotation of the tibia and inward rotation of the thigh can cause, for example, incomplete dislocation of the patella. The consequence of this indirect injury may be cartilage tearing, shearing of the medial edge of the patella or the lateral edge of the femoral condyle.

The most important cause of exogenous cartilage damage is chronic instability resulting from damage to the articular ligament apparatus, which leads to impaired gliding movements and irreversible damage to the articular cartilage.

An endogenous factor for cartilage damage is hemarthrosis, as a result of which the joint capsule stretches and compresses the capillaries, which disrupts the nutrition of the cartilage and leads to the release of lysosomal enzymes causing chondrolysis.

The common point of application of the force of exogenous and endogenous factors is the articular cartilage, the amount of damage to which depends on the intensity and duration of the factors acting on it. Initially, as a result of increased compressive and shearing forces, as well as impaired metabolism, thin cracks appear on the surface of the cartilage.

With the formation of cracks in the deeper layers, the collagen fibers arranged in arcades are destroyed, further destruction of cartilage occurs, and the germination of blood vessels from the bone side occurs, which manifests itself in the form of metachromasia and, as a consequence, a decrease in the ability of chondrocytes to synthesize.

The process of destruction is not limited to the articular cartilage, it extends to the bone layer. Small necrosis occurs on the bone, necrotic material enters the articular space through pityriasis-like peeling and is pressed into the spongiosa, and so-called scree pseudocysts are formed.

Thus, the anatomical and functional structure of the knee joint, the histological structure of tissues and metabolic processes in tissues, physiological and damaging effects, all of this has complex mechanisms of interaction with each other, therefore it is necessary to study these processes for the correct approach to treatment.

Innervation and blood supply of the knee

The blood supply to the knee joint is carried out due to the extensive vascular network, rete articulare genus, formed mainly by the branches of four large arteries: femoral (a. Genus descendens), popliteal (two upper, one middle and two lower articular), deep femoral artery (perforating and others branches) and the anterior tibial artery (a. Recurrens tibialis anterior).

These branches widely anastomose with each other, forming a series of choroid plexuses. S. S. Ryabokon describes 13 networks located on the surface of the joint and in its departments. The arterial network of the knee joint is important not only in its blood supply, but also in the development of collateral circulation in the process and ligation of the main trunk of the popliteal artery.

Based on the nature of the anatomical structure and the characteristics of its branching, the popliteal artery can be divided into three sections.

• The first section is above the superior articular arteries, where ligation of the popliteal artery gives the best results for the development of roundabout circulation due to the inclusion of a large number of vessels belonging to the a. Femoralis and a. Profunda femoris.
• The second section is at the level of the articular arteries of the knee, where ligation of the popliteal artery also gives good results due to the sufficiency of collateral vessels.
• The third section is below the articular branches; the results of ligation of the popliteal artery in this section are extremely unfavorable for the development of bypass circulation.

In the area of ​​the knee joint, the superficial veins are especially well developed on the anterior internal surface. Superficial veins are located in two layers. The more superficial layer is formed by the venous network from the additional great saphenous vein, the deeper layer is formed by the great saphenous vein.

The accessory great saphenous vein occurs in 60% of cases. It goes from the lower leg to the thigh parallel to v. Saphena magna and flows into it in the middle third of the thigh.

The small saphenous vein collects blood from the posterior surface of the joint. V. Saphena parva most often grows with one trunk and rarely with two. Place and level of confluence v. Saphena parva varies. V. Saphena parva can drain into the popliteal vein, femoral vein, great saphenous vein and deep muscular veins.

In 2/3 of all cases v. Saphena parva drains into the popliteal vein. Anastomosis between v. Saphena magna and v. Saphena parva, according to some authors (D.V. Geymam), as a rule, exists, according to others (E.P. Gladkova, 1949) - it is absent.

The deep veins of the knee joint include the popliteal vein, v. Poplitea, accessory, articular and muscular.

Additional branches of the popliteal vein are found in 1/3 of all cases (E. P. Gladkova). They are small-caliber veins located on the sides or on one side of the popliteal vein. Articular and muscular veins accompany the arteries of the same name.

What types of injuries are there?

If we talk about the most common injuries of the knee joint, doctors call sprains and tears of ligaments, muscles and menisci. It is important to understand that one of the elements can be partially or completely torn not only by performing complex physical exercises or working in heavy production, but also even with a minor but precise blow.

Quite often, this condition leads to a violation of the integrity of bone structures, that is, the patient is diagnosed with a fracture.

When considering the symptoms, they will almost always be identical, so it is important to carry out differential diagnosis. Most often, a person complains of an attack of severe and sharp pain in the knee joint. Further, swelling appears in this place, the soft tissues become swollen, fluid accumulates inside the joint, and the skin becomes red.

