Speaking of the knee, most people mean it Indeed, it is an important anatomical part, however, its functionality is impossible without muscles and tendons. When walking, running, playing sports, the specified area has a significant load, which increases the risk of injury. Let us consider in more detail the ligaments, the muscular apparatus and the problems that arise during the action of the traumatic factor.
Features of anatomy
Three bones take part in the formation of the joint: part of the femur, patella and part of the tibia. The patella is represented by the femoral-tibial and femoral-patellar joints. Anatomical features contribute to the simultaneous mutual movement of bones in several planes.
The menisci, represented by connective tissue cartilage, are "spacers" between the heads of the bones. Their function is to provide shock absorption, distribution of pressure and load while driving. On both sides, the menisci are connected to the joint capsule by means of the coronary ligaments.
Joint stabilizers are the following muscle groups, awareness of which is considered important in trauma:
- The quadriceps muscle occupies the front of the thigh. It is considered the strongest anatomical structure of the muscular apparatus of the indicated area.
- The sartorius muscle is the longest. It provides flexion to both the hip and lower leg by going around the knee joint.
- The slender muscle runs behind and slightly to the side of the joint, allowing the hip to adduct and flex the knee.
- A large adductor muscle is involved not only in adduction of the thigh, but also in its extension or extension of the pelvis in relation to the thigh.
- Behind along the transverse axis there is a double-headed one that allows you to bend the lower leg, unbend the thigh, and provide movement outward.
- The tendon muscle passes behind and inside the joint, which extends the thigh, flexes the lower leg and provides circular rotation of the limb.
- performs functions similar to the tendinous.
- The triceps muscle of the calf flexes the calf at the knee and the foot in
- Short and flat on the back. The function is to flex and rotate the lower leg.
Knee functions
The performance of the knee joint is important for the human body. It can move along the vertical and frontal axes. Extension and flexion occurs along the frontal axis, along the vertical - rotation of the limb.
Flexion of the joint allows the person's leg to take a step forward without hitting the limb on the ground, but placing it gently. Otherwise, the person's leg would be carried forward in the upper forward direction by raising the hip.
Ligamentous apparatus
The knee joint, the ligaments of which are represented by five main groups, is considered an anatomically complex part of the body. Its composition includes the following types of ligaments:
- collateral (tibial, peroneal);
- cruciform (front, back);
- transverse knee ligament;
- posterior (arcuate, popliteal, patellar ligament, medial and lateral);
- coronary (menisco-femoral, menisco-tibial).
With trauma, especially sports injuries, the main load occurs on the cruciate ligaments of the knee joint. The terms of recovery and rehabilitation period depend on the nature of the injury and the damaging factor, the characteristics of the victim's body, last from 4 to 6 months.
Cruciate ligaments and their functionality
The anterior ligament extends from the posterior upper part of the femoral meniscus through the knee cavity, attaching to the tibia, which is part of the articular conglomerate. Its function is to stabilize the knee joint by limiting forward movement of the lower leg.
The posterior ligament extends from the anterior part of the bony protrusion of the femur and, crossing the joint cavity, is attached to the tibia in the posterior part. The ligament does not allow the lower leg to move excessively back.
Cruciate ligament injury
Such injuries are considered the most difficult and dangerous, requiring full treatment. Incorrectly selected or untimely started therapy leads to the development of lameness and persistent limitation of functioning. Most often, such injuries are found in professional athletes when skiing, skating, jumping, wrestling, arising from a strong blow or an unsuccessful turn, fall.
Severe piercing pain and a characteristic click, a sharp restriction of mobility may indicate that the ligament of the knee joint is torn. The victim cannot move independently, only leaning on someone.
Injury to the posterior ligament occurs with strong hyperextension of the knee or during a blow to the front of the lower leg. Injury to the anterior cruciate ligament of the knee is most common. The symptoms of this injury are included in the Turner triad, along with a ruptured meniscus and an external ligament.
Clinical picture
The knee joint, the ligaments of which have a partial tear, becomes hyperemic, edematous, painful to the touch and when trying to move. Blood accumulates in the joint cavity (hemarthrosis). The knee joint, which has a similar clinic, should not be confused with the symptoms of injury that occurred a few days ago.
