Features of the structure of the knee joint in children. Anatomy of the knee joint and ligaments: structure in the photo

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 they differ in structure from adults somewhere up to 6 years old, so they are not visible in the x-ray.

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

Knee joints of newborns

A newly born baby has cups, but in infancy they are made of thin cartilage, not 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 in children?

The patella is the largest sesamoid bone of the human body, surrounded by tendons of the quadriceps muscle, located above the cavity of the articular joint of the knee. The patella can be easily felt under the skin, it moves effortlessly in different directions when the leg is relaxed. The main function of the knee cup is 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, and injury to the baby.

Cups 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 replaces bone tissue for the time being. At this stage of development in babies, the knee joints are soft and fragile. During pregnancy, there may be problems with the formation of the joint. 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 drugs;
infectious diseases of the mother during childbearing;
influence of radiation and unfavorable environment;
metabolic disturbances.

Exposure to any of these factors during the first 3 months of pregnancy may result in cups not forming at all. If problems with the health of the mother are discovered at such a crucial time, this gives rise to various defects in the knee joints in the child in the future.

The bones of the human skeleton are a reliable support for the whole body and protection for vital internal organs. It is the bones and muscles that enable the human body to move. Muscles have the ability to contract, which, in fact, sets the human body in motion. Thus, the human musculoskeletal system includes:

bones of the skeleton;
joints that connect individual bones of the skeleton to each other (the largest are the hip and knee joints);
muscles.

Human bones are constantly growing and changing. A newborn baby has about 350 bones. In the process of growing a baby, some bones grow together, so in an adult their number is 206. The human skeleton is finally formed by the age of thirty, and in women this process ends earlier than in men.

Anatomy and physiology of the joints of the human skeleton

As mentioned above, the joints of the bones of the skeleton are called joints. Some of them are motionless (cranial bones), others are almost motionless (cartilaginous joints of the spine), but most are mobile and provide various motor functions (flexion, extension, dilution, etc.). Movable joints are called synovial joints. This name is due to the anatomical structure of the joint, which is a kind of complex, including the following composition:

joint capsule;
articular surfaces;
articular cavity;
articular discs;
menisci;
articular lips.

The joint capsule is a complex combination of collagen and elastin fibers and connective tissue. Together, these tissues form a kind of filter, which has a huge number of different functions. The joint capsule is permeated with a complex network of blood vessels and nerve endings that provide nutrition to the joint, its blood supply and signaling function, that is, they send information about its position to the brain.

The articular surfaces are the smooth surfaces of the bones that carry out the connection. The ends of the bones are covered with a thin layer of cartilage and a special lubricant that reduces mechanical friction between the bones.

The movement in the joint directly depends on what its shape is. There is a certain classification, according to which it is customary to distinguish the following types of joints:

cylindrical (connecting the first two cervical vertebrae);
flat (connects the tarsal bones of the foot and the carpal bones of the human hand);
saddle (thumb);
elliptical (connects the radius to the wrist);
spherical (shoulder and hip joint);
articulated (knee joint, elbow joint and finger joints).

The articular cavity is a closed and completely sealed slit-like space that does not communicate with the environment. It is the articular cavity that contains the synovial membrane and synovial fluid. What it is? The synovial membrane is the inner layer of the joint capsule that lines the entire joint cavity, excluding its cartilaginous areas. The main function of the synovial membrane is protective, it is this structure that prevents friction and promotes cushioning. Ensuring the protective function of the synovial membrane is possible due to the fact that it is able to release a special lubricant, which is called synovial fluid.

Synovial fluid is a special substance that has a complex molecular structure and chemical composition. Without going into details, we note that the synovial fluid is a blood plasma and a protein-polysaccharide component that provides the viscosity and elasticity of this substance. The main function of the synovium is to reduce friction when the joints are loaded and to ensure optimal glide of the articular cartilage. Among other things, synovial fluid provides nutrition to the joint and prevents wear and tear.

