Back side of the knee
All people know where this part of the body is located, but no one understands its correct name. Wikipedia says this: back of the knee. Doctors use the name “popliteal fossa”. People without medical education, communicating on forums, call this area of the lower limb differently: popliteal knees, leg armpits, popliteal cavities, popliteal cavities. Some argue that this place has no name.
Google provides links to “knee bend” and (less commonly) “popliteal bend.” People often use the expression “back of the knee.” Knee is the colloquial name for the knee joint. It has front, back and side surfaces.
There is no single term; everyone is right in their own way.
Russian poet Alexey Fedorovich Merzlyakov wrote that language is a reflection of what we see around us and what exists. And since this part of the body exists, it should have a name.
Knee structure
The knee joint connects the bones and helps you move freely. At the same time, it can easily withstand the weight of a person. Because it performs such complex functions, it has a complex structure. Having understood the anatomy, you can understand what the inside of the knee is called. The joint consists of the following elements:
Between the bones are the menisci. This name is given to the cartilaginous plates that divide the knee into two parts located on both sides. The joint itself is formed by four elements:
Cartilage is elastic, and despite constant friction, remains smooth. Their main purpose is to cushion the bones during flexion and extension. To facilitate the sliding of bones, the knee joint contains synovial fluid, which lubricates the cartilage. In addition, it saturates the cartilage with necessary substances and minerals.
Everything else is located around the bones and joints, helping the motor system function normally:
The cruciate ligaments of the knee are essential for maintaining bone stability.
Interesting! The knee is the largest joint in the human body.
At the back of the bones and kneecap are muscles and large vessels. They form a diamond-shaped depression. This area is commonly called the popliteal fossa. From above, this area is limited by the semimembranosus and biceps femoris muscles, as well as the tendon. From below it is limited by the calf muscle. The sciatic and tibial nerves pass from top to bottom. Deep in the subcutaneous layer of the popliteal fossa are the small vein and popliteal artery. The fossa itself consists of a thin layer of fatty tissue that surrounds lymphatic and blood vessels. A nerve bundle passes in front of the muscles.
Features of the structure of the popliteal fossa
The popliteal fossa is a diamond-shaped depression located behind the knee joint. Above and on the sides are the tendons of the biceps femoris muscle, and below are the outer and inner heads of the gastrocnemius muscle. The skin in this area is thin and easily shifts; veins and nerves pass through the subcutaneous layer.
The length of the fossa in an adult is from 12 to 14 cm. The layer of fatty tissue contains superficial lymphatic and blood vessels. The muscles located on the border of the popliteal cavity are enclosed in peculiar capsules. If you bend your leg at the knee, you will see a gap between the muscles from behind, which has a scientific name - the gill fossa.
All structures present in the fossa are covered with subcutaneous tissue. Thanks to this design, harmful bacteria do not penetrate into the joint part.
Diseases that cause pain in the popliteal fossa
The back of the knee hurts with the following diseases:
- Baker's cyst. The pathology is manifested by swelling in the middle of the popliteal fossa, which is more noticeable when the knee is extended. A characteristic sign is that upon palpation, the fluid moves back into the joint, so the size of the cyst decreases. Usually the cyst appears on both legs at once. Treatment is carried out in a conservative form: tablets, injections, physiotherapy. If these methods are ineffective, surgery is performed.
- Meniscus cysts. They are located in the posterior horns, located behind the lateral ligaments. Causes pain in the knee socket. Sometimes cysts are small and not visible, but they lead to pronounced pain. To determine your health status, it is recommended to undergo a comprehensive examination and clarify the diagnosis. Meniscus cysts occur due to joint injuries during physical activity and sports training, and a lack of nutrients in the cartilage tissue.
- Meniscal tears. Pain in the area under the knee occurs when the posterior horn of the meniscus is torn off. More often this occurs on the inner meniscus with strong rotation of the lower leg. A tear of the posterior horn of the meniscus blocks the knee joint and impairs the function of the legs. Meniscus tears occur due to injury, disease, nutritional disorders and destruction of cartilage tissue. Initially, anti-inflammatory treatment and restriction of movements are provided.
- Inflammation of the tendon bursae of the semimembranosus muscle and the 2nd head muscle. In case of pathology, a compaction located near the inner or outer edge of the popliteal fossa is palpated.
- Infected wounds, abscess of the popliteal fossa. There are lymph nodes in the back of the knee, so infection from wounds, cracks and other minor injuries to the skin of the foot and leg is possible. The active development of the inflammatory process leads to lymphadenitis with the formation of pus. Lack of timely treatment threatens with an abscess of the popliteal fossa. Initially, the symptoms appear weakly, since the lymph nodes are located deep in the subcutaneous fat. There is no swelling or redness, there is only slight swelling and pain when moving the leg.