A complete rupture of the cruciate ligaments causes excessive movement of the lower leg in the anteroposterior plane. This symptom is checked by two specialists at the same time. The first one holds the back of the thigh and flexes the anesthetized limb at the knee at a right angle. A second doctor checks the forward and backward movement of the lower leg. When stretched or torn, a similar sign will be negative.
Ligament sprain involves a slight tear of the fibers, accompanied by moderate pain, slight edema, and absence of hemorrhage. Limitation of motor function occurs to an insignificant extent.
Diagnostics
Determination of the mechanism of injury makes it possible to find out possible damage to anatomical structures. Before examining the injured knee, the doctor examines the healthy one in order to find out the structural features. The state of internal structures is assessed using ultrasound and MRI.
Differential diagnosis allows to exclude fractures of bones, patella, meniscus rupture. In case of dislocation, the bones are displaced in relation to each other, there is no possibility of motor function, there is spring resistance when trying to passive movements. Ligament damage is not characterized by a complete lack of movement, it is limited due to pain. There is also no spring resistance.
The fracture is accompanied by deformation, crepitus and pathological mobility. However, there are fractures that do not show such signs. In this case, confirmation of the diagnosis requires X-ray examination, ultrasound or MRI.
Treatment principles
In case of partial injuries (stretching, tearing), help is provided in the emergency room. The limb should be in an elevated position, the first few days - bed rest. The first day after the injury requires applying cold to the damaged area. The joint is fixed with a tight elastic bandage, which allows maintaining the physiological position of the limb during movement. It is impossible to leave a bandage overnight, so that blood circulation does not occur. Pain relief requires the use of analgesics ("Ketanov", "Ketalong", "Nalbufin").
The knee joint, whose ligaments require not only conservative therapy, but also surgical treatment, requires a long rehabilitation period. After all the same measures as for partial injuries, physiotherapeutic measures are used, including massage, physiotherapy exercises, electrophoresis with medications.
Quite often, surgery is required when the cruciate ligament of the knee has been ruptured. An operation to restore the integrity of anatomical structures is necessary for normal functioning. Surgical intervention is performed six months after the joint injury.
A young athlete who needs to perform jerk movements with his limbs in his sport is considered an ideal candidate for this exercise. Older people who do not have a lot of physical activity are more suitable for conservative therapy and the use of physiotherapy exercises.
Cruciate ligament surgery of the knee requires the use of a graft from the patellar ligament or hamstring (autograft). It is also possible to use synthetic prostheses, however, their use can be rejected by the patient's body.
Suturing synthetic grafts is a common procedure when the knee joint is torn. Surgical treatment is considered the treatment of choice in this case.
Surgical practice has shown that simple stitching of injured structures practically does not provide restoration of functionality.
What are the complications of knee injury?
Among the common complications of knee injuries, the following are distinguished:
- Arthritis may develop 2-3 weeks after joint damage. The inflammatory reaction occurs as a result of circulatory disorders and the entry of pathological microorganisms into the injury zone. It is characterized by pain syndrome, the appearance of puffiness, hyperemia, limitation of mobility due to pain.
- The appearance of degenerative changes in the form of arthrosis is accompanied by the formation of osteophytes, thinning of cartilage tissues.
Forecast
After receiving an injury, most of the victims are interested in: "How long does a rupture of the ligaments of the knee heal?" A similar issue is considered in each clinical case individually. Depending on the nature of the injury and the characteristics of the body, full working capacity may return in six months, or maybe in a few months.
The mechanism of damage itself and how the victim received a rupture of the ligaments of the knee is important. How long the injury heals also depends on the exact adherence to the advice of the attending specialist. Early initiation of therapy, taking the necessary medications and adherence to the regime can speed up the healing process and prevent the development of complications.
Prevention
The list of preventive measures used to minimize joint damage is reduced to the following measures:
- adequate physical activity;
- inflammation of the ligaments of the knee joint should be subject to timely treatment;
- a balanced diet;
- refusal to abuse alcohol and tobacco;
- avoiding hypothermia of the body;
- control of the minimum stay of the limbs in static positions;
- the right choice of shoes, the rejection of high heels.
Injury to the knee joint can be prevented, which is simpler than restoring its functionality due to injury.
The knee joint, its structure in humans has a complex structure. It is designed to carry heavy loads. Nevertheless, the knee joint, the structure of which, it would seem, provides for everything, very often suffers various diseases. Diseases of the knee joint are not easy to treat, they can be associated with long-term increased stress on it due to overweight, knee injuries, metabolic disorders in the human body, lack of vitamins and minerals.