Articular discs are biconcave plates that are located between the articular surfaces of some joints and divide it into two cavities. They perform a shock-absorbing function and ensure the elimination of inconsistencies between the articular surfaces. The same function is performed by the meniscus - a kind of cartilage lining. The shape of the menisci depends on the shape of the ends of the bones. Another auxiliary formation of the joint is the articular lip. This formation is an annular fibrous cartilage. There is such a formation only in the hip and shoulder joint.

The knee joint contains another important structural unit - muscles. Under the influence of nerve impulses, the muscles of the knee joint contract, which ensures the motor function of a person, that is, allows him to walk. The knee joint has flexor and extensor muscles. Flexion occurs due to the muscles located on the back of the thigh and the area of the knee joint. Extension is possible thanks to the quadriceps muscle and the patella, which is an additional point of support.

Human joints are simple (from 2 bones) and complex (more than 2 bones). The largest joints in the human skeleton are the hip and knee joints. The latter has a rather complex anatomical structure, and therefore deserves special attention.

Features of the anatomical structure of the knee

In order to understand the cause of various pathological conditions of the knee, it is worth understanding its anatomical and functional features. The knee joint is the most complex articulation in its structure. It is he who is a vivid example of a complex block-shaped joint. The knee joint is formed at the junction of the distal femur and tibia. Part of the joint is the patella (or patella), which performs a protective function and prevents mechanical damage.

There is some discrepancy between the articular surfaces of the femur and tibia, so the menisci come to the aid of the knee joint, which are trihedral cartilage plates that compensate for the discrepancy between the tibia and femur. The knee joints have two menisci: external (lateral) and internal (medial). It is they who help to evenly distribute pressure when the load on the joint. The outer edge of both menisci almost completely repeats the shape of the condyles of the tibia. The menisci are attached to the joint capsule in a special way, with the inner meniscus attached more tightly and therefore less mobile and mobile than the outer meniscus. The medial meniscus tends to move backward when the knee is flexed. The outer meniscus is more mobile, which explains the fact that a lateral meniscus tear is much less common than a similar injury to the medial meniscus.

The structure and shape of the joint is characterized by the presence of several synovial bags (burs), which are located along the tendons and muscles.

The main bursae are located in front of the patella. The largest and most significant synovial bursae are suprapatellar and infrapatellar. Other burses are smaller, but no less significant. Bursae produce synovial fluid, which reduces friction in the joint and prevents wear and tear.

Here are the basic theoretical knowledge that every patient should have.

Functional load on the joint

The lower extremities of a person are the undisputed leaders in terms of the number of injuries and pathological changes, and there is an explanation for this. The hip and knee joints are the largest for a reason. It is these joints that bear the greatest load when walking and moving, and it is the knee that takes on the entire weight of the human body.

The knee joint is articulated and has complex biomechanics, that is, it provides a fairly large number of various movements (including the knee joint can produce circular rotational movements, which is not characteristic of most joints of the human skeleton).

The main functions of the knee joint are flexion, extension and support. Bones, ligaments and cartilage work as a single coherent mechanism and provide optimal mobility and cushioning of the joint.

Orthopedics as a branch of clinical medicine

Orthopedics studies the etiology and pathogenesis of various disorders and dysfunctions of the musculoskeletal system. Such violations can be the result of congenital pathology or malformations of intrauterine development, injuries and various diseases. In addition, orthopedics studies methods for diagnosing and treating various pathological conditions of the musculoskeletal system.

There are several branches of orthopedics:

Ambulatory orthopedics. The most significant section, since the majority of orthopedic patients are treated in an outpatient clinic or day hospital.
Pediatric and adolescent orthopedics. The musculoskeletal system of children and adolescents has certain physiological and anatomical features. The goal of pediatric and adolescent orthopedics is the prevention and timely elimination of congenital pathologies. Among the methods, it is customary to single out conservative therapy and surgical interventions.
Surgery. This area of orthopedics deals with the surgical correction of various pathologies.
Endoprosthetics or replacement of damaged joints and their parts with implants.
Sports orthopedics and traumatology.

Among the diagnostic methods in orthopedics, imaging methods such as radiography, magnetic resonance imaging, ultrasound examination of joints and presenting tissues, computed tomography, as well as podography, stabilometry, densitometry and optical tomography are used.