It is also characteristic that symptoms may not be observed immediately after the injury, but they will appear several hours later. It is important to seek medical help in a timely manner, because various injuries to the knee joint can lead to the development of serious complications, diseases, and a decrease in a person’s quality of life.

When considering less serious injuries, it is necessary to mention bruises. Most often, this condition is diagnosed in people who have received a side blow to the knee joint. This can happen when falling, or when a person did not notice an object and hit it.

Doctors often diagnose meniscus injuries in athletes. And so that they can recover and continue their career growth in this industry, they undergo surgical treatment. Dislocations that can occur due to incorrect leg position or weight distribution are also possible.

More than 20 million people every year seek help from doctors due to problems in the knee joint. The structure of the knee is very complex. Therefore, the injuries that occur can be varied. Here are just the most common options:

1. Bruises are the easiest injury. It occurs due to a blow to the knee from the side or in front. Most likely, a bruise occurs due to a person falling or hitting something.
2. Damage or tears to the menisci. Often observed in athletes. Often such damage requires immediate surgical intervention.
3. Ligament sprain or rupture. They arise due to the impact of a serious traumatic force on the knee (fall, car accidents, etc.).
4. Dislocations. They appear quite rarely. Most often this is a consequence of severe knee injuries.
5. Fractures. Most cases occur in older people. They receive such serious injury due to a fall.
6. Cartilage damage. This problem is a frequent companion to dislocations and bruises of the knee joint.

Pathological conditions

The causes of discomfort in the knee joint can be associated with various diseases:

• fees;
• meninskopathy;
• arthritis;
• bursitis;
• gout.

Gonarthosis is a disease in which the cartilage tissue of the knee joint is destroyed. In this case, its deformation occurs and its functions are disrupted. The pathology develops gradually.

Meniscopathy can develop at any age. Jumping and squats lead to its development. Risk groups include diabetics, patients with arthritis and gout. The main sign of meniscus damage is a click in the knee joint, which provokes severe and acute pain.

In the absence of therapy, meniscopathy turns into arthrosis. Arthritis affects the synovial membranes, capsules and cartilage. If the disease is not treated, the patient will lose ability to work. Arthritis can manifest itself in different forms, being acute and chronic. In this case, the patient experiences discomfort in the knee.

There is swelling and redness. When pus appears, the body temperature rises.

Periatritis affects periarticular tissues, including tendons, capsules, and muscles. More often, the disease affects areas that bear the maximum load during movement. The reason for such damage is chronic illness, hypothermia, problems with the endocrine system. Periatritis is characterized by pain in the knee joint and swelling.

Tendinitis manifests itself as inflammation of the tendon tissue at the site of its attachment to the bone. Causes of this condition include active sports, including basketball. Pathology can affect the patellar ligaments. Tendinitis occurs in 2 forms – tendobursitis and tendovaginitis.

Rheumatoid arthritis is a systemic disease that manifests itself as inflammation of the connective tissue. The reasons for its occurrence include genetic predisposition.

The active development of the disease occurs at the time of weakening of the body’s defenses. The pathology affects the connective tissue in the joint area. In this case, swelling appears and active division of inflamed cells occurs.

Bursitis, gout and other diseases affecting the knee

Bursitis is an inflammatory process that occurs inside the synovial bursa. The cause of the disease is the accumulation of exudate, which contains dangerous microbes. Bursitis develops after a knee injury. The disease is accompanied by pain and restricted movements. In this case, the patient loses appetite, experiencing malaise and weakness.

Gout is a chronic pathological process that occurs in the knee joint. The disease is characterized by the deposition of monosodium urate, which provokes an attack of acute pain in the joint. At the same time, the skin may turn red.

Paget's disease is manifested by a violation of the processes of bone tissue formation, which provokes skeletal deformation. The pathology in question can cause pain in the knee joint. To eliminate it, NSAID therapy is prescribed.

Fibromyalgia is rarely diagnosed. It is expressed by symmetrical pain in the muscles and skeleton, which often appears in the knee. This condition disrupts sleep, causing fatigue and loss of strength. Additionally, convulsions occur.

Osteomyelitis is associated with a purulent-necrotic process of the bone and tissues located around it. The disease develops against the background of a special group of bacteria that produce pus. Pathology can occur in hematogenous and traumatic form. Discomfort in the knee is accompanied by general weakness, malaise, and high fever.

A Baker's cyst is similar to a knee hernia. Its dimensions vary, but do not exceed a few centimeters. The cyst forms after severe damage to the knee. Arthritis can lead to its appearance.

Koenig's disease is characterized by the separation of cartilage along the bone and its movement in the knee joint. This phenomenon makes it difficult to move, causing severe pain. At the same time, fluid accumulates in the joint, causing inflammation and swelling.