The anatomy of the knee is designed to avoid friction between the bones, to mitigate shock effects.In addition, the patella protects the knee from external influences. However, if you regularly exceed the permissible loads and do not take care of your joints, then this can lead to various diseases.
The main parts of the knee are:
- bones and muscles: the main parts around which the entire structure is formed;
- menisci - play an important role in providing joint mobility;
- nerve endings and a network of blood vessels: revitalize the knee, making it sensitive to various influences;
- ligaments and cartilage: are the connecting link between bones and muscles, taking all the load on themselves.
The structure of the knee joint is the most complex in comparison with other human joints, in addition, this joint is the largest of all joints - that is, the knee takes the first two places at once: in complexity and in size. The complexity of the joint structure makes the treatment of related diseases difficult.
The knee consists of three bones - the femur and the tibia, or simply the tibia, the bones are covered from above by the patella, which protects the joint. The knee joint connects these bones and provides them with mobility, performing the main functions of the knee - flexion and extension.
Smooth cartilage allows one bone to slide comfortably over the other when the knee is bent. This cartilage covers those parts of the bones that come into contact with each other. It is part of all three constituent bones - the femur, tibia, and patella or patella.
In addition to cartilage, menisci are located in the interosseous space. They are special interlayers that produce a smoothing and shock-absorbing effect under load, increasing the contact area. But unlike cartilage, menisci exist only between the two main bones - the tibia and the femur.
A special shell covers the entire joint from the outside. The inner part of it is called the synovial bag. This pouch is filled with so-called joint fluid. This fluid is used to lubricate the cartilage, which further improves glide and reduces stress and friction in the joint. But that's not all: synovial fluid has another purpose - it is a nutrient for cartilage, providing and maintaining its unique properties.
The anatomy of the knee joint also includes the presence of ligaments. They are needed so that the bones are securely fixed relative to each other and fit snugly to the menisci. Such ligaments located in the knee are called cruciate because of their shape. The knee joint includes the anterior ligament, the posterior ligament and two lateral ligaments - the external and internal. In the event of damage to the ligaments, their treatment is carried out using fixing bandages and rest.
As mentioned, the knee joint consists of only three bones. The femur is located on top and bears the main load on the joint. The tibia or tibia is located below and takes the load from the femur. It is called the tibia, so as not to be confused with the other tibia - the fibula, but it is not part of the joint, so we will call the tibia more simply - the tibia. The third bone is the kneecap. It is a small bone with a slightly rounded shape - it can be compared to a triangle with strongly rounded corners. This bone is often called the patella.
The femur has two ball-shaped projections. These protrusions are called the femoral condyles. The condyles thus cover the lower surface of the femur and come into contact with the upper surface of the tibia.
The surface of the tibia has a symbolic name - plateau. The full name is tibial plateau. It consists of two halves - the almond and lateral plateau.
Integral parts of the joint are the patella and several synovial bags located in different parts of the joint - they are filled with fluid and facilitate the movement of the muscles and tendons attached to them.
The device of the kneecap is such that it is designed to be moved along a special groove. This groove lies between the femoral condyles, which form it. The patella itself is prone to injury while protecting the knee. In the event of a knee cap injury, immediate treatment is required.
The cartilage that covers the surfaces of the contacting parts of the bones has an average thickness of about 6 millimeters. Of course, in children, this indicator is less than that of an adult. The cartilage has a white color and a smooth, as if polished, surface. Cartilage is elastic. They easily cope with friction, reducing it to nothing, and are the damping elements of the joint. In the knee, cartilage covers all three bones.
Ligaments are dense connective tissue. They are needed to bind the bones that form the joint to each other. The literal ligaments are located on the side of the joint, and the so-called collateral ligaments also received their place there. In addition to general strengthening of the joint, these ligaments serve to prevent the bones from slipping to the side of the joint.
The cruciate ligaments of the knee joint, anterior and posterior, connect the ends of the femur and tibia, ensuring that they fit snugly together. The cruciate ligaments also serve as limiters for the movement of bones in unnecessary directions. The anterior and posterior ligaments are also needed in order to prevent the main bones from moving out relative to each other.