Laboratory and clinical studies are also widely used, which help to identify the presence of pathogenic microflora, changes in the chemical composition of the synovial fluid and establish the correct differential diagnosis.

Cause of knee pain: the most common pathologies

Pain in the knee is a consequence of its mechanical damage or injury that occurs due to severe overloads. What are and what symptoms should make the patient alert?

The main symptom of the presence of pathological changes in the knee joint is pain and inflammation. The intensity of pain and its localization depends on the etiology of the pathological condition and the degree of damage to the knee joint. The pain may be constant or intermittent or occur during certain loads. Another diagnostic sign of the lesion is a violation of movement in the knee joint (its limitation). When trying to bend or straighten the knee, when walking or leaning on the affected limb, the patient experiences discomfort and pain.

Effusion in the knee joint: etiology, pathogenesis and clinical picture

Among the most common diseases of the knee is an abnormal accumulation of synovial fluid or effusion in the cavity of the knee joint. The main sign of fluid accumulation is swelling, enlargement, limitation of joint mobility, and pain on movement. Such changes are visible to the naked eye and the diagnosis is not in doubt (see photo). If you find such changes, you should immediately seek medical help. Timely differential diagnosis and precise determination of the cause of the accumulation of synovial fluid is the key to successful treatment.

There can be many reasons for the occurrence of such a condition, but most often the effusion of the knee joint is formed as a result of injuries or various general diseases. The human body releases effusion as a response to aggressive external influences. Thus, the cause of the pathological accumulation of fluid can be a fracture, rupture of the tendons or menisci, severe dislocation or hemorrhage. The most dangerous are injuries in which pathogenic microflora enters directly into the joint cavity and purulent inflammation occurs. Synovial fluid is a favorable environment for the active reproduction of various bacteria. This condition is considered threatening and requires immediate medical attention. Also, effusion can be the result of various diseases, often infectious (tuberculosis, chlamydia, syphilis, streptococcus, etc.).

To diagnose the disease and select adequate therapy, it is necessary to find out the cause of its occurrence. The most reliable diagnostic method is a laboratory study of the synovial fluid, which changes its composition and consistency.

Bursitis, or inflammation of the bursae

Bursitis is an inflammation of synovial bags. Quite often, practitioners of sports orthopedics and traumatology encounter such a pathology. Permanent microtraumas and excessive loads are the cause of this pathology in people involved in sports (especially its power types). Moreover, often, ignoring the recommendations of orthopedic doctors to take care of the damaged knee joint, athletes continue intensive training, which only exacerbates the current situation.

Often bursitis is called the knee joint of housewives. From long kneeling while mopping, inflammation occurs in the synovial patella bag. Another fairly common form of this disease is goose foot bursitis or popliteal bursitis. The crow's foot is the junction of certain tendons on the inside of the knee joint. The synovial bag is located under the exit point of these tendons and can become inflamed under a certain load or injury.

With bursitis, the knee joint is painful on palpation, swelling and redness, deterioration of the general condition, local hyperthermia and a general increase in body temperature may occur. There may be slight stiffness or reduced range of motion in the knee joint.

Bursitis develops as a result of trauma and mechanical damage or infection of the bursa. Even a small injury or a shallow cut can cause a disease.

The medical prognosis depends on the degree of neglect of the disease, its ability to spread, and the immune status of the patient.

Meniscal injuries

About half of all knee injuries are meniscus injuries. The anatomical structure of the knee joint, as mentioned above, creates favorable conditions for various traumatic conditions, and the medial (inner) meniscus of the knee joint is injured 4-7 times more often. This pathology is called meniscopathy and is a degenerative-destructive pathology.

The cause of meniscopathy of the knee joint is acute and chronic injuries, which are often an occupational disease of athletes. An acute injury is most often accompanied by a phenomenon such as a blockage of the knee joint or a symptom of blockade. What it is? Immediately after the primary injury, the patient develops severe pain in the joint and a sharp limitation of its mobility. It seems that the patient's lower leg is fixed in the flexion position, there is a feeling of wedging.