- Tibial nerve tumor. Together with the artery and vein, the nerve passes through the popliteal fossa. When it becomes inflamed and tumors, a pronounced pain syndrome occurs. Uncomfortable sensations spread to the foot. Upon examination, changes in skin sensitivity, impaired muscle tone and problems with reflexes are revealed. Surgical treatment is performed to remove the tumor. If necessary, treatment includes taking medications.
- Aneurysm of the popliteal artery. The walls of the artery become stratified and form a sac-like protrusion. The main symptom is nagging and throbbing pain at the back of the knee joints. Externally, the aneurysm is similar to a Baker's cyst, but upon palpation, pulsation is clearly visible. The pathology is dangerous due to massive bleeding, so the use of a special bandage is required to protect the arteries of the legs. Subsequently, an operation is performed.
If the area behind the knee hurts, swells, or interferes with movement, you should consult a doctor. The main task is to conduct an examination to make an accurate diagnosis and prescribe effective treatment.
Damage and illness
Joints are an important component of the musculoskeletal system. Every day they are exposed to heavy loads. This is why injuries to the kneecap and popliteal region often occur. This part is complex, and if a person experiences pain there, it is always difficult to determine its cause. The following diseases are associated with the area of the back of the knee joint:
- Baker's cyst (popliteal hernia);
- nerve damage;
- inflammation of soft tissues;
- muscle strain or damage;
- neoplasms (lipomas, fibromas, sarcomas);
- bursitis that developed due to infectious or aseptic inflammation;
- injuries of intra-articular ligaments;
- phlebeurysm;
- damage to fatty tissue.
Pathological causes
Diseases of the knee joint can be the following:
- chronic and gradually developing;
- infectious;
- associated with mechanical trauma.
Despite the different factors in the occurrence of diseases, their symptoms are often very similar, and it is difficult to independently determine what kind of disease a person has.
Diseases resulting from mechanical injuries
Everyone has fallen or hit their knee at least once in their life. Many of these injuries ended in simple bruises or contusions. But it is not uncommon for mechanical damage to lead to serious consequences.
Ligament damage
There are only four ligaments in the knee. Their function is to connect the femur and fibula. Two ligaments are on the inside of the joint, and the other two are on the outside. When a fall or some kind of injury occurs, the ligaments rupture or sprain. In the future, even after the ligaments have fused, pain may occur. This indicates that small damaged areas remain.
If the posterior cruciate ligament ruptures, there is immediate pain, a feeling of instability and swelling in the popliteal fossa.
Important! After repeated injury, the ligament may harden, which can lead to deterioration of the musculoskeletal system.
Meniscus injury
Meniscal injuries are one of the most common knee injuries. When a meniscus tears, the torn part interferes with movement, causes pain, and can lead to joint blockage. Therefore, such an injury requires urgent medical attention.
Immediately after damage, the following symptoms appear:
- sharp cutting pain;
- swelling of the joint and swelling on the side of the popliteal fossa;
- painful clicks.
Several hours after the injury, fluid accumulates in the joint cavity, the pain becomes duller and less severe, and weakness in the muscles is felt.
Traumatic hemarthrosis
Hemarthrosis is bleeding into a joint. Occurs due to rupture of blood vessels. Traumatic hemarthrosis develops against the background of intra-articular displacements and fractures. It can also be accompanied by injuries such as torn menisci and ligaments. The following changes are observed:
- First, the joint increases slightly in volume. There is slight pain.
- In the second degree, the joint greatly enlarges and becomes spherical.
- In the third stage, the skin becomes blue. The joint is maximally swollen. In some cases, an increase in temperature is observed.
Description of the back of the knee
The popliteal fossa is a diamond-shaped depression located at the back of the knee. At the top of the right and left sides are the tendons of the biceps femoris muscle. At the bottom are the outer and inner heads of the gastrocnemius muscle.
The skin in this area is minimally thick. Veins and nerves run underneath it. The fatty tissue contains superficial, lymphatic and blood vessels. On the border of the popliteal cavity there are muscles in special capsules. They are located at a distance from each other, which is called the gill's fossa. The total length of the popliteal fossa is 12-14 centimeters.
All structures under the knee are covered with subcutaneous tissue. It protects joints from pathogenic bacteria. As a result, the risks of developing joint diseases and inflammatory processes are reduced.
If a person complains of pain under the knees during flexion and extension, it is recommended to pay attention to the condition of the popliteal fossa.
Main components of the knees:
The functional load of the knee sockets contributes to the manifestation of undesirable symptoms.