The cruciate ligaments of the knee have a very important role to play in controlling the movement of the bones within the joint.
Bone stability in the joint is also achieved through other ligament-like structures. These formations, called menisci, are located between the femur and tibia in the places of their protrusions on both sides. In terms of their structure, cartilage and menisci, although they are similar to each other in appearance, are very different in their structure and perform different tasks.
Meniscus diseases resulting from overload or injury are difficult to treat. If the meniscus is damaged, surgery is required.
Menisci and their purpose
Menisci have two basic functions:
- increase the area of \u200b\u200bcontact of the bones, thereby reducing the load, that is, the pressure per unit area of \u200b\u200bthe femur on the tibia;
- ensure the stability of the joint, helping the ligaments.
In case of loss of one of the functions of the meniscus, it is necessary to urgently consult a doctor for treatment.
Menisci are flexible pads under the contacting surfaces of bones and behave as if a ball-shaped surface lay on a flat surface covered with a pillow. In this case, the pillow to some extent repeats the roundness of the spherical surface - the meniscus behaves in the same way.
Being such soft cushions, menisci also fill the voids that could have formed in the places where the bones fit, if there were no menisci. The space to be filled is between the condyles and the tibial plateau.
Thus, the presence of menisci provides the best distribution of the human body weight to the tibia, distributing the load over the entire surface of the tibia plateau. Otherwise, if nature had not provided menisci in the joint design, the entire load would fall on one point of the plateau. The main role of the meniscus is precisely to protect the joint from too much stress.
The second function of the meniscus - ensuring joint stability - is achieved as follows. They sort of wedge the joint due to their wedge-shaped shape.
Geometrically, menisci resemble a crescent and have different thicknesses. So, in its central part, the menisci are thinner than along the edges. With this shape, the menisci, as it were, form a depression - this makes the joint very stable. The ability of the menisci to change their shape due to elasticity makes the distribution of the load optimal during movement - the joint does not lose its stability during dynamics.
So, the ligaments and menisci perform the most important tasks to ensure the mobility of the joints, their steady state when walking and at rest, and competently distributing the load on the bones, protecting them and removing friction. If we compare the knee joint with others, then its device will be fundamentally special - unique. No other joint in the body has such a structure. For example, the elbow joint is much simpler.
The muscles of the knee joint are presented in two groups - the extensor muscles and the flexor muscles. Their name speaks for itself.
The extensor muscles are located in front of the femur. Thanks to these muscles, a person can walk - when these muscles contract, the knee joint is straightened. The so-called quadriceps muscle is the main one, since it extends the leg at the knee. Flexors - the muscles that flex the knee - are attached to the back of the hip bone and play an important role in the functioning of the joint.
Nerves are responsible for transmitting commands to contract certain muscle groups. The largest in the structure of the knee joint is the so-called popliteal nerve - it is located behind, as if under the knee. Damaged nerves, for example, as a result of injuries, are the reason for urgent medical attention for treatment.
Further, the popliteal nerve itself branches out, forming the small and tibial nerves. The latter goes to the back of the lower leg. The peroneal nerve is located at the upper end of the fibula and ends already at the front of the lower leg.
Other important elements
The circulatory system of the knee joint is formed by the vessels passing through it, which are branched at the back of the joint in the same way as the popliteal nerve. There are only two main vessels - an artery and a vein. It is customary to add the popliteal prefix to the names of these vessels. The artery supplies the knee joint with enriched blood, and the popliteal vein returns the waste blood back.
Considering the structure of the knee, one cannot ignore the synovial bags - this is an important and rather difficult part of the knee joint. Such bags are often called bursae in medicine. Some diseases of the knee joints, for example, bursitis, are inflammations of the synovial bags, which are quite difficult to treat, are taken from them.
The task of the bursae is to ensure the sliding of the tendons when the muscles associated with them contract. The bursa is filled with a fluid called synovial fluid that lubricates the tendons. The cavity of some bursae is connected to the articular cavity.
There are 6 burs in the knee joint. All of them have very interesting names: supra-patellar, deep sub-patellar, subcutaneous pre-patellar, bursa of the semimembranosus muscle, the own bag of the semimembranous muscle and the popliteal.
All the considered elements - ligaments, bones, tendons, menisci, vessels, muscles, nerves and bursa - are a single scheme that is considered as a whole - after all, all elements are interconnected. Many parts of the knee are fragile and require careful handling. Take care of your knees - avoid unnecessary overload.