Damage to the meniscus can cause the formation of effusion, the occurrence of edema. In a later period, the pain becomes strictly localized directly along the line of the joint space. Differential diagnosis with a bruise or sprain is necessary. If the diagnosis is incorrect, then with repeated injury, the disease passes into the chronic stage, which is characterized by severe pain, a sharp limitation of movement in the joint, and various inflammatory and trophic disorders. In this case, conservative therapy may be ineffective, the patient is shown surgical intervention.

Some pathologies of the knee joint are found only in pediatric practice in adolescent children (from 10 to 15 years). The most striking example is Osgood-Schlatter disease. The most stable diagnostic sign of this pathology is the appearance of a kind of bump, which is located on the knee joint, just below the kneecap. At first, the course of the disease is sluggish, but later the pain constantly increases, the patient's movements become constrained, and the affected knee joint increases in volume.

The disease occurs as a result of aseptic destruction of the nucleus and tuberosity of the tibia. As a rule, the disease is asymmetrical and affects only one knee joint. The cause of this pathology is a violation due to various causes of blood circulation in the knee joint. The disease has a long course (from several weeks to several months), the knee joint is fully restored only after the completion of the formation of the skeleton (by about 30 years).

Here is a far from complete list of causes that can cause pain in the knee joint. This review does not indicate the methods of treatment of various diseases of the knee joint, since self-treatment is the cause of quite serious complications. Affected knee joints love the cold! If you have any symptoms of damage to the knee joints, then the only thing you can do is apply ice to the injured knee. This helps reduce pain and relieve swelling. You can apply ice every 3-4 hours for 10-15 minutes, and then you should seek medical help as soon as possible. An experienced specialist, having examined the patient's knee joint, can make a preliminary diagnosis and prescribe adequate treatment.

An extensive risk group for diseases of the knee joints are athletes and menopausal women. If you are overweight, have a sedentary lifestyle, or have certain hormonal or metabolic disorders, you may not feel completely safe.

Proper nutrition, a healthy lifestyle and moderate exercise help prevent. You should not endure pain in the knee joint, but you do not need to take painkillers without a doctor's prescription.

Stages of normal ossification of the structures of the knee joint

Age up to 1 year. One of the main indicators of the full-term fetus is the presence of ossification nuclei of the distal epiphysis of the femur and the proximal epiphysis of the tibia. The degree of ossification of the metaepiphyses of the femur and tibia and the patella differs slightly from that present at the time of birth. During the first year of life, the size of the ossification nuclei increases slightly, and the degree of ossification of the metaphyses of the femur and tibia also increases. The cartilaginous structure is preserved by about 2/3 of the epiphyses of both bones, including the intercondylar eminence of the epiphysis of the tibia, the tuberosity of this bone, the patella and the head of the fibula.

The shape of the conditional X-ray joint space of the knee joint is incorrect (conditional because the anatomical substrate of the gap between the bone parts of the articulating epiphyses is not only the articular space and menisci, but also the non-ossified parts of the cartilaginous models of the epiphyses). The height of the conditional x-ray joint space and the vertical dimensions of both epiphyses are equal and each make up 1/3 of the distance between the surfaces of the metaphyses of the femur and tibia facing each other.

On radiographs in the posterior projection, the criteria for the norm of anatomical relationships in the frontal plane are the location at the same level of the lateral edges of the os-

sified parts of the articulating epiphyses of the femur and tibia and the same value of the right and left edges of the intermetaphyseal distances. The uniformity of the height of the x-ray joint space for the analysis of the anatomical relationships in the knee joint cannot be used due to the irregularity of its shape. In young children, the true shape, contours and structure of the epimetaphyses of the articulating bones, the shape of the x-ray joint space and the location of the patella cannot be assessed.