Osgood-Schlatterl disease is characterized by the formation of a lump in the calyx area. Pathology is diagnosed in children and adults. The main symptom is swelling in the knee area. Additionally, swelling and sharp pain occur.

Treatment of the knee joint

At the first sensation of discomfort in the joint, you should allow the ligaments to recover:

1. Expose the joint as little as possible to any load that causes discomfort. Reduce the volume of loads; in some cases, you may need to stop doing leg exercises for a while or completely.
2. To reduce shock during the recovery period, wearing shoes with well-cushioned soles, such as sneakers, is appropriate. Shoes with very thin, rigid or poorly flexible soles, and especially high-heeled shoes, deprive the foot of its natural shock-absorbing function, increasing the impact load on the ligaments and cartilage of the joint. By the way, the shock load on the spine also increases, which is just as harmful.
3. Complete and balanced nutrition.
4. To relieve inflammation, it is appropriate to use anti-inflammatory drugs. For those who do not like “chemistry”, there is a homeopathic remedy – “traumeel”, produced in the form of injections, ointments and tablets, which relieves inflammation and accelerates recovery after injury. By the way, many drugs also have an analgesic effect, so if you stop feeling pain when using them, this does not mean that you have recovered.
5. After relieving inflammation, for further healing, warming agents and procedures, massage, physiotherapy, as well as various Ayurvedic preparations for internal and strained use, Chinese and Tibetan medicine are used.
6. Making light movements with a small amplitude will help increase trophism and restore the damaged structure.

The special structure of the knee joint requires complex and lengthy treatment. Before choosing the appropriate technique, it is necessary to undergo a full examination. After receiving the results, the doctor prescribes individual therapy.

It depends on the location of the injury, existing pathology and severity. Age indications and body characteristics are also taken into account.

Untimely or incorrect treatment leads to serious complications. Pathologies such as arthrosis of the knee joint, arthritis, and so on may develop. In particularly advanced cases, atrophy of the lower limb occurs.

For minor damage to the knee joint, treatment is carried out using injections and tablets. As a rule, the doctor prescribes non-steroidal anti-inflammatory drugs. For example, "Movalis", "Ibuprofen" and the like. Injections are used mainly to eliminate pain and to quickly restore the structure.

The patient must fix the sore leg with a knee pad and apply cooling compresses. You cannot lean on your leg, as it needs complete calm.

A few days after the injury, physiotherapeutic procedures are prescribed. And during the recovery period they are supplemented with special therapeutic exercises.

If the damage to the knee joint is severe, surgical intervention is used. Today, several innovative techniques are used that are painless and safe. For example, arthroscopy or meniscectomy.

In the first case, 2 small holes are made through which a special optical system with instruments is inserted. During the operation, the damaged elements are stitched from the inside. In the second case, the organ is removed partially or locally.

Strengthening the knee joint

It is important to keep your knees strong and healthy so that your mobility does not decrease as you age. We often take healthy knees for granted, not noticing impending problems until everyday activities, such as lifting heavy objects or climbing down, become painful. Try following the steps below to strengthen your knees and ensure you stay active for as long as possible.

Strengthen PBT. Spend some time stretching and warming up your PBT before you begin any active exercise. This will help strengthen your knees.

• Stand with your left foot in front of your right and extend your arms above your head. Bend your upper torso to the left as much as possible without bending your knees. Repeat the same, bringing your right leg in front of your left and tilting your upper body to the right.
• Sit on the floor with your legs extended in front of you. Place one leg on top of the other and pull your knee towards your chest as far as you can, holding this position for a few seconds. Repeat with the other leg.
• Before doing the main exercises, walk a little briskly. This will allow the PBT to warm up.

Do exercises to develop your quadriceps, hamstrings, and gluteal muscles.

• Do lunges to develop your quadriceps muscles. Stand straight with your hands on your hips. Take a big step forward with your left leg and lower your body down until your left leg is bent at a right angle. Your right knee will lower until it almost touches the floor. Repeat this exercise several times, then change legs.
• Strengthen your hamstrings with step classes. Stand in front of a raised surface and climb onto it first with one foot, then with the other. Repeat several times for both legs.
• Do squats to strengthen your gluteal muscles. Stand up straight and lower yourself down, bending your knees and keeping your back straight. For an easier version of the exercise, do it in front of a chair, sitting down and standing up again.
• Learn to jump well. Jumping is a great exercise and, if done correctly, will help strengthen your knees. Try jumping rope in front of a mirror so you can track your actions. Do you land with your knees straight or bent? Landing with straight knees puts too much stress on your joints and can lead to injury. To strengthen your knees, learn to land on bent knees in a half-squat.

Pay more attention to active rest to strengthen all the muscles of the body. If your leg muscles are not strong enough, your knees will not be strong either.