The knee joint is the largest and most complex in structure in the human body, its anatomy is extremely complex, because it must not only support the weight of the entire owner's body, but also allow him to perform a wide variety of movements: from dance steps to the lotus position in yoga.
Content:knee structure
Such a complex structure, an abundance of ligaments, muscles, nerve endings and blood vessels makes the knee very vulnerable to various diseases and injuries. One of the most common causes of disability is injury to this particular joint.
It consists of the following entities:
- bones - femur, tibia and patella,
- nerve endings and blood vessels,
- cruciate ligaments.
Functions
The knee joint is similar in structure to the hinge joints.This allows not only flexion and extension of the lower leg, but also pronation (inward rotation) and supination (outward movement), turning the lower leg bones.
Also, when flexing, the ligaments relax, and this makes it possible not only to turn the lower leg, but also to make rotational and circular movements.
Bone components
The knee joint consists of the femur and tibia, these tubular bones are interconnected by a system of ligaments and muscles, in addition, in the upper part of the knee there is a rounded bone - the patella or patella.
The femur ends in two spherical formations - the femoral condyles and together with the flat surface of the tibia form a connection - the tibial plateau.
bony components of the knee
The patella is attached to the main bones by ligaments and is located in front of the patella. Its movements are provided by sliding along special grooves and femoral condyles - a pallofemoral cavity. All 3 surfaces are covered with a thick layer of cartilaginous tissue, its thickness reaches 5-6 mm, which provides shock absorption and reduces thorns during movement.
Connecting components
The main ligaments, together with the bones that make up the device of the knee joint, are cruciate. In addition to them, lateral collateral ligaments are located on the sides - medial and lateral. Inside are the most powerful connective tissue formations - the cruciate ligaments. The anterior cruciate ligament connects the femur and the anterior surface of the tibia. It prevents the tibia from moving forward when moving.
The same is done by the posterior cruciate ligament, preventing the tibia from moving posteriorly from the thigh. Ligaments provide the connection of bones during movement and help to hold it, the rupture of the ligaments leads to the inability to make voluntary movements and lean on the injured leg.
knee ligaments
In addition to the ligaments, in the knee joint there are two more connective tissue formations that separate the cartilaginous surfaces of the femur and tibia - menisci, which are very important for its normal functioning.
Menisci are often called cartilages, but in their structure they are closer to the ligaments. Menisci are rounded plates of connective tissue located between the femur and the tibial plateau. They help to correctly distribute the weight of the human body, transferring it to a large surface and, in addition, stabilize the entire knee joint.
Their importance for the normal functioning of the joint is easy to understand by examining the structure of the human knee - the photo makes it possible to see the menisci located between the spherical epiphysis of the femur (lower part) and the flat surface of the tibia.
photo of the meniscus
Knee muscles
The 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 muscle, semimembranosus and semitendinosus muscles,
- medial (internal) group - adductor muscles - thin and large adductor muscles.
knee muscles
- One of the most powerful muscles in the human body is the quadriceps. It is divided into 4 independent muscles, located on the anterior surface of the thigh bone and attached to the knee pad. There, the tendon of the muscle turns into a ligament and connects to the tibial tuberosity. The intermediate muscle, one of the branches of the quadriceps muscle, also joins the knee capsule and forms the knee muscle. Contraction of this muscle promotes leg extension and hip flexion.
- The sartorius 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 goes along the inner surface to the knee. There it goes around it from the inside and attaches to the tuberosity of the tibia. This muscle is two-part and due to this it participates in flexion of both the thigh and lower leg, as well as in the movement of the lower leg inward and outward.
- Thin muscle - starts from the pubic joint, descends and attaches to the knee joint. It assists in hip adduction and lower leg flexion.
In addition to these muscles, the tendons of the biceps femoris, tendon, semimembranosus and popliteal muscles pass through the knee joint. They provide adduction and abduction movements of the lower leg. The popliteal muscle is located directly behind the knee and helps with flexion and inward rotation.
Innervation and blood supply to the knee
The knee joint is innervated by branches, which is divided into several parts and innervates the lower leg, foot and knee. Directly the knee joint is innervated by the popliteal nerve, it is located behind it, and is divided into the tibial and peroneal branches.
knee nerves
The tibial nerve is located on the back of the lower leg, and the peroneal nerve is located in the front. They provide sensitive and motor innervation of the lower leg.