Age 2-3 years(Fig. 19.90). During this age period, there is no ossification of new anatomical formations. There is only a change in the ratio pace ossification of the medial and lateral condyles of the femur and growth rates of the medial and lateral parts of the tibial body. The change in the ratio of the rates of ossification of the parts of the distal epiphysis of the femur is that the ossification of its central part is slower than that of both condyles, as a result of which the bone part of the epiphysis acquires a shape similar to that of the cartilaginous model. Indicators of compliance of local bone age with passport age for this period have not been established (Fig. 19.113, 19.114).

3,5-5 years - the age of onset of ossification of the patella and proximal epi- phys. The centers of ossification of both named anatomical formations appear almost simultaneously in the range from 3.5 to 4.5 years. Ossification of the patella occurs in multiple centers of ossification, the proximal epiphysis - due to a single center. During this age period, there is a more rapid increase in the vertical size of the bony part of the lateral condyle compared to the size of the bony part of the medial condyle. The norm of the ratio of the spatial positions of the thigh and lower leg is the valgus deviation of the latter, which is increased compared to the norm in adults. An indicator of the bone age of the child is the presence of centers of ossification of the central part of the patella and the head of the fibula (Fig. 19.108).

At 6-7 years of age, complete ossification of the central and dorsal (carrying the articular surface) parts of the patella occurs. Complete ossification of the central part of the patella as a result of an increase in size and fusion between individual centers of ossification ends by about 7 years. Additional centers of ossification of the epiphysis of the femur appear, which provide ossification of the lateral and posterior sections of the epiphysis. The ratio of the rates of ossification of the medial and lateral condyles of the femur changes. There is a more rapid increase in the vertical size of the bone part, now not the lateral, but the medial condyle, as a result of which the height of both condyles first becomes the same, and then the height of the medial condyle begins to predominate. Tentatively, the height of the x-ray joint space of the knee joint can be estimated based on the ratio of the height of its central part to the value of the intermetaphyseal distance (normally 1:7). An indicator of the local bone age of the child is the presence of additional centers of ossification of the distal epiphysis of the femur (Fig. 19.91).

Age 9-12 years (Fig. 19.92) corresponds to the timing of ossification of the tuberosity of the tibia and the marginal sections of the patella. The patella has 4 additional centers of ossification - two lateral, anterior and apical, appearing at the age of 9 years. Their fusion with the main part of the patella occurs by 10-12 years. Ossification of the tibial tuberosity occurs partly due to the spread of the ossification process from the anterior parts of the metaphysis of the tibia, partly due to independent ossification centers that appear at the age of 9 years. Complete ossification of the epiphyses of the femur, tibia and fibula is completed somewhat earlier (about 8 years), and by 13

Rice. 19.90. Radiographs of the knee joint.

a, b - 2 d 4 months (posterior and lateral projections).

1 - epiphysis of the femur; 2 - epiphysis of the tibia; 3 - metaphysis of the fibula (the epiphysis is not yet visualized); 4 - diaphysis of the femur; 5 - growth zone; 6 - "cartilaginous" patella; 7 - infrapatellar fat body (rhomboid space), c, d - 8 years old (posterior and lateral projections).

1 - epiphysis of the femur; 2 - epiphysis of the tibia; 3 - epiphysis of the fibula; 4 - diaphysis of the femur; 5 - growth zone; 6 - core of ossification of the patella; 7 - infrapatellar fat body; 8 - cartilaginous region of the tibial tuberosity; 9 - intercondylar eminence (with smoothed contours due to incomplete ossification).

Rice. 19.91. X-ray of the knee joint, 10 years old.

1 - epiphysis of the femur (medial condyle); 2 - epiphysis of the tibia; 3 - epiphysis of the fibula; 4 - lateral condyle of the femur (the area of attachment of the tendon m. popliteus); 5 - growth zone; 6 - patella; 7 - inter-condylar eminence of the tibia.

For years, the cartilaginous structure is preserved only by the metaepiphyseal growth zones and a small part of the tibial tuberosity (Fig. 19.93).

At 12-14 years of age, complete ossification of the tibial tuberosity occurs. Separate points of ossification, gradually merging with each other, fulfill almost the entire cartilaginous model of tuberosity, with the exception of a small area in the lower section (Fig. 19.94). Cartilaginous tissue also remains for some time between the dorsal surface of the bone part of the tubercle.

Rice. 19.92. X-ray of the knee joint (12 years old).

Rice. 19.93. X-rays of the knee joint

(lateral projection). 13 years old. Ossification options

tuberosity of the tibia.

1 - nuclei of the tibial tuberosity; 2 - epiphysis of the tibia; 3 - the epiphysis of the fibula.

Rice. 19.94. X-ray of the knee joint (lateral view). 14-15 years old.

Incompletely ossified tibial tuberosity. The growth zones of the femur and tibia are traced.

1 - tuberosity of the tibia; 2 - patella; 3 - suprapatellar fat body; 4 - infrapatellar fat body.

stoma and anterior surface of the metaphysis of the tibia. The set of indicators of the anatomical structure of the knee joint available for analysis is identical to that in adults. An indicator of local bone age is complete or almost complete ossification of the tibial tuberosity (Fig. 19.95, 19.109).

15-17 years - the period of the final stage of the postnatal formation of the bone components of the knee joint, namely the synostosis of the metaepiphyseal growth zones and the growth zone of the tibial tuberosity (Fig. 19.96).

Rice. 19.95. Radiographs of the knee joints. 18 years. Complete ossification of the knee joint.

Rice. 19.96. X-ray of the knee joint. Adult.

Normal anatomy of the knee joint

In the knee joint, in addition to bone structures (Fig. 19.135), there are a number of large external and internal structures that maintain its stability, as well as creating a cushioning effect.

Menisci of the knee joint- crescent-shaped fibrocartilaginous plates, which largely compensate for the discrepancies between the articular surfaces of the femoral condyles and the articular surface of the tibia. They protect them from a local increase in pressure, evenly redistributing body weight over a large area. In an adult in a standing position, 40-60% of body weight is transferred through the menisci, which reduces the compression of the articular cartilage (Fig. 19.97).

The height of the menisci on the periphery is 3-4 mm and decreases to 0.5 mm in the region of the inner free edge. Both menisci have an anterior and posterior horn and an intermediate part (pars intermedia), which makes up the central 2/3 of the meniscus. The outer meniscus has a more spherical shape and, when viewed from above, a more rounded configuration. It covers 2/3 of the underlying plane of the lateral condyle of the tibia and has the same capsular attachments as the internal meniscus, except for a defect where the popliteus tendon (m. Popliteus) passes through the body of the meniscus and attaches to the lateral condyle of the thigh (Fig. 19.99 ). It is through this hamstring canal that the outer meniscus has greater mobility. This explains the fact that ruptures of the outer meniscus are less common than the inner ones. Posterolaterally, the outer meniscus is attached to the hamstring tendon. It is fixed anteriorly and posteriorly in the region of the anterior and posterior sections of the intercondylar region of the tibia, respectively, and only in some places is loosely fused with the joint capsule. In 30-40% of cases, two ligaments from the posterior horn of the lateral meniscus approach the medial condyle of the thigh - the posterior and anterior meniscofemoral ligaments behind and in front of the posterior cruciate ligament.

Rice. 19.97. Menisci and ligaments of the knee joint in the axial plane.

1 - anterior cruciate ligament; 2 - posterior cruciate ligament; 3 - lateral meniscus; 4 - medial meniscus; 5 - menisco-femoral ligament.

Rice. 19.98. Menisci and ligaments of the knee joint in the axial plane.

1 - anterior cruciate ligament; 2 - posterior cruciate ligament; 3 - lateral meniscus; 4 - medial meniscus; 5 - menisco-femoral ligament; 6 - anterior intermeniscal ligament; 7 - ligament of the patella; 8 - infrapatellar fat body (Goff's fat body).