The blood supply to the knee joint is carried out using the popliteal arteries and veins, whose course follows the course of the nerve endings.
blood supply to the knee
What is the risk of injury
Depending on which of the components of the knee is damaged, the classification of injuries, diseases and pathologies occurs. It can be:
- dislocations,
- fractures of the bones surrounding the joint,
- inflammatory and dystrophic diseases,
- damage to tissues inside and around the joint, that is, cartilage, capsules, ligaments, and adipose tissue.
The knee joint is one of the most complex in structure in the human body. It is formed by the fusion of the surfaces of such bones as the femur, tibia and knee pad.
Inside the joint there is a meniscus: medial and lateral - which act as shock absorbers for the knee joint.
Since the knee joint has a large load, it is strengthened with a large number of ligaments. All ligaments are divided into external and intra-articular.
External ligaments of the knee joint:
- peroneal collateral ligament;
- tibial collateral ligament;
- oblique popliteal ligament;
- arcuate popliteal ligament;
- patellar ligament;
- patellar ligament support (medial and lateral patellar ligament support);
Intra-articular ligaments:
- anterior cruciate ligament;
- posterior cruciate ligament;
External ligaments of the knee
Peroneal collateral ligament - is formed from the outer epicondyle of the femur and follows to the outer surface of the head of the fibula. It is not fused to the capsule.
Tibial collateral ligament - goes from the inner epicondyle to the inner surface of the tibia. Spliced \u200b\u200bwith the capsule of the joint in front and behind. And on the inside, it is firmly connected to the edge of the medial meniscus.
Functions Collateral Ligaments - Hold the condyles of the thigh and tibia together. Thus, protecting the knee joint from lateral bending from side to side and rotation.
Patella ligament (patella) - is formed by the tendons of the quadriceps femoris muscle. The fibrous cords of this ligament, going down, are attached to the upper edge of the patella and its anterior surface. And they end on the tuberosity of the tibial surface, which is located on the anterior surface of the bone.
Function- serves to suspend the cup, which is expelled along the inner surface by cartilage for better sliding of the bone condyles.
Medial (internal) and lateral (external) patellar support ligaments - also formed by the tendons of the quadriceps femoris muscle. Partly the bundles are directed to the patella, and partly to the tibia, its anterior surface, near the articular cartilage.
Function- serves for hanging the cup, as in the previous bundle.
Oblique popliteal ligament - runs behind the joint capsule.
It is formed from the tendons of the semimembranosus muscle and begins at the medial-posterior edge of the inner condyle of the tibia. Then it follows upward and outward along the posterior surface of the capsule, where it ends, partially interwoven into the articular capsule, and partially attached to the femur along the posterior surface.
Arcuate popliteal ligament - also located on the back of the knee joint.
It originates from two bones of the head of the fibula at once, from the posterior surface, and the outer epicondyle of the thigh. The place of attachment is the posterior surface of the tibia. From the place of attachment, they follow in an arc, rise up, bend to the inner side and partially attach to the oblique popliteal ligament.
Intra-articular ligaments of the knee
The cruciate ligaments are intra-articular and are covered with a synovial membrane, and cross with each other crosswise.
Anterior cruciate ligament - covered with a synovial membrane. It starts from the outer edge of the bony protrusion of the femur, and attaches to the tibia, the anterior intercondylar field, and passes through the joint cavity.
Functions- restricts the movement of the femur forward in relation to the lower leg.
Posterior cruciate ligament - stretched between the medial femoral condyle and the posterior intercondylar field of the tibia, and also penetrates into the knee joint. Also covered with a synovial membrane.
F ounces - stabilizes the knee joint so that the thigh does not move back in relation to the lower leg.
Preventing movement back and forth, the cruciate ligaments hold the condyles of the femur in one place, as if rolling them over the condyles of the tibia. Without the cruciate ligaments, the thigh will move backward when flexed and forward when extended.
Each person tries in every possible way to protect himself from various diseases, because health is the main thing.
In order to avoid diseases, you must first of all know the characteristics of the organism.
In this article we will look at the structure of the knee joint.
The knee joint is classified as blocky, so it has one axis of motion that runs along the length of the joint itself.