Rice. 19.99.MPTadult knee joint.

a - parasagittal scanning through the lateral sections (T2-WI with fat suppression): 1 - fibula; 2 - tibiofibular joint; 3 - tibia; 4 - tendon t. popliteus; 5 - lateral collateral ligament; 6 - lateral meniscus (body); 7 - m. gastrocnemius. b - parasagittal scanning through the lateral sections (T1-B 1):

1 - head of the fibula; 2 - tendon m. popliteus; 3 - lateral collateral ligament; 4 - m. gastrocnemius.

c - coronal scanning plane through the posterior sections (T2-WI with fat suppression): 1 - fibula; 2 - tibiofibular joint; 3 - medial condyle of the thigh; 4 - lateral condyle of the thigh; 5 - lateral collateral ligament; 6 - medial meniscus; 7 - lateral meniscus; 8 - medial collateral ligament; 9 - posterior cruciate ligament; 10.11 - tendon m. popliteus.

The medial meniscus has a much larger radius and oval shape, in some cases it resembles a comma in configuration. Its width is greater in the region of the posterior horn. The anterior, narrower horn attaches to the anterior intercondylar region of the tibia. The pontic is attached to the inner layer of the medial collateral ligament. The anterior horns of both menisci are connected by the meniscofemoral ligament, which in about 10% of cases consists of several parts.

The menisci are composed of fibrocartilaginous tissue with a high content of collagen fibers. Stronger collagen fibers are located mainly on the periphery

41 At

Rice. 19.100. MRI of the knee joint.

a - 11 years old. Median sagittal plane (T1-VI): 1 - epiphysis of the femur; 2 - epiphysis of the tibia; 3 - posterior cruciate ligament; 4 - metadiaphysis of the femur; 5 - growth zone; 6 - patella; 7 - infrapatellar fat body; 8 - tuberosity of the tibia; 9 - fibers of the patella's own ligament; 10 - m. popliteus.

b - MRI of the knee joint of an adult. Parasagittal plane:

1 - posterior horn of the medial meniscus; 2 - epiphysis of the femur; 3 - articular cartilage; 4 - posterolateral section of the joint capsule; 5 - ossified growth zone, c - 11 years old. Parasagittal plane through the lateral meniscus (T2-VI):

1 - epiphysis of the fibula; 2 - peroneal-tibial joint; 3 - epiphysis of the tibia; 4 - lateral meniscus (anterior horn); 5 - tendon t. popliteus; 6 - epiphysis of the femur; 7 - patella; 8 - growth zone.

and oriented longitudinally. They are crossed by thin, radially running fibers. In adults, the menisci are poorly vascularized. The capillary network of the vascularized peripheral zone provides nourishment for the internal avascular zone.

Anterior cruciate ligament(Fig. 19.102, 19.103). It stabilizes the joint and limits it from anterior subluxation of the tibia. It starts from the posterior part of the inner surface of the lateral condyle of the thigh and is attached anteriorly and laterally from the anterior intercondylar eminence. Its length is about 35 mm, thickness

Rice. 19.101. MRI of the knee.

a - 14 years old. Coronal plane (T2-VI):

1 - body of the medial meniscus; 2 - medial collateral ligament; 3 - body of the lateral meniscus; 4 - lateral collateral ligament (fragmentary); 5 - growth zone. b - MRI of the knee joint of an adult. Coronal plane (anterior):

1 - anterior horn of the lateral meniscus; 2 - condyles (epiphysis) of the femur; 3 - anterior horn of the medial meniscus; 4 - intercondylar eminence; 5 - posterior sections of the infrapatellar fat body; 6 - tractus iliotibialis.

c - MRI of the knee joint of an adult. Axial plane:

1 - lig.patellae; 2 - medial collateral ligament; 3 - tendon m. popliteus; 4 - retinaculum patellae mediale; 5 - retinaculum patellae laterale; 6 - anterior cruciate ligament; 7 - m. biceps femoris. d - MRI of the knee joints. Axial plane:

1 - patella and ligament of the patella; 2 - medial condyle; 3 - lateral condyle; 4 - medial collateral ligament; 5 - infrapatellar fat body; 6 - anterior cruciate ligament; 7 - m. biceps femoris; 8 - posterior cruciate ligament; 9 - m. plantaris; 10 - t. gastrocnemius.