The knee joint is one of the most complex body systems
The structure of the human knee joint is one of the most complex body systems. It is formed by three bones: on top of the femur, on the bottom of the tibia, and in front of the kneecap, the structure of which is also quite complex.
It is the largest sesamoid bone in the human body.
The patella is located in the tendons of the quadriceps muscle. It can be felt without any problems. The kneecap can easily slide to the sides and move up or down. The upper part (base of the patella) of the calyx is rounded. The lower part (the top of the patella) has an elongated shape.
Almost the entire surface of the calyx is slightly rough. Behind, the patella is divided into two asymmetrical parts: (medial and lateral). The main function of the cup is protective, it protects the joint from injury.
Menisci
The structure of the knee also includes menisci - a kind of layers (cartilaginous pads), with the help of which the stability of the joint is increased. In other words, they are knee shock absorbers. They are located between the tibia and femur. When a person moves, the menisci of the knee joint change shape (contract).
Menisci are knee shock absorbers
Specialists distinguish several types of knee meniscus:
- Lateral (sometimes called external). He is very mobile, while being injured less often of the second type;
- Medial (internal). The meniscus is inactive, associated with the collateral (internal) lateral ligament of the knee joint. This structure often causes joint and collateral joints.
Knee capsule
The system includes a knee joint capsule. This is a kind of fibrous sheath with which the bones are in contact with each other. The shape of this capsule can be compared to an elongated cylinder, the back wall of which is concave inward.
The knee capsule is a kind of case
The joint capsule is attached to the tibia and to the femur.
The inside of the capsule is called the synovium.
The structure of the knee joint is very well thought out by nature. It contains synovial fluid (lubricant for cartilage), which makes sliding painless.
It also nourishes the cartilage with beneficial substances that slow down their wear.
From the upper and lower bones, protrusions are formed, which are called the condyle of the knee joint (inner and outer). Their scientific name is lateral (external) and medial (internal) condyle.
The surface of the tibia and femur, the patella (patella), which are in contact with each other, are covered with smooth cartilage. This makes sliding easy.
Knee bags
The muscles and ligaments of the knee joint form the tendons in which the patella is located.
A very important component of this structure is the bags of the knee joint, thanks to which muscles, tendons, fascia can move freely and painlessly.
Scientists count six main bags, which include:
- Supra-patellar bag;
- Deep patellar bag;
- Subcutaneous pre-patellar bag;
- Semimembranosus bag;
- Own bag of the semimembranosus muscle;
- Popliteal muscle bag.
Knee ligament structure
With ligament injuries, a person experiences discomfort, cannot move normally and do physical exercises. Knee ligaments and their anatomy are quite complex.
It includes the following elements:
1. Anterior cruciate ligament of the knee joint.
- It begins on the inner femoral condyle. The ligament crosses the joint. At the end, it is attached in the area of \u200b\u200bthe intercondylar fossa. The cruciate ligament of the knee joint helps stabilize the knee joint and controls the movement of the lower leg.
Knee ligaments and their anatomy are complex systems.
3. Collateral (internal) lateral ligament of the knee joint.
- Experts distinguish three parts of this bundle:
- Upper (has the largest size in the system of external ligaments. Has an oval shape, attached to the inner side of the condyle. Closer to the bottom, the ligament is divided into two parts;
- Back (located behind the upper ligament, interacts with the semimembranous muscle);
- The deep part of the ligament (connected to the inside of the meniscus).
The medial collateral ligament of the knee joint normalizes the movement of the lower leg.
4. External lateral ligament.
In the lower part, the lateral ligament of the knee joint is connected to the fibula. It starts from the external condyle. When the leg is extended, the ligament is tense, and when bent, it is relaxed. It has no connection with the meniscus, because there is a fatty layer between them.
Just below the patella is the so-called patellar ligament. It is attached to the tibia.
All of them provide a person with a normal life: walking, the ability to exercise, while it is the ligaments that most often cause various injuries of the knee joint.
Video about the anatomy of the knee joint.
Based on the above information, it can be argued that the knee joint has a very complex structure.
This part of the human body performs important functions: it allows you to bend and unbend the leg, turn it to the sides.
The knee also allows a person to do a lot of exercise and move around. In this case, the joint is the place that most often lends itself to damage. First of all, this is due precisely to the complex anatomy of the knee.