The kneecap plays an important role in the body and the human body. It is worth noting that this is a large sesamoid bone. Starting from the age of three, this bone can be easily felt through the skin, and can be shifted to the left and right when the knee is bent or unbent. The main function of this joint is to protect against displacement of the part of the femur and tibia, which is the knee joint. There is a myth that babies are born without a kneecap. But whether this is true or not, we will figure it out further.

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Anatomical features

The patella (another name for the patella) belongs to the type of sesamoid bones and is the largest of this entire group. The kneecap is shaped like a triangle, it is slightly convex on the outside and concave on the inside. The inner surface is covered with articular cartilage. It is the patella that helps us bend and unbend the legs, and also protects the knee joint from excessive displacement to the sides.

calyx formation

There is a myth that the patella in newborns is completely absent, and is formed closer to four months. But in reality, things are somewhat different. The cup is formed in children already in the womb at the fourth month of pregnancy. But it is not always possible to detect it on an ultrasound examination, since it consists of cartilage tissue, while in adults it is made of bone.

From two to six years old, a child around this cartilage forms ossification nuclei. Gradually, all these zones merge with each other, forming the familiar kneecap. This happens around the seventh year of a child's life. Children have kneecaps since fetal development, and do not appear at any particular age.

Role and functions

The main and very important function of the patella is to protect the femur and tibia from displacement. When we bend and unbend the knee, the patella moves up and down, preventing the joint from moving to the sides.

In addition, cruciate ligaments are located on the sides of the knee joint, which additionally protect and increase the strength of the joint. That is why children need to be careful with falls and bumps, because they do not yet have the protection of the knee joint, like adults.

Pathologies and lack of a cup

Can the kneecap be missing? Yes, but this already belongs to the category of pathology. The problem is quite rare. And more likely it can occur in those children who have some other disorders of the musculoskeletal system.

Doctors say that anomalies with the appearance and development of the patella occur in children who have genetic failures or a negative effect on the mother during pregnancy. The main factors that can lead to improper development of the calyx or lead to its absence include:

Radiation.
Taking medications.
Infections.
Hormonal disorders.

If any of these factors affect the mother in the first three months of bearing a child, then the patella will be absent in the newborn. If the expectant mother was negatively affected in the subsequent months of pregnancy, then the child's patella will be underdeveloped. If there is a suspicion that this bone is developing incorrectly, then after the birth of the baby, he is prescribed an X-ray examination and a complete examination by an orthopedist.

Complete absence of the patella

This pathology is extremely rare. And if it is already observed in a baby, then only together with the pathological development of the tibia and femur. Children who were born without a patella often have congenital dislocation of the hip, lower leg, and clubfoot.

This anomaly does not affect motor functions in any way. The child can jump, walk, run, while there is no pain or discomfort. The defect appears only as an aesthetic one. A slight lameness, weakness of the leg, its rapid fatigue are visible.

As such, there is no treatment for this pathology. Although some resort to surgical intervention.

Lobular patella

This pathology is detected in almost two percent of people who have done x-rays of the knee joint. Often the problem is discovered incidentally, and it occurs more often in men than in women. The lobular knee pad is in two or three pieces, but the size is normal and there is no pain or discomfort.

There is also no therapy. But you should always keep in mind that in children and adults with such a defect, the risk of developing arthrosis is much higher. Therefore, it is necessary to deal with the prevention of this disease in advance.

Congenital dislocation of the patella

In most cases, this anomaly is inherited and occurs more often in boys. This pathological condition is characterized by the fact that instability appears when walking. The doctor on examination may detect a displacement of the knee bone or note a limitation in the movements of the joint.

As they grow older, this pathology can lead to the fact that the child will develop an X-shaped deviation of the lower leg. And this anomaly also increases the risk of arthrosis. This pathology can be cured only by surgical intervention.

In order not to confuse invented myths with reality, you should always consult a professional and experienced doctor. Only he can explain in detail and clearly how the baby develops in the womb, what he has and what appears later. And how to deal with the treatment of a particular deviation or pathology. Do not consult with those who are incompetent in this area. Thus, you can harm both yourself and the baby.

Video "What is the kneecap for"

From this video you will learn why a person needs kneecaps.